EU study of external costs of energy: What you pay with your flesh.

[NNadir]

The European Union has put together a study quantifying the external cost of different energy sources. By external costs, they mean the cost to the environment (greenhouse, mining damage etc), human health, damage to crops, and damage to material possessions such as works of art, structures, etc. These are not the costs you pay directly in fuel prices, these are the uncharged costs that you pay with your lungs, your children's future, the productivity of your country's land, your property and your aesthetic values.

The pdf file can be found here: http://www.externe.info/externpr.pdf

It is not surprising that wind energy has the lowest external cost for electrical generation. In most countries where such capacity is installed, the external cost of wind is only approached by either nuclear or hydro energy.

Only one country, Germany, had enough PV power installed to quantify its external costs. Surprisingly, even to me, the external cost of PV power in Germany is three times that of nuclear power (0.6 Euros/KW-Hr to 0.2 Euros/kW-hr).

France has the most varied energy equation. The lowest external cost in France belongs to nuclear energy (0.3 Eur/Kw-Hr.) Surprisingly, in France, hydro-electricity has an external cost over three times higher than nuclear (0.3Euro/kW-Hr compared to 1 Euro/kWhr.) It would seem that France doesn't do hydroelectric power very safely, although the cost may reflect overly sensitive ecosystems affected by hydroelectric power or some such thing. (I don't know this; I'm guessing.) Hydro does much better in most countries. Biomass in France has an external cost the same as hydro, three times higher than nuclear.

The external cost of biomass in Germany is 15 times the external cost of nuclear energy, possibly because of Germany's reliance on chemically intensive fertilization.

In one or two countries biomass does quite well, and is comparable to nuclear in some of the nuclear countries. In the Netherlands, biomass actually beats nuclear 0.7 Euros/kw-hr to 0.5 Euros/kw-hr.
The external cost of nuclear energy is the highest for the Netherlands of any country in the EU.

It seems like all of Europe could learn from the Norwegians (who are included in this study although they do not belong to the EU). Their external cost for biomass is 0.2 Euro/kw-hr. It is the only place in the EU where the cost for biomass is this low. This is probably because Norway has a significant business in processed wood products.

In the UK, the external cost of biomass to nuclear is greater by a factor of 4, 0.25 Euros/kw-hr for nuclear and 1 Euro/kw-hr for biomass.

Compared with any of the above-mentioned forms of energy, the report makes clear that oil and coal are vastly subsidized forms of energy with huge external costs. My opinion is that they should both be shut down as quickly as is possible, though I'm sure I'm just like Cassandra here: My predictions are correct but no one believes me.

This report is pretty much consistent with my particular bete-noire that it is very difficult to be an environmentalist and anti-nuclear power at the same time, the common perception to the contrary notwithstanding. I suspect nonetheless I will shortly be given all kinds of reasons why this study by the European Union is completely bogus. Fire away!

[villager]

1. external costs of Chernobyl?

Three Mile Island?

Storing radioactive waste safely for 10,000 years?

[NNadir]

4. At Three Mile Island the external costs were essentially zero.

There was no loss of life and no damage to the surrounding area. The owner of the facility paid most of the cost. They lost a valuable reactor.

At Chernobyl the loss of life (currently) is well under 1000, a figure a typical city exceeds by 40 apparently every year. (That's right, New York has 40 Chernobyls every year from air pollution.) Nevertheless a huge area was evacuated and deaths continue to occur today. Though this is tragic, it does not approach the costs of air pollution of other forms of energy. The authors of the study have studied only the EU. The EU does not have RBMK reactors, nor does any Western Country, unless you consider Cuba as being in the West.

Right now the Chernobyl exclusion zone is home to over 40 endangered species, all of which thrive owing to the exclusion of human beings.
This is reported in the scientific journal Environmental Science and Toxicology, a copy of which is available on the Internet: http://www.nsrl.ttu.edu/chernobyl/wildlifepreserve.htm

Here is a quote from the article: "We discussed such matters with Dr. Victor Baryakhtar, Vice President for Ukraine's Academy of Sciences. When comparing the ecological consequences of the Chornobyl region to those in the highly industrialized heavily populated areas of eastern and southern Ukraine, he observed, 'Northern Ukraine is the cleanest part of the nation. It has only radiation.'"

That's at ground zero and it gives a very good idea of the magnitude of the costs of other energy in the Ukraine.


I would guess that the 2700 square km of the exclusion zone - reported is relatively tiny when compared with the amount of strip mines that are used to provide coal - and strip mines BTW do not become thriving ecosystems as the Chernobyl exclusion zone has become.

Simply because you ignore strip mines and air pollution does not mean that they are free from external cost.

I say this every day here: The 10,000 year figure of concern (why not pick 2,000,000 years BTW) is based on ignorance of physics. The use of nuclear power in an actinide recycling scheme (as used in France, the UK and Japan) will reduce the overall radioactivity of the planet in about 1000 years. This is because nuclear fission destroys radioactive Uranium and Thorium, each of which decay (depending on mass number) through 10 to 12 nuclear (radioactive) daughter nuclei, such as radon, radium and protactinium. Many fission products decay completely to non-radioactive daughters before they are even removed from the reactor. Some do not, but because they are more radioactive than Uranium, they also decay faster: Hence the (real) 1000 year figure. See William Stacy, Nuclear Reactor Physics, John Wiley and Sons, 2001, pg 231 and references therein.

Yours is a reaction that is pretty typical, and pretty wrong, as the study given above proves.

[villager]

6. "Yours is a reaction that is pretty typical, and pretty wrong"

I might add that that reaction is pretty typical of the condescension used by nuclear power proponents.

I'm not ignoring strip mines, et al -- I agree completely that the external costs are staggering. Whether your argument will hold that we can expect nuclear exclusion zones to always become "thriving" ecosystems -- are you positing that the exclusion zones created by nuclear mishaps are good things? -- remains to be seen in the nuclearized future you envision.

And whether your argument that the multi-generational genetic mutation(s) that can be expected from the steady release of nuclear material in the ecosystem (even in your "rosy" scenario of a "mere" 1000 year radioactive/toxicity rate is not reassuring -- increased dependence on fission freeing us from the side effects of fission?)is a "zero" external cost is probably better left as a question for those affected, and their descendents.

[NNadir]

16. The condescension derives from scientific reality.

My arguments are based merely on scientific study of the Chernobyl exclusion zone. The geneticist Robert Baker has extensively studied the Chernobyl exclusion zone and finds ambiguous evidence at best for the "multi-generational genetic mutations" to which you glibly refer, as though it were an indisputable fact.

Here is a fact, mere arithmetic: If you count the number of species (diversity) and the population of those species, the Chernobyl exclusion zone is the richest ecosystem in the Ukraine, if not in all of Eastern Europe. This is certainly surprising, but it is nonetheless true. Whether or not it is a "good thing" is not for me to judge; it is a wholly aesthetic issue and not a scientific one. No one, not even I, is advocating more Chernobyls. I am merely pointing out that the alleged danger of radiation is vastly and hysterically overstated.

The geneticist Robert Baker has been studying the Chernobyl exclusion zone for well over a decade. Here is a list of Dr. Baker's publications: http://www.nsrl.ttu.edu/chernobyl/publications.htm Unlike you, he has been to Chernobyl 15 times, and his home page has a nice picture of him standing in a wooded area right in front of the reactor in a tee shirt. Here is an abstract from one of his papers, "Small mammals from the most radioactive sites near the Chernobyl nuclear power plant." Journal of Mammalogy. 77:155-170:

"This study was designed to estimate the impact of pollution resulting from the meltdown of Reactor 4, Chornobyl, Ukraine, on the taxonomic diversity and abundance of small mammals in the surrounding area. Trap sites included the most radioactive areas within the 10-km exclusion zone, a site within the 30-km exclusion zone that received minimal radioactive pollution, and five sites outside of the 30-km exclusion zone. Within the exclusion zones, 355 specimens representing 11 species of small mammals were obtained, whereas 224 specimens representing 12 species were obtained from outside the exclusion zone. It is concluded that diversity and abundance of the small-mammal fauna is not presently reduced at the most radioactive sites. Specimens from the most radioactive areas do not demonstrate aberrant gross morphological features other than enlargement of the spleen. Examination of karyotypes does not document gross chromosomal rearrangements."

It happens that Dr. Baker has found genetic abnormalities in some species living in the exclusion zone, but he has yet to find gross abnormalities in any species, including the catfish living in the destroyed reactor's cooling ponds. I note that these catfish, like the voles he studies have been through many generations since the accident. While we cannot rigorously exclude that long term effects will be found, they are clearly nowhere as dramatic as was widely expected, even to the point of wild charicature. In any case, while the experience of Chernobyl is illustrative of nuclear risks as a worst case demonstration, it is not illustrative of the future risks of nuclear power. No one will ever again build a graphite moderated RBMK analogue with a positive void coefficient. The Chernobyl experience is thus a measure of a risk that will be avoided by failure analysis, just as failure analysis minimizes risks in every other industry, from automobiles, to aircraft, to step ladders.

It is widely suspected on an epidemiological basis that the claim of linearity of biological effects from high doses to low doses is invalid. Indeed, many people on the basis of epidemiological studies suspect the existence of a "hormesis" effect wherein low level radiation is actually beneficial. I am not convinced of that claim, but nonetheless, neither you nor I can categorically disprove it. Here is a list of 35 scientific references addressing exactly that issue (scroll down): http://www.angelfire.com/mo/radioadaptive/pollycove2.html

This certainly does not support the notion that you glibly claim that "the multi-generational genetic mutation(s) can be expected." We all "expected" Chernobyl to be a nuclear desert. It is not.

As to the claim that decisions about the issue only belongs to those affected, I note that I live in the part of the country, New Jersey, that is the MOST polluted in North America by heavy metal deposition from Midwest coal fired power plants. My soil contains the heaviest Mercury contamination in the nation. That YOU are completely indifferent to my plight does not make me feel very comforted. My child was born with a birth defect and neither you nor I can prove that heavy metal pollution was not the cause. That you value some theoretical unproven risk over my experienced risk simply because one has the word nuclear in it, and the other does not, has absolutely no moral standing with me.

The fact is that whenever life expectancy rises, relative risk goes down. The age of energy has been marked by an increase in life expectancy. The take away from this is that energy overall has a beneficial effect on the minimization of risk. It happens, as I point out repeatedly, that all forms of energy on the other hand involve external risk. Nuclear energy is merely risk minimized as an energy source. When you use nuclear energy, fewer people die than with it's alternatives. It is neither risk free or "rosy" however and the claim that I have represented as such is gratuitous, or shall we say, "condescending."

I have pointed out here many times that so called nuclear "waste" is subject to an equilibrium condition and therefore has absolute maxima on its potential accumulation since it, alone among large scale industrialized energy solutions, decays even as it is created. In fact, most fission products do not even get out of the reactor, they decay within it, generating about 4% of the heat that drives the turbines. I invite you to name another form of energy that offers such a condition. When you have done so, I will accept that you actually care about issues of waste. I note that lead mines from ROMAN times are still causing toxicity issues in many European localities today, and there is no reason to expect that cadmium mines serving the solar industry will be any different. Why exactly is it that a thousand years is worse than eternity? One can walk around in Europe and see examples of many structures that old. Indeed I invite you to name one other form of energy whose effects will last LESS than 1000 years.

The study I have posted gives a full external cost of all known industrialized forms of energy in the European Union. I am sorry that you are not comforted by it, but still, speaking only for myself, data impresses me far more than common uninformed biases based on emotion, assumption and hysteria. I note that I began my study of nuclear energy as an attempt to prove that it was unacceptable. I am, in fact, one of the morons who stopped the Shoreham Nuclear Plant in service to a process begun the rich folks in Lloyd's Neck on Long Island on NIMBY grounds. (They risked having their own nuclear plant near their golf courses.) As I have been on both sides I can claim an open mind.

Your claim that you actually care about strip mines and the like leaves me unimpressed. If in fact, you are NOT ignoring strip mines and the like, you'd best have a workable, proved alternative. You do not. I stand by my claim that you and others making the same (specious) arguments against the broad adoption of risk minimized nuclear power are indeed ignoring something. That something is reality.

[Name removed]

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[Name removed]

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[jpak]

123. Nice tombstone treepig

Hormesis is psuedo-science bullshit - their is NO published evidence to support this nonsense

Here's what the Health Physics Society sez about hormesis and the effects of low-dose radiation...

http://hps.org/publicinformation/ate/q10.html

http://hps.org/publicinformation/ate/q87.html

http://hps.org/publicinformation/ate/q299.html

end of argument

[NNadir]

127. Yeah right.

:eyes:

[Bdog]

19. Chernobyl's soiled legacy

http://www.nature.com/nsu/001005/001005-11.html
"Fourteen years after the Chernobyl nuclear accident, crops grown in contaminated land surrounding the former power station show a mutation rate six times higher than normal.
5 October 2000

Fourteen years after the Chernobyl nuclear accident, crops grown in contaminated land surrounding the former power station show a mutation rate six times higher than normal, researchers now report in Nature1. Similar but controversial results have previously been seen in humans and rats.

Olga Kovalchuk from the Friedrich Miescher Institute, Basel, Switzerland, and colleagues investigated the effect of chronic radiation exposure on wheat plants. They compared identical populations planted in heavily contaminated land near Chernobyl and in clean soil roughly 30 kilometres away.

After just one plant generation -- ten months -- Kovalchuk's team saw an increased mutation rate in plant offspring. Each plant received relatively low radiation doses, which theoretically should not cause so many mutations. This suggests "that chronic exposure to ionizing radiation has effects that are as yet unknown," they say...



It is estimated that five million people were exposed to radiation in the Ukraine, Belarus and Russia, but the exact genetic consequences of these effects is not yet clear. The World Health Organization says that, so far, there has been a large increase in thyroid cancer among children in the affected areas.

"Our findings raise the important issue of the genetic hazard of chronic radiation exposure to the germline," Kovalchuk's team point out. The 'germline' of an organism consists of the cells involved in reproduction, such as sperm and eggs in humans; these cells pass hereditary characteristics from generation to generation."

[NNadir]

23. I have the full one page article in front of me and will type the data...

listing the ratio to controls to wheat grown in the highly contaminated zone. The ratios posted dimensionless numbers are exposed/control frequencies.

Type of variant Ratio to control
Nulls (homozygotes): 1.17
Losses (heterozygotes) 6.45
Losses (homozygotes) 1.88
Gains (Heterozygotes) 2.82
Gains (Homozygotes) 1.34
Heterozygotes losses + gains 3.73
Homozygotes (losses + gains) 1.61.

And the point is?

Well, it seems that there is a natural mutation rate (the existance of which is probably a good thing, or else we would all be bacteria) and the mutation rate resulting from the Chernobyl disaster has indeed lead to one particular species (wheat) suffering genetic mutations faster than they normally do. The authors here point out that the natural mutation rate is estimated at 1.03X10^(-3) for naturally occuring wheat, and 6.63X10^(-3) for Chernobyl exclusion zone wheat.

Note that the Wheat grows, it breeds, and no gross morphological (phenotypical) changes are seen in this single species. It seems pretty clear that many species react differently to radioactivity. In the case of Chernobyl for instance, Scotch pines are definitely doing poorly, whereas birch is proliferating. Presumably wheat has some sort of genetic repair mechanism as do most species so it, unlike Scotch Pine, is able to reproduce after irradiation. My own impression of this paper is that what we have here is more variable Wheat. Since I'm a fan of evolution (both the theory and the physical consequences of the event) I'm really not driven to hysteria about this paper. It has reasonable and unsurprising conclusions: Radiation of wheat increases (but does not create) mutation rates.

Obviously some species do better than others: These nice photographs from inside the exclusion zone (from Dr. Baker's website) show some damaged Scotch Pine Seedlings in a highly contaminated area. (Ignore the swans in the lake near the reactor and the verdant areas surrounding the lake: Some of the scotch pine seedlings are yellowed.) This means that the Viridian Park at Chernobyl long term will probably have a selection pressure in favor of birch.




Here are some other nice pictures from inside the exclusion zone:



Those are some rather pretty mutants.

The original poster entitled "Nuclear Desert" from Dr. Baker's group, who spend quite a bit of time at Chernobyl can be found here:

http://www.nsrl.ttu.edu/chernobyl/posters.htm

It doesn't look like a desert to me, but I might be missing something. I think, of course, is supect the researcher's title for their poster is a somewhat ironic response to the Time magazine cover from the time of the accident that they reproduce therein actual time of the accident.

Failure analysis of Chernobyl is a very important undertaking both from an engineering sense (no one will ever again built commercial graphite moderated positive void power reactors), an administrative sense, (a nuclear power program must be subject to a full, enforced regulatory set of checks and balances that did not exist in the Soviet workers state), and a sober well examined of the ecological consequences of radioactive pollution. I applaud the efforts of the authors of the Nature paper and Dr. Baker, who have done so much to foster clear scientific analysis of this event, a natural laboratory that can help us to make clear, well reasoned decisions about how will try to save a collapsing earth.

I note that mutation rates can rise dramatically from chemotoxic agents as well. With that in mind I will opine that this particular sub-discussion of course does nothing at all to whether nuclear energy is to be preferred to its competitors, since it is a discussion ONLY of a biological effect of a nuclear failure and does not reference in any way the biological effects of OTHER forms of energy. Molecularly planar species such as are created in air pollution, particularly in particulate matter, are well known to interact strongly with nucleic acids. That of course, is the real value of the study with which this thread began: It compares.

One can look at anything in the universe and if one scrutinizes it carefully enough, find something that may be recognized to be pretty scary. This, more than any single feature, is applied to subjects having the word "nuclear" in it, and why nuclear issues are so resistant to critical thinking.

The scientists in the Nature paper have something that the post to which I am responding seems to be untroubled by: A control group. Control groups are what make data meaningful. Without them, in fact, data is completely meaningless.

[NNadir]

24. On the subject of controls and comparisons.

To cite some references relevant to my earlier post:

"Air pollution induces heritable DNA mutations" by Christopher M. Somers, Carole L. Yauk, Paul A. White, Craig L. J. Parfett, and James S. Quinn Published online before print
December 9, 2002, 10.1073/pnas.252499499; Proc. Natl. Acad. Sci. USA, Vol. 99, Issue 25, 15904-15907, December 10, 2002

Air pollution induces heritable DNA mutations - Christopher M. Somers*, Carole L. Yauk, Paul A. White, Craig L. J. Parfett, and James S. Quinn*,
* Department of Biology, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4K1; and Mutagenesis Section, Environmental and Occupational Toxicology Division, Health Canada, Environmental Health Centre, 0803A, Tunney's Pasture, Ottawa, ON, Canada K1A 0L2 Edited by Richard B. Setlow, Brookhaven National Laboratory, Upton, NY, and approved October 28, 2002 (received for review August 19, 2002)

[Bdog]

37. It proves, once again

It proves, one again, that low levels of radiation causes mutations in DNA.

Our DNA is 95% junk DNA. Only 5% of the code is useful programming.

A strand of DNA can have many corrupted data points with out affecting its usefulness. It takes an ionizing event in one of the 5% regions to corrupt the DNA’s function.

It proves the DNA data is becoming corrupted

How much corrupted data can you have on your had drive before the computer becomes useless and wont even boot up.

Radiation hormesies & zero-risk threshold dose are not the accepted guidelines for radiation safety any where.

http://www.gfstrahlenschutz.de/docs/hormeng2.pdf

[NNadir]

41. I hate corrupt DNA.

My own often makes proteins I don't want and I don't need because Halliburton pays it off. I've got a piece of my 17th chromosome that should definitely be arrested, and once an honest justice department is restored, I'm going to have it looked into.

It is not a surprise that you didn't notice anywhere in all these scientific postings that the "corruption" of DNA is a part of a process that some people call "molecular biology." It's a big part of that little business they call "evolution." It seems to me that in spite of lots of broken DNA going back billions of years, that life as managed to survive and thrive.

Sometimes it seems that people get increasingly desperate to prove a bit of dogma. May I suggest that we now discuss insurance companies?

[Bdog]

44. I know...

I know you don’t care about nuclear pollution, nuclear proliferation, or this country’s safety.

Thanks for sharing with every one.

[Bdog]

45. DNA is the program of life.

A living cell is a machine. DNA is the program it runs on.

Radiation hormesies & zero-risk threshold dose are not accepted as guidelines for radiation safety any where on this planet.

[Name removed]

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[Bdog]

49. 'Sophisticated Molecular Machine' Is Found To Govern Cell's Reading Of DNA

ITHACA, N.Y. -- The process by which a cell reads the genetic code in its DNA in order to manufacture a protein is complex, involving dozens of enzymes and other biological molecules working together.

Now, research at Cornell University, using the fruit fly as a model system, has confirmed a theory about one step in the process by showing that a protein complex known as FACT is positioned in living cells at sites where chromosomal DNA is unpacked so that its code can be read. It is part of what the researchers call "a sophisticated molecular machine" that is not yet completely understood. The research is reported in the latest edition (Aug. 22) of the journal Science .
http://www.sciencedaily.com/releases/2003/08/030822074008.htm

Radiation hormesies & zero-risk threshold dose are not accepted as guidelines for radiation safety any where on this planet.

[Name removed]

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[NNadir]

51. No, I care very deeply. Which is why I have spent decades understanding

the problem and comparing safety.

Someone who claims to care about safety and in the same token denies the sources of pollution that causes the most lost life in an unthinking quasi-religious way is someone who indifferent.

I would put up the body of my posts and the level of understanding of technology, problems and consequences up against any of my most persistent critics any day.

Thank you, though, for demonstrating the level of understanding my critics embrace.

[Name removed]

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[NNadir]

27. Thanx for jumping in here.

Well done.

From my experience with the matter though, I would question whether "honest debate" is necessarily the endpoint of some arguments I see where consideration of nuclear technology is involved. Sometimes, as takes place in other areas of debate, the goal is to attempt to validate dogma in the face of evidence that places the dogma into question.

I have no data, but my "gut" opinion that statements containing the word "nuclear" generate more out of context responses than one usually finds in most arguments about most subjects. Indeed, the Occupant-In-Chief was able to generate a huge groundswell of support for the "War for Halliburton," -whoops, I mean "The War Against Terror" by repeating the word "nuclear" (or at least "Nook-kul-ar") as often as possible, even though it turns out that nuclear matters were not actually involved at all.

These types of non-contextual responses are exactly what makes it so easy to dismiss some our best options with pat, rote, hand waving.

Thanx again.

[Name removed]

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[NNadir]

31. I hate to disagree, but Chernobyl is rarely discussed so dispassionately.

I've been dealing with Chernobyl mythology for years, ever since I switched sides in the nuclear power debate.

There are certain mantras chanted by anti-nuclear power folks and the content of these chants are words like these: "Chernobyl! Chernobyl! Waste! Waste! Waste! Radiation! Radiation! Radiation! Bomb! Bomb! Bomb!" If you attempt to bring these mystic words out of the darkness and into the light of serious examination, well it's much like trying to persuade a fundementalist that it just is possible that Jesus was just an ordinary Jewish guy in Roman occupied Judea.

My own trek from anti-nuclear power activist to nuclear power promoter began, strangely enough, with Chernobyl. I, like most people on the planet, thought it prove to the worst environmental disaster ever to have happened. Seeking more information on some of the contaminating isotopes, I looked them up in the Handbook of Chemistry and Physics and came upon the values for neutron capture cross sections, the variable most closely connected with nuclear transmutation. When I explored this conception a little more carefully, my odyssey began. I confess, I was so niave that I thought that the idea of transmutation of nuclear waste was original with me. Only later did I understand that it is a widely understood concept, one that is likely to play a serious role in reducing the health and safety risks of nuclear power very close to the vanishing point. After some time, I rather became obsessed with the idea and later took it upon myself to explore subjects like nuclear engineering, risk analysis, and nuclear chemistry.

Even you accepted the ludicrous claim that 2,000,000 people (or 4% of the Ukrainian population) were killed by Chernobyl, which neither you nor I do, you would still have a death rate for the entire history of nuclear power (40+ years) of 2,000,000/40 = 50,000 persons a year dying from nuclear power worldwide. This is a number easily dwarfed by the deaths per year from air pollution in some single cities, never mind the planet as a whole. There is no such thing as risk free energy and anyone who claims there is, is either deluded or a liar.

The questions of Chernobyl need to be studied; they need to be discussed and we need to learn the lessons that the tragedy has to teach us and spread them as widely as possible. I contend, and I know you agree, that one lesson that should NOT be taken is that nuclear power should be abandoned. The more carefully we look at the issues surrounding Chernobyl, the easier it will become to make intelligent decisions. If there's one thing that people need to do in times when the threat to the planet is as serious as it is, it is clear thinking. We ought to do everything to we can to make sure that our energy choices have the least possible environmental, health, and aesthetic consequences. The tragedy at Chernobyl is an important sign post in the road to accomplishing this difficult task.

Again, your posts to this thread have been very fine, and I thank you again for the time you invested in putting them together.

[Commie Pinko Dirtbag]

38. My only beef with nuclear power is

that it's non-renewable, just like oil. That is, it doesn't solve the main problem of oil -- it's going to dry up somewhere in the future and screw us all.

About the harm statistics, I agree with you.

[NNadir]

39. This is true. The resource will only last about three millenia.

If we can't figure out an alternative in 3000 years, another generation will experience a depleted source of energy.

[Commie Pinko Dirtbag]

40. Would it last 3000 years...

...AFTER oil runs out and we have to use nuclear for everything? Ot is it based on current use?

[NNadir]

61. It would last about 3000 years if world-wide energy consumption stabilized

at about 1000 exajoules per year, with 100% of the energy being obtained by nuclear fission means. This 1000 exajoule (exajoule = 10^18 joules) figure is expected to be reached in about the year 2050.

Sometimes you will see it written that Uranium supplies will last only another 50 to 60 years. This figure represents the amount of intrinsic energy of the single naturally occurring fissionable isotope, U-235. Actually though, only 1% of the energy available in Uranium is recovered in the American nuclear program. (It is higher elsewhere because of recycling.) The other 99% is currently defined as "waste." There is actually ten times more Thorium (an alternate, and in many ways better nuclear fuel) than there is Uranium. My 3000 year figure includes all of the Thorium and all of the Uranium. There is estimated to be about four billion tons of Uranium in seawater. A process for its recovery has been worked out, but the price of Uranium would need to rise to around $200-300/kg for it to be profitable. It is only a fraction of that value now.

I am running off at the mouth in a thread called "What would a nuclear Actinide recycling..." describing various technologies for the exploitation of fissionable resources. I will develop the idea there eventually that it is actually not possible to recover 100% of the energy in Uranium using the current generation of nuclear reactors, which are essentially thermal spectrum reactors with breeding ratios less than one. Several new types of reactors that will come on line in the 21st century (assuming the planet survives) will make it possible to get around this problem.

By developing alternate sources, it should be possible to extend nuclear fission resources much further than 3000 years. Note though that if in the long term a fusion program serves this purpose, it may well always require a fission program to support it.

It goes without saying that huge energy resources should NOT be allowed to lead to profligate use as it did with oil. It is still responsible on both environmental and moral grounds to conserve as much as is possible. Although nuclear energy is much better than many of its alternatives, this is certainly not to say that it is 100% benign. I hope we will have learned something by the process of running out of oil and behave decently in the future.

[jpak]

119. 3000 year supply??? Don't think so...

Russia's Limit on Uranium Exports Sends Prices Higher (excerpted) (Bloomberg, 5 May 2004)

http://npc.sarov.ru/english/digest/142004/section4p1.html

    Cameco Corp. plans to boost annual output 18 percent at Canada's McArthur River mine, the world's richest uranium deposit. Areva SA of France is investing $90 million to develop a mine in southern Kazakhstan. And International Uranium Corp. is searching the Gobi Desert.

Producers are scouring the world for uranium. The price of the radioactive element has risen 51 percent since the Russian government decided in October to limit its uranium exports, which are used to generate half of all U.S. nuclear power. At the same time, world demand will outpace supply by 11 percent in the decade ending in 2013 as inventories decline, the World Nuclear Association trade group forecasts.

"You just have to look at the supply and demand of uranium to see there's going to be a huge shortage," said Len Racioppo, president of Montreal-based Jarislowsky Fraser Ltd., Cameco's second-biggest shareholder, with 3.44 million shares as of March.

Uranium reached a 20-year high of $17.75 a pound on the spot market in March after Russia decided to use more of the metal for 25 nuclear plants it plans to build by 2020. To keep prices from rising further, power companies began avoiding spot purchases, and prices leveled off in April. Buyers are instead focused on material needed in 2005 and 2006.

<<<<<

There is no 3000 year supply of uranium.

Extraction of uranium from seawater would consume more energy that it would yield, and on a scale needed to supply current US U demand would be an environmental disaster.

Furthermore, there are no thorium cycle reactors - and there is no thorium cycle to support them.

More flat-earth-green-cheese-moon-pseudoscience nonsense.

[NNadir]

120. Yeah right.

A few million people have worked on this problem, but none as smart as the sloganeers.

:boring:

[jpak]

124. The concentration of uranium in seawater is 3 µg (micrograms) per liter

That's elemental uranium - not U3O8.

Current US U3O8 requirements are 22727 metric tonnes per year .

How many cubic kilometers of seawater would you need to process to meet current US uranium demand (assuming 100% extraction efficiency - which is highly unrealistic)?????

...and then compare that to the annual discharge of the Mississippi River (580 cubic kilometers per year).

Answer: extraction of uranium from seawater is pure fantasy.

[NNadir]

126. Yeah right.

:boring:

[cprise]

32. Honesty and politics

Before the commiseration gets out of hand, I'll be happy to point out the hysteria a certain DUer generated over the "carcinogenic" effects of biodiesel. You know- millions of deaths, chemistry similar to Agent Orange, heavy alkanes... complete bunk.

So I sympathize. :D

Although... as someone who is not opposed so much to the technical aspects of nuclear energy, as to its politics, I'm still waiting to hear how America (and other countries) will not turn proliferation of nuclear power into a pretext for almost constant war. Throwing engineering data at the issue won't cut it, because that doesn't address nationalistic campaigns of fear and innuendo. With this being DU and all, I think this lack of willingness to respond to the politics of RIGHT WING nuclear hysteria reflects poorly on your role (professional or otherwise) as a nuclear advocate.

[Name removed]

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[Name removed]

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[NNadir]

35. Actually it is not "hysteria". The study I included shows that while

biomass is done quite well in some EU countries, it still has a higher external cost than nuclear in many countries: All of this is related presumably to air pollution.

Air pollution is real; biodiesel is a heavy alkane in the sense that lineoleic acid has seventeen carbons (octane has eight). Are you claiming that the molecular weight of lineoleic acid makes it a light molecule? This would seem to contradict high school chemistry, where one learns to calculate molecular weights. I did however make one error when I said that biodiesel in general produces more particulates in general than ordinary diesel. Further research into the matter shows that this is sometimes the case, but not always the case. Generally biodiesel produces lower particulates than ordinary diesel, but it still produces them. Biodiesel also produces a higher amount of NOx (accross the board) than does ordinary diesel. Both particulates and NOx are air pollution, and air pollution kills millions yearly. Biodiesiel is better than the status quo, and will eliminate some air pollution deaths but not enough. Biodiesel is still not as good as DME, which produces zero particulates, thus no PAH, and much lower NOx.

I think you are trying to misrepresent what I said.

When we speak of hysteria, maybe someone will explain what exactly does nuclear power have to do with pretexts for constant war? Last I looked the only major wars the United States has participated in for the last 15 years have been oil wars. Can some one give me an example of a time when someone went to war to obtain Uranium or Thorium? The United States has reserves of Uranium and Thorium that could last for millenia. All serious nuclear programs are carefully looking at ways to destroy weapons grade material, convert it to energy, and finally make it much more difficult to reconstruct. Many nuclear engineers today labor for peace, and most know that their work gives the greatest possibility of obtaining it.

[Bdog]

20. Chernobyl raised mutations 600%

http://www.guardian.co.uk/international/story/0,3604,487857,00.html
Paul Brown, environment correspondent
Wednesday May 9, 2001
The Guardian

Children of the "liquidators" - those drafted in to clear up the Chernobyl disaster - suffer seven times the mutation rate of offspring whose parents were not exposed to radiation, research published today by the Royal Society shows.
The "unexpectedly high" mutation rate, discovered by using DNA fingerprinting techniques, means that a significant proportion of the world's population doing jobs where even low-level radiation is present are exposing their unborn children to increased risk, the researchers say.

This will be of serious concern to the nuclear industry, which has repeatedly rejected claims that exposure to radiation among its workers can affect children yet to be conceived. The theory was put forward by a team at Southampton University as the reason for the leukaemia cluster at Sellafield, but later rejected.

The new findings show that the radiation from the striken Ukrainian reactor affected the sperm of fathers, leading to mutation in the DNA of the children. None of them showed physical deformities, because the DNA changes were slight, but the long-term effects are not known.

[Name removed]

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[Bdog]

21. Fitness loss and germline mutations in barn swallows breeding in Chernobyl

http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v389/n6651/abs/389593a0_fs.html&dynoptions=doi1079298396
The severe nuclear accident at Chernobyl in 1986 resulted in the worst reported accidental exposure of radioactive material to free-living organisms. Short-term effects on human populations inhabiting polluted areas include increased incidence of thyroid cancer, infant leukaemia, and congenital malformations in newborns. Two recent studies, have reported, although with some controversy,, that germline mutation rates were increased in humans and voles living close to Chernobyl, but little is known about the viability of the organisms affected. Here we report an increased frequency of partial albinism, a morphological aberration associated with a loss of fitness, among barn swallows, Hirundo rustica, breeding close to Chernobyl. Heritability estimates indicate that mutations causing albinism were at least partly of germline origin. Furthermore, evidence for an increased germline mutation rate was obtained from segregation analysis at two hypervariable microsatellite loci, indicating that mutation events in barn swallows from Chernobyl were two- to tenfold higher than in birds from control areas in Ukraine and Italy.

[Name removed]

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[Bdog]

36. It proves, once again

It proves, one again, that low levels of radiation causes mutations in DNA.

Our DNA is 95% junk DNA. Only 5% of the code is useful programming.

A strand of DNA can have many corrupted data points with out affecting its usefulness. It takes an ionizing event in one of the 5% regions to corrupt the DNA’s function.

It proves the DNA data is becoming corrupted

How much corrupted data can you have on your had drive before the computer becomes useless and wont even boot up?

Radiation hormesies & zero-risk threshold dose are not the accepted guidelines for radiation safety any where.

http://www.gfstrahlenschutz.de/docs/hormeng2.pdf

[Name removed]

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[Bdog]

43. Perhaps you don’t understand what you are reading and quoting.

1 & 2) 95% of DNA is junk DNA. That’s why damage to the DNA has a relative small
chance hitting the program section. No mater what caused the damage.

3) It is a very good way to describe DNA. DNA is the program of life. A living cell is a machine. DNA is the program it runs on.

4) Radiation hormesies & zero-risk threshold dose are not accepted as guidelines for radiation safety any where on this planet.

[Name removed]

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[NNadir]

48. Just some advice.

You have been exceedingly clear in your discussions Treepig, but occasionally one encounters a person who is not really capable of moving beyond a particular fixed idea, and who will not be dissuaded by facts, reason, analysis or any such thing.

You can find well structured arguments for the existence of Noah's Ark, sometimes couched even in scientific terms, but if you attempt to examine and refute these claims, you will have a very difficult task on your hands. So it is with so called "creationism."

If you have had occasion to confront members of certain religious cults, you will encounter much the same kind of thinking. Many people in cults can appear quite sophisticated, until you get at the core of what they are saying. Ultimately you approach a point at which you recognize willful irrationality.

For some reason I really can't explain radiation is a topic inspiring willful irrationality in many places. It may be that it's because, like Satan, you can't see radiation (except of course light), feel it, or touch it, but it nonetheless presumed by some to have an effect. At this point, when one discusses the subject with people of a certain kind, the technical is not involved quite so much as is the emotional impulses and visceral dogma.

This may be slightly off topic, but somehow it seems relevant. Thanks though for all your good work.

[Bdog]

50. Meow

1&2)…The barn swallows have had their active DNA damaged.

3)…ITHACA, N.Y. – The process by which a cell reads the genetic code in its DNA in order to manufacture a protein is complex, involving dozens of enzymes and other biological molecules working together.

Now, research at Cornell University, using the fruit fly as a model system, has confirmed a theory about one step in the process by showing that a protein complex known as FACT is positioned in living cells at sites where chromosomal DNA is unpacked so that its code can be read. It is part of what the researchers call "a sophisticated molecular machine" that is not yet completely understood. The research is reported in the latest edition (Aug. 22) of the journal Science .
http://www.sciencedaily.com/releases/2003/08/030822074008.htm

4)…I have worked around medical x-ray equipment and radiology departments for over 12 years.

And I can assure you that Radiation hormesies & zero-risk threshold dose are not accepted as guidelines for radiation safety any where on this planet.

The best you can hope for is to reduce your risks to the point that you hope it become statistically meaningless.

Riding an airplane is statistically meaningless. Ingesting a radio active heavy metal and having it irradiate an organ for the rest of your life is not statistically meaningless.

Less radiation is always better.

http://dceg.cancer.gov/people/LinetMartha.html
Ionizing Radiation Exposure and Cancer Risks in Radiologic Technologists
There have been relatively few epidemiological studies of medical radiation workers, and only a small number include individual dose estimates, most of which are limited or problematic. In a collaborative investigation with the University of Minnesota, we have investigated cancer incidence and mortality among a nationwide cohort of 146,022 U.S. radiologic technologists certified for two or more years during 1926-82. Most cohort members were certified in radiology (97%); small numbers were certified in nuclear medicine and radiation therapy. The chronic fractionated exposures occurring over many years have resulted in cumulative doses for most technologists estimated as 1-10 cGy. The cohort members are 73% female, mostly (75%) certified under age 25, and the average age is currently about 55 years. Mortality risks were low for all causes (standardized mortality ratio, SMR=0.76) and for all cancers (SMR=0.82). Based on data obtained in a mail survey conducted during 1983-89, we found higher risks for all cancers (relative risk, RR=1.28) and breast cancer (RR=2.92) among those radiologic technologists first employed prior to 1940 compared to those first employed in 1960 or later, and risks declined with more recent calendar year of first employment, irrespective of employment duration. Risk for the combined category of acute lymphocytic, acute myeloid, and chronic myeloid leukemia was increased among those first employed prior to 1950 (RR=1.64), compared to those first employed in 1950 or later. Risks rose for breast cancer, and for the combined grouping of the radiogenic leukemias with increasing duration of employment as a radiologic technologist prior to 1950. The elevated mortality risks for breast cancer and for the radiogenic leukemias is consistent with a radiation etiology, given greater occupational exposures to ionizing radiation prior to 1950. With expert health physicists and dosimetrists, we are reconstructing exposures to estimate doses for individual workers using computerized badge dose monitoring records, microfiche and hard copy dose records from a commercial dosimetry provider and employers, and published badge dose data. We are analyzing cancer incidence data for selected sites according to work history, procedures, behavior, and protective measures. Currently, we are completing the dose reconstruction, and will quantify the radiation dose-response and the influence of effect modifiers for specific cancers and benign conditions associated with increased cancer risks. We will also study the role of specific molecular and selected genetic factors thought to be directly or indirectly involved in radiation carcinogenesis, and examine possible gene-radiation interactions for selected cancers and benign conditions associated with increased cancer risks.

[Name removed]

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[Bdog]

54. Name one place ...

that accepts Radiation hormesies & zero-risk threshold as guidelines for radiation safety.

You can't because there aren't any on this planet.

Not even in a Nuclear power plant.

[Name removed]

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[Bdog]

58. Your posts are silly and meaningless.

You have proved nothing.

You don’t have a clue as to what you are writing about.

Those are dose limits.

Those radiation levels have been determined to be acceptable.

There is no way any one can work around ionizing radiation and not be exposed. There is no way any one can get a chest x-ray and not get radiation.

These numbers were derived from the linear no-threshold (LNT) theory.

According to LNT theory:
1-The effects of low doses of ionizing radiation can be estimated by linear extrapolation from effects observed by linear extrapolation from effects observed by high doses.
2-There is not any safe dose because even very low doses of ionizing radiation produce some biological effect.

Based on the LNT theory, those dose limits are statistically acceptable to society.

Those numbers have absolutely nothing to do with radiation hormesis, & zero-risk threshold…absolutely nothing…you have proved nothing.

But thanks for giving LNT and it's aplication an introduction.

[Name removed]

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[NNadir]

60. Well done.

Having been there, I think I can say that is quite an achievement actually to be called "meaningless." Unlike many other things with which you've been presented in this conversation this actually happens to be true. This of course is meant as praise for you, certainly not censure. I've learned quite a bit from you. I'm sure with your fine understanding of the nature of science, you are aware that to have meaning, most conversations about the subject require that both parties have a respect for it as well as a passing familiarity. If not, the party without the understanding will not be able to grasp what is being said will find hence find the conversation meaningless.

Though it can be annoying, I think though it is not entirely useless to engage people who are incapable of grasping basic concepts. I do it all the time. Galileo in his "Dialogues" invented a foil to advance the ideas he sought to discredit the ideologies of his time that were so demonstrably wrong. Neither you nor I have needed that invention.

[Name removed]

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[NNadir]

63. Well the question of hormesis arose, as I understand it, because

there seemed to be lower incidences of cancer among radiation workers rather than the expected higher incidence. It also seems clear that the linear hypothesis by which the effects of low level radiation were modeled by linear extrapolation from atomic bomb victims is probably invalid.

I'm sure the mechanisms of biological interactions with radiation are very complex indeed, but the public policy ramifications are nonetheless clear. Nuclear facilities are much lower risk than the public is aware. This has lead to some very foolish choices in the energy equation. Of course, a few decades ago, nuclear risks were calculated and not derived by analysis of the actual operating conditions, so maybe then the excessive caution was warranted. Today though, with our atmosphere and land under violent assault for the purposes of providing energy, excess caution is actually killing us.

[Name removed]

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[Ready4Change]

2. Fascinating what a mixed bag it is!

I would have thought the results would be more consistent. It's also interesting how low in this "external cost" nuclear is, compared to it's reputation.

[RoadRunner]

3. I'm not so surprised to see PV at 0.6

since there's a substantial amount of embodied energy in PV panels, energy from conventional sources most likely. The latest research I've seen concludes that it takes about 2 years for a PV panel in full operation to pay back the energy that went into manufacturing it. Some studies show even more.

I wonder if these results would differ if they looked at the entire life of a PV system.

Thanks for the info!

[NNadir]

5. When you look at the numbers PV does quite well.

I think it is acceptable. This study looks only at external costs, not internal costs.

PV has a very valuable niche to which nuclear (because of high capital costs) is not particularly well suited: Providing peak load power. It does not make economic sense at night to power down extra nuclear reactors built to meet peak loads during the day. Nuclear reactors run best (and produce the least waste) when they are run flat out at as high a load as is possible. They are constant load machines. Indeed, because of a (temporary) effect known as Xenon poisoning, you often cannot start a nuclear reactor for several hours after it has shut down. PV cells are peak load machines. I think they would have excellent synergies with nuclear plants.

I'm quite sure you're right about the external costs over an extended period falling over the PV cells lifetime.

[cprise]

7. PV is more valuable than that

It is becoming a primary choice for electrification of rural villages in the 3rd world. It doesn't provide a lot of electricity but appears to be enough for these adopters for now. Big-screen TVs will have to wait.

Grid-bound solutions are far too expensive for these people (about 2 billion are off-grid), and that includes nuclear and most fossil energy.

With that said, the form of renewable energy with the most to offer in the home is solar heat. It can already save you money over fossil fuel.

[NNadir]

8. Now it's worth it to look at total cost, external + generating.

I am trying to put together some data on this subject. It will not do if a form of energy has an extremely low external cost but has such a high internal (i.e. charged) cost that no one can afford it.

Ideally, of course, the price paid by the consumer would reflect both costs, perhaps via a mechanism such as a carbon tax or pollution tax.

The official data for the EU is somewhat problematic to find right now, but this chart from the Paul Scherrer Institut in Switzerland http://gabe.web.psi.ch/eia-external%20costs.html (valid only for Switzerland) gives one perspective on total cost. The calculation may be suspect in Switzerland with respect to both wind and solar because of Switzerland's local conditions. For example a wind turbine might amortize very slowly if the wind blows more infrequently in Switzerland than it does, say, in Denmark.

The actual cost of energy is in general a function of local conditions. For instance a coal fired plant near a coal mine has a very low internal cost, since it is not necessary to ship the coal extended distances.



The dual bars represent a range. I will update this as I acquire more information from OECD, IEA, or other reports.

[Bdog]

9. There is a huge difference between refereed journals and promotional

Even the French don't have any place to store their long term waste. It just stacks up in some temporary place.

It has no home.

How much does it cost to store all of the long term waste?

Apparently its so expensive, no one can afford to build a long term dump.

How much did Chernobyl cost and how much is it costing now?

[NNadir]

10. Oh jeeze...

How much does a strip mine cost? How much does the increase in neurological symptoms from Mercury cost? How much does air pollution cost? A strip mine is cheap because NOBODY CARES.

This is a study of comparitive costs. If one thinks that 2000 lives lost from radiation is much worse than millions who are killed by air pollution, toxicological symptoms, this particular myopia will prevent one from seeing any value in a study like this. This of course is not thinking, it is religion.

France recycles the vast majority of their nuclear waste, by the way, and none of it has injured anyone anywhere. But someday, somewhere someone might die, from it, I guess. I guess your argument is that that conceivable death someday is much much worse than the thousands of energy related deaths that take place every day. It would be awfully difficult, I suppose, no I know, to argue with a person who takes that particular tack.

The original study I have posted here, not that it has any power to convince the knee jerk opponents who hate nuclear energy because it starts with an N, is an official publication of the European community with the research work being farmed out among universities.

NO DATA OR SCIENCE OR RELATED FACTORS WILL CONVINCE SOME PEOPLE OF REALITY. So one might ask, "what's the point?"

[Bdog]

15. toxic uranium tailings next to river that supplies water to southern CA

http://moab-utah.com/rack/atlasm.html

http://www.antenna.nl/wise/uranium/uwai.html

You mean that huge pile of toxic uranium tailings is located on a major fault line right next to the river that supplies all the water to 18,000,000 Southern Californians? No! I don't think so! Never! Couldn't happen. Not here! No!!!

Well, here's the story. It's leaking into the river. They don't want to move it somewhere else (where?) because of the dangerous vapors that will stir up. They don't want to leave it there because it's polluting the water. Tsk, tsk. What a shame... Hope we don't have an earthquake anytime soon.

(Photo by Brad Weis, Copyright June 15, 1998)

[cprise]

11. There is a problem with that chart

It seperates fossil fuels into three categories according to source, but lumps biomass together into one category.

As you pointed out, the external cost of biomass varies greatly. They should at least show the two main sources plus 'other'.

[NNadir]

13. Gee, I hate to agree with you on something, but that's a valid criticism.

From my side though, I'd like to note that they do not distinguish between reactor types. Very clearly some nuclear reactors are better than others. I personally believe for instance that RBMK reactors which have instabilities owing to the absense of any passive systems in the form of negative void coefficients, should all be shut down and replaced forthwith with modern PWRs.

I note that this study clearly shows biomass is demonstrably superior to oil and coal in external costs. This is a study to examine general trends. It may be a function of the fact that biomass is still relatively small in its contribution, and thus is difficult to sort into categories based on the size of the data set. This is a study of industrialized processes, not theoretical processes.

I think that biomass, at least for the short term, can be a very useful means of carbon fixation. But as anyone who has choked outside in an area with lots of fireplaces knows, biomass under many circumstances can indeed be polluting. I think we ought to give a very serious look at how we use biomass to minimize it's risks, but it very clear that of all the carbon sources available at present, those provided by chlorophyll/light interactions are definitely the best.

[Dogmudgeon]

12. Generator

This song is from the long-lost band The Balancing Act, which achieved cult status in the late 1980s. They did folky pop music and were under the wing of Peter Case at one point.

They weren't wingnuts, and I never did learn the story behind this song, but it's on their last album, Curtains. An excellent song whatever your take is on nuclear power.

Generator

Cities need a powersource
More than the elements provide
Since we built the generator
Power's been supplied

I stood on a Hilltop
A million lights burned below
People hate the generator
But we love its flow

Generator generator
Atoms burst and boil water
Steam rises up
Steam turns the turbine
And the power moves
Down the power line

We can talk we can shout
But the plug is in or the plug is out
You try to live the things you talk about
It's hard to live without the generator

If you're anything like me
You breathe hypocrisies and lie
People hate the generator
But love to light up the sky

(Words and music by Jeff Davis)

--bkl

[NNadir]

14. Cool song. I remember the fool Sting, a blatant consumer if there ever

was one, making a whole movie ("Bring on the Night") dedicated to displaying his piggish life style.

He of course makes a grand display of his concern for the environment, something he contradictorily displays in an anti-nuclear stance. The fucking concert he filmed was in Paris, the city of light, where almost all the light is derived from nuclear power. He probably was burning half a million watts to shine to power his amplifiers and shine lights on his insipid face.

[JetCityLiberal]

22. What a great debate

Energy in our world today is one of the biggest economic and environmental costs. Where do you make the choices?

Several of the threads on this forum have made me look much harder at nuclear, because air, water, and soil pollution from all types of burning has a big impact on day to day health as well as long term health, including birth defects.

I see the effects of burning many evenings where the sunset reveals the layers of pollution caused by cars, burning of wood in fireplaces and for land clearing(I know there is no energy produced for consumption, but had to say it because it pisses me off), a near by electric generation plant that uses wood byproducts at a paper mill, and refinery more than 25 miles away.

When people question me about why I fight air pollution I say "you can live without food for 2-3 weeks, you can live without water for 2-3 days, but you can live with out air for only 2-3 minutes".

I do believe we should look much harder at cleaner energy whether it be solar, wind, biomass, or yes nuclear.

Thanks for all the thought provoking information. There are several here on this post that have put in a lot of work.

JetCityLiberal

[NNadir]

65. If no one objects, I would like to kick this thread up so it's

convenient to locate. I have a feeling I'm going to need it soon since I love these conversational circles so much.

If anyone does object, it's too late. I've already kicked it.

[NNadir]

66. I would like to repeat the statement in post #65.

Unless the moderator objects, I would like to keep this thread handy. Many of my arguments appeal to it, and saves time devoted to repetition.

[NNadir]

67. As I am referring to this study in another thread, I'm kicking it again.

[Name removed]

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[NNadir]

69. I recall you from the old days at SmirkingChimp.

I aslo recall your recent post claiming that the decline of Lobsters is because nuclear plant exists in New England. I remember your vast studies of Stronium-90 in baby teeth, on SmirkingChimp, which you claimed was leading to the end of life on earth.

I recall you are an attorney. You jump rather readily to extreme conclusions, counselor and you can. You have zero proof that you have radiation sickness, just a supposition from your doctor. Exactly what are your symptoms and how exactly does your "regular MD" know the etiology derives from the presence of a nuclear plant? In the case of lobsters you claimed that the nuclear plant caused the lobster depletion, but you gave zero information proving that it did not derive from over fishing, water pollution or global warming, all of which are possible causes. Even if you really had radiation sickness, which I very, very, very, very, very, very much doubt, there are still other causes. For instance, have you ever been to Denver? Background radiation is very close to Denver. Have you ever been exposed to cigarette smoke? Cigarrette smoke concentrates Polonium that naturally occurs in Uranium containing soils? Did you ever spend any time near a coal fired plant. Coal fired plants put out far more radioactivity than do nuclear plants. Do you know that counselor?

Let me compare the quality of your website radiation.org and the study cited here. The difference between the two refernces is that the study here is a layman's report on the work of many academic institutions commissioned by an international government agency. It is not an expression of paranoia by folks owning a domain on the internet.

[Name removed]

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[jpak]

136. Nice strawman seventhson

and nice tombstone too.

[NNadir]

71. I bump this thread every once in a while when I need it in another thread.

Excuse me.

[Moderator]

72. Bump away. Its a good thread.

Quite informative.

:thumbsup: :thumbsup:

[NNadir]

73. If you don't mind, I will do it again, as I need it again.

[NNadir]

74. Once again.

[Mackenzie]

75. I have studied these issues.

Put me down in the pro nuclear power camp.

I would not mind having a nuclear power plant in my neighborhood. Just as long as it was far enough away that the noise from the plant and its associated traffic wouldn't bother me.

How loud is a nuclear power plant? And are there a lot of noisy trucks going in and out? That's my only concern.

Put it in the business district, along with the movie theaters, grocery stores, and restaurants. That's about a 10 minute walk from where I live. Maybe I could even get a job working there. It'd be nice to work so close to home.

[Dogmudgeon]

76. My own main "objections"

Nuclear power is quite promising, but it requires strict attention to the details of its operation -- like issues of security and disposal of the nuclear materials.

My fear is that a massive nuclear program in the face of a disastrous power-down will mean a large number of nukes built without even fundamental safeguards. And, in spite of the radionucleide recycling program NNadir proposes, the crisis program will simply ignore radioactive waste products, rather than recycling.

I also fear that for reasons of concentrating political and economic power over people, the use of alternative energy sources for domestic use will be discouraged. A truly decentralized system for household energy would prevent an economic collapse from becoming a human disaster. And I don't think such a program will happen until we have a sub-extinction human die-off.

The nuclear industry has been relatively very safe, in spite of the many bone-headed blunders that have been made. In a crisis program, you can count on that stupidity being amplified.

All of the decisions are being made with respect to making money off the problem. I think this guarantees more, and more lethal, problems.

--bkl

[NNadir]

78. These are valid concerns.

I share them to some extent.

However, nuclear power design is much better understood than it was in the 1960's and 1970's. These reactors have performed spectacularly and they were built before we had the materials science and computational capacity we have now. Still it must be said that the emphasis on engineering in our country has fallen precipitiously since that time.

It is true that we are more or less ignoring spent fuel concerns right now, at least in the United States, since little fuel has been treated either for recycling or for long term stabilization. However it must be said that even with this unfortunate situation, the problem of spent fuel has hardly come anywhere near to crisis.

In 1957, when I was 5 years old, and was still a member of a "future" generation that needed protection, the Shippingport nuclear reactor became the first reactor to produce nuclear power commercially in the US. None of that fuel has interfered in my life in any way since that time. All of the Cerium-144 produced in that reactors first cycle is now stable Neodymium-144; all of the I-131 is now harmless xenon-131. Sixty four percent of the dangerous Cesium-137 is now stable non-radioactive Barium-137. All of the Strontium-89 is now stable Yttrium-89. 68% of the Strontium-90 has decayed to Zirconium-90. All of the Ruthenium-103 has decayed to valuable Rhodium-103, and all of the Rutheium-106 has decayed to valuable Palladium-106. All of this has happened inside the Zirconium fuel rod with no intervention; in some sense, the fuel rod has been passively safe and continues to be so.

I think, I know, we can do infinitely better than the folks who built Shippingport. We have thousands upon thousands of reactor years of experience, we have better materials, we have better computational capability.

Still, you are correct in noting that nuclear energy will require a very strict regulatory environment in order to succeed. Moreover, there will be errors and some of them will lead, most likely, to loss of life. Some of those errors will derive from incompetance and greed. It is not that nuclear energy is 100% safe or perfect, it is merely that nuclear energy has a lower risk than its alternatives.

I am especially concerned, from a non-proliferation standpoint, about reprocessing facilities, and much worse, enrichment facilities. I believe that these need international monitoring by international authorities with the power to pull surprise audits and to revoke licensing. This type of system clearly doesn't exist now, although I think the IAEA is definitely on the path to getting there. We need these reprocessing facilities if we are to survive. On the other hand, we also need to maximize the certainty that materials are monitored and handled safely. This will especially be the case in the happy event that weapons grade material is sent to these facilities to be processed into fuel. (Just such an event happened recently at LaHavre, and the Russians are doing it as well with their Radowsky configured reactor.)

I believe that enrichment facilities are a particular hazard. There is really very, very, very little need for them for commercial purposes once a Thorium based/denatured Plutonium fuel cycle is established. I hope they will be stringently controlled and the number of them minimized in the future, that is, if there is a future, that is, if the coal and oil don't kill us before we get there.

[NNadir]

77. In terms of noise and traffic, it is rather like an office park, from what

I've seen from the few times I've been near nuclear facilities. I've been near the facilities at Oyster Creek, San Onofre, both being places where people swim and surf, and at Seabrooke in New Hampshire. (I once had dinner with a woman whose husband worked at Seabrooke: He loved his job.)

Typically the plants are fueled once every year (or longer), and so there are no fuel trains as one would see with coal plants, and they don't emit very much and their are no ashfalls.

The tax revenues in communities with nuclear power plants are substantial, so I certainly wouldn't object to one in my town either.

It is difficult to say if, as was the case at Shoreham and Seabrooke, whether protesters would be the same problem they were in the 1970's. I was an anti-Shoreham protester (I have since done a 180 degree turn on the subject obviously) and I am sure that some our protests made for local inconvenience. The people in Wading River, NY, where Shoreham was being built were rather upset about the loss of tax revenue for their school district when the plant was sold off to the Long Island Power Authority when protests succeeded in keeping the plant off line.

I very much regret my participation in those events, but I was young and gullible.

[Mackenzie]

79. Thank you.

Thank you for answering my questions.

I think that if the protesters truly believed that the nuclear power plants were dangerous, they would hold their protests far away from the plants, instead of right in front of them.

Your past experience of being on the other side at least gives you a perspective of what the other side believes and feels. This can actually give you an advantage in thinking of ways to persuade them to change their minds.

I know of plenty of cases of people who had been opposed to nuclear power, who later changed their minds when they discovered the real facts and the truth. On the other hand, I have never heard of even one person who was pro nuclear power, who later switched to being against it. This is very telling. Once you develop an interest and knowledge and love of science, you never go back.

The United States currently gets 20% of its electricity from nuclear power. But because of people who wrongly call themselves "environmentalists," we haven't built even one major new nuclear power plant since the 1970s. If we hadn't stopped building them, we would have so much more nuclear power today that the issue of coal power plants, fossil fuels, and global warming emissions would probably be a moot point.

I will support the Kyoto Treaty as soon as it calls for major large scale construction of hundreds of new nuclear power plants all over the world in every free and civilized democratic nation. Ironically, most current supporters of the Kyoto Treaty are opposed to nuclear power. And for this reason, I cannot support the Kyoto Treaty as it currently stands.

[NNadir]

80. In defense of those of us who protested; we had very little history

to go on.

We didn't have knowledge of global warming, neither did we have much sense of what a total nuclear failure might actually look like. Nor did we recognize that nuclear reactors could operate for decades without problems and without creating much external pollution.

When Three Mile Island occurred, most people didn't believe that the health effects of the accident would end up being negligible.

I was still anti-nuclear power when Chernobyl exploded, and I remember feeling sick to my stomach the morning I learned of it, thinking that millions of Europeans would die from the event, particularly in Kiev. Actually (and thankfully) most of those deaths never occurred. Strangely enough my odyssey to pro-nuclear began with Chernobyl: I pulled out my Handbook of Chemistry and Physics to learn about the properties of the isotopes in the news and encountered the variable known as the "neutron capture cross section." The idea of transmutation then occurred to me (I was still naive enough to think it was original with me) and I began exhaustive reading on the subject. I've been reading about the engineering, physics and nuclear chemistry of nuclear power ever since then.

I have never said that nuclear power will be totally harmless, but I do believe that it is safer than any known alternative except for intermittent wind power. Like you, I would have no problem whatsoever living near a nuclear facility; and I would love to work in one: If I had my career to do over, I would definitely be a nuclear engineer as much as I love being a chemist.

[NNadir]

81. Let us now consider how much waste is generated by coal.

In response to some interesting data and links posted by AZCat in this thread:

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x18218

I will do some back of the envelope calculations on the mass of various types of waste materials produced by various energy forms. (I am doing it is this thread, because I frequently refer to it in other threads, and I'd like, with DU's permission, to keep these type of calculations in a central place.)

The first such waste

The data files I will use can be found at these links (the first found through AZCat's link):

http://www.eia.doe.gov/oiaf/ieo/pdf/electricity.pdf (especially Table 16)

and

http://www.epa.gov/ttn/chief/ap42/appendix/appa.pdf

To use the data in the second link it will be necessary to make some assumptions about the nature of the coal used. These assumptions are as follows:

1) I'll cut coal a break, and assume that the sulfur content is at the highest level given for anthracite, 1%. Bituminous coals can contain significantly more sulfur, up to 5.4%.

2) I'll also cut coal a break on ash, and use the midpoint range for ash content for anthracite, 11.5%, for calculations involving the ash generated each year by coal.

3) I'll cut coal yet another break, in that I will take the energy value for coal to be close to that anthracite, 7.00 million kilocalories/metric ton (or kcal/MT), written in link two as 7.00 X 10^6 kcal/Mg.

4) For calculations giving the volume of CO2 released each year, I will use the Ideal Gas Law as an approximation, and 300K (27C), the temperature on a nice late spring day as the temperature.

Now let's calculate from the values given for 2001 in the first link provided by AZcat.

We see that the thermal energy consumed by coal burning electricity generating plants is 6.11 X 10^16 BTU. There are 1054.8 Joules in a BTU so this is the equivalent of 64.4 exajoules or 6.4X10^19 Joules of energy. When we multiply 7.00 X 10^6 kcal/MT by 4184 J/kcal we find that each ton of coal contains 2.9 X 10^10 Joules of energy. This means that to provide the annual requirement for thermal energy provided for the generation of electricity, about 5.5 billion metric tons of coal.

What does 5.5 billion metric tons of coal mean in terms of pollutants?

Sulfur dioxide: Again we will take the (generously understated) value of 1% sulfur in (anthracite) coal as representative. This implies that 55 million tons of sulfur will be burned. We will (again generously) assume that the sulfur is only oxidized to sulfur dioxide and not sulfur trioxide (which is of course complete nonsense), and therefore calculate that the mass of the pollutant is only 50% sulfur. Therefore the amount of sulfur oxide injected into the air is (minimally) 110 million metric tons.

Ash: Taking the values for ash in coal as I described above, the anthracite midpoint, we find that the amount of ash generated in is 630 million metric tons.

And now let’s get to the most important pollutant, carbon dioxide:

If we subtract the amount of ash and the amount of sulfur in coal, we are then left with a close approximation of the amount of carbon from coal. Using the data we see that the amount of carbon contained in the burned coal is 4.8 billion metric tons.

Carbon dioxide is only 27.29% carbon. Thus we see that the amount of carbon dioxide injected to the atmosphere in 2001 by coal fired electrical generation plants was 17.6 billion metric tons. To see how much this is, let us consider this is let’s use some visual imagery. The number of moles of carbon dioxide represented by this amount is roughly 400 trillion. If we use the familiar ideal gas law PV = nRT, we see that at 300K (27C) and atmospheric pressure (1.01X10^5 Pa), the volume of the carbon dioxide released uncontrolled into the atmosphere is 9.9 trillion cubic meters of gas.

Let us imagine that we were to contain all of this gas in a cylindrical balloon that was one kilometer in height, or almost three times the height of the Empire State Building. Suppose this cylindrical balloon were now placed in such a way as to locate its center exactly at the location of the Empire State Building. The radius of the balloon would then be 56 kilometers, and would extend far into Southern New York, almost all the way across New Jersey towards Pennsylvania, Southward across all of Staten Island into the sea, and half way across Long Island almost out to Smithtown.

If, instead, the balloon were spherical, and we were able to somehow make it isobaric and isothermal in violation of the Maxwell-Boltzman relation, the diameter of this balloon would be 39 kilometers. Resting at sea level the balloon would rise to 4.4 times the height of Mount Everest.

Of course both of these balloons contain only pure carbon dioxide. As the citizens around Lake Nyos in Cameroon discovered, the fatal concentration of carbon dioxide is far lower than 100%. It is, in fact, fatal within a few minutes at a concentration of 10%. The radius of a 1 km high cylindrical balloon containing a fatal concentration of carbon dioxide would extend 177 km from the Empire State Building, covering all of Long Island and most of Connecticut, and all of Northern New Jersey. The diameter of a spherical balloon containing a toxic concentration of carbon dioxide would be 84 kilometers.

And all these numbers refer to just one year’s worth.

[NNadir]

169. For my discussion of radioiodide I need these figures on mercury from coal

http://www.biperusa.biz/1005CoalHumanToll_Article_%20Template.htm

""Startling new research shows that one out of every six women of child bearing age in the United States may have blood mercury concentrations high enough to damage a developing fetus. This means that 630,000 of the 4 million babies born in the country each year are at risk of neurological damage because of exposure to dangerous mercury levels in the womb.
Fetuses, infants, and young children are most at risk for mercury damage to their nervous systems. New studies show that mercury exposure may also damage cardiovascular, immune, and reproductive systems. Chronic low-level exposure prenatally or in the early years of life can delay development and hamper performance in tests of attention, fine motor skills, language,
visual spatial skills, and verbal memory. At high concentrations, mercury can cause mental retardation, cerebral palsy, deafness, blindness, and even death...

...The 600 plus coal-fired power plants in the United States, which produce over half of the country?s electricity, burn 1 billion tons of coal and release 98,000 pounds (44 metric tons) of mercury into the air each year. Power plants yield an additional 81,000 pounds of mercury pollution in the form of solid waste, including fly ash and scrubber sludge, and 20,000 pounds of mercury from 'cleaning' coal before it is burned. In sum, coal-fired power plants pollute the environment with some 200,000 pounds of mercury annually."

I'm not 100% certain of the veracity of this numbers, since they do not come from a referreed journal, but they make a good working approximation for the general discussion of Mercury (I) Iodide.

[NNadir]

82. Let us now consider the quantity and quality of "nuclear waste."

Under this heading, I will analyze the chemistry and nuclear properties of the fission products obtained when one uses nuclear energy to generate electricity or other forms of usable energy. Where relevant, I will touch on the biochemistry of the fission product. I will also touch upon means, time permitting, of mitigation and/or use of the element via or in technological systems. I will also compare it to existing materials, where relevant, in the natural environment, as it existed before perturbation by humanity.

I will for convenience consider the set of nuclides contained for each of the important elements of the periodic table that are generated via nuclear fission. For instance, the first (and in many ways the most problematic and well publicized) fission product element I will analyze will be Cesium. The properties of all isotopes of Cesium generated in nuclear reactors will be discussed, when I get to that post. (I have already completed most of the calculations for that element, but may not have time to "write it up" this weekend.)

Now I will reproduce, slightly edited to improve clarity and grammar, a post I placed on another thread. This will serve as a general description of the methods and sources I have used for the data that I will ultimately (when I have time) enter here.

The partially reproduced post from (http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x18218):

For accumulations of nuclear materials, years ago I derived the (simplified) relationship A = P(1-exp(-kt)) for how fission products accumulate. Here A is the accumulated mass (in most of my spreadsheets, given in metric tons), P is the maximal amount of a fission product that can accumulate before the fission product is decaying at exactly the rate it is created at a particular output for nuclear generated power, k is the decay constant for the nuclide decay constant, which is simply the natural logarithm of 2 divided by the half life, and t is the time at which a given power output has been generated by nuclear means. For convenience, I always use time units of seconds in values involving time.

As I usually do, I will not treat any Uranium, Plutonium, or minor actinides as "waste" since I find such a conception most unfortunate. (I regard these materials as resources.) I am aware however that public policy in the United States - though not elsewhere - my objection notwithstanding has managed to define these materials as "wastes."

Some simplifying assumptions went into this derivation. The differential equations that nuclear engineers call the "fuel depletion" equations can be quite complex and are often solved numerically using sophisticated fuel depletion programs like ORIGEN (to which I have no access). These programs account for issues like neutron fluxes and capture cross sections, sometimes - as I understand it - using "multigroup" analyses - in which neutron energy distributions, of which the cross sections are functions, are considered.

I have fudged all this by simply using the "accumulated fission yield" available for each nuclide in the Table of Nuclides. http://atom.kaeri.re.kr / Fission yields actually vary with the particular nuclide being fissioned. The "big four nuclides" under modern conditions can be considered to be Uranium-235 (by far now the biggest), Plutonium-239 (the next most important), Uranium-233 (which one hopes, for non-proliferation reasons, will become more important) and Plutonium-241, which becomes important when fuel is recycled. Because as a practical matter, most nuclear energy is still generated using U-235 enriched natural Uranium, and the vast majority of reactors in the world are thermal, I have used the values given for fission in U-235 under thermal conditions (0.253 MeV neutrons) in the tables. Note that the (internet) tables do not even give the values for Uranium-233 or Plutonium-241. This is trivial though: Most heavy nuclides have fission product distributions that look like camel humps and fissioning heavier nuclides move the hump reflecting the higher mass nuclides, that on the right, slightly to the right, toward heavier fission products. (The effect on the most important element in the heavy part of the fission product hump, Cesium, is slight.)

In general the values given here are better when we consider so called "nuclear wastes" that have been removed from the reactor as spent fuel, since the mass of such materials is only a function of nuclear decay, and not exposure to a neutron flux. I don't think this makes all that much difference in most of the important cases, though. In any case, these are the most important values for people who are considering what to do with fission products, whether or not one regards them as "wastes" or as useful materials. The "constant" P I have used above, is obtained from from the fission yields, the power output and conversion factors (the electron charge, Avogadro's number, the energy yield per fission - generally taken to be 190 MeV per fission.)

[NNadir]

83. First links to some discussions here of the induction product tritium.

Tritium, a radioactive form of hydrogen is formed in tiny amounts in all nuclear reactors, and recoverable amounts in CANDU reactors via neutron captures in deuterium, deuterium being a naturally occurring form of hydrogen that is heavier than normal hydrogen. (Deuterium is found in all water, although in proportionally low amounts.) When stable atoms absorb neutrons, they sometimes become radioactive. This process, which occurs only rarely with deuterium is known as "radioactive induction." Thus the formation of tritium in nuclear reactors needs to be considered if one is to assess the advantages and dangers of nuclear power.

There is a brief thread on tritium on this site that discusses pros and cons of tritium and it is linked here: http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x19287

In another thread when discussing fusion reactors, which will depend on the use of tritium, I posted a link to this site which gives some idea about how much tritium is produced word wide in nuclear reactors; which is basically kilogram quantities under the best or worst conditions. Here is that link:

http://public.lanl.gov/willms/Presentations/Tritium_Supply_Considerations.pdf.

The thread in which I originally posted that link is here:

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=115&topic_id=18893&mesg_id=19317&page=

The post in that thread where I discuss fusion and tritium is #122.

[NNadir]

84. Cesium, Sakarhov, and Pauling. My first impressions of radiocesium.

Of all the elements found among the fission products, the one that has troubled me most, looking back, is cesium. Be that as it may, although I’ve done a great deal of thinking about cesium, I must say that I’ve not given the problem of radiocesium quite as careful an analysis as I have done in preparation for the series of posts that will follow.

Radiocesium used to be in the news quite a bit, especially back in the late 1950’s and early 1960’s. In those days certain scientists, including two time Nobel Laureate (Chemistry and Peace) Linus Pauling in the United States, and Andrei Sakharov (ultimately a hero to the cause of international peace, and a recipient of the 1975 Nobel Prize for the same) in the Soviet Union, began agitating for a ban on the atmospheric testing of nuclear weapons. Because I was a child in this era, when the subject was constantly in the news, I can say that radiocesium, which along with radiostrontium, was an important constituent of what was then known as “nuclear fallout,” was probably the first radioisotope of which I was aware. (I was, of course, afraid of it.)

http://www.aip.org/history/sakharov/index.htm

The reason for the special focus on cesium, strontium, and to a lesser extent, iodine as constituents of nuclear fallout relates to the fact that all of these elements are readily absorbed by living systems, cesium as an analogue of potassium, strontium as an analogue of calcium, and iodine as a constituent of the important metabolic hormone thyroxin which is produced in the thyroid gland.

When I grew older, and actually learned some nuclear science, cesium still concerned me for reasons that did not show up in newspapers back in the 1950s and 1960s.

Lest anyone accuse me of being cavalier about nuclear risks, or lest anyone claim that I am trying to obscure or obfuscate any facts connected with my pronuclear position, I will list these reasons for my concern about cesium in some (possibly boringly technical) detail in a series of posts under the heading of "Cesium: The Bad News" to follow in this thread.

I will then point up in another series of posts (some of which may appear at the same rate as the series of negative cesium posts) the mitigating factors in the chemistry, physics and technology of cesium through which cesium can be managed.

[NNadir]

85. Cesium: The bad news.

In the series of posts by me under this heading, I will list all of the problematic and negative things about Cesium of which I can think.

If anti-environmental anti-nuclear activists would like to chime in with any thing I have not addressed about this fission product, I invite them to do so.

[NNadir]

86. #1: Cesium forms lots of soluble compounds.

1) Cesium’s chemistry is rather unique among the common elements associated with nuclear issues inasmuch as cesium forms very few stable water insoluble compounds. Almost all common cesium compounds are soluble in water, most highly so. Moreover, some compounds of cesium, notably the oxide, are highly corrosive. Aqueous solutions of cesium hydroxide (which form upon dissolving the oxide) for instance, dissolve (albeit slowly) glass. Thus the immobilization of cesium can be problematic. Moreover, if radiocesium contaminates bodies of water, as it did during the era of nuclear testing and after the accident at Chernobyl, it is almost impossible to remove through technological interventions or means. Persons or animals drinking such water, or plants taking it up, moreover, will readily absorb this contamination and distribute it widely in tissues, especially if they are nutritionally deprived of potassium.

[NNadir]

87. #2. Cesium is a rather common fission product.

The accumulated fission yields of cesium-133 (which is naturally occurring cesium and is not radioactive), cesium-135, and cesium-137 for fission by thermal neutrons of uranium-235 are respectively, 6.70%, 6.53% and 6.27%. Thus almost 13% of fissions result in the formation of a radioactive cesium isotope. While cesium-133 is relatively harmless, unless one engages in isotopic separation this stable isotope adds bulk to the amount of cesium that must be handled. Moreover, the placement of Cesium-133 in a sustained neutron flux can lead to the formation of radioactive Cesium-134 via the mechanism of neutron absorption, aka “radioactive induction.”

Cesium-134, with a half-life of 2.0648 years, does not accumulate as a fission product because of the stability of Xe-134, an isotope of the gas Xenon. Since Xenon has a lower atomic number than Cesium (54, compared to 55) the stability of this isotope prevents the formation of cesium-134 as a constituent a beta decay chain. As only trace amounts of Cesium-134 are formed as direct fission products, this means cesium-134 is not an important isotope among fission products. (It can, though, as indicated above, accumulate with high "burn-ups" in nuclear reactors however. See Journal of NUCLEAR SCIENCE and TECHNOLOGY, Vol. 41, No. 4, p. 448–456 (April 2004), http://wwwsoc.nii.ac.jp/aesj/publication/JNST2004/No.4/41_448-456.pdf) The same situation holds for Cesium-136, with a half-life of 13.16 days, because of the proximity of the stable Xe-136 isotope. (Xenon-136 is actually slightly unstable and slightly radioactive, but its half-life is longer than the age of the universe. Its infinitesimal and nearly undetectable radioactivity has only recently been detected with sophisticated instrumentation.) Even so, if Xe-136 did not exist or were not so stable or metastable, the vast majority of Cs-136 would quickly decay to Barium-136 before being removed from the reactor in any case, as a result of its short half-life. I have analyzed these two isotopes, Cs-134 and Cs-136 in my study, but as a “nuclear waste” issue, they are trivial, at best and I will not refer to them in too much detail later.

[NNadir]

88. #3 Cesium is not of vast economic importance.

Right now, cesium has relatively few industrial uses and thus it is of relatively low economic value. The main use of cesium is to make a salt, cesium formate, that is used as a lubricant in drilling operations. Cesium is also used as a counter ion for salts of fatty acids. These are mainly used in the powders found in surgical gloves. Cesium is also used in atomic clocks, in photoelectric tubes, in vacuum tubes still used by some in the high end stereo market, and in the preparation of certain types crystals for optical uses. Cesium fluoride, and a few other cesium compounds can be useful in organic synthesis. These applications, of course, are hardly wise situations for using mixtures of radioactive isotopes, however, and have almost no bearing on the issue of what we might do with radiocesium.

Cesium has a huge potential use in ion propulsion engines in outer space, and the isotope Cesium-135 is the best possible substance known for this purpose, but such an application would require, of course, an active presence of humanity beyond earth’s atmosphere. Because of cost, it is somewhat dubious to expect an age of interplanetary travel will actually occur but I will nonetheless further discuss this possibility briefly below and see how much Cesium such operations might consume.

The radioisotope Cs-137 has many uses, although hardly enough, currently, to utilize even a fraction of that which is generated. That said, one of the worst radiological accidents in history, one of the very rare cases where someone has actually been injured by a commercially generated fission product, involves Cesium-137. This accident occurred in Goiana, Brazil, when a cancer treatment machine in which Cesium-137 was used, was stolen by scrap dealers. Four people died and an indeterminate number, possibly in the hundreds, were injured. It is expected that some of those exposed will ultimately get leukemia, a disease they probably not have gotten without such exposure.

http://www.nbc-med.org/SiteContent/MedRef/OnlineRef/CaseStudies/csGoiania.html

[NNadir]

89. #4. The isotope Cs-135 has a very long half-life.

One cesium isotope, Cs-135, is extremely long lived relative to most fission products. Its half-life is 2.3 million years. Even I, a proponent of the rapid expansion of nuclear power, cannot be absolutely (as in perfectly or 100%) certain that cesium-135 can be stabilized for millions of years, especially given its chemical properties. Cesium-135 is one of three radioisotopes produced as fission products in nuclear reactors that can be expected to actually persist for millions of years barring an intervention like transmutation. (The other two are Iodine-129 and Technetium-99.)

[NNadir]

90. #5. The transmutation of Cesium isotopes is complicated and difficult.

This is concern is somewhat technical: Cesium-137 (half-life 30.07 years) cannot be usefully transmuted by neutrons. Almost uniquely among fission products, Cesium-137 has a very low neutron absorption cross section through most of the fission neutron energy spectrum, invalidating the mechanism through which nuclear transmutation occurs. There are only a few resonance peaks in the entire spectrum, and even these narrow peaks do not exceed 10 barns by very much. Therefore it is not possible to shorten the half-life of Cesium-137 by very much by placing it in a neutron flux. Use of a proton flux might ameliorate this problem, but such a solution is likely to be very expensive and cumbersome, even if it could be made to work.

A related concern, should anyone so technical as to care ever read this post, is that the neutron absorption cross section of Cesium-134 is generally higher throughout the fission energy spectrum than that the same cross section is for Cesium-135. Fortunately, this is likely to cause few difficulties, since it is difficult to imagine circumstances in which the concentration of Cesium-134 would ever be high enough to actually create more Cesium-135 than is destroyed as the result of a transmutation scheme. Even were one able to locate conditions under which one could do so, one could easily take advantages of resonances by shifting the neutron energy distribution to another value through the introduction of moderating nuclei with an appropriate mass in an appropriate concentration. Still, such a consideration might slow the rate at which cesium-135 could be transmuted, should humanity elect to do so.

[RafterMan]

93. Do you have any well-documented sources

describing the volume of cesium-137 vs. -135 produced as waste by current nuclear reactors? I can't seem to find it on the web.

I know that the cesium/strontium portion of spent fuel is said to decrease in radioactivity below that of uranium ore in a few hundreds of years, but I don't know what percentage of the remaining radioactivity is due to the presence of longer-lived isotopes.

Thanks.

[NNadir]

94. I have a non-internet source in my home library.

This is Stacy, "Nuclear Power Physics" Wiley and Sons, NY 2001, table 6-8 pages 225-227. Unfortunately the units are in Ci per THM and thus need to be converted with the specific activities to mass. I'll try to get that up here, when I have a chance. I have lots of spreadsheets with calculated specific activities.

I often calculate these values myself through the use of data from the table of nuclides, http://atom.kaeri.re.kr/ ,using an equilibrium approach relation I developed some years ago. My calculations are first order however and they do not reflect variables like fuel distribution, flux leveling, changes in fuel composition with burn-up, etc. But they're a good first approximation of the fission product/power relationship.

I'll get back to you on this.

[NNadir]

102. You may wish to check post #100, (my #5) below which addresses this

question.

Best regards,
NN

[NNadir]

91. #6. Cesium-137 is a powerful gamma emitter.

Cesium-137, or rather its daughter nuclide, Ba-137m, with which it is in constant equilibrium, is a powerful gamma emitter. This means that mixtures containing Cesium-137 must usually be handled remotely. For the purposes of clarification though, barium-137m decays rapidly (half-life 2.552 minutes) to its nuclear isomer, stable Ba-137.

[NNadir]

92. Cesium: Mitigating factors and good news.

In the posts #85-91 above I have listed all of the bad news and technical problems of which I can think with respect to radiocesium as produced in nuclear reactors.

I invite anyone who can suggest more negatives about cesium to add them, and I will be happy to address them.

Below this thread I will include a series of posts that suggest mitigating concerns and possible solutions to the problem of fission-product cesium.

I won't do this tonight however, since, although I've already written many of these posts, I'm too tired to post them.

For now let's just chew on the bad news.

[RafterMan]

95. Here is my source

for the good news about cesium and strontium as waste products in the current nuclear fuel cycle:

http://nucleartimes.jrc.nl/Doc/Rodriguez.pdf

According to table 1 (page 2), radioactive cesium and strontium make up just 0.3% of the waste from spent reactor fuel. Even if nuclear sources produced all of the electricity in America today, along with the estimated 300 GWe extra capacity to produce hydrogen for fuel cells to replace all current ground transportation, we'd still only be talking about a volume of under 25 cubic meters per year of radioactive strontium and cesium with which to contend.

This is a tiny amount.

[NNadir]

96. #1: At full power, the yield of Cesium-135 is substantially reduced.

The yield of Cesium-135 can be reduced considerably by running a reactor at full power for as long as is possible. The direct yield of Cesium-135 in the fission of a Uranium-235 nucleus is essentially zero, meaning that when a U-235 nucleus splits it never splits into a Cesium-135 nucleus. Instead cesium-135 forms from neutron rich nuclei having a lower atomic number, such as Tellurium-135 and Xenon-135, that are the direct fission products formed for the mass number 135. (The half-life of Tellurium-135 is so short that one should be comfortable in treating all of the Xenon-135 as if it were directly formed in the fission reaction.) Xenon-135 has one of the highest neutron capture cross sections known, 2,943,100 barns at 0.253 MeV, where a barn in 10^-24 cm.. This means it absorbs neutrons very readily to form another isotope, Xenon-136 that is stable and presents no radiological hazard. (Xenon-136 theoretically could be directly removed from a reactor and used to manufacture Xenon headlamps like those found on expensive cars.) Xenon-135 is not a stable nuclide even absent a neutron flux. It decays to give Cesium-135 with a half-life of 9.14 hours.

The mathematical structure of what all this means, in more detail is given here:

http://www.tpub.com/content/doe/h1019v2/css/h1019v2_59.htm

Here we see the production and destruction equation for Xe-135, which reaches an equilibrium value that is a function of the neutron flux maintained in the reactor. The power, in turn is a function of the flux. It follows therefore that higher the power, the lower the equilibrium value for Xe-135. This means that that Xe-135 is being consumed by two paths, one in which it is transformed into non-radioactive Xe-136 and one in which it decays to radioactive Cesium-135. If one looks at form of the solution to the differential equation (a simplified case of a Bateman equation) given above a few observations can be made.

http://www.neutron.kth.se/courses/transmutation/Bateman/Bateman.html

The first is that the fraction of Xenon-135 that does not decay into Cesium-135 is a function of the neutron flux, which is closely linked to the energy output of the reactor.

If f is the fraction that is transmuted we have: f = ps/(ps+k) where p, is the neutron flux in inverse (cm^2-sec), and s is the cross section in cm^2, and k is the decay constant for Xe-135. (One barn = 10^-24 cm^2).

(Note: The DU editor does not support Greek letters. In most normal nuclear physics and nuclear engineering texts, the letter p that I have used is phi, the s is sigma, and the k is lambda.)

Plugging in the appropriate numbers for a range of typical fluxes from 10^12 to 7.5X10^12, we see that anywhere between 10% and 50% of the Xenon-135 can be transformed into Xenon-136 without decaying further. We see that depending on the flux, which we vary from 1012 to 7.5 X 1012 neutrons per square centimeter per second, the fraction of Xenon decaying into Cesium-135 can vary from 90% to less than 50%.

(Note: The equation I have used here is very simplified – and would apply strictly to a model reactor – specifically one that is homogenized and contains monoenergetic neutrons. Real reactors are not homogeneous – the fuel is lumped - and neutrons in them exist at a range of energies. Still my equation is illustrative, much as the ideal gas law is illustrative for qualitative purposes, though engineering calculations often involve use of the Van de Wal’s equation or even more sophisticated gas laws. A far more exacting – and necessarily more complex equation for the levels of Xenon-135 in nuclear reactors can be found in William Stacy’s “Nuclear Reactor Physics,” Wiley, 2001, page 213.)

The main point is this: By running reactors at full flat out power, the yield of Cs-135, a long lived fission product that excites proponents of the theory that “nuclear waste” exists, can be reduced from around 6% to values under 4%. On reflection, this is another reason that nuclear power is well suited for base load, but not necessarily peak load, energy demands.

[NNadir]

97. #2 The bioavailability of cesium isotopes decrease quickly in soils.

The biological half-life of radiocesium isotopes, that is the half-life with which is available for incorporation into to living organisms, is considerably less than the physical radioactive half life. Millions of curies of Cesium-137 were released by the Chernobyl accident (and millions more by nuclear weapons testing in places like Nevada) and the behavior of this isotope, which has a half life of 30.07 years, has been extensively studied. The injection of this radioisotope into the environment, both deliberately and accidentally, has been of interest not only for its radiological health and environmental implications, but has also been used as a tracer to track things like ocean and atmospheric currents, river sedimentation patterns, convection, stratification and mixing in lakes, mineral flows in soils, ice flows in glaciers, growth patterns in forests, etc.

Chemists tend casually to think of the group one elements (Lithium, Sodium, Potassium, Rubidium and Cesium, and, oh yes, Francium) as being relatively simple in their chemistry. What is notable about these elements besides the fact that they have only two oxidation states, 0 and 1, is the high solubility of almost all of their salts, as noted above. This solubility gives cause for one to think, somewhat naively, that cesium, like sodium, would have a tendency to “wash out” and distribute freely wherever water flowed. Moreover, one would expect that cesium would encounter few barriers to biological uptake. On a little reflection however, it is clearly not the case that the biochemistry or geochemistry of these elements are identical. Obviously, for instance, the biochemistry of potassium and sodium are very different; owing to the differences one can have a potassium deficiency even if one soaks his or her French fries in table salt. Also the congener element Rubidium, which is also naturally radioactive, has the highest concentration of any element in tissue that has no known physiological role.

The physiological properties of Cesium reflect these subtle differences: It has been known for some time that to everyone’s surprise that after contamination of an ecosystem with radiocesium, the concentration of Cesium-137 in living tissues falls much faster than the half-life attributable to radioactive decay. The half life for uptake of cesium into plants growing in contaminated soils is considerably shorter than thirty years; it is actually about two years. (See, for instance, Environ. Sci. Technol., 33 (1), 49 -54, 1999.) This means that although almost 19 years after the Chernobyl accident about 64% of the cesium-137 injected into the environment still exists, less than 0.1% of that is actually available for biological uptake. The mechanism for this property, according to this paper, seems to result from the tendency of cesium to form stable complexes with minerals found in certain types of soils.

In any case, were one to ingest Cesium-137, unlike other radioisotopes, it has very little tendency to concentrate in organs. It is relatively easy to flush it out by increasing one’s potassium intake. One could significantly lower one’s internal Cesium-137 level for instance, by eating bananas.

[NNadir]

98. #3The earth naturally contains hundreds of billions of curies of K and Rb.

Since we are now comparing cesium and potassium, it is probably a good point to compare the total radioactivity on earth associated with each of these elements, radioactivity that in the case of potassium (and rubidium) occurs naturally, and in the case of radiocesium, is a result of technology. Since the chemistry of cesium is closely tied to that of these two elements, if there is a lot of them, we would expect the biological and physical properties of group I elements that are radioactive to be of less concern than is advertised.

First let’s look at how much potassium is in the ocean, since it is the major source of radioactivity from among the group 1 elements (the elements in the first column of the periodic table). The volume of the ocean can be taken to be about 1.37 X 10^9 cubic kilometers.

http://www.geocities.com/ultrastupidneal/Knowledge-Geography-World-Ocean.html

http://xtide.ldeo.columbia.edu/mpa/Clim-Wat/Climate/lectures/ocean/

According to this website from the EPA, http://omp.gso.uri.edu/doee/science/physical/chsal1.htm, the average salinity of the ocean should be taken as 35 grams of salt for each kilogram of seawater. Of this salt, 1.13% of this is potassium.

According to this website, http://hypertextbook.com/facts/2002/EdwardLaValley.shtml, the average density of seawater is 1030 kg/m^3.

From this data it is straightforward to calculate how much potassium is found in the ocean: 6.7 X 10^(20) grams. Of this, 0.00117% is radioactive potassium-40, almost all of this radioactivity being left over from the supernova(e) from out of which the earth was created. This means that there is that there is 7.8 X 10^(16) grams of potassium-40 in the ocean, or in different units, 78 billion metric tons of this radioactive isotope. From the half-life of potassium-40, 1.28 billion years, it is also straightforward to calculate its specific activity, which is 259,000 Becquerel (Beq) per gram. Thus it is now possible to calculate the total radioactivity of the ocean, and when one does so, one finds that the ocean has 2.0 X 10^(22) Beq. Converting to other familiar units of radioactivity, Curies, by dividing this number by 3.7 X 10^10, we see that the ocean has about 550 billion curies of radiopotassium in it.

Similarly, this website http://www.stanford.edu/group/Urchin/mineral.html shows that the molar concentration of rubidium in seawater is 2.4 X 10^-6 M. Knowing this, and that 27.835% of rubidium is Rb-87, a radioactive isotope with a half life of 47.5 billion years, it is straightforward to show that the radioactivity attributable to rubidium in the ocean is about 6.9 billion curies. Thus the total radioactivity in the ocean from naturally occurring group I elements is about 560 billion curies over all.

[NNadir]

99. #4 A very stable water insoluble cesium mineral is known.

This mineral, pollucite, is rare, owing to the intrinsic rarity of cesium itself. The mineral, which has the chemical formula (Cs, Na)2Al2Si4O12.H2O) is found in the largest concentrations in the Tanco mine in Bernic Lake Manitobia, which represents 60% of the world’s supply of recoverable cesium. It happens that these rocks are Precambrian pegamatites, and are part of the so called Canadian Shield, which contain some of the oldest known rocks on earth. Some of rocks in the Canadian Shield are over 4 billion years old. They are found in very wet areas, mottled with lakes. Therefore the claim that cesium cannot be immobilized forever is very dubious.

Synthetic pollucite containing Cs-137 have been studied by the Department of Energy to test their radiolytic stability and were allowed to decay for decades.

http://emsp.em.doe.gov/EMSPprojects1996_2003/completed/55382.pdf

As I remarked elsewhere, the result was clear. Not much changed. It's pretty much exactly what it was in the first place: A fucking rock. Since the half-life of the most dangerous isotope of cesium, cesium-137 is 30.23 years, this demonstration is pretty compelling. Indeed any of the less dangerous but far longer lived cesium-135 found in pegmatitic pollucite in the Canadian shield would have decayed to barium over billions of years without ever finding its way into the biological environment. In fact, geologically formed Canadian Shield pollucite does contain immobilized radioactive material, specifically the radiorubidium (Rb-87) that I described in the post above #3 of this series on cesium mitigation. There seems to be no evidence of damage to this pollucite from the decay of Rb-87 into Sr-87 and no mobilization of the group I elements resulting from it.

[NNadir]

100. #5. At constant power, less and less cesium forms every year.

Be careful of how you read this:

More and more cesium is accumulating, but the rate of increase is falling. This is because all radioactive cesium isotopes, like all radioactive isotopes formed in nuclear reactors, ultimately reach, albeit asymptotically, an equilibrium value at which they decay as fast as they are formed. Nuclear energy is unique in this regard, there is a maximal amount of so called “nuclear waste” that can form, after which the power is generated without any increase in waste materials whatsoever.

The actual amounts of these equilibrium values vary with the half-life of the fission product in question, and they are a function of the speed of neutrons used in the fission (thermal or fast) and the nature of the fissile nuclei (U-233, U-235, Pu-239, Pu-241…), the power output and the fission yields of the isotopes under consideration.

The rate at which new cesium radioactive isotopes form is given by a relation of the form dN = Nmax*(1-exp(-kt)) where k is the decay constant, t is the time and Nmax is the calculated maximal output for cesium. (Note, this equation is somewhat simplified and does not account for isotopic transmutation, which actually generally has the effect of reducing accumulations, at least for cesium under most conditions. More complex equations are available, and sophisticated programs, like ORIGEN, are available to solve them.)

I have a spreadsheet that I built that calculates the Nmax values for cesium isotopes, as well as the rate of increase for each isotope for various power outputs derived from thermal reactors fissioning U-235, which represents the vast of majority of reactors in the world today. I have assumed for this calculation that the reactors are running at 90% of capacity, which is also a good bet since the bugs of nuclear operations have been worked out.

Here are the maximal accumulations possible for cesium isotopes if our existing reactors ran forever and forever and forever at an world wide output of 90% of 364 Gigawatts of electricity:

Cesium-134: 28 grams.
Cesium-135: 16.5 million metric tons.
Cesium-136: 217 grams.
Cesium-137: 210 metric tons.

Now, again, this is only the amount that could be accumulated if we ran these reactors forever at constant power, it is NOT the amount that is actually formed each year. To understand a typical annual output, we will have to assume that the reactors have been running with no changes in capacity for a number of years and that they all started at once. This is an idealized situation, but it is useful for understanding how nuclear fission products accumulate.

In the first year of such a program here would be the world wide output of the various isotopes.

Cesium-134: 8 grams.
Cesium-135: 4.97 metric tons.
Cesium-136: 22 grams.
Cesium-137: 4.78 metric tons.

After 20 years the accumulation of new cesium isotopes would be lower, because more and more is decaying.

Here are the twenty year figures:

Cesium-134: approximately zero, equilibrium approached.
Cesium-135: 4.97 metric tons.
Cesium-136: approximately zero, equilibrium approached
Cesium-137: 3.09 metric tons.

Here are the 233 year (as far as I carried my spreadsheet out) figures:

Cesium-134: approximately zero, equilibrium approached.
Cesium-135: 4.97 metric tons.
Cesium-136: approximately zero, equilibrium approached
Cesium-137: 22.7 kilograms

Clearly, however, one wishes to treat cesium, either as an item of commerce (as I will describe in later posts in this series) or as an item of waste, the need for new capacity for dealing with it is eventually dominated by Cs-135, an isotope that I will show later is not particularly dangerous at all, unless you eat lots and lots of it.

The spreadsheet also shows the total accumulation of cesium and includes the mass of the stable isotope Cs-133, which though not radioactive, is also a fission product.

The first year, 15 metric tons of total world wide cesium had accumulated.
The twentieth year, 277 metric tons of total world wide cesium had accumulated.
In the 233rd year, 2574 metric tons of total world wide cesium will have accumulated.

A single typical coal plant puts out more than 2574 metric tons of waste in a few hours. For comparison purposes this is the world wide accumulation of cesium "waste" for more than two centuries.

[NNadir]

103. There is a typo in this post.

I have inadvertantly written an equation in differential form that should not be in that form.

The correct equation for the accumulated isotope of interest should be written N = Nmax*(1-exp(-kt)) not dN = Nmax*(1-exp(-kt)). Moreover my wording was bad and I made it seem as if this relationship gives the amount of new isotopes formed. This is not the case. The new isotope formed in each year is the difference for the accumulated values for subsequent years. To wit:

dN(t1,t2) = Nmax*(1-exp(-k(t2))) - Nmax*(1-exp(-k(t1))) where t2 and t1 are the times given in years between measurements of total accumulations.

Here I have written dN merely to represent a changing value, and strictly this is not a differential equation. If a delta were available in this editor, I would substitute a delta for the d.

Even though I wrote the formulas incorrectly in the post text, the values in the described spreadsheet were calculated using the correct formulas. Thus there is no change in any of the results posted. But the transcription of the formulas into written language was done sloppily, for which I apologize.

[RafterMan]

105. I think there's another typo

An equal production of cesium-135 and -137 as shown in your second list sounds way off. If it is correct, then the total of just under 3x that amount in the first list is impossible, given cesium-135's long life. One or the other number must be wrong.

[NNadir]

106. I think you may be making a mistake.

I'm not sure exactly what you're refering to, but I don't see an error in this post.

The production rate and the decay rate are not related in any way. One is related to the fission yield, which is constant. The other is related to the amount of material that has accumulated. Radioactive equilibrium is established when the amount decaying is exactly equal to the amount decaying.

Actually the accumulated fission yields for Cs-135 and Cs-137 are very close for thermal neutrons fissioning U-235. (Cs-135, as noted above in another post is not a direct fission product, but is the most stable radioactive member of the 135 decay chain which usually starts with Te-135.) Because of the short half-lives of Te-135 and Xe-135, the fission yield for Cs-135 can be considered as 6.53% of fissions. The fission yield for Cs-137 is 6.27%, which is very close to that of its sister isotope. Therefore, before there has been much time to decay, the amounts of these two isotopes are very close.

The difference in the amount that can accumulate is a function of half life. This is because the competing process is radioactive decay. If the reactor is running at constant power (as I have assumed in this spreadsheet) the amount of cesium-137 being formed remains constant. 6.27% of the fissions used to maintain the power result in a Cs-137 nucleus. However, at more and more Cs-137 accumulates, both inside the reactor in its fuel assembles and outside the reactor in spent and reprocessed fuel, the number of decays is actually rising. If we look at the radioactive decay law (dN = -Nk dt) we see that the more stuff you have the more that decays per unit time. Eventually so much Cs-137 will accumulate outside and inside the reactor that it will be decaying as quickly as it is formed. This second process, getting the decay to match production, is very slow for Cs-135 and relatively faster for Cs-137 because of their differening half-lives.

In the spreadsheet, it looks as if the rate of accumulation of Cs-135 has not changed at all, it is a constant 4.97 tons per year. This is because I've only used three significant figures. Actually, if I carried the calculation out for a hundred thousand years, this would not be the case. Doing the calculation at 100,000 years for instance, I have just seen that the new accumulation would fall to 4.82 metric tons per year.

Note that in my spreadsheet, I am not reporting total accumulation but rather new accumulation. In 233 years cesium-137 is still being produced at the same rate, which is 6.74 X 10^20 atoms per second in the example I am using, but now so much has accumulated inside and outside the reactor that all but 22.7 kg is matched by Cs-137 somewhere decaying in the 209 metric tons that have accumulated.

Please consider this and get back to me and let me know if I have clarified this in any way. I have a lot of respect for you. You think.

[jpak]

125. It's just plain wrong -period.

It is mathematically and physically impossible for any long-lived radioisotope (90-Sr, Cs-137 or 239-Pu) to reach "equilibrium" in real-world reactors.

The half-lifes of Cs-137 and Sr-90 are ~30 years and the half-life of 239-Pu is 24390 years.

The operational life of a typical US nuclear plant is 40 years (or 60 years if relicensed).

The rates of fission production of these isotopes are ALWAYS greater than their rates of decay.

At no time over the operational life of the reactor do the rates of 90-Sr, 137-Cs or 239-Pu production equal the rate of decay.

No isotopic equilibrium is possible - period.

The assertion that there is some magical upper limit to Cs137, Sr-90 and 239-Pu production is nothing more than flat-earth-green-cheese-moon-babies-come-from-the-cabbage-patch bullshit.

Garbage In

Garbage Out

[NNadir]

128. Yeah right.

dN = -kN dt

The equilibrium solution to the depletion equation 6.13, also an expression of dN (too many greek letters to reproduce here) is also untrue in Stacy's Nuclear Reactor Physics (Wiley 2001) pg, 211 is wrong too.

Why? Because it's been declared wrong by all the saints and the saints know everyyyyyyything!

Yeah right.

:crazy:

[NNadir]

129. If anyone serious wants a more detailed description of radioequilibrium

than is provided in post #82, I will be happy to extend the description. I won't respond seriously to unserious dogma however, since well, it would sort of like trying to explain things to George Bush.

The basic concept is that the amount of material which decays (dN) in any time interval (dt) is proportional to the quantity of material that exists. As material accumulates therefore, the value of dN rises. Since at constant power the number of atoms of a particular fission product produced remains constant and is simply the product of the fission yield and the number of nuclei that must be fissioned to maintain power, eventually the two values (asymtotically when you actually do the integrations required), an equilibrium is established.

Without too much mathematical ability it should be possible to recognize that a function that increases eventually exceeds a constant function, but man, you'd have no idea how little math some people know.

The reference cited in the previous post (Stacy) gives an excellent mathematical explanation of fuel burn-ups on pages 195-239 (Chapter 6.) Be forewarned though this reference assumes facility and comfort with partial differential equations. (The well educated reader will understand that as if often the case when modelling physical systems by mathematical models, I have made simplifying assumptions in post #82. This is clearly stated, I believe.)

Further as noted elsewhere, post #82 does contain a minor error on my part inasmuch as I (mis)stated that the light group mass distribution remains constant and the heavy group varies with the mass of fissioning nuclei. The opposite is correct, as I realized when re-reading the references for my technetium posts below.

[NNadir]

101. I have more on this subject of mitigation, good news, and technology but

I may take some time posting it. It's been a lot of work and I haven't finished writing up all the results of my study of radiocesium.

[NNadir]

104. #6 Even if 100% escaped, radiocesium would have trivial biological effects

This is an extraordinary claim that I am making, a result that frankly shocked me when I recently recognized it.

Before I take too much flak about it, before I set out to back this claim up, I want to be clear: I am NOT, nor will I ever, advocate dumping radiocesium into the sea or releasing it in a soluble form anywhere or any time. This is because (1) I don't believe we should accept any risk when making the risk be almost zero is relatively simple, (2) I am not convinced that we will not want to have lots of radiocesium available for use in the future for technological purposes.

On the other hand, anti-environmentalist anti-nuclear activists frequently make extraordinary claims which, when you come down to it, are arguments - based on a poor understanding of risk analysis in particular and science in general - that the total release of any accumulated nuclear material including radiocesium is inevitable and a certainty, no matter what technological systems are used to prevent it. I contend frequently and repeatedly that this notion is absurd and is the product of dogmatic quasi-religious thinking. Even so, at this point, it is probably worthwhile to play a ridiculous game and examine the consequences of the extremely, tiny, absurdly, vanishingly low probability that they are right and I am wrong, to wit: Let's pretend that all of the radiocesium, 100%, actually escapes into the environment. What then?

I will rely heavily in this post on my previous posts, specifically posts #3 and #5 in this series on cesium mitigation and, in particular I will refer to the spreadsheet I described in post #5 in this series. I will also basically forget about post #2, which refers to the experimental observation that cesium released into the environment doesn’t retain bioavailability for very long. I will also assume that the release of 100% of the radiocesium will occur in 233 years and that all of this cesium will have magically been rendered into a soluble form of maximum bioavailability. Not only that I will go even further and state that this cesium will have been distributed as widely as is possible.

Recall that in post #5, I indicated that the total output of cesium after running nuclear reactors at 90% of the current capacity of 364 Gigawatts for 233 years would be 2574 metric tons. Of this quantity, nearly half, 1170 metric tons would be represented by the stable isotope Cs-133, which of course, being stable, is not radioactive at all. (However, unless some means of isotopic separation has been employed, it would be necessary to treat this stable cesium in the same manner as the radiocesium, since they would be mixed.) How much total radioactivity is represented by this cesium? Here is the breakdown as calculated in my spreadsheet:

Cesium-134: 37,000 Curies.
Cesium-135: 1.3 million Curies.
Cesium-136: 15 million Curies
Cesium-137: 18 billion curies.

Here we see that looked at from the standpoint of activity rather than mass, the dominant effect of cesium belongs by a factor of more than 1000 to cesium-137.

This is an enormous amount of activity though, isn’t it? 18 billion curies?

Not really. Recall from post #3 in this series that the radioactivity from potassium the ion of biological importance which most resembles cesium is, in the ocean alone, all told, 550 billion curies. Thus the activity of cesium, which upon release and distribution would necessarily find its way ultimately into the ocean, would result in an increase of radioactivity of about 3%.

“Now NNadir,” you say, “you’re making like this is nothing at all, but a 3% increase of the total radioactivity in the ocean would enormous. How do you know that 3% more radioactivity will not wipe out life on earth?”

“Simple,” I reply, “because I am aware from the fossil record that vibrant ecosystems thrived on earth bathed in exactly that much radioactivity about 60 million years ago.”

I remind you that the 550 billion curies of radioactivity attributable to potassium-40 is what is there now, but that this is only after more than 4 billion years of decay. For most of the earth’s history it has been much more radioactive than it is now. It has been cooling off, in a radiation sense, for billions of years and it is quite nearly less radioactive than it has ever been in its history. If I take the natural logarithm of the ratio of 570 billion curies to 550 billion curies and then divide this number by the negative value of the radioactive decay constant of potassium 40 (all this according to the radioactive decay law) I get a value for the number of years ago that the oceans contained the amount of radioactivity that it would have if (and only if) 100% of the radioactive inventory of cesium were magically released. This value is 60 million years in the case now described. Thus releasing radioactivity into the ocean can be viewed solely in terms of setting back the clock to a historical time. This doesn’t mean that we should do it, but it does mean that the impact would hardly be equivalent to the mass extinction we are now immanently expecting from global warming. (I may touch on the subject of expectation values later in this conversation.)

Please note that I have, in this calculation, completely ignored all the radioactivity associated with Uranium, Thorium and the three existent decay chains, all of which are found in the ocean. Were I to do this and include all these isotopes, the amount of radioactivity potentially associated with 100% release of all the inventory of radioactive cesium would seem even more trivial.

Were we to set the clock back in the radiochemical sense through the accidental release of the world’s entire radiocesium inventory, the effect would not actually be observable for very long, a few centuries at best. This is because the activity is again dominated by cesium-137, the half life of which is about 30 years.

[jpak]

130. The - most - bizarre - post - ever

"Even if 100% escaped, (18 billion curies of) radiocesium would have trivial biological effects."

This is nuts. It is beyond rationality. OMFG...

The US currently possesses 7,300 strategic nuclear weapons with a total yield of ~2.3 million kilotons (2352 megatons).

http://www.cdi.org/nuclear/database/nukestab.html#United%20States

Thermonuclear weapons produce 200 curies of 137-Cs fallout are per kiloton of explosive yield.

http://nuclearweaponarchive.org/Nwfaq/Nfaq5.html

If the entire strategic nuclear arsenal of the United States were expended in an all-out nuclear war it would produce 47 MILLION curies of 137-Cs fallout.

This amount of fallout would indeed kill tens of millions of people - it would be a global fucking catastrophy.

http://www.nap.edu/openbook/0309036925/html/207.html#pagetop

http://www.nap.edu/openbook/0309036925/html/

http://books.nap.edu/books/0309036925/html/167.html#pagetop

http://books.nap.edu/books/0309036925/html/155.html#pagetop

And the release of 18 BILLION curies of 137-Cs would have trivial biological effects?????

This is not science, this is sickness.

[NNadir]

131. Yeah right.

:eyes:

Post #40 on this thread:

http://www.democraticunderground.com/discuss/duboard.php?az=show_topic&forum=115&topic_id=20306

explains for us how 500 billion curies is less harmful than 18 billion curies.

500 billion < 18 billion. Great math. Teach us some more.

[jpak]

132. The annual dose from K-40 in human tissue is

~142 µGy

The amount of K-40 in soils or seawater is measured in pCi per kg.

The annual dose you receive from all those billions of curies of K-40 in the environment is vanishingly small.

18 billion curies of 137-Cs spread over the US in the aftermath of a nuclear war would kill millions.

To say there is nothing to worry about from the catastrophic release of large quantities of 137-Cs is a sick fucking conceit.

Breath-taking greenwash bullshit.

[NNadir]

135. Yeah right.

If your argument is pathetically weak, change the subject.I'm NOT discussing nuclear war but nuclear fuel.

Try to stay on topic. No never mind. Just be scatter brained. It makes things clearer.

[NNadir]

107. Cesium-135 is the most potent ion propulsion engine fuel known.

Cesium has the lowest work function (or put another way, the lowest ionization energy) of any element except for the transiently existent francium.

I don't like to go into the realm of science fiction, but it actually happens that "artificial gravity" is actually possible, if one manages to accelerate a spacecraft continuously.

It is generally known that the best and most powerful accelerating engines known are ion propulsion engines, which can only operate in the vacuum of space. Such engines are most efficient when they use high atomic mass elements with low work functions.

Such engines are actually linear accelerators, like those that are used here on earth for fundemental research into the nature of matter. Such accelerators can accelerate ions to within 99% the speed of light. It is not widely known, but if you think about it, Newton's third law indicates that the acceleration of particles produces a significant force on the accelerator itself. If the accelerator is part of a space ship, the space ship is accelerated in space.

A few engines of this type have already flown in space on interplanetary missions. They used the heavy element xenon as a fuel.

The best material, bar none, for this purpose, however is not xenon. The best material, owing to its high isotopic (atomic) weight and ease of ionization is Cesium-135, the slightly radioactive fission product I have described in more detail above.

Using a relativistic correction (which is numerically convenient at an acceleration to six tenths the speed of light), an easily achievable acceleration for ions, we see that one gram of Cesium-135 would theoretically accelerate a spaceship weighing more than 38 metric tons at the gravitational acceleration of 9.8 m/sec^2, for one second. According to the laws of relativity, an astronaut inside such a spaceship would feel exactly as he would standing on the surface of the earth, ie, he would feel exactly as if he were in an earthbound gravitational field. Such a spaceship (ignoring for a minute the weight of the fuel itself) could accelerate at such a speed for one day on just 86 kg of such fuel. (Non radioactive Cesium-133, which is also a fission product, is just slightly less suitable for this purpose.)

There is a practical upper limit to how generally applicable such a scheme would be, because as I indicated above, the world's nuclear power stations are probably only producing less than 5 tons of Cesium-135 a year. Still, this case is a good demonstration on why it is probably NOT a good idea to attempt to dispose of cesium isotopes, but rather to keep them available for potential use.

I don't happen to be a big fan of human space travel. I am however, very fond of space robots like Cassini. Engines such as I have described, some of which could actually be made reusable, would go a long way to reducing the costs and difficulty of such missions.

[NNadir]

108. Technetium: The first synthetic element; still being made by doctors.

In my series of pedantic monologues :-) on the nature of fission products, the next element I would like to explore is Technetium.

I will cover this fascinating and widely used completely synthetic element much as I did above with cesium, giving a brief introduction followed by a section which will describe the dangers and problems associated with Technetium, followed by a section describing the mitigating factors and important technological.

My references will include a volume of the wonderful Analytical Chemistry of the Elements Series, a series of books written in the 1960's and 1970's by Russian Chemists and later translated into English by Israeli chemists. The particular volume is entitled "The Analytical Chemistry of Technetium, Promethium, Astatine and Francium." (Ann Arbor-Humphrey Science Publishers, 1970) I will refer to this fabulous text as ACTPAF.

An aside: This series has been out of print for years, but if you look hard enough you can always find a used copy of a particular volume you want to buy. I bought my first volume back in the early 80's. Last year my wife found a volume on line for the Analytical chemistry of Plutonium. It's wonderful to be loved.

I shall also be using the fourth edition of Cotton and Wilkinson's "Advanced Inorganic Chemistry" John Wiley 1980 (I need a newer addition, but I'll call this AC), and the National Research Council's "Nuclear Wastes" published by the National Academy Press. This work was published in 1996. (I'll call it Nus) I will also briefly refer to th 26th Edition of the Handbook of Chemistry and Physics, (HO CAP), which was released was current during 1942-1943, the years the Manhattan Project was under full steam.

Technetium was first known as "manganese" by Mendeleev, who predicted, although no such element was then known, that an element with atomic number 43 should exist and that it should have chemical properties very much like Manganese or perhaps like Rhenium, the very rare and exotic element that has limited use because of its high cost. After Mendeleev's elegant prediction, scientists lusted heartily after element 43. Some deluded themselves into thinking they had discovered it. Names like aluminum, Devin, lyceum, Nippon and Mariam were all proposed and even adopted. (My 1943 HO CAP calls element 43 Mariam. (ACTCAP pg 1)

Then the Italian Chemists Segre and Perrier bombarded molybdenum (element 42) with deuteron's. The product was unambiguously identified and ultimately the name Technetium was given in honor of the fact that this was the first artificial element ever made.

Technetium is a fission product, and is readily available at a metric ton scale from so called "nuclear waste." However much of the technetium in the environment comes from not from nuclear plants but from small portable cyclotrons in hospitals. These use the original reaction in which Mo-98 is bombarded with deuterons. The resultant technetium is then injected into a patient complexed variously for the purpose intended for its action. Of all the fission products it seems that technetium is the most widely used. Many hundreds of thousands of people have been treated with Technetium either by eating it or having it injected. It is also used to treat cancers by providing a targetable means of getting to bind to troublesome cells, like cancer cells.

More will follow.

[NNadir]

109. Errata and additions.

I wrote the post above while quite literally half asleep. In an effort to get it up before losing consciousness, I relied heavily on the spell checker which "corrected" some words it shouldn't have.

The correct names for the names of element 43 proposed by people who erroneously claimed to have discovered it were as follows:

Ilmenium (1877) claimed by R.J. Herman (Bulletin de la societe imperiale de Moscow, 15, 4105 (1877).)

Devium (also 1877) claimed by S. Kern (Comptes Rendu 85, pg 72 (1877))

Lucium (1896) claimed by M. Barriere (Chem Trade News, 74 (1896))

Nipponium (1908) M. Ogawa (J. Chem Soc. pg 952 (1908))

Masurium (1925) W. Noddack and J Noddak (Naturwiss. 13 (1925)) One of the Noddacks was the first to isolate a gram technetium's cogener, Rhenium. AC (page 886)

Masurium seems to have been the name with the most sticking power, and is generally the one cited most often in historical descriptions of the discovery of technetium. This list of references comes from ACTPAF.

The chemistry and physics of technetium are well understood because the element is available in ton quantities if desired. (And I will argue later in this series that it should be desired.) My rough calculation suggests that the entire worldwide inventory is around 70 MT today.

Now that the properties of the element are known it has been possible to identify the element in natural sources. Traces of Tc are found in Uranium ores, especially those containing traces of molybdenum. Most uranium ores actually have subcritical neutron fluxes. The bombardment of molybdenum by neutrons and spontaneous fission in U-238 and U-235 lead to tiny amounts of Tc being formed.

The amount of Technetium found on earth may be very difficult to detect on earth, but it is well known that the element is commonly found in stars, where it is a product of the s-process. One confirmation of the existence of the s-process in fact was the realization that Tc was present.

AC remarks that technology allows for the possibility of increasing the supply of Tc to amounts vastly larger than it's naturally occurring precious cogener rhenium. AC, page 886.

The largest use for rhenium is as a reforming catalyst in petroleum refining. Of course, if the world supply of technetium is increased beyond that of rhenium, it is most likely that petroleum refining will no longer be an industrial process. This, in my view, would be a good thing.

[NNadir]

143. An interesting note on the Noddacks, "Masurium" and Rhenium.

It appears that the Noddack's discovery of element 43, which they named "Masurium" may not have been incorrect.

"It wasn't until 1998 that I took a real look at element 43. I was now at the National Institute of Standards & Technology (NIST), in the Surface & Microanalysis Science Division. One day, an exuberant Belgian physicist, Pieter van Assche, came into my office to ask my interpretation of an X-ray emission spectrum. The spectrum was from a 1925 article by Ida Noddack-Tacke, Walter Noddack, and Otto Berg, who claimed to have discovered element 43 (which they named "masurium") in samples from uranium-rich ores.
Van Assche speculated that, although the researchers didn't realize it, they had isolated terrestrial technetium-99 formed from the spontaneous fission of uranium. I was skeptical, but after studying their paper, I realized that they were clearly not crackpots or, as Ernest Lawrence called them, "apparently deluded." In the same article, the authors claimed discovery of element 75, naming it "rhenium." Both claims were widely disputed at the time, but three years later, the Noddacks isolated weighable amounts of rhenium and were accepted as its discoverers. They weren't able to so concentrate masurium, and the International Union of Pure & Applied Chemistry eventually rejected that discovery. The controversy clearly affected their reputations.

Little attention was paid to Ida Noddack-Tacke's article in 1935 questioning Enrico Fermi's claim that he discovered the transuranium element 93 (for which he received the Nobel Prize) and suggesting that his neutron bombardment of uranium may have resulted in the atoms disintegrating into fragments. It was not until Lise Meitner and colleagues' "discovery" of nuclear fission in 1939 that she was proved right. After this time, the Noddacks led lives of relative scientific obscurity...

...The Noddacks were clearly among the finest analytical geochemists of their time. Their search for the "missing" elements below manganese in the periodic table was part of a larger effort to accurately determine the abundance of the chemical elements in the earth and meteorites--data that provided a foundation for the science of geochemistry. Their work complemented rather than detracted from that of Perrier and Segrè..."

http://pubs.acs.org/cen/80th/technetium.html

[NNadir]

113. Technetium: Fission yield then the bad news about Technetium.

There are in my mind only three really seriously problematic fission products (as distinguished from actinides) found in so called "nuclear waste." In this series of a detailed examination of the properties of the fission products that many people, most people probably, define as "nuclear wastes," I have already examined the first of these, the isotope of the element cesium that has a mass number of 135. I have discussed this isotope at length above.

The second of these nuclei is iodine-129 which I will discuss later in the series.

(Some people might include Zr-93, but I don't.)

For the present discussion of technetium, the element I introduced above, I will follow very much the same format as I used with cesium. I will discuss the problems of the chemistry and physics of technetium and the difficulties dealing with it, the "bad news" so to speak. This post will serve as an introduction to the bad news.

Technetium is rather routinely produced in all of the worlds nuclear fission reactors. Most of the world's nuclear reactors operate on a thermal neutron spectrum and for the time being, the majority of the fission events take place in the isotope U-235. Some fissions, generally around 20%, take place in Pu-239, the fissionable plutonium isotope that is produced in all fission reactors from neutron capture in the uranium isotope U-238.

The fission yield (the percentage of fission events resulting in the production of a technetium) for Tc-99 is for thermal neutron fission (0.0253 eV) U-235 and Pu-239 respectively, 6.11047% and 6.14029%.

It is significant that the yield of technetium is somewhat higher in Pu-239 than it is in U-235. The distributions of fission products for the fission for almost all actinides (excepting some of the exotic superheavies) is not symmetric, there is a heavy group with a mass number distribution centered around the mass number 139 (which yields all fissioning actinides. Fission products that are exactly most probable in the heavy group, those having a mass number of 139, quickly yield the stable non-radioactive isotope of lanthanum, La-139, and no isotopes with a mass number of 139 can be considered problematic as the radioactive ones are all extremely short lived. There is also a light group in the distribution of fission products. The most probable mass number in the light group distribution varies with the mass of the fissioning actinide.

As an element that is a constituent of the "light" group, the yield of technetium therefore varies significantly depending on the size of the fissioning nucleus. The mass numbers of maximum probability in the light group (for thermal neutrons) are as follows: For U-233, not yet widely used in nuclear reactors, in spite of its many advantages, the most probable isotope the mass number 90, which yields the radioactive isotope of Strontium, Sr-90, which decays with about a 30 year half-life to the stable isotope of zirconium, Zr-90, with Yttrium-90 as a short-lived intermediate in the decay chain. For U-235, again the most probable mass number in the light group is 92, which yields (rapidly) the stable nonradioactive zirconium isotope, Zr-92. No isotopes with a mass number of 93 are problematic. For Pu-239, the maximum probability in the light group belongs to the mass number 95. This yields over a period of about 1 year's decay, the stable isotope of Molybdenum, Mo-95. For Pu-241, the maximally probable mass number in the light fragment is 99, the mass number that yields technetium (and ultimately over a period of hundreds of thousands of years, the valuable precious metal ruthenium, the isotope Ru-99.

It is worth noting that an actinide recycling program will certainly involve the fissioning of significant quantities of Pu-241. Thus in a sensible world sensibly using nuclear resources, the management of technetium is a serious matter involving serious attention.

(For the discussion of fission yields from which most of this post is paraphrased, please see Seaborg and Loveland, "The Elements beyond Uranium", Wiley and Sons, 1990, pp 176-184.)

[NNadir]

115. #1: Technetium has an "intermediate" half-life of 211,100 years.

Technetium, wherever it exists, unless it is destroyed, will be Technetium for a long time.

Sometimes people with a poor understanding of radioactivity get into a trap of saying that some constituent of so called "nuclear waste" is dangerous because it will be radioactive for a long time. For instance, one of the more amusing things one hears along these lines is that uranium radioactivity is dangerous because "its half life is four and a half billion years." I suppose that the thinking here is derived from the notion that it is impossible to isolate a long lived isotope since someday it will necessarily escape. In the case of uranium, this is true. Uranium has been cycling through the geosphere, the hydrosphere, and even the atmosphere for billions of years. It has always been here, and unless we fission all of it, it always will be here, for at least as long as the earth exists. Uranium has never been contained anywhere in a single place for a time that is comparable to its half life except in the case of some rare very old rocks in Canada and Australia.

What people ignore, of course, in this type of thinking is that uranium, because of its long half-life isn't really that radioactive. This is reflected in a variable known as "specific activity," which is a measure of how many decays a particular radioactive substance undergoes per unit of mass. One gram of Curium-242, with a half life of 162.8 days, for instance, has a specific activity of more than 3,300 curies. One gram of Uranium-238, on the other hand, with a half life of 4.468 billion years has an activity of just over 3 ten millionths of a curie. Many people (people who fly on commercial aircraft for instance) have been very close to multi-kilogram quantities of uranium without coming to any real harm. On the other hand, an amount of curium-242 that is just barely visible could potentially be fatal. This is a demonstration that the specific activity is inversely proportional to the half life.

(If anyone wishes to know how to calculate a specific activity, I will be happy to explain how to do it.)

On the other hand, it is very easy to contemplate getting rid of curium-242 (Cm-242). All you do is put it in a shielded container for say, five years or so, and when you come back, all of it will have decayed to something else. (In this case, Cm-242, the "something else" will also be radioactive, but this is not always the case for all radioisotopes.) You don't have to worry about building a structure or matrix that will be intact for millions of years. Five years is more than enough.

In the case of technetium-99, (Tc-99) the situation is somewhat intermediate however. The specific activity of Tc-99 0.017 curies per gram. While this is nowhere near as dangerous as Cm-242, it is nonetheless a serious amount of radioactivity, 17 millicuries. It would be unwise for a person to put a gram of Tc-99 metal in one's pocket and carry it around for long periods, for instance. Such a practice would possibly result in serious health consequences, even death.

Therefore, if one insists on allowing Tc-99 to decay naturally, one must be sure of isolating it for periods of over a million years. I am not saying that I regard this as impossible. I certainly do not, but even so, even I, who am very aware of the risks and benefits of radioactivity in comparison to other energy alternatives, concede that it is difficult to assert with absolute assurance that no one ever at any time would be injured by an attempt to isolate technetium for million year periods.

Some of the complicating factors involved of stabilizing technetium for long periods concern the chemistry of technetium, a subject I will cover in subsequent posts.

[NNadir]

116. #2: The aqueous chemistry of Technetium is dominated by an anion.

Most metals, as people who have taken a course in chemistry know, have cationic chemistry, meaning that they are generally characterized by positively charged ions, many of which have simple salts, several of which are generally water insoluble.

This is not the case with technetium. The most common oxidation state for technetium is +7, but it does not exist as an ion with such a high charge (which would be extraordinary) but instead is bonded to four oxygens (each of which have an oxidation state of -2). This means that the charge on the ion that represents the most common oxidation state for technetium is represented by the Tc04- or pertechnate ion (similar to the familiar purple permanganate ion for those who have taken an introductory college chemistry course). The pertechnate ion forms many soluble salts and can be quite mobile. (Most interestingly to an inorganic chemist, the cesium and potassium salts of pertechnate are at best sparingly soluble.) Pertechnate is in fact leaching out of the Hanford waste tanks filled during the 1950's by the folks who were building nuclear weapons in those days. The pertechnate so released is moving in the water table under the Hanford reservation in this form. Eventually some of it is expected to reach the Columbia River.

Because the common form of technetium is anionic as opposed to cationic, this complicates the removal of this species through agencies like ion exchange resins. The necessity of adding two types of resin, both cationic and anionic, as opposed to just a cationic resin adds expense. In addition, although one can capture technetium on strong anion exchange resins having quaternary ammonium salts, the behavior of these resins with respect to pertechnate is very sensitive to the chemical conditions of the waste water, the pH and types of other anions present. Therefore their management is problematic and difficult.

The pertechnate ion's chemistry has also been a problem at least one commercial nuclear fuel reprocessing plant. Technetium that was discharged from the Sellafield nuclear fuel reprocessing plant in the UK is detectable throughout the North Sea. Measures have been taken to ameliorate this unfortunate state of affairs that was both unnecessary and wasteful, but frankly, it's been the source of considerable public anxiety. This has had an untoward effect in a time where the crisis at hand almost demands public acceptance of nuclear energy.

The geochemistry of technetium is well understood from the naturally occurring Oklo nuclear reactors that operated almost two billion years ago.

http://www.curtin.edu.au/curtin/centre/waisrc/OKLO/Why/Why.html

Here is the Oklo periodic table which shows the long term fate of the radionuclides under experimentally verifiable geological conditions:



Note that the technetium moved. It didn't go far, but it definitely moved.

[NNadir]

117. #3: Pertechnic acid and ditechnetium heptaoxide are volatile compounds.

I include this fact under the "bad news" because I am well acquainted with the mentality of anti-nuclear anti-environmentalist activists. Their mentality consists of the kind of thinking that assumes that if something bad involving nuclear energy can happen, it then will happen.

Sometimes this sort of thing is taken to impossible extremes. For instance we hear all the time about the extreme danger of driving nuclear materials around on trucks, how the truck will crash (a very real possibility, but not a certainty) and then how the crash will take place in a populated area, and then how the cask - which is designed not to breach extreme crashes - will be pierced under extreme circumstances, and finally how all the fuel rods will then be broken into tiny pieces and widely distributed. Each event is possible, but improbable. If you multiply all of these probabilities together (standard practice) you find that the probability is so low as to be absurd, and that finally, even were the event to happen, it would still kill less people than the normal operations of fossil fueled systems. Someone recently told me that nuclear power is unacceptable because such canisters can be pierced by tank shells after a truck crash in downtown Chicago. He claimed it would kill 1200 people. Air pollution already kills far more people than that every day, and the probability of there being air pollution in the current state of affairs is 100%. In fact nuclear materials are transported all over the world for all sorts of purposes already. Nobody has ever been killed by the transportation of commercial nuclear fuel. Ever. At any time. Anywhere. This is because such an event is highly improbable. It doesn't mean that it will never happen, only that it is extremely unlikely.

There is for instance a certain probability that if you work in a tall building, terrorists will seize a plane and crash it into it thus killing you. In fact, such events have already occurred. This doesn't mean that all tall buildings should be abandoned and blown up. (This also does not mean that we should tear up the constitutions of all democracy's where events like this occur - but that's another matter.)

Now it needs to be said that if certain salts of technetium are heated to very high temperatures, they will become radioactive gases. Technetium metal when heated to about 600C in oxygen, it will form Tc207 and distill off. Ammonium pertechnate will form this compound at somewhat lower temperatures. The boiling point of Tc207 is 200C higher than that of water, which is quite high. (The vapor pressure is given by the relation log P = 18.279-7205/T where P is given in mm of mercury and T is the absolute temperature. See ACTPAF, page 15.) A similar state of affairs is true for pertechnic acid, HTcO4. It is possible, if highly improbable, that technetium might accidentally be volatilized somewhere someday. I invite our antinuclear activists to dream up scenarios where this will happen and then to present them as certainties.

In fact, if you think about it, an accidental ditechnetium heptaoxide distillation has already most likely already happened at Chernobyl. Undoubtedly during the reactor fire some Tc207 distilled off the burning reactor. Everyone in the Ukraine will die.

I know I am supposed to be focusing on negatives about Technetium in this section, but I can't help pointing this out: We have already seen the worst possible nuclear disaster at Chernobyl. It was a tremendous tragedy. However, it is trivial when compared to the daily tragedy of the use of fossil fuels.

[NNadir]

118. #4: The radioequilibrium value for Tc accumulation is theoretically high.

Right now the world's nuclear capacity is about 361 Gigawatts. Although this capacity can be expected to grow rapidly in the coming decades, with lots of reactors under construction or in late planning stages in countries where people think, I have been treating this capacity as if it were more or less constant, because for many years, it was quite nearly so. This is the caveat of this post.

As described in the founding post of this series, it is relatively easy to show mathematically that there is a maximal amount of any particular fission product that can accumulate before it begins to decay at exactly the rate at which it is formed. (This, again, assumes a constant power output.)

I have prepared spreadsheets at home for most important fission products showing first the maximum accumulation value, and the rate of annual accumulation at any level of constant power output.

For technetium, with it's long half life and relatively high fission yield (around 6%) this maximal accumulation value is just under 1.144 million MT. Note this is not how much has accumulated but is merely a value that represents how much can accumulate.

Actually technetium accumulates at around 4 MT per year worldwide. If the power output of Tc has been 361 Gigwatts for twenty years, just under 80 tons now exists.

[NNadir]

121. #5: Technetium heptafluoride is volatile.

This is a technical problem that probably would be an obvious drawback only to specialists.

A most interesting and impressive type of reactor that has run on the thorium fuel cycle is the MSR or Molten Salt Reactor. This reactor was designed by Alvin Weinberg and was rather special inasmuch as it had breeding capacity with a thermal neutron spectrum. This was because the reactor was designed to build up a concentration of uranium-233. Under the right conditions - and the commercially available CANDU reactor is also suitable for this type of strategy (and will be used in India for exactly this purpose) - the fissioning of U-233 fuel results in a breeding ration greater than 1.

The Molten Salt Reactor project was shut down after many years of successful operation because of a decision by the AEC - now succeeded by the DOE - to develop liquid metal fast breeder reactors rather than in Weinberg's novel homogeneous design. In my view this was a poor decision, one that may have been motivated by dual use (as in military) considerations than by engineering, economic and safety decisions.

However there is a drawback to MSR's that can result in the reduction of their breeding capacity. Uranium-233 is made from thorium when thorium captures a neutron and goes through two beta decays. The first beta decay, of thorium-233 is very fast, but the second, of protactinium-233 (Pa-233) is not. This isotope has a half life of 26.967 days. Moreover, Pa-233 has a fairly large thermal neutron capture cross section, about 53 barns. If a neutron is captured in Pa-233, that neutron is wasted when Pa-234 is formed, and the breeding capacity is reduced. (Pa-234 decays to give U-234, which is not especially fissionable, though it is fertile in thermal neutron spectra.) Weinberg designed and tested an interesting solution to this problem. The MSR is a type of reactor of a very special class, a homogeneous reactor. The fuel is not contained in fuel rods; it is in a hot solution of molten salt. This meant that one could do in line fuel reprocessing. You could simply remove the Pa-233 as it formed, isolate it from the neutron flux, let it decay to U-233 and put it back in the reactor.

The key step in this process, one of the first examples of what is now called pyroprocessing, was the formation of actinide hexafluorides, several of which, those of uranium, protactinium, neptunium and - to a lesser extent - plutonium are stable distillable volatile compounds. Although Weinberg's system worked very well, a problem was that technetium heptaflouride is also a volatile compound. Thus it was inevitable that the actinides would be contaminated with technetium.

This is not a huge problem, really, since as I will discuss when I get to the "good news" section of this series on Technetium, there is good reason to keep technetium mixed with fuels - it increases the yield of the valuable metal ruthenium and reduces even further the small risk of fuel diversion for weapons proliferation purposes. Still, it does create some minor problems in reprocessing schemes and under some circumstances can add expense, particularly if fractional distillation becomes necessary. There is always a chemical solution through converting the fluorides to oxides (see above.) The oxides of the actinides, unlike the oxides of technetium, are not volatile.

[NNadir]

122. Note my error in post #82. I noticed this in preparation for the Tc

series.

I wrote in #82: "Most heavy nuclides have fission product distributions that look like camel humps and fissioning heavier nuclides move the hump reflecting the higher mass nuclides, that on the right, slightly to the right, toward heavier fission products. (The effect on the most important element in the heavy part of the fission product hump, Cesium, is slight.)"

I wrote this relying on my memory. However, in preparing post #113 on technetium, I actually re-read the (Seaborg and Loveland) text in my home library on the asymmetry of fission and note that it is the heavy group is more or less constant, and it is the light group (on the left) that moves toward higher atomic mass numbers. Thus my post #113 is correct and my post #82 is incorrect with respect to fission asymmetry. I think it's minor but I apologize for my lack of self checking in that case. I've been working too hard lately.

This concludes my series on the special dangers and "bad news" about the long lived fission product technetium, since I can't think of any more difficulties about the stuff. If however any one has any factual additions or corrections, I welcome them.

I will soon begin posting to a series discussing the mitigating factors, uses, and risk reduction strategies available for technetium management and applications.

[jpak]

133. Stenography is not Science

"Paraphrasing" textbook material has another name as well.

and the point of all this is?????

[NNadir]

134. Yeah right.

You're clearly an expert on what science is.

500 billion < 18 billion.

:crazy:

[jpak]

145. Nonsense

To repeat:

That 500 billion curies of 40K is distributed throughout the ocean and upper crust of the Earth.

The activity of 40K in natural materials (including human tissues) is vanishingly small - trillionths of a curie per kilogram (pCi . kg-1).

(FYI: A curie is a measure of radioactivity. It is defined as 37 billion disintegrations per second).

The human dose from naturally occurring 40K is also vanishingly small - ~140 micro-Grays.

(FYI: Gray is a measure of absorbed ionizing radiation. 1 Gray = 1 joule of absorbed energy per kg. A micro-Gray is a millionth of a Gray)

The statement that 18 billion Ci of 137Cs will have NO biological effect is pure lunacy.

~1 million curies of 137Cs were released during the Chernobyl disaster.

Did this amount of 137Cs have any adverse effect on any humans in the area?????

Has it magically disappeared from the surrounding environment?????

The amount of 137Cs released from Chernobyl was 15 orders of magnitude less than the inventory of 137Cs in US spent nuclear fuel.

The total explosive yield of the US strategic nuclear arsenal is ~2350 MT.

Thermonuclear weapons produce ~200 Ci of 137Cs per kiloton of yield.

The expenditure of the US strategic arsenal would produce 470 million curies of 137Cs fallout.

That amount of fallout is 2 orders of magnitude less than the inventory of 137Cs in US spent fuel.

And this would have no biological effects??????

The National Academy of Sciences estimated that the fallout produced by a "limited" nuclear attack would kill between 13 and 16 million Americans.

See: The Medical Implications of Nuclear War.

http://books.nap.edu/books/0309036925/html/228.html#pagetop

and we are to believe that the release 18 billion Ci of 137 Cs would have NO biological effects????????

This is beyond pseudoscience - it's just plain nuts.

18 billion Ci of 137Cs spread along a 50 mile-wide corridor from DC to Boston would kill everyone in that zone. It would render the land uninhabitable for decades or centuries. It would render the fish and shellfish in the adjacent coastal waters unfit for human consumption for decades or centuries.

It would be a hideous human and environmental disaster.

So please, no more fairy tales.

And eating bananas will significantly reduce uptake of 137Cs????

Bullshit.

Iodine tablets will saturate thyroid and prevent subsequent uptake of radio-iodine. The amount of iodine required, however, is extremely small, <2 mg per kg body mass.

Potassium, on the other hand, is found throughout human tissue - in every cell and body fluid and, compared to iodine, in relatively high concentrations.

The amount of potassium salts you would have to ingest to have a measurable effect on 137Cs uptake would kill you.

The notion that "eating bananas will prevent the uptake of 137Cs" is - well - bananas...

(and pseudoscience bullshit)

[NNadir]

146. Whatever.

Like I said, when your argument is weak, change the subject.

I am not discussing nuclear war, in which one seeks maximal distribution of radiation, but nuclear fuel and its management, where the goal is to contain and control nuclear materials created for constructive and peaceful use.

One of the mechanisms used by people who have an irrational and frankly dangerous fear of radiation and the promotion of irrational judgment resulting from that fear is to confuse the spectra of nuclear war with nuclear power. This is the equivalent of confusing a fear of napalm firebombs with gasoline. No one is calling for the banning of gasoline by appealing to arguments about Dresden or Tokyo or Hamburg or Hanoi although people feel perfectly free to call for the banning of safe clean nuclear reactors because of 60 year old events at Hiroshima and Nagasaki.

If, however, one insists, that war and power must always be confused, I note that nuclear wars have not killed anyone in recent years, whereas fossil fuel wars and weapons manufactured from fossil fuels for use in war have been killing people almost continuously on this planet for as long as I can remember.

There is no mechanism whereby 18 billion curies of cesium from commercial nuclear power could escape all at once and be confined to an area between Boston and New York and no amount of irrelevant blather about nuclear war can make it so. Right now that material is widely distributed, and is contained in such a way as to prevent access only by elaborate means. I am merely stating that if all the ridiculous fantasies of people who know doodly squat about radiation and chemistry came true, and somehow all 18 billion curies of Cs-137 were to magically escape, it certainly would not be more dangerous as the collapse of earth's atmosphere. It would be very easy, btw, to dilute cesium to the same concentration of potassium in the sea. I don't advocate that because I don't pretend that diluted natural radiation as represented by K-40 is harmless simply because it naturally occurs and is dilute. But then again, I know what I'm talking about.

[jpak]

147. Some of us know all about chemistry and radiation

and we know bullshit when we see it.

Furthermore...

There are two major international crises developing in world today.

One in Southwest Asia and one on the Korean Peninsula.

In each case, "peaceful" "life saving" nuclear technologies and their role in developing nuclear weapons are the central issues.

Nuclear power and nuclear weapons have been and always will be intimately interrelated.

Denial of that is lunacy too.

[NNadir]

148. Yeah right.

:eyes:

[NNadir]

137. Technetium: Mitigating Factors and Good News.

Over thirty years ago the Soviet chemist A.A. Podznyakov, author of the ACTPAF monograph I have referenced above wrote: "...as the use of nuclear energy progresses, it will be possible to obtain technetium in large amounts. Unfortunately, large amounts of this valuable element are frequently discarded with waste solutions after treatment of the nuclear fuel. In some countries a part of such solutions, waste of the nuclear industry is used to obtain technetium. The solutions contain technetium in amounts of 5-50 mg per liter..." ACTPAF page 8.

(I note that Podznyakov's country had some of the most egregrious nuclear materials handling policies the world has ever seen...)

Of course Podznyakov was not a popular writer, he was a scientist, and like many scientists his prescient views have escaped the world's attention, or at least most of the world's attention. I do recall some years ago posting remarks on some web site somewhere along the lines of how much I regretted that the properties of technetium had not sufficiently been explored, especially in light of the many remarkable properties that this once unknown metal exhibits. Someone, apparently a National Lab metallurgist, emailed me to write, and I paraphrase because I have lost the original message, "You are right..." He then when on to describe some remarkable mechanical properties of technetium alloys he had prepared.

In a series of subsequent posts over the next few nights, I will report on the many fascinating features and hazard mitigating circumstances that suggest that we might worry not that we have too much of this metal, but that we have too little of it.

[NNadir]

138. #1: Ammonium pertechnate is one of the best corrosion inhibitors known.

This fact is widely reported in brief descriptions of the uses of technetium. (Google Technetium, Corrosion to see many of these descriptions repeated in lots of places.)

The work describing this property is rather old, and dates from the happy time when people were fascinated with the potential uses for fission products. This was quite charming and probably reflected the high value placed on engineering and untrammeled scientific exploration. It compares quite favorably with the modern day practice of our modern culture of MBAs and other risk obsessed cowards cowering in the corner as if fission products were some kind of magically endowed boogie men.

Here are some of the papers referencing this long ago work.

J. Am. Chem. Soc.; 1955; 77(9); 2658-2659.

J. Phys. Chem.; 1956; 60(1); 32-36.

J. Phys. Chem.; 1960; 64(12); 1882-1887.

The pertechnate ion (the corrosion inhibitor) could easily be added to nuclear reactor cores. Under these conditions, the technetium would ultimately be converted (via neutron captures) to Ruthenium, which is, of course, a precious metal. The neutron capture cross section of technetium for thermal neutrons is roughly 20 barns, but the concentrations required (on the order of 50 ppm) are so low that profound effects on reactivity should not be expected.

Ruthenium and other precious metals formed by nuclear fission tended to "plate out" on reactor parts in Weinberg's Molten Salt Reactor, and this was something of a problem in that particular design. It is difficult to see how this would be much of a problem in a water moderated reactor though, since, again, the concentrations are low.

Such a practice would have the effect of shortening technetium's half life, and thus it's equilibrium mass per unit of constant power.

[NNadir]

139. #2: People routinely have technetium injected into their veins.

Technetium is a constituent of many approved drugs (most are imaging agents, actually.)

Teboroxime, technetium-99m-sestamibi,Mertiatide are just a few of the technetium imagining in wide use. There are many others.

The IAEA has published a monograph on Technetium imaging agents for neurological systems:

http://www-pub.iaea.org/MTCD/publications/PubDetails.asp?pubId=6896

"Technical Reports Series No. 426
Radiopharmaceuticals for imaging the receptors in the brain are of great interest in the management of several receptor related diseases such as epilepsy, Alzheimer’s disease, Parkinson’s disease and depression and other psychiatric disorders. Technetium-99m is the ideal radioisotope for imaging, due to its low cost, its easy and universal availability through commercially available generator systems..."

Technetium has also been investigated (and is still being investigated) as a targetable antibody linked radiotherapeutic agent for certain types of cancers.

Technetium labeled compounds in imaging and radiotherapy do not in general contain the fission product Tc-99, but instead its precursor Tc-99m, a nuclear isomer. (The neutron deficient isotope Tc-94m is also under investigation.) Although Tc-99m is available from a fission product, Mo-99, more commonly it is made using bench top accelerators.

http://faculty.smu.edu/jbuynak/PowerPoint.ppt#15 (See slide 15 and 16.)

The low-level toxicity of technetium as well as organ clearance are thus well understood. It is worth noting that technetium-99m decays to give the very same technetium-99 that is found in so called "nuclear waste." Thus patients who have been scanned with such agents, routinely clear it from their bodies with little or no long term harm.

[NNadir]

140. #3. Monoisotopic Tc is easily transmutable into valuable ruthenium.

Unlike the other long lived isotopes found among the fission products, in particular Cs-135 (discussed above) and I-129, Tc that is removed from a nuclear reactor consists essentially of isotopically pure Tc-99 (Tc-98 is found in trace ppb quantities.)

Because it is relatively easy to separate via volatilization, as well as ion-exchange methods, Tc theoretically could collected for transmutation in existing LWR reactors, where it could offer additional benefits in providing superior corrosion inhibition.

The neutron capture cross section for Tc is a healthy 20 barns, not large enough to effect reactivity in dilute form, but high enough to ensure transmutation. No special accelerator driven systems are necessary although, of course, such are suitable for Tc transmutation.

In the process of transmutation, a certain amount of energy is invariably released and is recoverable. The product is the non-radioactive precious metal ruthenium.

As a precious metal, the transmutation product, ruthenium, is not incredibly valuable, spot prices at 100 troy ounces run about $60/tr oz. or roughly $2,000/kilogram, but the transmutation of 5 MT/year would provide roughly $100 million dollars in addition to the ruthenium already provided as a direct fission product (Ru-100, Ru-101, Ru-102, Ru-104, and Ru-105.)

Technetium may have interesting properties as a structural material that I will cover in a later post. Were such a material used in a nuclear reactor and submitted to a prolonged neutron flux, it is theoretically possible to obtain some quantities of rhodium from technetium transmutation. Rhodium has a spot price of around $52,000/kg.

Japan already has a program planned to recover precious metals from so called "nuclear waste," in particular, ruthenium, rhodium, and palladium. This program is expected to yield many hundreds of millions of dollars in revenues. The transmutation of Tc could theoretically add to this revenue stream.

[NNadir]

141. Technetium has a high melting point, and excellent mechanical properties.

Caveat: Some of technetium's mechanical properties such as it's bulk modulus are not readily available at least on the Internet or in my personal library. That said, these properties (which are indubitably available somewhere) can be inferred from it's position in the periodic table.

http://www.webelements.com/webelements/properties/text/image-balls/bulk-modulus.html

The melting point of technetium is 2430 K. Here are the list of elements having higher melting points, also in K.

technetium: 2430
hafnium: 2506
ruthenium: 2607
iridium: 2739
niobium: 2750
tantalum: 3290
osmium: 3306
rhenium: 3459
tungsten: 3695
carbon: 3800

With the exception of carbon, all of these elements are relatively rare and very expensive. (The mining of tantalum, which is obtained from the mineral coltan and which is critical in the manufacture of high performance capacitors in cell phones and other devices, is the subject of much environmental and human criminality in the third world.) In spite of many developments in materials science, carbon, especially because of its flammability and non metallic nature (poor machinability in particular) is problematic in the construction of refractory devices. (One such refractory device was the nuclear reactor at Chernobyl.)

Note that the melting point of zirconium, the main constituent of zircalloy used in the construction of nuclear reactors, is 2128 K, a little over 300 K (or C) less than that of technetium.


It is widely reported on the Internet that technetium-steel alloys are highly resistant to corrosion and harder than steel. Here's the first such link that pops up on Google: http://www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0010179.html I have read elsewhere that technetium is an excellent hardener for lead and other metals. It is probably true that further exploration of the mechanical properties of technetium and its alloys will avail us of many technologically important materials.

I can think of one very important nuclear application for technetium other than as a corrosion inhibitor in reactor cores.

One area in which nuclear reactors are widely used is in the propulsion of ships, almost all of which are currently and unfortunately war ships. There is however, no reason that as oil becomes more scarce and global concern with climate change in civilized countries (which for now excludes the United States) that commercial shipping cannot use the same technology.

In general, nuclear reactors on ships are small, and their design constraints in size and weight call for designs that are no longer used in commercial power plants. One feature of these ship bound reactors concerns their control rods which are often made from materials that are very different from those in land based reactors.

Most people understand that a chain reaction depends on the ability of a fissioning nucleus to produce two or more neutrons than what is required to fission the first one. In theory (and in practice) it is possible therefore to have an exponential increase in the number of fissioned nuclei in each generation, resulting, in a nuclear weapon, in an explosion. In a nuclear reactor, such a situation is obviously to be avoided, and in fact, with a few rare exceptions, is generally made to be impossible. One means of preventing runaway nuclear reactions in nuclear reactors involves geometry, a certain number of neutrons leak out of the reactor before they can split another nucleus. Another method concerns the richness of the fuel itself: One can play with the isotopic mixtures in which fissionable materials are contained so that the effect of the neutrons is delayed through a "breeding mechanism. But probably the most important means in controlling what is known as the "multiplication factor" of a reactor, the stability of its power output, is very much dependent on having materials that remove neutrons without creating new ones. These materials can be added to solutions in which nuclear reactors are bathed or in the fuel itself, where they are called "burnable poisons," or they can be placed in mechanical objects that can be pulled in and out of the reactor as necessary, depending on the desired power level. In this case they are called "control rods." Examples of elements having neutron properties are the elements boron, cadmium, silver, samarium and europium. (There are many others.) Another such element, hafnium, is always found in zirconium ores. In order to make zircalloy for use in a nuclear reactor, it is necessary to make hafnium free zirconium, which is not a particularly easy process, even if it is now industrial.

(Interestingly, besides chemical separation, another way to make hafnium free zirconium is to collect it from the decay of strontium-90 or from so called "nuclear waste." Zirconium is a prominent fission product.)

Hafnium, after its removal from zirconium, has an important use as the structural material for control rods in nuclear powered ships. Hafnium is excellent for these purposes because of its high melting point and its mechanical strength which it shares with its cogener zirconium and its strong ability to absorb neutrons, which zirconium does not share. Because cadmium, europium and samarium are all soft metals that easily react with hot water, the use of hafnium cylinders to contain them, makes it possible for the control rods on space and weight limited ships to be compact.

However hafnium has a slight draw back inasmuch as there is one isotope formed by neutron absorption (induction of radioactivity) that has a long half-life. Although this is probably a minor point because of the low probability of the formation of this isotope, Hf-182, even its trace existence will make certain people insane. So it is best to be avoided.

Technetium may be a suitable replacement for hafnium. When it absorbs neutrons, radioactivity is destroyed rather than induced. It's mechanical properties are very good, it inhibits corrosion, and it has a reasonable ability to absorb neutrons, albeit not as high as that of hafnium. It's melting point is close to that of hafnium as well. Moreover after a few years of use, when the rod has burned out, one can collect from it ruthenium and rhodium and make a few extra bucks.

I am working on another application for technetium but regretfully must keep it proprietary.

[NNadir]

142. #5. Technetium is a pure beta emitter with no decay chain.

Not all radioactivity is created equal. Some radioactivity, alpha particles - which are helium nuclei traveling at relativistic speeds - can be stopped by a sheet of paper. Some very energetic gamma rays on the other hand, can pass through thick layers of concrete. Beta particles, the third general class of radiations available to neutron rich nuclei are somewhat intermediate. In general, though, they can be stopped rather easily, by light shielding or by a few centimeters of air. The shielding actually required in most cases depends on the characteristic energy of the particle or electromagnetic radiation (gamma, x-ray, or hard UV).

Not all radioactive nuclei decay with only one kind of emission. Many alpha emitters, for instance, also release considerable amounts of gamma radiation. For instance, Americium-241, the radionuclide contained in nearly every smoke detector on the planet, is an alpha emitter, but it actually works by ionizing smoke particles with its high energy gamma radiation that is released simultaneously with the alpha particle. In this case, the characteristic energy of decay is the sum of the alpha particles kinetic energy and the electromagnetic energy of the gamma rays emitted.

The same situation holds true for beta emitters. Some beta emitters, like Cesium-137 that I have discussed in posts above, emit powerful gamma rays and can be very dangerous without extensive shielding. However some nuclei, like strontium-90, its daughter yttrium-90 and technetium are pure beta emitters. None of the radiation is carried off in the form of electromagnetic radiation like gamma or x-rays. All of it is contained in the kinetic energy of the beta particle (an electron) that is emitted from the nucleus undergoing decay. This means that in general, the use of these materials requires very little shielding.

Basically this means that a person standing next to a few tons of technetium would face very little risk if he or she merely stood a meter away. In order for technetium to represent a real danger one needs to be in direct contact with it. In the case of technetium, even eating it would probably have little effect. This is because, as described above, technetium has very little tendency to remain in the human body. It is easily excreted, as many imaging experiments and imaging diagnostic tests have shown.

Many nuclei decay into other radioactive nuclei, creating a series of decays called a decay chain. The number of decays in the uranium decay chain is 14 for instance. Since uranium has long since the formation of the earth had sufficient time to reach radioactive equilibrium in its decay chain, the amount of activity attributed to uranium in its ores (as opposed to in isolated uranium) must actually be multiplied by 14. (This is one factor that accounts for the reason that it is actually possible to reduce the radioactivity of the earth via the use of nuclear power.) Technetium isotopes formed in nuclear reactors (almost 100% Tc-99) however do not have decay chains. Technetium-99 decays directly into stable non-radioactive ruthenium-99. If technetium-99 captures a neutron in a neutron flux, it becomes technetium-100 which decays with a 17 second half-life into stable ruthenium-100.

[NNadir]

144. #6. The rate of migration of Tc at Oklo was 0.01 mm/year.

The naturally occurring nuclear reactors that operated at Oklo, Gabon a little less than two billion years tell us quite a bit about the behavior of fission product radionuclides left unattended for billions of years without human intervention. From examination of the geochemistry at Oklo, we can see that without any treatment whatsoever it was possible to contain most of the materials in so called "nuclear waste" in a single place (in this case the core of the natural reactor) with no special treatment.

This suggests that with special treatment, it should be possible to do even better.

It is very easy to see what the behavior of the technetium generated at Oklo, thought to be about 730 kg, was like by examining the distribution of ruthenium isotopes found there. All of the technetium created at Oklo has now decayed to ruthenium. Ruthenium that was created from the decay of technetium is thus highly enriched with respect to the isotope Ru-99.

At Oklo it was found that in the millions of years that passed after the reactor shut down (naturally) that the technetium migrated a few tens of meters, about 10^-5 meters per year.

http://lib-www.lanl.gov/cgi-bin/getfile?00285784.pdf

I oppose the Yucca mountain program on the grounds that I regard it as a waste of good nuclear materials. That said, the Oklo data suggests that the claim, at least where technetium is concerned, that so called "nuclear waste" will escape the repository and then somehow find its way directly into human bodies, and do so in concentrations high enough to cause actual harm, is extremely dubious.

At the egregious once unregulated Hanford nuclear weapons waste tanks, technetium is leaking into ground water. This technetium is migrating presumably because it, unlike the Oklo waste, has been oxidized to the Tc(VII) oxo anion and because it is in the continuous presence of chromate. It is nonetheless expected that by the time the Tc reaches the Columbia river, it will already be so dilute as to be relatively harmless. (Of more serious concern is tritium and I-129 in certain wells.) There is some evidence to suggest that the actual migration of Tc will be slowed after the non-radioactive chromate ion in the waste is reduced by iron containing minerals, allowing Tc to be reduced to the less mobile dioxide.

http://gwmodeling.pnl.gov/reports/pnnl-11801/execcole.html

http://www.pnl.gov/emsp/fy2002/presentations/hess-szecsody70177.pdf

[NNadir]

150. Just to be a little more graphic about this, this means that if the Tc

migrated 100 meters, roughly the length of a football field, only 5.5 X 10(-15) th of it would remain, or 5.5 quadrillionths of it. This means that a gram of the material that started migrating today and made across the football field ten million years from now would be responsible for 2 or 3 nuclear decays per day! A typical room anywhere on this planet on the other hand has, in every liter of air, more than 130 decays per minute from radon gas.

http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/radon.html#c4

This should give some insight as to how ridiculous and irrational some of the nuclear fear mongers can be. They want you to believe that somehow all of this radioactivity is going to defy the laws of physics and get into your body just by virtue of its existence but in fact, most of it isn't going anywhere near you.

[NNadir]

149. #7. Technetium fluoride is volatile.

I mentioned this same feature as a drawback in the chemistry of Technetium in post #5 in the "bad news" section for this element, but actually this property is something of a double edged sword.

The reason is that reprocessing systems that utilize fluorine stream volatilization as a separation scheme will invariably involve the carry over of a certain amount of technetium with the volatile actinides protactinium, uranium, neptunium, and (to a lesser extent) plutonium. The presence of technetium as a diluent will, in the case of plutonium and uranium greatly lower the already low risk of the diversion of commercial fuel for weapons purposes. (The biggest reduction of this risk actually comes from isotopic mixing, but that's another story.) The presence of technetium in actinides with potential for weapons applications will complicate weapons design by making the mechanical handling of metallic forms very different (the compressibility of technetium is very low), by changing the density of the alloy and by exposure of the chemical explosive blanket to short range beta particles that will impact their stability.

The presence of technetium will also have certain advantages in fuels by representing a burnable poison that will remove excess reactivity from the reactor. Furthermore technetium's high melting point and excellent mechanical stability may offer considerable advantages. One disadvantage will be that fuel burn-up is often measured by the build-up of technetium in the fuel. Thus this approach will require the recalibration of some instruments and/or methods.

I have already mentioned that the transmutation of technetium that would occur under these circumstances might represent further economic advantages to the already high value of nuclear energy.

[NNadir]

151. #8. I happen to be in a university library (not the library I usually...

...hang out in) and I stumbled across an interesting volume that covers many of the issues I have covered in these posts, in far more detail than I can do. (Leafing through it deepened my understanding of some issues with which I was unfamiliar, like for instance, the 1980's German standard for beta emitters in fuel - 10% of that of equilibrated natural Uranium - that's right, before loading in the reactor the fuel had to be safer than natural uranium.)

The work in question (which dates from the 1980's) is "Technetium in the Environment" and it covers the environmental chemistry and many issues in Tc production and destruction quite well. The book is edited by G. Desmet and C. Myttlenaar. Some of the chapters are in French, but it's pretty simple scientific French and you get get the gist of it even if, like my French, your French is less than perfect. Most of the articles, including those written by Swedes are in English.

If anyone is actually interested in this topic :-) you may stumble across it somewhere, and it's very enlightening. The call letters (LOC) are QH545.T37S46 1984

The big problem with technetium? Dectecting it reliably.

[NNadir]

156. Radioiodine: In medicine, in nuclear catastrophe, in injury, & in death.

It would probably be safe to say that, with the obvious exception of Hiroshima and Nagasaki, that by far the greatest number of serious injuries and or deaths associated with nuclear "catastrophes," by which we mean nuclear war, nuclear weapons testing and Chernobyl, are related to fission products that exist for parts of their lifetimes as iodine. Even if these nuclear "castrophes" are small when compared with the castrophe of fossil fuels, particularly coal and oil, that cannot be dismissed with simple handwaving on my part.

All of the following isotopes of iodine are prominently represented among the fission products: I-127 (natural iodine, which is NOT radioactive), I-129, I-131, I-132, I-133, I-134 and I-135. (Even heavier iodine isotopes are present in fission product decay chains, but their half-lives are so short, that they can reasonably considered, from a risk standpoint, only as their nuclear daughters.)

It is known very well that many "downwinders" from nuclear testing, which include notably the citizens of Nevada, Utah, the Marshall Islands but also many other places on earth, some of which are still rarely discussed, were injured by exposure to radioiodine. Of all releases associated with these events, the effects of this element have been most clearly observed.

The injuries associated with the prodigious release of radioactivity as represented by iodine isotopes, especially Iodine-131, at Chernobyl has been the focus of considerable international attention, and rightly so. The cloud of denial, obfuscation, confusion and deliberate lying that surrounded the events at Chernobyl on the part of Soviet authorities prevented the prompt action on iodine that might have saved many health effects associated with that disaster. (The communist Polish government on the other hand, acted with relative speed and decisiveness at this same time.) Although radioequilibrium is quickly established in nuclear reactors with the most radioactive iodine isotopes (excepting I-129), the high volatility and ready biological uptake of iodine and iodine compounds makes its risk very high when compared with many other fission products.

Although the most serious effects associated with radioiodine are limited to the first few weeks of exposure, owing to the 8.02 day half life of I-131, it cannot be said that the possible effects of radioiodine should be limited to a few weeks. I-129 has a half-life of 15,700,000 years, and among the fission products, it should be expected that maybe, barring efforts like transmutation, the last fission product signature of both commercial and weaponized nuclear energy to be found on earth will be this isotope. In the Mississippi River today, about 1 in every three billion atoms of iodine found, are radioactive I-129. (See Santschi et al Environ. Sci. Technol.2001, 35,4470-4476) Releases of this isotope from the commercial nuclear fuel reprocessing plants in Europe have been fairly prodigious.

Moreover, radioiodine is an important product used in modern nuclear medicine, not only isotopes produced as fission products, but also some neutron deficient isotopes like I-125 and I-123. The use of these isotopes are important not only in diverse areas like imagining and diagnostics, but also in treatment. In the case of treatment, it is ironic that in quite a few cases, radioiodine has been used to treat disease caused by radioiodine itself.

For these reasons the discussion of the properties and risks associated with radioiodine need serious consideration when one assesses the risks of nuclear energy. As I have previously done with cesium and technetium in this thread I will consider, in some detail, both the risks and ameliorating factors associated with the chemistry and physics of radioiodine in a series of posts to follow.

As I have noted elsewhere, I have direct experience with radioiodine. I used measure the presence of I-125 in my own thyroid, and a I was engaged in that activity for more than three years.

[NNadir]

157. Radioiodine, risks, difficulties, concerns and problems.

As I have done before with the long lived fission products represented by the cesium isotopic mix and by technetium-99, I will discuss under this general heading some of the problems associated with radioiodine, it's chemistry and it's physics.

Posts will follow here.

[NNadir]

158. #1: Iodine is important in the chemistry of life.

Some people here are probably familiar with the nuclear binding energy curve of the elements.

http://hyperphysics.phy-astr.gsu.edu/hbase/nucene/nucbin.html

It has been known for quite some time that the so called "mass defect" of the elements is lowest for iron (or put alternatively, the binding energy is the highest). This means, to the initiated, that iron may be thought of as the most "thermodynamically stable" of all of the elements in the periodic table. In order to make elements either lighter or heavier than iron from iron by nuclear means, one needs to add energy. With the exception of hydrogen, some helium, and all of the lithium, beryllium and boron, which occur either as a result of the big bang or by spallation reactions involving cosmic rays interacting with interstellar clouds, all of the elements in the universe originate in stars. Elements lighter than iron can be made by intrastellar fusion reactions, although in practice, elements heavier than carbon generally result only relatively late in a stars life cycle when much of the hydrogen and helium have already been consumed. Elements heavier than iron are also made in stars but their formation is endothermic, not exothermic. Put differently, there are by two processes by which they are created, the s (or slow) process and the r (or rapid) process, but their formation represents a net energy sink: Stars are actually cooled by their formation, not heated as they are when elements lighter than iron fuse. (The r process occurs only in supernovae and is responsible for the existence of uranium and thorium, from which nuclear energy is now conveniently obtained. Thus even nuclear fission energy is really star power. These are common elements only because they represent long lived "door stops" in the nuclear decay chains of super heavy elements.)

I apologize for the typically long winded introduction, but there is a point:

People do not often think about it, but this thermodynamic situation has important consequences in the chemistry of life: As elements become heavier, their bioinorganic chemistry becomes more and more exotic and rare. Although many metalloproteins are known having transition metals up to the atomic number associated with zinc, a slightly endothermic element being just four atomic numbers beyond iron, only three elements heavier than zinc are known to be play important roles in the chemistry life, selenium, molybdenum, and iodine. (I often think that this property is indicative of a possible extra-solar origin of life, that life seems mainly to use elements with binding energies and atomic numbers lower or at least very close to iron. Such elements are present more broadly than those that require supernovae to form. Thus though we clearly live in a region of historical supernovae ejecta, life may do fine without this condition elsewhere.)

Selenium is interesting in as much as it may be thought of as a constituent of a twenty-first "naturally occurring" amino acid: Selenocysteine. Selenocysteine was actually once thought to exist as a result of postranslational modifications of other amino acids, a process in which an amino acid in a protein is converted after biosynthesis of the protein. (Phosphotyrosine, for instance is not a naturally occurring amino acid; the protein is phosphorylated after protein synthesis.) Actually though, to the surprise of everyone, it turns out that selenocysteine has a codon in nucleic acids of certain bacteria, and is thus incorporated into their proteins much like the other twenty amino acids, via direct incorporation via an aminoacyl t-RNA. This surprising finding is exotic but of limited practical importance.

Molybdenum containing enzymes are known, and many of them are important in cellular processes. Some of the most important of these are the nitrogenases, which are important in nitrogen fixation. These enzymes have co-factors that are iron-sulfur-molybdenum cluster compounds. Molybdenum is the metal that has direct protein co-ordination in these clusters, through a histidine imidazole group in the protein.

Molybdenum is in fact one of only two elements in the fifth period of the periodic table that has an important physiological role. The other is the topic of this section of this thread: Iodine.

Enzymes for the accumulation of iodine are very old; transthyretin has been evolutionarily traced back to the very earliest vertebrates. The enzyme is also found in insects. One of the important functions of this enzyme is to concentrate iodine, something that it does by collecting it, quite literally, in a rather large sack. Most people are of course aware of the important role that iodine plays in human physiology as part of the thyroxine hormone. Thyroxine is actually an amino acid, albeit a post- transitional amino acid, unlike selenocysteine, mentioned above. It is biosynthesized from the iodination of codon coded amino acid tyrosine when it is present in the glycoprotein thyroglobulin. Two tyrosine residues in the first 130 amino acids this protein, which has about 2,750 amino acids overall are iodinated. After iodination and two of them are coupled to form a diphenyl ether, through a mechanism wherein one residue is dealkylated, and the protein is finally degraded to give the thyroxine hormone. I cannot claim that I have overwhelming familiarity with the mechanistic biochemistry of thyroxine. (One can say, almost a priori, that an important consequence of the structure of thyroxine is that it accounts for many of the biological effects of the important class of pollutants known as polyhalogenated biphenyls and polyhalogenated diphenyl ethers.)

I can, however, say this: I do know that thyroxine has allosteric interactions in certain proteins that are responsible for gene transcription, thus we can be certain that radioiodinated thyroxine almost certainly, in some of its biochemical interactions, finds itself in close proximity to DNA.

The consequence of course of the fact that iodine is in the fifth period of the periodic table, unlike most other atoms of biological significance is that iodine is a fission product produced in nuclear reactors. (A few fission products are found late in the fourth period, but the vast majority is in the fifth and sixth periods, including of course, the lanthanides.) Moreover, as I have pointed out in my long, possibly quite boring digression, this element is actively concentrated by living things. Moreover, iodine is not only concentrated, but it is concentrated in at least one case, for such a purpose as to bring it in very close contact with DNA.

This suggests that radioactive iodine deserves a very special look when we consider the risks and benefits of nuclear power.

[NNadir]

159. #2. Iodine easily escapes in nuclear war, accidents and reprocessing.

In the article I referenced in the scientific journal Environmental Science and Technology Envir. Sci. Tech. 2001, 35, 4470-4476 I wrote that about 1 atom in about every three billion iodine atoms now found in the Mississippi River is actually the radioactive isotope I-129, as opposed to the stable ordinary isotope I-127. Although tiny amounts of the I-129 isotope occur naturally, as the result of the solar proton flux interacting with Xe-128 in the air, Xenon is a very rare gas, especially at high altitudes, and Xe-128 is a small (1.91%) fraction of the already thin population of those atoms. Thus this reaction accounts for amounts of I-129 that should strain even the best detection techniques and equipment. It would absurd to claim that this effect can account for I-129 in the Mississippi River. In fact, according to the paper and citations therein, the amount of I-129 generated by this effect is approximately 100 kg, worldwide.

In fact the vast majority of this radioiodine is the result of human technology. Most of us are immediately aware of Chernobyl and of atmospheric nuclear testing as sources of this material. Many of may not know, however, that underground nuclear testing also releases I-129 (and I-131 for that matter). Again, according to the paper, the iodine released in this way seems to account for about another 150 kg of I-129. In fact, studies of radioisotope distribution in alpine ice cores shows quite clearly that the contribution of this effect of the cold war peaked in 1963, just as it should have done. It is known in addition, that the amount of radioactive I-129 released by Chernobyl amounted to about 1.3 kg of material.

The reality of the situation is demonstrated by the fact that, according to the paper, the distribution of I-129 in the Mississippi river is not constant, but actually fluctuates seasonally. Although not conclusively so, this is an indication that the source is not historic but is relatively fresh.

It turns out that by far the most important contributor to radioiodine in the Mississippi River is not natural processes, nuclear weapons testing, or the results of the Chernobyl accident. The vast majority of the world's inventory of radioiodine comes from an industrial process that I very much support, nuclear fuel reprocessing. Over 2 MT of I-129, according to the paper 2,360 kg, was released by operations between 1966 and 1997 at the Sellafield and La Hague nuclear fuel reprocessing plants located respectively in the UK and in France.

To those with some background (though not necessarily a professional background) in chemistry it might seem somewhat strange that this state of affairs is the case since one might naively think that iodine in nuclear fuel is present as a salt. In fact, radiation chemistry is rarely so simple. Many transient species exist that one would not normally encounter, free I+1 ions, and unusual Iodooxygen species, probably, given that fission products are traveling near the speed of light before being slowed to thermal speeds (generally within a few millimeters) by collisions with other atoms, even iodine-xenon compounds or even iodine-krypton compounds. Some of these compounds are highly oxidizing. Given the ease with which I-1 is oxidized, it is not really surprising that free elemental iodine should be present in nuclear fuel.

As anyone who has ever seen a vial of elemental iodine knows, iodine sublimes; solid iodine has a vapor pressure of around 1 torr at 40C. Thus one would expect that radioiodine easily escapes from failed nuclear fuel rods. Thus much of the radioactivity in the containment dome at Three Mile Island, and much of the radioactivity released at Chernobyl was in the form of iodine. In both cases, the fast majority of this activity was accounted for the highly radioactive isotopes such as I-131, and although all of this isotope from both accidents has now decayed to xenon, thus greatly reducing the burden of radioactivity, the iodine-129 from both events still persists, almost completely unchanged.

In nuclear fuel reprocessing as now practiced industrially, generally by what is known as the Purex process, several factors exist that make this situation even worse. First the fuel is dissolved under oxidizing conditions, typically in nitric acid. Next elements of the fuel are extracted into organic solvents, usually tributyl phosphate/kerosene mixtures. All solutions, including aqueous solutions and organic solutions, suffer damage when exposed to intense radiation, as they are in nuclear reprocessing. Invariably some molecules in the solution - especially organic moieties - are subject to cleavage. This cleavage can be either heterolytic - resulting in charged ions - or hmoolytic - resulting in free radicals. In either case conditions are favorable for the formation of organoiodine species like methyl iodide. Methyl iodide is a low boiling liquid and it easily evaporates into the air. In fact the escape of organoiodines is thought to be a prominent mode of escape of radioiodine from reprocessing plants.

Once out in the environment alkyl iodides are fairly reactive, and quickly react with oxygen and nitrogen species to give the iodide ion. (Before anyone points this out, I know that methyl iodide is also an ozone depleting agent. However in comparison to other quantities of similar agents, 2 MT is pretty trivial, not that this will stop our less well educated and less perceptive fellow members from working themselves into an illustrative absurd tizzy over this fact.)

I might claim, correctly, that it is easy to imagine systems that trap this iodine - if they have not been built already - but this is a dodge I do not allow my detractors. Thus when people come up with pie-in-the-sky claims about the availability of PV solar power some day, or CO2 sequestration systems for coal, I am often rude and dismissive. The emergency is not some day, I say, it is now. Thus I will not allow myself the same dodge:

When nuclear fuel is reprocessed, radioiodine is released in the form of I-129 into the environment.

[NNadir]

162. #3. Radioequilibrium places few limits on the accumulation of I-129.

Assuming 30% thermal efficiency, at constant power the current nuclear energy capacity would allow for the accumulation of over 43 million metric tons of Iodine-131 before radioequilibrium was reached and the I-129 fission product was decaying as fast as it was formed.

Fortunately it would take millions of years of continuous operation of nuclear plants to accumulate such an amount: Currently the total worldwide annual production of I-129 amounts to less than 2 MT per year. Because of the extremely long half life of I-129, over 15 million years, the effect of nuclear decay on the accumulation of this isotope is currently close to negligible.

It is interesting to speculate how much I-129 could theoretically accumulate if 100% of the world's energy capacity were provided by nuclear energy. If we assume, as some people do, that world energy demand will rise to 1000 exajoules by 2050, and if we also assume that all of this energy were produced by nuclear fission, the theoretical maximum would be about 1 billion tons. The rate of accumulation would be initially about 50 tons per year at the outset, the rate of accumulation slowing over the hundreds of millions of years that the approach to equilibrium would require. Of course the world's supply of uranium and thorium will likely have been depleted by that time.

[NNadir]

163. #4. Physical decontamination of I-129 is technically impossible.

The I-129 in the Mississippi River that I described in post #159 (#2 of this series) is effectively there for the rest of our lives, our great grandchildren's lives, and their great-great-great-great grandchildren lives (assuming of course that some humanity survives long enough for these generations to exist).

It is impossible to remove I-129 from any body of water anywhere, including the ocean, without removing all of the iodine from the water. When I discussed cesium and technetium above, I didn't really focus on the idea that it is possible to remove, via ion exchange and similar complexation techniques, trace quantities of these elements from water. Since neither technetium or cesium have any physiological function whatsoever, their removal is without consequence. Specifically while it is true that cesium acts in biological systems as a potassium mimetic, cesium is neither essential or even desirable for any purpose in any known cells anywhere. Until the invention of nuclear technology, almost no technetium existed anywhere; therefore it has no natural biochemistry. The case is very different for iodine. Since iodine is an essential nutrient, it goes without saying it is not really possible to chemically or physicochemically remove iodine from water without inducing unacceptable physiological consequences.

In the case of short lived isotopes like I-131, or the medical isotopes I-125 and I-123, one can always wait long enough for the isotopes to decay to xenon or tellurium. However no one can wait out the decay of I-129. Its half life is far too long.

Iodine's chemistry is such that any iodine that escapes into the biosphere will mix intimately with all the other iodine on the planet, with the possible exception of some iodine in relatively rare deposits in the Chilean desert. This means that everyone on earth right now has radioactive I-129 in their thyroids and in their cellular receptors for thyroxine. It is impossible to do anything about this. It is irreversible.

Everyone on earth will die.

[NNadir]

164. #5. At the Oklo nuclear reactors, iodine was not retained in the reactor.

The Oklo reactors were naturally occurring nuclear reactors that operated in very rich uranium ores about 2 billion years ago, when all of the uranium on earth was "enriched" like modern uranium fuel. I have referred repeatedly to these reactors elsewhere, since they give some perspective on how long term repositories for so called "nuclear waste" might be expected to behave over billions of years of geological time.

As we have seen, most elements in the fission products were retained in the geological formations where they formed, in spite of the fact that these reactors are found in region that until recently was a rain forest in equatorial Africa.

However the iodine formed in this reactor is not found in the reactor core and is believed to have been released.

I did, in researching this post, however find an interesting paper that suggests that it didn't go all that far. The paper, published in 2004 in the Physical Review Letters can be found here: http://presolar.wustl.edu/ref/Meshik2004PRL.pdf The purpose of this paper is to examine the lifetime of the reactor and it's operating parameters, which are elucidated by the distribution of fission products. (The authors conclude the reactors operated about 150,000 years in a cyclic fashion.)

Any iodine found in the area of the reactors would now have decayed into xenon, thus the properties of xenon found trapped in the reactors in inclusion cages will have bearing on the behavior of iodine. (Xenon, of course, is a gas.)

"In all experiments, the amount of extracted gases was sufficient for precise measurement of their isotopic compositions. Various U oxides contained from 10^-5 to 10^-3 cm3 STP=g of 136Xe (Fig. 1), while U-free alumophosphates had even more fission Xe, up to 0:03 cm3 STP/g, the highest Xe concentration ever found in natural material." (Edited to allow for display of the exponential terms.)

The authors estimate from their study of xenon isotopic distributions that about 37% of the iodine-129 escaped into the environment. The rest didn't get very far.

[NNadir]

165. #6. I-129 is always produced in the presence of I-127.

In nuclear fission of actinides both I-127, the stable isotope of iodine, and I-129 are produced. After the short lived isotopes such as I-128 and I-131 have decayed, all of the iodine that remains is a mixture of a stable isotope and a radioactive one.

For U-235 fissioned under thermal conditions, the I-129/I-127 ratio is about 85%. For Pu-239 fissioned thermally, the I-129/I-127 ratio is about 74%.

This raises two difficulties. The first is that in a circumstance where geological disposal is contemplated, bulk is unnecessarily raised by 15-25%. The second is that in the case of transmutation being chosen, between 15-25% of the transmuting neutrons or protons will be wasted transmuting a non-radioactive species.

On the plus side, as I will cover in the next series on mitigating factors, this property of there always being an isotopic mix, somewhat serves to dilute the effect that I-129 can have with respect to health.

[NNadir]

168. #7: Iodine has little economic value.

Many professional bench top organic chemists have probably used methyl iodide as a methylating agent. Unlike the other methyl halides, it's a liquid and the easily polarized iodine is an excellent leaving group. Methyl iodide is convenient; it's easy to use, and - for a methylating agent anyway - it's relatively non-toxic.

Process chemists, for those who may not be familiar with their ways, on the other hand avoid methyl iodide like the plague: They regard it as way too expensive. This is probably true when one is handling metric ton quantities of compounds in need of methyl groups. That said, the real issue is not that methyl iodide is so expensive, but that dimethyl sulfate is so cheap. Such is the way of the world.

It is true that iodine prices are high when compared with very cheap reagents like sulfuric acid. Still, at roughly $13/kg, (http://me.smenet.org/200306/pdf/min0306_15.pdf) iodine isn't exactly gold, or palladium, or even technetium (see above). I estimate that all of the iodine produced in nuclear reactors, which is a mixture of two isotopes, naturally occurring I-127 and slightly radioactive I-129, is about 60 MT. The street value of this iodine is thus a little under one million dollars. This would hardly cover the cost of extracting the iodine from the so called "nuclear waste" and in any case, the mild radioactivity of this material would make it problematic in the minds of many people.

Even as a radioactive isotope, I-129 is of little value as say, a tracer. There may have been isolated instances of such use, but as a pure beta emitter of low specific activity, I-129 is probably to difficult to reliably detect without sensitive (and thus difficult to calibrate) equipment. As a tracer more energetic radioactive isotopes like I-125, I-131, and I-123 are more useful.

I personally have a use that I can propose for I-129, but right now I regard that use as proprietary, and in any case, it's merely a proposal, not an existing technology that renders radioiodine valuable.

The only other use I can think of for I-129, might have been is as a source of isotopically pure Xe-129. (It happens that Xe-129 has a magnetic moment that makes it convenient for use in nuclear magnetic imaging. This isotope has been used to image lungs in a particularly non-toxic non-invasive way.) Unfortunately however, the long half-life of I-129 makes this potential use rather moot. 40 MT of iodine-129 emits just under two grams of Xe-129 a year. This would hardly justify the expense of storing the I-129, much less isolating it. That's too bad. The xenon-129 technology is cool, but still very expensive. A shorter half life (which also means higher radioactivity) would have made I-129 a potentially very valuable isotope.

[NNadir]

166. Iodine, the Greenpeace Headlines and Reality.

"Radioactive Iodine Gravitates Toward DNA, Say Scientists!"

"Scientific Report: Metric Tons of Radioactive Iodine Released by Two Nuclear Plants"

"According to Experts, Nuclear Power Could Results in a Billion Tons of Radioactive Iodine Waste!

"Scientists Say Nuclear Contamination Impossible to Eliminate!"

"Ancient Nuclear Reactor Leaked Isotopes Into the Environment!"

"Nuclear Power Contaminates Important Essential Human Nutrient, Scientists Say!"

"In Nuclear Plants, an Important Natural Nutrient Gets Mixed with Radioactivity!"

I had great fun writing the posts I have just finished in this thread, posts 158 through 165, (#1 through #6 in the radioiodine risks section) because all the time I was writing them I could only imagine how the twits at Greenpeace might spin these articles for the maximum effect in one of their propaganda rags or websites.

The spun headlines I am writing here are, of course, more than a little tongue in cheek, but I think they are illustrative of how much stupidity is involved in the way nuclear issues are reported. Sadly, not one of these headlines is too incredible to inspire orgies of ignorance breaking out among the illiterate masses.

Nothing gets too well examined in the age of Bush, the age of the lie and the delusion, the age of spin, but nonetheless we can all get a critical thinking workout by looking at the situation with radioiodine and whether or not it is unacceptably dangerous. My tenure at DU is nothing but an exercise is demystifying nuclear energy, an exercise that will require the working of those mental muscles that pull critical thinking together. Hopefully we can apply skills learned here in other areas in which credulity and obfuscation rule over reason and clearsightedness.

As before with cesium and technetium, I will in a series of following posts under this post explore whether the risks of the fission products that become or are iodine, products sometimes referred to as "nuclear waste," are nearly as great as advertised. I will also touch on possible uses for this material, and strategies whereby its effects may be either mitigated or completely prevented or eliminated.

In the process I hope we all, myself included - I have learned a great deal in preparing these posts - will learn something.

[NNadir]

167. #1. Iodine is a trace biological element; I-129, a trace of a trace.

Although iodine is an essential element, it is necessary only in trace amounts. A typical human being, depending on his location, diet, and physiology has only between 20 and 50 milligrams of iodine (as iodide) in his or her body. Of this, about 80% is in the thyroid gland, with the balance distributed in tissues.

With a half-life of 15,700,000 years, I-129 has relatively low specific activity: The decay constant in inverse seconds is 1.40X10^-15, meaning that the molar activity is around 6.5 X 10^6 Beq or 0.18 millicuries per gram. This means that a person whose entire compliment of iodine were saturated with I-129 alone, and no natural iodine, would have - if they contained 50 milligrams of iodine - would have 3.3 X 10^5 Beq or about 8 microcuries of iodine activity.

However, as we saw earlier in this thread, from the Environmental Science and Technology paper, the I-129 burden in the Mississippi River, almost all of which results from the use of nuclear power, actually contributes 1 I-129 atom for every three billion I-127 atoms. This means that a person whose I-129 burden is equivalent to that of Mississippi river water (probably representative of US food content) has about 1.1 X 10-4 Beq, or nine decays per day of iodine in their bodies. Compare this with about 4,200 decays per second from potassium-40 and you get an idea of how trivial such a risk is. The decay of potassium-40, by the way, is about 10 times more energetic that the decay of iodine-129. The radioactive contamination of I-129, even ignoring this energy difference between decays, would have to grow by a factor of almost 40 million to be equivalent to the risk of ordinary potassium in our bodies.

This situation is very, very, very, very, very, very different than how it might be represented by say, a Greenpeace type of anti-environmental anti-nuclear activist.

Is there a zero risk? No. Is the risk extremely trivial compared to say the risk of having a diesel engine in your neighborhood? Yes.

[NNadir]

170. #2: Iodine can be recovered and contained, but is it worth it to do so?

There are many insoluble iodides and iodates. Here is a list of some of them and their solubility products, which as chemists know, are very small numbers for essentially insoluble compounds:

Barium iodate: Ksp = 1.57 X 10^(-9)
Copper (I) iodide: Ksp = 1 X 10^(-12)
Lanthanum iodate: Ksp = 1 X 10^(-11)
Lead iodide: Ksp = 7.9 X 10^(-9)
Silver iodate: Ksp = 3.1 X 10^(-8)
Silver iodide: Ksp = 8.3 X 10^(-17).

Here’s a cool one, mercury (I) iodide, Ksp = 4.7 X 10-29.

If one has not wasted one’s college career attending campus anti-environmental Greenpeace rallies instead of doing one’s Chemistry 1 homework, one may be able to use this last figure to calculate how much water would be required to dissolve one gram of mercury (I) iodide. (To do this one needs to be reminded that the mercurous ion is actually dimeric, having an overall charge of +2, meaning that the formula for mercurous iodide is actually Hg2I2.) One can show that the amount of water to dissolve 1 gram of Hg2I2 is over 6.7 million liters. Moreover of this one gram, assuming that all of it was radioactive I-129, (which is actually not very likely) only about 38%, or 380 milligrams (0.38 grams) would actually be represented by I-129. The rest would be mercury. As I showed in post #167 (#1 of this series), the amount of radioactivity represented by this iodide that one would get from drinking 6.7 million liters would still be trivial. The mercury would probably kill you first.

This suggests an interesting use for the iodine produced in nuclear reactors: Sequestering the mercury that rains down on our heads minute after minute, day after day, 365.24 days a year, 10 years a decade, ten decades a century without let up. I have just posted in post #169 a link to some rough numbers on the amount of mercury released into the environment by coal processing and coal burning each year in the United States: About 200,000 pounds, which translates into civilized units as about 90 MT per year. Now, even though scientifically illiterate Greenpeace twits spend nowhere near as much time addressing the real danger of mercury, which actually kills, maims and otherwise injures people, as they do representing a “danger” of so called “nuclear waste,” which has actually killed no one, it actually happens that mercury is a very serious problem.

It is therefore a valid question to ask how much mercury can be sequestered by nuclear generated iodine. A reasonable estimate for the amount of all the iodine produced in nuclear reactors for the entire history of commercial nuclear power worldwide, I-127 (non-radioactive) and I-129 (long lived radioactive) inclusive, is roughly 60 MT, of which more than 2/3, or more than 40 tons, is the radioactive isotope. If one does a little stoichiometry one sees that, even if one could somehow capture all of the mercury released by coal use in the United States, all of the world’s nuclear generated iodine would just be to sequester even a year’s worth of US coal related mercury releases. (It happens, that irrespective of what “clean coal” liars tell you, trusting in your credulity, it is actually not feasible to capture “all” of the mercury released by coal burning and processing. And even if they do capture it, all they do is dump it somewhere, and probably not, one guesses as an insoluble iodide.)

Of course, were one to use mixed iodine isotopes from spent nuclear fuel for this purpose, one would actually have to recover it. This is certainly technically feasible. However as I noted in post #159 (#2 in the series on Iodine risks), the Purex process that is now commercially used to reprocess nuclear fuel allows for the release of I-129 to the environment. Over 2 metric tons, or 5% of the I-129 generated, has already been released into the environment and has been distributed worldwide. As I noted also in post #159, this iodine accounts for about one in every three billion iodine atoms found in the Mississippi River today. But then I showed in post #167 (#1 in the present series) that the risk of this iodine is actually less than one forty millionth of the risk associated with the potassium in our bodies, some of which is also radioactive. This raises an important question. Is it worth it to capture I-129 at all?

People do not often actually think too much about the costs of risk mitigation, since everyone seems to operate under the tacit, albeit ridiculous, notion that every life has infinite worth. Still there is fantasy and then there is the real world. Let us assume that it takes ten million dollars a year to install and operate iodine scrubbers on the world’s Purex reprocessing reactors. Let us also assume in the absence of any real evidence that this is actually the case, that the tiny amount of radioactivity associated with the release of I-129 to the environment actually causes the death of one person per year somewhere on the planet. Then the cost of saving this life is ten million dollars. Now, I fully recognize that among the scientifically illiterate Greenpeace twits, one life lost to a causation related to nuclear technology is worth millions of lives lost to other forms of pollution, but I am not addressing scientifically illiterate Greenpeace twits. Instead I am addressing reasonable people. How many lives can be saved by the use of ten million dollars a year for the purpose of extending health benefits to uninsured children?

I ask again, is it really worth it to remove one slightly radioactive atom out of every three billion from the Mississippi River?

[NNadir]

171. Relevant to this case, consider this article.

"Half of All Cancer Deaths Preventable: Report

Thu Mar 31,10:57 AM ET Health - Reuters


By Maggie Fox

WASHINGTON (Reuters) - More than 60 percent of all cancer deaths could be prevented if Americans stopped smoking, exercised more, ate healthier food and underwent recommended cancer screenings, the American Cancer Society reported on Thursday.


Americans could realistically cut the death rate in half, the report says. This year 1.368 million Americans will learn they have cancer and 563,700 will die of it..."

http://news.yahoo.com/news?tmpl=story&u=/nm/20050331/hl_nm/cancer_prevention_dc


How many lives could be saved for 7 million dollars worth of cancer screenings?

[NNadir]

172. #3: The creation of one atom of I-129 prevents 71 actinide decays.

Greenpeace anti-nuclear anti-environmentalist types would like you to believe that the use of nuclear power is leading to a dangerous increase in worldwide radioactivity that is intractable and cannot be safely managed. This is patent nonsense. In fact the fissioning of uranium and thorium derived elements has for the short term actually increased the radioactivity of the planet as a whole, but for the long term the use of nuclear power will significantly reduce worldwide radioactivity.

To see who this is so, let us consider I-129, which can, with it's long half-life, be considered the penultimate "nuclear waste."

The case that follows, and to which the title of this post applies (for my convenience) to Uranium-238 transmuted into Pu-239 and then fissioned thermally in a nuclear reactor to generate energy. Thus I will speak of the radioactivity associated the U-238 decay chain, although similar considerations show qualitatively that there is little difference in the Thorium-232 and U-235 decay chains that also find use as nuclear fuels.

When an atom of plutonium-239 is fissioned to drive a turbine, it represents an atom of uranium-238 that is removed from a reactor and then destroyed forever by making it into two smaller atoms and some neutrons. For instance, if a plutonium-239 fissions in such a way as to produce an atom of I-129, which is known to occur 1.39% of the time, and if it produces 2 neutrons, it also produces an element having a mass number of 108, which ends up, ultimately, being an atom of cadmium. Now we know that some of the atoms of I-129 will end up being around for at least 100 million years. Is this a terrible thought? No, not really. By inverting the fraction of iodine atoms produced (0.0139) we see that for thermal fission of Pu-239, in order to make 1 atom of this long lived isotope I-129 we needed to destroy (fission) 71 atoms of Pu-239. Moreover the creation of this Pu-239 actually resulted from the destruction of 71 (technically slightly more) atoms of naturally occurring U-238, so called "depleted uranium," that often is appealed to in orgies of scientific illiteracy.

As most people know, "depleted uranium," U-238, is radioactive with a half life that is roughly comparable to the age of the earth, about 4.46 billion years. Although pure uranium is slightly radioactive it is nowhere near as radioactive as the ores from which it comes. In uranium ores, the uranium is in radioactive equilibrium with all of its decay daughters, which are: Thorium-234, protactinium-234, uranium-234, thorium-230, radium-226, radon-222, polonium-218, lead-214, bismuth-214, polonium-214, lead-210, bismuth-210, and polonium-210. Polonium-210 decays into stable lead-206 and for lead-206 we no longer speak of equilibrium but of accumulation. Now in any sample of uranium-238 that is more than 3.5 million years old and therefore at equilibrium, for each 238 grams of uranium present (in other words for each mole) it can be shown that each uranium-238 atom and every single one of its daughter atoms (all 13 of them) will contribute 2,965,800 Beq of radioactivity to the sample. All told and summed, this means that one mole of uranium at equilibrium has about 41 million Beq or about 1.1 millicuries of radioactivity associated it.

Now let's compare this to I-129. First of all, ignoring the fact that I-129 will be around for a lot shorter time than uranium-238, since its half-life is 1/300th that of uranium, we also have to recognize that creating it required the destruction of 71 atoms. Therefore to get one mole of I-129, we need to destroy 71 moles of uranium (which will also prevent the formation of 923 moles of new uranium daughter atoms). Therefore the total activity destroyed in making the I-129 is about 3 billion Beq or about 80 millicuries of equilibrated U-238.

What is the radioactivity of the mole of I-129 created? It turns out that the specific molar activity of I-129 is about 22 millicuries, or roughly a fourth of the original activity of the uranium used to make it. But wait, it gets better. Let's let the equilibrated uranium and the I-129 sit in their ores for 100 million years. Under these circumstances, the activity of the I-129 is only 1.2% of what it was at the outset, the total activity having declined to 0.3 millicuries. In the same time span the uranium ores will have only decayed to 98.5% of its original activity or to about 79 millicuries. Almost all of the "danger" of I-129 is now gone, whereas the "danger" associated with uranium ores is almost unchanged.

This type of analysis has been done for all of the known fission products and has incorporated a factor for the health risks associated with the ingestion of the involved isotopes. (One such place that such an analysis is given is William Stacy's Nuclear Reactor Physics, Wiley, 2001 page 228-232.) When one engages in this exercise, one quickly finds that for fission products alone, the risks fall below the risks of uranium ores in between 500 to 1000 years. From there are in, if actinides are removed and recycled to make more energy, the risks associated with radioactivity are decreased dramatically through the use nuclear power plants to produce energy.

Greenpeace idiots often speak of the "need to store 'nuclear wastes' for 'millions of years'." Like almost everything else they have to say on the subject of nuclear energy, it's pure specious garbage. In an educated world such statements would not even be considered by serious people.

[NNadir]

173. Iodine is easily transmutable into valuable xenon.

After a few weeks of decay, the only iodine found in spent fuel is a mixture of I-127, the natural isotope of iodine, and I-129, the slightly radioactive isotope. Both of these isotopes have reasonably high neutron capture cross sections, and both exhibit fairly strong capture cross section resonances for epithermal neutrons. This means that they are easily converted by neutron bombardment into xenon. (One can also accomplish this with proton bombardment.)

Xenon is a relatively expensive material. It is useful to produce very energy efficient light bulbs that give off very bright light resembling natural daylight. You may have already seen such light bulbs in the headlamps of very expensive cars, which offer them as an option. The production of xenon unfortunately usually involves cryogenic processes like the fractional distillation of liquid air. Such processes are energetically expensive.

Xenon can already be obtained from spent nuclear fuel, since xenon isotopes are fairly common fission products. All of xenon's radioactive isotopes are very short lived, and thus the xenon itself is not radioactive if one waits a few days. However, the xenon is generally contaminated with krypton-85, which is radioactive, having a half-life of almost 11 years. It is relatively easy to chemically separate xenon and krypton, since xenon has a much more extensive chemistry than krypton, but this involves expense and fluorine. One could also store the gas in cylinders for a few decades, but this too would be expensive.

Xenon obtained from the transmutation of iodine has no such problems. Sale of any such xenon would offset at least some fraction of the cost of transmutation. Still, any transmutation of iodine would be for cultural and not for economic or safety reasons: Basically one would be attempting to satisfy the bizarre paranoia of persons who believe that all things radioactive are unacceptably risky. This is nonsense, of course, but it seems to need addressing.

[NNadir]

174. #5. The main cancer associated with I-131 is largely curable.

If you really want to see ignorance in action, you need to drop by drop by www.ratical.org where you can find gems like this one:

50,000 thryoid cancers.


Apparently, though, the fellows who do the editing over there have such poor educations that a little bit of the truth slips through inadvertently, to wit:

"In a population of 141,068 children under four, less than six cases would have been expected - in fact in the first 10 years there were 131. Over their lifetimes another 50,200 can expect to develop thyroid cancer, the researchers say..."

So the difference in real numbers of thyroid cancers that have actually occurred is 131-6 = 125. Almost 20 years have passed since Chernobyl. People better hurry up and get those cancers, or else they risk getting old before they have a chance to be victims.

Now 125 cancers is not really a small matter, particularly when it was unnecessary, but how is it that these 125 cancers are somehow more important that the millions of people who die from air pollution every year? How is that they are more important than the deaths caused by the mercury output of coal fired plants in normal operations? How is that they are more important than the lives of coal miners?

And do these 125 cases of cancer represent cancer deaths? No, they do not.

"Some people refer to thyroid cancer as a "good cancer," primarily because it has very high survival rates. This is a an understatement, as thyroid cancer is still a cancer that requires treatment and lifelong monitoring, and can have debilitating effects on patients. Survival rates, are, however, high, with 95% of all thyroid cancer patients achieving what would be considered a cure, or long-term survival without reoccurrence. Annually, in the U.S., an estimated 14,000 new cases of thyroid cancer are diagnosed each year, and only 1100 people die each year from thyroid cancer."

http://www.thyroid-info.com/articles/cancerintro.htm

So let's assume, in spite of the lack of any evidence that they actually know what they're talking about, that the poorly educated poor thinking crowd at www.ratical.org have a point. Let's say that 50,000 people will ultimately get thyroid cancer from the only nuclear power plant accident in the last 50 years to have resulted in fatalities. Then 0.05*50,000= 2,500 people will actually die from the disease, over a period of many, many decades.

More people will die in New York city alone this year, and every year hereafter (unless something is done), from air pollution. Why are these Chernobyl deaths worth more than the lives of air pollution victims?

It is disgusting, really disgusting when you think of it.

Oh, and while we're on the subject of distortions, misrepresentations, and outright lies, I note that the ratical.org link refers to a "Greenpeace nuclear expert." The existence of such a thing, a "Greenpeace nuclear expert," is roughly comparable to the existence of the Easter Bunny. No such thing exists. People who are childlike in their thinking might believe in such things, but they are not real.

[NNadir]

175. Radionuclides with intermediate half-lives.

In the earlier series of posts on the subject of so called "nuclear waste," I deliberately covered the long lived nuclei. I did so because one feature of the general scientific illiteracy that marks the modern (or should we say re-medievalized?) United States is the belief that if something remains radioactive for a long time, it is somehow more dangerous than something that remains radioactive a short time. Actually the inverse is true, the longer the half-life of a particular nuclei, the less dangerous it is. The shorter the half-life, the more dangerous it is.

One will, irrespective of how much education one attempts to provide, always hear appalling nonsense like, "'nuclear waste' stays radioactive for millions of years..." stated as if to mean "'nuclear waste' is dangerous for millions of years." This is specious balderdash of course. It is true that the earth has always been radioactive, and always will be, unless we build so many nuclear power plants (not likely) that we actually eliminate radioactivity from the planet. In fact the only way to reduce the radioactivity of the planet overall - although it would take about a millennium to do so - is to build lots and lots of nuclear power plants. Even then, it is really not possible to eliminate radioactivity since there are some naturally occurring radionuclides, K-40 being the most problematic, that are not consumed in nuclear reactors as the radioactive elements thorium and uranium are.

Because this particular bit of illiteracy, the confusion between half-life and danger, has such staying power, I have deliberately chosen to discuss first, among the fission products, the elements that have the longest half-lives (leaving out zirconium), iodine (I-129), cesium (Cs-135) and technetium (Tc-99). However, since whatever danger is associated with particular nuclides is a function as much of their chemistry as it is of their radiological features, I have included discussions of nuclides like I-131 (half-life about 8 days) that are not particularly long lived but which, being isotopes, pretty much share the chemistry of this long lived radioisotopes with which they are associated.

In the section on cesium, I also discussed one of the more problematic nuclei in the fission product series, Cs-137. Cesium-137 (half-life 30.23 years) is what I like to think of as an "intermediate" nucleus. It has a half life that is sufficiently long lived that it is not extremely easy to simply get rid of it by letting it decay for a short period; on the other hand it is really easy to imagine - for the reasonably sensible anyway - isolating it for a few generations during which time it will decay.

In a series of posts that follow, I will discuss other elements with radioisotopes that fit this class, but which are not associated with radioisotopes having half-lives on the order of hundreds of thousands or millions of years. Some of these elements are elements like strontium, cerium, ruthenium, europium and samarium, each of which has isotopes among the fission products that have half-lives in the general range of just under 1 year to just under 100 years.

As before, I will discuss these elements in two sections, one that examines the problematic aspects of these elements, and another that examines mitigating circumstances by which such elements can be managed or rendered into uniquely useful materials.

[NNadir]

176. The chemistry, biochemistry and nuclear physics of Strontium.

As I wrote in post #84 in this series, speaking then of cesium, I am a child of the era of atmospheric nuclear testing. I was born in 1952, just a few months before the "Mike Test," the atmospheric explosion of the first "hydrogen" bomb, a test so large in scale that an entire island, Elugelab, in the Eniwetok Atoll, was completely obliterated and vanished forever from the face of the Earth.

While I was growing up, the United States government, the Soviet government, the British government, the French government and the Chinese government were all conducting open air nuclear tests at an ever accelerating pace. Many of these tests were on an unimaginable scale and radioactive particles were injected high into the stratosphere and circled the globe, drifting in clearly detectable amounts into the troposphere, lithosphere, hydrosphere and ultimately the biosphere including that portion of the biosphere represented by humanity itself.

As I wrote, again in post #84, the pace of this rather dubious insanity was slowed by the heroic efforts of two great scientists who would each later be awarded the Nobel Peace Prize, on the American side, Linus Pauling, already a chemistry Laureate (and the only person ever to win two prizes in unrelated areas), and, on the Soviet side, Andrei Sakharov.

Sakharov, in particular, would later suffer greatly for his efforts and would set out on a career of elevating human dignity that has seldom been equaled. Pauling later hawked vitamins.

In the rhetoric of those days, rhetoric embraced by Sakharov and Pauling, much was made of "the children." I was one of those children. My bones grew rapidly in the period between 1952 and 1962 when the Americans and Soviets agreed to stop atmospheric testing. By then, in my case, I'm sure that much of the damage was already done. I drank lots of milk in those days, milk from cows who ate strontium laced grass. This lace of strontium was of course, radioactive fallout. Strontium behaves almost identically to calcium in milk. So cow's milk was enriched in strontium, including radioactive Strontium-90. When this milk was fed to babies like me, my proteins worked hard to deliver this strontium to my bones, where some of it undoubtedly remains today.

One encapsulated in bones, most of the calcium and strontium deposited there remains in incorporated in them throughout one's lifetime, unless one develops severe osteoporosis. Of the Strontium-90 incorporated into my bones as a result of the "Mike Test" that vaporized Eugelab, one would see that about 28% remains, if one does the calculation. The rest has decayed to Yttrium-90 and then to Zirconium-90 over my life time.

Should I die and should someone wish to check my claim of being radioactive as a result of the Mike and other nuclear tests, one could always go to the laboratory of Ernest Sternglass with a piece of my bone to check it out. Dr. Sternglass has generated many thousands of Internet links with his project to collect baby teeth and measure the amount of radiostrontium in them, thus trying to prove that everyone on earth will die from nuclear power plants. The use of baby teeth in this project, rather than the bones of dead old people, is brilliant marketing, since it evokes "baby" and radioactivity in the same sentence. This has allowed Dr. Sternglass to become rather famous among anti-nuclear anti-environmental activists. Thousands of them spend their days creating websites with links to his "research" and links to other websites having links about "baby teeth" and gas "radiation." (Too bad there aren't so many people similarly obsessively devoted to global climate change, but there are not.) So we see that strontium, through the agency of Dr. Sternglass, is an precious cog in the annals of nuclear paranoia.

In the unlikely case that anyone who actually bothers to read this is unfamiliar with my position, I will state that my bias is to think of Dr. Sternglass as being an over hyped, inappropriately respected flake. That said, I will try to present what I think his side of the story might be, because under certain circumstances, Sr-90 can indeed be dangerous.

In a series of posts that will follow, I will discuss the chemistry, biochemistry, physics, difficulties, risks, mitigating circumstances, use and potential use of strontium isotopes, especially Sr-90, that exists as a fission product from nuclear power plants.

[NNadir]

179. Strontium, risks, difficulties, concerns and problems.

In a series of posts following this one, I will list some of the concerns associated with the chemistry and physics of strontium as derived from nuclear reactors. In particular I will focus on the fission product Sr-90, the isotope that represents the largest concern among the strontium isotopes produced in commercial nuclear power.

[BlueEyedSon]

110. Total newbie question here.

What is the SOTA on thermal pollution from nukes?

Nice thread, amazing longevity!

[NNadir]

111. An excellent question,

although I'm not sure what SOTA means.

Older nuclear plants have slightly lower thermodynamic efficiency than do newer nuclear plants, and thus per watt generated, they reject more heat to the atmosphere than do coal plants, gas plants or solar systems.

To be perfectly clear, I haven't done this calculation over the broad field of energy systems since nuclear power is so much cleaner in every other area than any other form of energy in just about every other area, since I regard the matter as somewhat trivial. I'm sure though, nuclear power would be the worst form of energy in this respect, especially because the fuel is so cheap. I do recall that some surfers in the cooler months used to like to surf near San Onofre nuclear station because the water was a little warmer there than elsewhere.

However thermodynamic efficiency of a particular type of plant is hardly the whole story on the thermal effects of energy generation. The most obvious effect of energy generation is the production of greenhouse gases, which change the equilibrium value of the total energy flux of the planet as a whole. (That's a fancy way of saying Greenhouse effect).

Both nuclear energy and fossil energy change this flux by injecting new energy that was previously stored (as potential energy) into the atmosphere. However these outputs are dwarfed by the solar influx.

The solar out flux is very much effected by the composition of the atmosphere. Temperatures on Venus exceed 600C not because Venus is that much closer to the sun, but because its atmosphere is chiefly CO2. Mars too, is warmer than it should be. Although its atmosphere is very thin, it's atmosphere too, is mostly CO2. Two forms of energy put out very low amounts of CO2, nuclear energy and solar energy. Their overwhelming advantages in these areas make them desirable, and therefore, if we are to avoid a runaway greenhouse effect, our only options are nuclear and solar energy.

Please note that neither nuclear or solar energy are strictly carbon or greenhouse gas neutral. Both require the use of CO2 spitting systems, mainly in trucking and transportation and manufacturing systems. Because of the low mass efficiency of solar systems, relative to nuclear, (it takes the movement of lots of weight to build solar capacity per watt vis a vis nuclear energy) solar is somewhat worse than nuclear in this regard, but still very acceptable with respect to coal.

Both nuclear and PV solar industry use fluorine chemistry and both are responsible for the output of carbon tetrafluoride gas. This is an extremely long lived gas with a global warming potential that is 6500 times as great as carbon dioxide.

http://www.fluorideaction.org/pesticides/carbon.tetrafluoride-page.htm

Both industries however are trivial with respect to other anthropogenic sources of this gas. This because of the extremely high mass efficiency of nuclear energy, and because of the lack of economic viability for the PV solar industry: The PV solar industry is so small, because of its high cost, that it's toxic effects can be ignored.

The major source of output of anthropogenic carbon tetrafluoride is the aluminum industry, where it is a side product in the electrolysis of bauxite in a cryolite matrix. Cryolyte is a fluoride of aluminum and invariably some carbon is in the system, so rather large amounts of carbon tetrafluoride are put out by this huge energy soaking industry.

Recently a poster here informed me that solar cells will all be manufactured using aluminum. I don't know if that's true or not, but if so, it will slightly raise the greenhouse global warming potential of solar energy further. I don't really worry about it though. The poster in question seems to have a very poor understanding of energy issues in particular and science in general, and in any case, aluminum manufacturers are being pressured to reduce the output of this gas.

[BlueEyedSon]

112. SOTA = state of the art. Years ago the thermal problem with

nukes was mostly about using river water as part of the cooling strategy. I assume that has changed (more whatever-to-air cooling towers).

[NNadir]

114. It has changed for some reactors, not all.

Thermal pollution from nuclear reactors is a negative impact of nuclear energy generation at many plants, I'm sure. Not all have cooling towers, which are in general fairly expensive. People have begun to associate cooling towers with nuclear plants, but the problem of cooling is not unique to them. Thermal pollution is a problem at all heat engine type plants, including coal plants, gas plants, and oil fired plants, the latter type being very rare.

The move toward higher plant efficiencies, which is a measure of recovering greater fractions of the energy as electricity, in plants of all types is of consequence here. The only way to increase efficiency is to raise the temperature of the steam in the reactor. In many systems, including some nuclear reactors and newer coal plants, the steam is actually not "steam" per se, it is supercritical water. On some level this can make for extreme localized heating effects in any type of plant.

Most of the new designs for nuclear reactors call for higher temperatures. Two types of reactors that are widely discussed, Pebble Bed Reactors and High Temperature Gas Cooled Reactors, (HTGCR) will operate at very high temperatures, more than 900C. A third type, my favorite kind, the molten salt reactor (MSR), will also operate as very high temperatures. HTGCR and MSR may use their high temperature modes for the initiation of processes for the production of liquid and liquifiable gas fuels, with step downs through electric turbines, and finally processing such as distillation. These systems will have the highest thermal efficiency of any type of heat engine systems ever industrialized. That said, I'm not a fan of PBR's for reasons that have to do with resource utilization.

In every case, including that of the extremely dirty fuel coal, some of this waste heat energy can be recovered through co-generation, wherein the heat is utilized for some process or other use. Practically every automobile on the planet just about is a cogeneration system when, in winter, the waste heat warms the air in the passenger compartment. Industrial cogeneration systems are becoming, happily, more and more common. This idea is hardly new. In the Soviet era, the waste heat from Soviet nuclear plants was commonly used to heat houses in nearby towns.

[dcfirefighter]

160. PBR, and not the beer

I've read most of your nuclear discourse this sitting, and the entire time i've been thinking "what about those Chinese pebble bed reactors?". Whats your resource utilization angle?

Most of DC has a bg radiation level of 5-10 uR/h, more in the big stone buildings.

[NNadir]

161. I am often asked this question.

In general, I'm not a wild enthusiast for these reactors, although they have some nice features.

They are not a Chinese design, they are a South African design.

Here's what I like:

1) They're cheap and quick to build.

2) They run at high temperatures, which means they offer flexibility for use other than simple electric power generation, such as hydrogen production for motor fuel synthesis.

3) They rachet up the safety profile of nuclear power to even more absurd levels, although no level of safety will ever satisfy anti-nuclear anti-environmentalists. (They are not interested in reason so much as religion.)

Here's what I don't like about PBRs:

1) They are "once through." The chemical nature of the fuel, which is designed for extreme stability, makes it problematic to recover valuable nuclear materials. This is extremely wasteful.

2) They use helium as a moderator and heat transfer agent. Helium is going to get very expensive some day. Only a few wells in the world produce it; and helium released into the air slowly boils off into space.

#1 in the "don't like" section is my most important concern. I think it is essential that we recover as much energy as possible from uranium and thorium. I, in general, don't like "waste" mentalities.

I still like HTGCR (high temperature gas cooled reactors) better than PBR as a high temperature reactor, especially since they can run as thorium based breeders. However they also have helium moderators and heat transfer fluids. One of the HTGCR's built in the US at Fort Collins, Colorado was a spectacular commercial and technical failure. The Chinese are now building one as a hydrogen generator; we will see how well they learned from our mistakes at Fort Collins.

The reactor that intrigues me the most from the high temperature standpoint is the molten salt reactor. This is just a spectacular design.

[MountainKeeper]

152. I Live in the Heart of Coal Country

I live in an area ravaged by the mining method called mountain top removal. They will blast away as much as 900 ft of mountain for a small seam of coal. All the refuse is dumped in the valleys covering everything in it's path. Over 1,200 miles of streams have been destroyed by this mining method. Whole communites have been destroyed by the blasting and the dust that comes from these sites. We are the best kept dirty little secret in America. The coal is low grade at best from these sites, which means that it has to be blended with a higher grade of coal to get the BTU desired. the clear cutting of the forests in preparation for these mining sites have caused widespread flooding in areas that have never been flooded before. The Bush administration is making it easier to get the permitting done in record time. The citizenry have no voice in the matter. We call this America? This is like a 3rd world country. Thanks Bushco.

[NNadir]

153. I feel for you. I am very much aware of what is being done to your home.

The sad thing is that it isn't necessary.

[jpak]

154. Yes, the State of West Virginia could ban that practice today

Congress could ban it too for that matter.

No nuclear power plants necessary...

[NNadir]

155. Yeah right.

[Filius Nullius]

177. PV has higher externalities than nuclear????

It sounds pretty wacked out for anyone to say that PV could have higher externalities anywhere or under any conditions than nuclear. Plutonium is a very radioactive substance. It is extremely toxic and has no safe levels of exposure to the human body. Exposure to miniscule doses of plutonium, even inhalation of one milligram or less, can cause cancer. Once it finds its way into the body, plutonium remains there for longer than the average human life span. Inside a person, plutonium may expose very sensitive parts of the body to harmful radiation. This can cause genetic damage, leading to birth defects in offspring.

Plutonium has a half life of 24,000 years, which means that half of the harmful radiation is still present after 24,000 years. Thus, it would take hundreds of thousands, if not millions of years to arrive at safe levels of radiation. Did they calculate the cost of guarding it for that long to keep it from falling into the hands of terrorists? For that matter, is it even possible to plan to guard it for that long since no civilization has ever lasted for more than a few thousand years. The longest I know of is ancient Egypt, but even it had 31 dynasties (think regime changes). Did they calculate the cost of failing to guard it and allowing terrorists to incorporate it into a dirty bomb?

[NNadir]

178. This is calculation, not religion. Their methods are given.

If you think that saying plutonium is hazardous has any bearing the hazards of PV chemistry, you are wrong.

I know your type. You write about the dangers only of nuclear technology and ignore the dangers associated with every other technology. The only way to view nuclear power as dangerous is to ignore the environmental costs of every other form of energy, including the much hyped, and incredibly expensive and poorly available PV solar energy.

For the record, they do not bury plutonium in Europe. They are sensible. They recover it and fission it.