Fukushima Daiichi nuclear disaster

[Barking_Mad]

Japanese officials grappling on Sunday to end the world's worst nuclear crisis since Chernobyl were focussing on a crack in a concrete pit that was leaking radiation into the ocean from a crippled reactor.

Tokyo Electric Power Co (TEPCO) said it had found a crack in the pit at its No.2 reactor in Fukushima, generating readings 1,000 millisieverts of radiation per hour in the air inside the pit.

"With radiation levels rising in the seawater near the plant, we have been trying to confirm the reason why, and in that context, this could be one source," said Hidehiko Nishiyama, deputy head of the Nuclear and Industrial Safety Agency (NISA), said on Saturday.

He cautioned, however: "We can't really say for certain until we've studied the results." <

Leakage did not stop even after concrete was poured into the pit, and Tokyo Electric is now planning to use water-absorbent polymer to prevent contaminated water from leaking out into the sea.

Officials from the utility said checks of the other five reactors found no cracks.

Nishiyama said that to cool the damaged reactor, NISA was looking at alternatives to pumping in water, including an improvised air conditioning system, spraying the reactor fuel rods with vaporized water or using the plant's cleaning system.

PM UNDER PRESSURE

As the disaster that has left more than 27,000 dead or missing dragged into a fourth week, Prime Minister Naoto Kan toured devastated coastal towns in northern Japan on Saturday, offering refugees government support for rebuilding homes and livelihoods.

"It will be kind of a long battle, but the government will be working hard together with you until the end," Kyodo news agency quoted him as telling people in a shelter in Rikuzentakata, a fishing port flattened by the tsunami which struck on March 11 after a massive earthquake.

Unpopular and under pressure to quit or call a snap poll before the disaster, Kan has been criticised for his management of the humanitarian and nuclear crisis. Some tsunami survivors said he came to visit them too late.

Kan also entered the 20-km (12-mile) evacuation zone and visited J-village just inside the zone, a sports facility serving as the headquarters for emergency teams trying to cool the six-reactor Fukushima Daiichi plant.

Operators of the plant are no closer to regaining control of damaged reactors, as fuel rods remain overheated and high levels of radiation are flowing into the sea.

Japan is facing a damages bill which may top $300 billion (186 billion pounds) -- the world's biggest from a natural disaster.

The International Monetary Fund (IMF) said on Friday the Japanese economy would take a short-term hit and it could not rule out further intervention for the yen.

http://uk.reuters.com/article/2011/04/02/uk-japan-idUKTRE72A0UU20110402

 

[Open Sauce]

I've had nowhere near enough sleep so not much discussion from me today, but here is a story that adds another layer to the evacuation stupidity:

http://www3.nhk.or.jp/daily/english/04_10.html

What matters, and what may or may not come out, is whether how SPEEDI projections are input into their planning procedures for this kind of accident. This begs the question whether they have planning procedures for this plus tsunami plus earthquake. The pro nukes keep on telling us that it was a one in a lifetime earthquake combined with a one in a lifetime tsunami and the power plant had multiple unlikely failures - as though one did not cause the rest - so I wonder about such a plan existing at all.

 

[Open Sauce]

http://uk.reuters.com/article/2011/04/02/uk-japan-idUKTRE72A0UU20110402

Pictures of the water leaking into the well (too big to link to) and the failed attempt to stop the flow with concrete

http://cryptome.org/eyeball/daiichi-npp2/daiichi-photos2.htm

 

[Dr Jon]

...
As for the idea that I come across like nuclear PR, lol, unless the PR newsletter is named Clusterfukushima I dont think Im cu out for that job somehow.

3-Week Update on Japan’s Nuclear Crisis

I also see this comment Chris Martenson:

The general lack of staged materials anywhere in the vicinity indicates that authorities have not yet decided on a plan of action, feeding our assessment that they are still in 'react mode' and that we are weeks away from nominal stabilization.

 

[Barking_Mad]

http://www3.nhk.or.jp/daily/english/04_10.html

It has been learned that the Japanese government withheld the release of computer projections indicating high levels of radioactivity in areas more than 30 kilometers from the troubled Fukushima Daiichi nuclear power plant.

The estimates were made on March 16th following explosions at the plant by an institute commissioned by the government using a computer system called SPEEDI. The system made its projections on the assumption that radioactive substances had been released for 24 hours from midnight on March 14th, based on the available data.

But the government was reluctant to reveal the SPEEDI projections, and did not release them until March 23rd.
The released data showed that higher levels of radioactive substances would flow over areas to the northwest and southwest of the plant.

The estimates showed that the radiation would exceed 100 millisieverts in some areas more than 30 kilometers from the nuclear plant if people remained outdoors for 24 hours between March 12th and 24th.

That is 100 times higher than the 1 millisievert-per-year long-term reference level for humans as recommended by the International Commission on Radiological Protection.

The Nuclear Safety Commission says it did not release the projections because the location or the amount of radioactive leakage was not specified at the time.

Professor emeritus Shigenobu Nagataki of Nagasaki University, says the government should release more data about the dangers of possible radiation exposure and draw up evacuation plans and other measures together with residents.

Monday, April 04, 2011 12:38 +0900 (JST)

 

[Barking_Mad]

Another good video update from the dude from Fairewinds.

http://www.fairewinds.com/updates

 

[Dr Jon]

I'm just trying to do some sums to work out what level of contamination we might be looking at here.

I was thinking that to get a rough guess at this would be to work out what level of contamination just one fuel rod would produce when dispersed over the surface of the Earth.

From a quick Wiki, I see that a BWR has anywhere between 368 and 800 fuel bundles, each comprising 90 or so fuel rods.
I can't find any data on the fuel bundles used in these particular reactors, particularly what quantity of fuel they contain. A bundle of fuel for a CANDU reactor is about 20 kg, and Earth's surface area is 510072000 km², so one fuel bundle could give potentially

20000 / 510072000000 = 0.039 µg/m²

was saying that 1 µg of Plutonium, if ingested, is potentially lethal. So, if this were all evenly distributed, we'd need about 25 times the above amount for a potentially lethal dose per square metre of Earth.

So, how many fuel rods have been 'lost' into the environment?
If it's more than 25 we might possibly be looking at very serious problems.

Or maybe not, not here, in UK.

It will depend on a lot of things, like the mobility of the various radionuclides in the environment and the degree of dispersal. Then there is their behaviour in biological systems: how does the accumulation / bio-fractionation play out?

All sorts of unknowns.
Such questions remain unanswered 25 years after Chernobyl and I don't expect this to be any different.

 

[Open Sauce]

I'm just trying to do some sums to work out what level of contamination we might be looking at here.

I was thinking that to get a rough guess at this would be to work out what level of contamination just one fuel rod would produce when dispersed over the surface of the Earth.

From a quick Wiki, I see that a BWR has anywhere between 368 and 800 fuel bundles, each comprising 90 or so fuel rods.
I can't find any data on the fuel bundles used in these particular reactors, particularly what quantity of fuel they contain. A bundle of fuel for a CANDU reactor is about 20 kg, and Earth's surface area is 510072000 km², so one fuel bundle could give potentially

20000 / 510072000000 = 0.039 µg/m²

was saying that 1 µg of Plutonium, if ingested, is potentially lethal. So, if this were all evenly distributed, we'd need about 25 times the above amount for a potentially lethal dose per square metre of Earth.

So, how many fuel rods have been 'lost' into the environment?
If it's more than 25 we might possibly be looking at very serious problems.

Or maybe not, not here, in UK.

It will depend on a lot of things, like the mobility of the various radionuclides in the environment and the degree of dispersal. Then there is their behaviour in biological systems: how does the accumulation / bio-fractionation play out?

All sorts of unknowns.
Such questions remain unanswered 25 years after Chernobyl and I don't expect this to be any different.

Are you assuming a rod of 20kg 100% plutonium?

http://me1065.wikidot.com/fuel-assemblies-in-nuclear-reactors

 

[Dr Jon]

Are you assuming a rod of 20kg 100% plutonium?

http://me1065.wikidot.com/fuel-assemblies-in-nuclear-reactors

I was, yes. Have been chatting to a mate who knows about nukes and he says that 1mg of Pu has the same toxicity as 1kg of U235, so the state of reactor 3 with the MOX fuel is of most interest.

Thanks for the info will take a look tomorrow.

 

[Fuchs66]

I think the point was that it would be a false assumption. Along with the assumption that all of the material would somehow spread itself homogenously throughout the world. I'm not trying to play down the events but your thoughts and calculations are way OTT.

 

[Dr Jon]

I see that the weight quoted for one of those BWR fuel assemblies is 273kg, 10x the weight I had assumed. How much of that is the weight of fuel? I think that my guesstimate of 20kg Pu would be a considerable underestimate in that case.

I think the point was that it would be a false assumption. Along with the assumption that all of the material would somehow spread itself homogenously throughout the world. I'm not trying to play down the events but your thoughts and calculations are way OTT.

Yeah, I know it won't spread evenly around the world. What I am trying to do is to get a rough idea of what level of contamination we could be looking at. That's what I was said about unknowns re dispersal and bio-fractionation. I don't see any of this as being OTT at all. If anything, I thought my calcs and assumptions were very conservative.

Chernobyl involved 1 reactor and 150 tonnes of Uranium.
Here we have 4 reactors and nearly 1200 tonnes of Uranium, Plutonium and who knows what.

Work it out for yourself.

 

[Tankus]

Wait until the typhoon season hits ...you can forget controlled releases into the pacific

 

[stowpirate]

I wonder what type of concrete they tried to use in their panic to seal the leak?

Something like this?
http://www.darpor.co.uk/quickcrete.html

Does any body know if the details have been released?

 

[elbows]

I was, yes. Have been chatting to a mate who knows about nukes and he says that 1mg of Pu has the same toxicity as 1kg of U235, so the state of reactor 3 with the MOX fuel is of most interest.

Thanks for the info will take a look tomorrow.

Plutonium is created in the other reactors too, as part of the normal process. So singling out the MOX fuel is not as useful as might think.

My understanding is that plutonium is rather heavy, making it far from the biggest threat in terms of wide dispersal.

Nothing wrong with playing around with numbers but Im not sure that your calculations really tell us much.

 

[elbows]

Another good video update from the dude from Fairewinds.

http://www.fairewinds.com/updates

Pretty sure we already talked about the April 3rd criticality video earlier.

I find these videos very interesting but I dont take them as fact. I have some doubt about the previous video, about exposed fuel at unit 4 pool, and what the video actually shows. If I look at other video or photos of the same area, its not so clear to me that the green crane collapsed and that the little boxes he shows on the video are the fuel storage container grids. They might be, but the evidence I've seen so far is inconclusive.

 

[elbows]

I wonder what type of concrete they tried to use in their panic to seal the leak?

Something like this?
http://www.darpor.co.uk/quickcrete.html

Does any body know if the details have been released?

I havent seen more details, other than it failed. The news today continues to be dominated by attempts to fix these leaks, and further news of very high levels of contamination in the sea near the plant. They are looking at further measures to try to halt the leak, including adding something to gravel pit(s) to firm them up. Also looking at whether the do stuff in the sea itself, in the form of underwater silt barriers. Other efforts include moving water around on the site to free up space for the real nasty water, and also discharging some water that is a bit radioactive into the sea deliberately.

http://www3.nhk.or.jp/daily/english/05_18.html

http://www3.nhk.or.jp/daily/english/05_16.html

Other news is regarding the contaminated locations to the north-west of the plant continues to dribble in, and I still consider it a total disgrace that these locations have not been evacuated.

http://www3.nhk.or.jp/daily/english/05_23.html

 

[elbows]

Jut catching up with data from the reactors. Unit 1 has come down in temp & radioactivity compared to several days ago, but one of the reactor pressure readings is now the highest I've ever seen it. Of the spent fuel pools where data is available, the temp at unit 2 pool keep going back up to the 70's degrees C, sometimes falling as low as 48C. Temp data which was available for unit 4 pool a while ago has been unavailable for many days now. Temp at common fuel pool seems low and well under control.

 

[laptop]

was saying that 1 µg of Plutonium, if ingested, is potentially lethal. So, if this were all evenly distributed, we'd need about 25 times the above amount for a potentially lethal dose per square metre of Earth.

That runs straight into the controversy over plutonium's radiation hazards.

Safety standards assume it's evenly distributed through the biosphere - including even distribution throughout your body: 1 µg distributed through 50-80 kg probably isn't that much to worry about.

Critics say: "No, look, it's in the environment as insoluble oxide. One 1 µg particle lodged in my lung sits there, irradiating 20 or so neighbouring cells - and is likely to turn one or more of them cancerous."

To deliver one 1 µg particle to every inhabitant of the planet would take rather extreme bad luck, if you see what I mean...

 

[ATOMIC SUPLEX]

I ate the spinich today.

 

[Dr Jon]

...
To deliver one 1 µg particle to every inhabitant of the planet would take rather extreme bad luck, if you see what I mean...

Yes. I would guess that the sea would also 'soak up' a lot of this too. I was just trying to get a feel for how much of a problem this could be.

I wonder if TEPCO will ever know how much nuclear material has escaped and would they tell the truth if they did?

 

[gentlegreen]

Plutonium being rather dense, presumably it would end up concentrated in calm waters very near where it escapes ?

 

[laptop]

Plutonium being rather dense, presumably it would end up concentrated in calm waters very near where it escapes ?

Up to a point. If it oxidises at a high temperature*, it's likely to form very fine particles that will disperse...

* Burns

 

[Dr Jon]

Up to a point. If it oxidises at a high temperature*, it's likely to form very fine particles that will disperse...

* Burns

I believe the Pu in MOX fuel is already in oxide form.

 

[laptop]

I believe the Pu in MOX fuel is already in oxide form.

Good point. Hope that means there's less reason for it to form a fine aerosol...

 

[elbows]

Thanks for the thoughts on substances, please keep it up as Im not so hot with that side of things so I am reliant on others to share knowledge on this stuff.

 

[elbows]

The sheet idea always sounded a bit shit, but now that timescales are being discussed it seems even worse:

http://english.kyodonews.jp/news/2011/04/83374.html

A plan to cover damaged reactor buildings at the crisis-hit Fukushima nuclear plant with special sheets to halt radiation leakage cannot offer a quick remedy, as the sheeting will be installed in September at the earliest due to high-level radioactivity hampering work at the site, government sources said Tuesday.

The government had asked Tokyo Electric Power Co., operator of the Fukushima Daiichi power station crippled by the March 11 quake and tsunami, to study the installment of radiation-shielding sheets, and a major construction firm commissioned to examine the idea said the construction will not start until June, the sources told Kyodo News.

Oh my!

But perhaps there are sensible reasons why this is being considered as a medium-long term plan for the site, as opposed to the old 'cover it in concrete' idea that people are very tempted to shout for.

At the gathering, a specialist from the U.S. Nuclear Regulatory Commission said the structure of the special sheets should guarantee that spent nuclear fuel pools in the reactor buildings will not be damaged even if the sheeting is toppled by quakes or typhoons, according to the sources.

Specialists in the government are planning to stem possible surges in radiation levels or further explosions in the reactor buildings to be wrapped by the sheets, by attaching materials that absorb radioactive materials to the inner side of the sheeting and installing air vents with filters to let out hydrogen, they said.

OK so on the face of it this bit of the story just sounds like the usual attempts to stick to fancier plans that involve keeping greater control of the plant for a long time, at the expense of stuff getting into the environment today, tomorrow, the day after etc. If they are only doing this because of some denial or need to look like they are salvaging the situation, then I condemn it utterly. But perhaps there are real practical considerations at work here. Further generation of heat, hydrogen, or further earthquakes in the area, all sound a bit like reasons why just covering it in concrete etc may not be a great idea, but without being highly knowledgable in such fields I cannot really judge.

 

[elbows]

Not surprising to hear that fish with too much radioactive cesium in them have now been detected, still sad to hear it though, and its another sign of the problems that may last a very long time. Or not, for I dont think the world of science has had much opportunity to study radioactive releases in seas and oceans for a long time, and the older studies are probably largely based on nuclear bomb tests back in the day.

http://www3.nhk.or.jp/daily/english/05_34.html

High level of cesium detected in sand lances
Small fish caught in waters off the coast of Ibaraki have been found to contain radioactive cesium above the legal limit.

Ibaraki is south of Fukushima prefecture, where the crippled Fukushima Daiichi nuclear power plant is located.

Ibaraki Prefecture says 526 becquerels of radioactive cesium was detected in one kilogram of sand lances. The acceptable limit is 500 becquerels. It is the first time that higher-than-permitted levels of radioactive cesium have been found in fish.

All local fishery cooperatives in the prefecture have agreed to suspend sand lance fishing at the request of the prefectural government.
Tuesday, April 05, 2011 18:58 +0900 (JST)

Also, in regards to the radioactive water that they have started deliberately putting into the sea to free up storage space on site, they havent handled it very well on the international diplomacy front

http://www3.nhk.or.jp/daily/english/05_43.html

Japan's Nuclear and Industrial Safety Agency has apologized to neighboring countries for causing concern over the release of contaminated water into the sea from the crippled Fukushima Daiichi nuclear power plant.

A senior official of the agency, Hidehiko Nishiyama, told a news conference on Tuesday that Japan failed to contact South Korea before taking the measure.

South Korea's foreign ministry expressed concern on Monday that Japan hadn't notified the country of the release in advance.

 

[elbows]

Ah here we go, a significant step in reporting what has probably been obvious for weeks now, but isnt often said too clearly. We started to actually hear about this stuff, rather than just presume, when the stories about the different pools of radioactive water came out over the last week or so, but I think this story goes a step beyond that:

http://www3.nhk.or.jp/daily/english/05_38.html

A radiation monitor at the troubled Fukushima Daiichi nuclear power plant says workers there are exposed to immeasurable levels of radiation.

The monitor told NHK that no one can enter the plant's No. 1 through 3 reactor buildings because radiation levels are so high that monitoring devices have been rendered useless. He said even levels outside the buildings exceed 100 millisieverts in some places.

Pools and streams of water contaminated by high-level radiation are being found throughout the facility.

The monitor expressed frustration, likening the situation to looking up a mountain that one has to climb, without having taken a step up.

 

[elbows]

A Guardian article that has a reasonable stab at describing some of the specific problems with the reporting of this crisis, including the various attempts to explain what figures mean that we have seen.

http://www.guardian.co.uk/commentisfree/2011/apr/04/open-door-explaining-fukushima-crisis

Another problem area for the use of the word "equivalent" is in saying such-and-such a dose of radiation in an hour is "equivalent" to, for instance, twice the natural background radiation in a year. It is accurate to talk about equivalent amounts of radiation, but journalists are on dangerous ground if we make out they have equivalent health risks. The Guardian's science correspondent puts the point this way: "You can think of it like exposure to the sun's rays. I could move somewhere and get twice as much sunshine in a year, but if I received all that sun in one hour, I would be toast. Because one hour in very intense sunlight will do me more harm than the same amount of sunlight evened out over the year."

 

[nick h.]

Do the high levels in reactors 1,2 and 3 mean that vital work can't take place, thereby prolonging the leaks? Or do they have robots to do the jobs the humans can't?