Nuclear safety: U.S. Nuclear Waste Problem Gains New Scrutiny

[Wilms]

Nuclear safety: U.S. Nuclear Waste Problem Gains New Scrutiny

Japan's nuclear accident has focused attention on the U.S. practice of packing spent-fuel pools at power plants far beyond their capacity, which some scientists call a serious compromise in safety.

March 23, 2011|By Ralph Vartabedian, Los Angeles Times

snip

The risks taken at the Fukushima Daiichi plant were actually less than those in the U.S., nuclear scientists say, because utilities here have been forced to pack more fuel rods into pools than they were designed to hold, increasing the density and therefore the chance that they could catch fire if they were to lose the water that cools them.

"The pools in Fukushima were not filled to capacity, and the accident could have been a lot worse if they were filled as densely as ours are," said Edwin Lyman, a physicist with the Union of Concerned Scientists.

snip

Nuclear safety experts say that plants have packed up to five times more spent fuel rods than the pools were designed to store, though Nuclear Energy Institute officials say the pools contain no more than twice their original capacity.

The only advantage to keeping the pools packed so tightly is the cost of the dry casks, which would run about $5 billion to $10 billion nationwide, said Frank N. von Hippel, a Princeton University physicist who first disclosed the problem in a paper he co-wrote in 2003. He said he considers fixing the fuel pool problem one of the most important steps toward making U.S. nuclear plants safer.

snip

http://articles.latimes.com/2011/mar/23/science/la-sci-spent-fuel-us-20110323

[TheMadMonk]

1. The advantage to keeping the spent fuel in pools...

...as opposed to processing into less volatile forms and moving it to long term storage is that it's easily weaponisable.

Truly viable long term storage/management options do exist.

Several years back I happened to be peripherally involved with an Australian Company working on "glassification" (mixing waste with glass (not quite window glass) and casting it in billets (approx a foot long and 4" in diameter IIRC)). In the end it died because it proved impossible to cast the billets absolutely flawlessly as per the requirements. Even though it could be shown that the physical flaws presented zero risk (even ground to a powder the glass could not be induced to release its radioactive payload in a biologically active form.)

Several types of reactor can be induced to produce a strong neutron beam. A beam dense enough to transmute nuclear materials with middling to long halflives into stable isotopes, or isotopes with a halflife short enough to remove the need for long term storage altogether.

A thorium cycle reactor would give us the best of both worlds: Far less (about 10%), and far shorter lived (300 as oposed to 10,000 years) waste than for either uranium or plutonium fueled reactors, and enough stray neutrons to incinerate old waste from uranium fueled reactors.

And finally, there exists a way to generate a dense free neutron beam with a tabletop device that can be switched on and off at will. Potentially this device can be used in a number of ways: To burn nuclear fuels in arbitrary amounts too small to ever present an appreciable radiological danger (Theory allows anything from a few kilowatts to several tens of megawatts); To transmute nuclear waste into a more managable form; and finally (and I think the reason this tech has "fallen off the face of the Earth") it can be used to easily produce plutonium in ton lots.

Utter stupidity. There are no such things as "technological secrets", simply discoveries made and as yet unmade. And once a discovery has been made once there is no suppressing it. The simple fact of knowledge that something CAN be done, is sufficient to make the doing of it a second time a mere matter of sufficient application.

So instead of consumer level nuclear reactors theoretically small enough to fit into a motor car, the inventor suddenly decides to pursue a completely different field of study. It just does not make any sense. Even if we ignore the possibility of a micro-nuke in every basement (or even for every few streets) the possibility of completely neutralising all radioactive waste for the price of a little (or even a lot of) electricity should be too great to ignore.

Instead on the heels of announcing what should have been the greatest breakthrough in nuclear physics in half a century (Burning nuclear fuel WITHOUT piling it up until it spontaneously catches "alight" as is done in a conventional reactor AND the cheap(ish), controlable transmutation of elements without the backstrain of aiming 10,000 tons of nuclear reactor), the inventor/discoverer abandons research in cutting edge nuclear physics for a mature field where incremental refinement rather than momentous discovery is generally the name of the game. And his invention disappears into a black hole. Common sense CANNOT explain. DARPA very stupidly trying to secure/protect a non-existant monopoly on plutonium production does explain.

My take is that we as a species have now invented so many possible ways to wipe ourselves out or even destroy the planet entirely that speculation over exactly WHICH path to destruction might be chosen is a fucking moot point. Either we figure out how to NOT use any of them, or someone should do the world the favour of selecting the one which is most specific for homo sapiens sapiens.

[Wilms]

2. Thanks for the post.

I'm interested in alternatives that will use up the fuel, and render it less harmful, even if only to eliminate the stockpile of spent fuel and decommission the entire industry.

As it stands now, it's more a matter of when and how often and how bad an accident--not if.

[TheMadMonk]

6. When and how often? Unknowable since we still don't have enough...

...bad events to discern a statistically meaningful figure.

The best we can say is if a complete dickhead ignores all safe operating guidelines, in a manually managed reactor, without containment, can trigger a Chernobly level event if he tries hard enough and ignores enough warning signs and overides enough voices of sanity.

What we do know, is that the reactors (at close to the end of their operational lives) did survive an earthquake 5 times more powerful than designed for 40 years earlier. The emergency shutdown system performed exactly as it was intended to. The backup generators cut in as they were supposed to, and then the tsunami hit and took out the generators. Even then battery power continued to cool the reactors until it ran out.

Ultimately lack of cooling is the cause of the damage we are seeing now, and I think a big part of the problem is no one ever anticipated the reactors surviving what they did. No one anticipated having to deal with substantially intact reactors with no way to get power to them. They figured that if things were that bad they would be dealing with an already fully compromised reactor, not scrambling to prevent it from happening in the middle of handling a double dose of catastrophic natural disaster.

[Octafish]

3. But-but-but it's supposed to be green energy of the future brave new world order thing.

From the LA Times article:

The utilities erroneously thought the pools would be for temporary storage only: The federal government had promised it would find a safe place to bury the used-up fuel rods, which remain radioactive for thousands of years.

It has yet to make good on that commitment.

Thank you for the vital information, wilms. A must-know about the who's and what's and where this is all going.

EDIT:

Nuclear reactors are made
by fools like me,
but only God
could make a nuclear reactor
that's 93,000,000 miles
from the nearest elementary school.

-- Anne Herbert


Source w more background on radiation storage: NULCEAR GUARDIANSHIP FORUM - On The Responsible Care of Radioactive Materials

[Wilms]

5. You're welcome. And thank YOU.

That's a valuable link you've posted.

I've been recalling, though haven't looked up, an article I read years ago describing an effort to design warning signs that could be placed at nuclear sites. The challenge included making the signs effectively understandable to future generations of tens of thousands of years to come. Quite a problem when you think about it.

[enough]

4. The waste/spent fuel problem is one place that the proponents and opponents of nuclear power

can vehemently AGREE. This needs to be dealt with, if you want to go on with the industry or if you want to end it.

[wordpix]

7. +1 & it needs to be solved NOW before any more nukes are built

and more waste is piled up in "temporary" storage for the next 40 yrs.