Radiation levels at damaged plant drop. Containment remains intact.

[Statistical]

(Reuters) - Japan has told the U.N. atomic watchdog there was an initial increase of radioactivity around a quake-hit plant on Saturday but that levels "have been observed to lessen in recent hours," the Vienna-based agency said.

The International Atomic Energy Agency (IAEA) also said it had been informed by Japanese authorities that Saturday's explosion at the Fukushima Daiichi plant occurred outside the primary containment vessel.

"The plant operator, Tokyo Electric Power Company (TEPCO), has confirmed that the integrity of the primary containment vessel remains intact," it said in a statement.

http://www.reuters.com/article/2011/03/12/japan-quake-iaea-idUSLDE72B0J320110312

[Warren DeMontague]

1. Good.

Really good.

[thewiseguy]

2. Care to explain how 3 people tested positive for radiation?

[OmmmSweetOmmm]

5. +1! Link

http://www.cnn.com/2011/WORLD/asiapcf/03/12/japan.nuclear/index.html?hpt=T1&iref=BN1

snip

On Saturday night, three patients at a hospital tested positive for radiation exposure, according to the Japanese public broadcasting station NHK, citing a statement from Fukushima Prefecture.

The three were randomly selected from a group of 90 hospital workers and patients who were already at the medical facility -- about three kilometers from the Daiichi plant -- before Friday's massive quake. The patients were outside of the hospital awaiting evacuation at the time of the explosion.

[Statistical]

6. Even IF 3 people "tested positive for radiation" that doesn't contrradict the OP.

Both statements can be accurate.

It is possible that
a) 3 people tested positive for exposure to radiation
AND
b) levels around the plant are dropping
AND
c) the explosion didn't damage primary containment.

They aren't mutually exclusive.


PS: You can't test positive (or negative) for radiation. You can be contaminated with radioactive material (dust) or you can show signs or radiation sickness symptoms. Once exposed to radiation there is no "test positive for radiation" test. For example you have been exposed to radiation. You have been your entire life. After the fact there is no way to know how much radiation you have been exposed to.

[sixmile]

8. Now it's 9

Per Reuters twit feed

'Japan nuclear safety agency says there is a possibility at least 9 people have been exposed to radiation from Fukushima facility.'

[jpak]

29. Now it's 160

n/t

[jpak]

20. 3 with radiation sickness - huge exposures - 160 now confirmed exposed

yup

[Hannah Bell]

21. because they were in the open a mile from a radioactive release?

[thewiseguy]

24. Wrong

Radioactive release contained very little levels of radioactivity.

To show possible signs of radiation sickness you need to be exposed to at least 1-2 sv.

That is far higher than what the Japanese government was reporting.

[Paradoxical]

26. The secondary barrier was breached.

The resulting explosion and dust cloud likely picked up the radioactive particles in the building and carried them downwind. Anyone exposed to that cloud is going to get a massive dose of radiation.

[Hannah Bell]

32. and 1) the cnn article you mentioned said "radiation exposure" not "radiation sickness"

http://edition.cnn.com/2011/WORLD/asiapcf/03/12/japan.nuclear/


2) According to this source, 1 SV exposure = "risk of cancer later in life"

http://www.ccohs.ca/oshanswers/phys_agents/ionizing.html

3) The last, & highest measure before the explosion was 1015 micro SV. It isn't completely clear where this was taken, either inside the containment facility or on its perimeter.

[Tx4obama]

3. A got a bridge here to sell to anyone that believes levels have dropped to a safe level. n/t

[denem]

14. An Alaskan Bridge maybe?

[joshcryer]

4. OK, I know it's bad to make this observation.

But 0 recs is bullshit, this is information that is important. It's not even editoralized by the OP. It's a simple info post.

[HuckleB]

33. This is why some at DU see others as hoping for disaster.

It's like any hopeful news must be hidden.

[thewiseguy]

7. Official: 160 may have been exposed to radiation from the plant (Reuters)

Reuters: Nine people already exposed to radiation from the nuclear power plant in Japan but total could reach up to 160, an official said

[Tx4obama]

36. Number of ppl that HAVE TESTED POSITIVE * is 160 * - see link below

From AJ Live Blog

Yesterday, we reported that three people had tested positive for elevated radiation levels. That number has now jumped to 160, says a Japanese nuclear safety official.

http://blogs.aljazeera.net/live/africa/japans-twin-disasters-march-13-liveblog

[Tom Rinaldo]

9. Good. I hope it continues to remain intact

The alternative is not one I would want anyone to face

[pinto]

10. Good to hear.

:thumbsup:

[kristopher]

11. That seems questionable

The explosion is said to be a result of hydrogen leaking from the reactor vessel in the containment structure and then into the building where it exploded. That does not seem possible unless containment has been breached to some extent.

When the explosion originally occurred Japanese public TV cut the film footage of the actual explosion, showing still before and after photos that played down the event. In other words, they are actively trying to manage public perception by falsifying the data.

[joshcryer]

15. You do realize that hydrogen will permate through 6 inch steel right?

Hydrogen is notoriously hard to contain (which is why tritium handling is so damn difficult).

[denem]

22. What about Iodine and Cesium isotopes?

... the those Take around the plant after the explosion? Maybe there was some fissile material lying around in the outer container just for fun?

[joshcryer]

27. I believe those were released when they intentionally went to vent steam.

Which is why they stopped venting the steam, and which is why the hydrogen buildup occurred. It was a lesser of two evils. Release steam that is more radioactive than thought, or let it build up and create a chain reaction. What's more worrisome is that the containment building is probably extraordinarily oxidized right now. I only hope it holds up.

[denem]

12. The plant operator ... has confirmed that ....

The IAEA nor the Japanese Government has nobody on site.

[leveymg]

13. Next time, we won't be so fortunate. It's like juggling nitroglycerine.

[Tom Rinaldo]

17. This could still become next time

There is more than one plant that continue to be in trouble.

[leveymg]

19. No doubt. We're all in trouble so long as they continue to operate these things

in the defiance of the odds and the gods.

[leveymg]

16. Self-delete. Technical glitch.

See, even DU isn't foolproof. :evilgrin: :nuke:

[denem]

18. Sarah Palin, spokesperson for Tokyo Electric Power Company (TEPCO), has confirmed that ...

Not convinced?

Then why take at 100% face value the statement form the Operator that is in (very big) trouble?

[kristopher]

30. That's the difference between those who support nuclear and those who don't

Trust in the nuclear industry.

I see no reason to trust them anymore than the coal industry. Less in fact because the security issues result in substantially less transparency.

[divvy]

23. Third generation PWRs .....

The "third generation" PWRs, as exemplified by the Westinghouse AP1400 and the Areva EPR, are "passively safe" in the sense that they can survive a design basis accident (a double-eneded shear of the reactor coolant piping, resulting in instant depressurization) without fuel failure or release of any fission products, WITHOUT any electrically- or mechanically-operated equipment or any operator intervention. In other words, a total loss of AC power and no operator action. It basically relies upon reserve cooling water, natural circulation, and some flywheel-driven pumps (in the first few seconds).

It's too early to know what's going on in Japan. My prayers are with them... Erryl and I know what the consequences of exceeding Critical Heat Flux (CHF) or Peak Central Temperature (PCT) of fuel elements are - potential release of fission products including xenon and other gases - a catastrophe that is the last thing Japan needs. Good luck to them.

[divvy]

25. BWR's (boiling water reactors) and radiation.

the unit that has the reactor building collapsed has probably had valves, pumps, wiring, switchgear, piping, etc so damaged by the roof and walls falling in on it that it is probably too late for a mobile generator to save the day. My training, and I heard one report that it was a Mark I containment like the one I trained on, was as a last resort you fill the primary containment with water... We had river water, they have sea water... and you drain the RX vessel. Draining the core gives it air/steam cooling but the core would lose its geometry and you would have massive cladding failure of the fuel... but that is the only remaining way to depressurize the RX vessel. What you don't want is a high pressure rupture of the RX vessel to destroy primary containment and spread the radioactive material. The fuel may melt through the vessel, but it most likely wouldn't through the primary containment. If the reports of flooding the containment with sea water is true, I think this is what they are doing or going to do. This would be worse than TMI, which melted fuel without any loss of vessel integrity... And they were able to reflood their core once they realized that it had been uncovered. Expect radiation levels to rise dramatically if the core is uncovered. The question I don't know the answer to is the status of the other Units... When will they be in cold shutdown? They need to get them to cold shutdown in case the control rooms becomes uninhabitable. I suspect that they have gotten emergency generators to them... If not, you are right... Hurry up! They need power, sooner the better. I suspect that they have gotten emergency generators there, though. Some reports say that they are pumping sea water into the RX vessel, not the containment. I don't know why they would be doing that. If they could pump sea water, they should have been able to pump clean water. Flooding the much larger containment would probably have required the larger supply (sea water). Some reports are that there are 2 units in desperate condition. Not good... Radiation control troops are on the way. That implies to me that there has been or there is an expected radiological release.

[divvy]

31. SCRAM'd

"Shutdown" is a misnomer. They SCRAM'd, inserting control rods and ceased electrical generation. They couldn't have reached cold shutdown in an hour... If radiation levels are really declining, then they are probably keeping the reactor cores covered. That is obviously a good thing, but I doubt they have enough equipment running to get the Units in cold shutdown, especially at the plant with a collapsed reactor building. BWR's have 2 containments - primary and secondary... it looked like a secondary containment going down (a building). There is still a concrete or steel primary containment around the reactor vessel... I think. They must have a different fuel storage system than the one I am used to. Like I said, the Japanese engineers are good... It is good that the plant is in a country so technologically advanced. I am sure they have experts worldwide on "speed dial." Reports say 4 were hurt when the reactor building collapsed. Other reports say that some of the plant workers "walked" into a Tsunami when they initially evacuated non-essential personnel. That may have also taken out the emergency generators. It would explain the loss of all 14 of them. These operators are facing great challenges without much rest. They are well trained and I am sure they are doing everything they can... I pray it is enough. Loss of offsite power and all emergency generators is a typical training scenario, but it isn't usually one that any nuclear professional would want to see. Fuel damage and evacuation is likely. Times 3, not good! I am not sure what is keeping the 2 reactors in better shape than the 3rd, but they are all in grave danger if they cannot restore AC power or site radiation levels rise greatly due to the 1 reactor in more desperate condition.

[divvy]

35. TMI

is that what the effected reactors are? There are new designs that are far safer than the US plants I am familiar with. I assumed it wasn't a BWR, what I am most familiar with, when the reactor building collapsed and radiation wasn't off the charts. The spent fuel pool is in the top of our reactor building. There are blowout panels to prevent an explosion from destroying the reactor building. I agree that it is too early to know how much damage will be done. The first goal is to prevent core damage... some damage, like TMI, is a financial disaster, but not a human catastrophe, like Chernobyl. The expanded evacuation zone and the reports of Cesium in the air means that some Coolant release is happening, probably intentional to control RX pressure. The hydrogen explosion that has destroyed one containment building could very well be from "melting" fuel cladding, but I can't say that for certain. No offsite power... No emergency generators... No containment... Expanding evacuation zone... I'm worried! I understand politicians saying things to avoid panic, but there is plenty to worry about. Because of the time that has elapsed since the units SCRAM'd, it looks like they have managed to keep the reactor cores cooled and pressure under control, but they lack the ability to take the reactor(s) to shutdown. Low pressure injection has probably been lost. They need electrical power! Bad! Not easy in an earthquake damaged country. One unconfirmed report that they were injecting sea water into the containment means that normal emergency systems have failed and the situation is pretty desperate. The other 2 plants? Fuel pools? The fuel pools are probably OK, because they could keep them full with a fire truck tanker... As long as radiation levels onsite stay reasonably low. I don't think any plants, but the most recent designs, would do well after control rooms become uninhabitable. The collapsed reactor building probably eliminated most, if not all, remaining capabilities of that stricken reactor. If it was a sub, you would get out and sink it. Not good... Pumping sea water in the containment is the equivalent. I hope that report is false. I don't mean to frighten anyone, but this is very serious and could get a lot worse. Obviously, the news may not have all the info one would need to have to now how serious this will become, but it is bad now!

[divvy]

37. TEPCO status update

I forgot... They may have the vessel full of water (BWR's are usually about 2/3rd full of water) and relief valves open to run the water into the primary containment. This might be necessary if the torus water has heated up over the last day and they can't cool it (can't w/o emergency power). The torus is the normal heat sink for pressure control. They have to fill the torus (a huge steel donut shaped tank below in vessel) before they can fill the metal containment around the RX vessel. Yes, they are probably injecting water into the RX to fill the torus which will fill and then flood the upside down light bulb shaped drywell containment.. To do this very quickly, they probably have power to the ordinary condensate system. They would have to have gotten power to the site. The emergency systems were probably damaged beyond quick repair when the roof fell in. In this scenario, you would not have to drain the RX vessel. Severe core damage averted... THAT is the problem! They can't cool the torus... that explains why the radiation levels have been fairly low. The core is still covered. If they don't flood the containment, the torus will overheat, over-pressurize, and you will eventually lose primary containment. Flooding the vessel and containment with sea water totals the plant, but probably avoids a serious radiological release. I think they can do it, if I am right about the circumstances in the plant. By the way, the other plants need containment cooling to, but they are different designs. The plant with the collapsed RX building is more urgent, because returning torus cooling to service any time soon was probably not possible.

TEPCO status updates here: http://www.tepco.co.jp/en/index-e.html

[divvy]

38. TEPCO release post

Press Release (Mar 13,2011)
Plant Status of Fukushima Daiichi Nuclear Power Station (as of 2am March 13th)


All 6 units of Fukushima Daiichi Nuclear Power Station have been shut down.

Unit 1(Shut down)
- Reactor has been shut down. However, the unit is under inspection due to
the explosive sound and white smoke that was confirmed after the big
quake occurred at 3:36PM.
- We have been injecting sea water and boric acid which absorbs neutron
into the reactor core.

Unit 2(Shut down)
- Reactor and Reactor Core Isolation Cooling System have been shut down.
Current reactor water level is lower than normal level, but the water
level is steady. After fully securing safety, we are preparing to
implement a measure to reduce the pressure of the reactor containment
vessels under the instruction of the national government.

Unit 3(Shut down)
- Reactor has been shut down and we continue injecting water by High
Pressure Core Injection System. After fully securing safety, we are
preparing to implement a measure to reduce the pressure of the reactor
containment vessels under the instruction of the national government.
- Currently, we do not believe there is any reactor coolant leakage
inside the reactor containment vessel.

Unit 4 (shut down due to regular inspection)
- Reactor has been shut down and sufficient level of reactor coolant to
ensure safety is maintained.
- Currently, we do not believe there is any reactor coolant leakage inside
the reactor containment vessel.

Unit 5 (outage due to regular inspection)
- Reactor has been shut down and sufficient level of reactor coolant to
ensure safety is maintained.
- Currently, we do not believe there is any reactor coolant leakage inside
the reactor containment vessel.

Unit 6 (outage due to regular inspection)
- Reactor has been shut down and sufficient level of reactor coolant to
ensure safety is maintained.
- Currently, we do not believe there is any reactor coolant leakage
inside the reactor containment vessel.

Casualty
- 2 workers of cooperative firm were injured at the occurrence of the
earthquake, and were transported to the hospital.
- 1 TEPCO employee who was not able to stand by his own with his hand
holding left chest was transported to the hospital by an ambulance.
- 1 subcontract worker at important earthquake-proof building was
unconscious and transported to the hospital by an ambulance.
- The radiation exposure of 1 TEPCO employee, who was working inside the
reactor building, exceeded 100mSv and was transported to the hospital.
- 4 workers were injured and transported to the hospital after explosive
sound and white smoke were confirmed around the Unit 1.
- Presence of 2 TEPCO employees at the site are not confirmed

Others
- We measured radioactive materials inside of the nuclear power station
area (outdoor) by monitoring car and confirmed that radioactive
materials level is higher than ordinary level. Also, the level at
monitoring post is higher than ordinary level. We will continue to
monitor in detail the possibility of radioactive material being
discharged from exhaust stack or discharge canal. The national
government has instructed evacuation for those local residents within
20km radius of the periphery because it's possible that radioactive
materials are discharged.

- We will continue to take all measures to restore the security of
the site and to monitor the environment of the site periphery.

[cali]

28. that was posted at 3:38. Here's another Reuter's story posted at 4:15

Japan Fukushima nuclear plant faces new reactor problem


03/11/2011

TOKYO, March 13 | Sat Mar 12, 2011 4:15pm EST

TOKYO, March 13 (Reuters) - A quake-hit Japanese nuclear plant reeling from an explosion at one of its reactors has also lost its emergency cooling system at another reactor, Japan's nuclear power safety agency said on Sunday.

The emergency cooling system is no longer functioning at the No.3 reactor at Tokyo Electric Power Co's Fukushima Daiichi nuclear power facility, requiring the facility to urgently secure a means to supply water to the reactor, an official of the Japan Nuclear and Industrial Safety Agency told a news conference.

On Saturday, an explosion blew off the roof and upper walls of the building housing the facility's No. 1 reactor, stirring alarm over a possible major radiation release, although the government later said the explosion had not affected the reactor's core vessel and that only a small amount of radiation had been released.
http://www.reuters.com/article/2011/03/12/japan-quake-nuclear-cooling-idUSLHE7EB02D20110312

The nuclear safety agency official said there was a possibility that at least nine individuals had been exposed to radiation, according to information gathered from municipal governments and other sources. (Reporting by Risa Maeda; Editing by Edmund Klamann)

[Paradoxical]

34. BBC says patients waiting for a helicopter were exposed.

Patients evacuating from a hospital near the plant were exposed to radiation following the explosion.

[OmmmSweetOmmm]

39. Kick and unrec