Meltdown Likely Under Way At Japan Nuclear Reactor

[atsiii]

Mitsuhiko Tanaka, a Fukushima nuclear plant designer turned anti-nuclear activist, said utility officials aren't fully equipped to orchestrate the response to the crisis. He says they aren't familiar enough with reactor designs, any more than pilots or stewardesses know the design of a jet engine. He urges more involvement of designers and other experts.

"When a jet begins to crash, you don't ask the pilots for answers to what's gone wrong," he said in an interview.

http://www.boston.co...gain_and_again/

Flying... an interesting analogy. As a pilot I can say that commercial pilots are trained in emergency procedures--probably much like nuc plant operators--and also CRM (Cockpit Resource Management). As an example of CRM, I'll relay what I can remember about the flight of United #232 from Denver to Chicago in about 1989. First, the DC-10 is flown with hydraulics and hydraulics only. As a result, there are three fully redundant hydraulics systems in the a/c. Upon departure from DEN, however, the tail engine ripped off and somehow managed to take all three hydraulics systems with it! Statistically impossible. With no control of the flight surfaces, the pilot quickly discovered that the only control he had was the throttles of the remaining two engines under the wings. If he increased both throttles, the a/c would climb; decreasing both throttles would result in a descent; and differential throttles would lift one wing relative to the other and initiate a turn. That was all he had.

Amazingly, there was a McDonnell Douglas DC-10 design engineer onboard the flight as a pax. The engineer informed the flight crew of his expertise and asked if the Captain wanted him to come forward to help. In the middle of the emergency--trying desperately to keep a severely damaged DC-10 flying with only throttles--the Captain's response was to say, "sure, we can use all the help up here we can get." This is a quintessential example of CRM... in the middle of dealing with an emergency, the Captain welcomed the offer of additional expertise. After years of training, it was the, "Houston, we've got a problem" type response. Openness and honesty, "sure, we can use all the help we can get right now." Now... compare this response to what we have seen from TEPCO and the Japanese Government.

At any rate, to finish the story... upon reaching the cockpit and being briefed on their status, the engineer stated (as engineers often do), "that's impossible! There are three fully redundant hydraulics systems onboard." In time, he learned an important engineering lesson: impossible things do happen! The pilot managed to fly the a/c to Sioux City or Sioux Falls (I can't remember), where he crash landed at the airport saving many of the passengers--and the engineer.

I'm on my way back to Bangkok now... so I will check in tomorrow to see--I hope and pray--better news about Fukushima. Until then, my message to TEPCO and the Japanese Government is: 1) impossible things can and do happen; and 2) when faced with an emergency, be open to using any and every possible resource you may have at your disposal.

bye.

[Organicpete]

Good analogy Atsiii.

It was Sioux City.

Pete

[Chopperboy]

Mitsuhiko Tanaka, a Fukushima nuclear plant designer

"When a jet begins to crash, you don't ask the pilots for answers to what's gone wrong," he said in an interview.

http://www.boston.co...gain_and_again/

This is a quintessential example of CRM... in the middle of dealing with an emergency, the Captain welcomed the offer of additional expertise. After years of training, it was the, "Houston, we've got a problem" type response. Openness and honesty, "sure, we can use all the help we can get right now." Now... compare this response to what we have seen from TEPCO and the Japanese Government.

I agree, well written!

In my opinion (and that of a few others here) the experts they need to call in right now are the concrete engineers!

Edited March 29, 2011 by Chopperboy

[Chopperboy]

CHINA DAILY March 29

Greenpeace said its experts had confirmed radiation levels of up to 10 microsieverts per hour in a village 40 km northwest of the plant. It called for the extension of a 20-km evacuation zone.

"It is clearly not safe for people to remain in Iitate, especially children and pregnant women, when it could mean receiving the maximum allowed annual dose of radiation in only a few days," Greenpeace said in a statement, referring to the village where the radiation reading was taken.

http://www.cdeclips.com/en/world/fullstory.html?id=63250

[metisdead]

Reminder:

Thai Visa is an English language forum, English is the only acceptable language, except within the Thai language forum, where of course using Thai is allowed.

Post links to English language sites, thanks.

[canuckamuck]

I assume Greenpeace will be causing a lot of confusion and scaring people that already have too much to deal with.

10 microsieverts is nothing especially without a per time exposed attached to it.

[Chopperboy]

Tokyo Electric Power Co., said that it had detected an increase in levels of plutonium in soil samples taken from within the compound a week ago. The highest levels in the soil, of plutonium 238, were found about 500 yards from the most heavily damaged reactors, the company said. It said lower levels of plutonium 239 and 240 had also been found, at amounts not significantly higher than normal.

All the reported readings are within the safe range of plutonium levels in sediment and soil given by the U.S. Agency for Toxic Substances and Disease Registry. But Tokyo Electric said the highest reading was more than three times the level found in Japan compared to the average over the past 20 years. U.S. nuclear experts expressed confusion Monday about the company’s latest report that one form of plutonium was found at elevated levels at the Fukushima plant while other forms were not, and suggested it could be a measurement error.

http://telegram.com/article/20110329/NEWS/103290384/1052/rss01&source=rss

[StreetCowboy]

Tokyo Electric Power Co., said that it had detected an increase in levels of plutonium in soil samples taken from within the compound a week ago. The highest levels in the soil, of plutonium 238, were found about 500 yards from the most heavily damaged reactors, the company said. It said lower levels of plutonium 239 and 240 had also been found, at amounts not significantly higher than normal.

All the reported readings are within the safe range of plutonium levels in sediment and soil given by the U.S. Agency for Toxic Substances and Disease Registry. But Tokyo Electric said the highest reading was more than three times the level found in Japan compared to the average over the past 20 years. U.S. nuclear experts expressed confusion Monday about the company’s latest report that one form of plutonium was found at elevated levels at the Fukushima plant while other forms were not, and suggested it could be a measurement error.

http://telegram.com/...ss01&source=rss

Was that plutonium that the US nuclear experts had left in Japan some time previously?

SC

[JetsetBkk]

I assume Greenpeace will be causing a lot of confusion and scaring people that already have too much to deal with.

10 microsieverts is nothing especially without a per time exposed attached to it.

It was reportedly "up to 10 microsieverts per hour".

Is that the same as having an Internet connection of "up to 10 mbps"?

[Organicpete]

http://www.guardian.co.uk/world/2011/mar/29/japan-lost-race-save-nuclear-reactor

'The radioactive core in a reactor at the crippled Fukushima nuclear power plant appears to have melted through the bottom of its containment vessel and on to a concrete floor, experts say, raising fears of a major release of radiation at the site................'

great...

Pete

[canuckamuck]

Fukishima!!

[midas]

http://www.guardian.co.uk/world/2011/mar/29/japan-lost-race-save-nuclear-reactor

'The radioactive core in a reactor at the crippled Fukushima nuclear power plant appears to have melted through the bottom of its containment vessel and on to a concrete floor, experts say, raising fears of a major release of radiation at the site................'

great...

Pete

SO who do you believe ?

" Richard Lahey, who was head of safety research for boiling-water reactors at General Electric when the company installed the units at Fukushima, told the Guardian workers at the site appeared to have "lost the race" to save the reactor, but said there was no danger of a Chernobyl-style catastrophe."

or

" Dr. Helen Caldicott called the situation in Japan an “absolute disaster” that could be many, many times worse than Chernobyl. Dr Helen Caldicott raised the possibility of cataclysmic loss of life and suggested the emergency could be far more severe than Chernobyl."

Edited March 30, 2011 by midas

[Lite Beer]

FLASH: Japan govt: seawater near Fukushima plant 3,000 times more radioactive than legal limit - Kyodo/RT@Reuters

[midas]

FLASH: Japan govt: seawater near Fukushima plant 3,000 times more radioactive than legal limit - Kyodo/RT@Reuters

after reading this I have answered my own question ........i am kind of leaning towards Caldicott

[Crushdepth]

From that Guardian article:

"What is fundamentally disturbing the public is reports of drinking water one day being above some limit, and then a day or two later it's suddenly safe to drink. People don't know if the first instance was alarmist or whether the second one was untrue," said Gale.

People can't live like that. The authorities need to stop talking bullshit and start telling people what's really going on.

[JulianLS]

http://www.guardian....nuclear-reactor

'The radioactive core in a reactor at the crippled Fukushima nuclear power plant appears to have melted through the bottom of its containment vessel and on to a concrete floor, experts say, raising fears of a major release of radiation at the site................'

great...

Pete

SO who do you believe ?

" Richard Lahey, who was head of safety research for boiling-water reactors at General Electric when the company installed the units at Fukushima, told the Guardian workers at the site appeared to have "lost the race" to save the reactor, but said there was no danger of a Chernobyl-style catastrophe."

or

" Dr. Helen Caldicott called the situation in Japan an "absolute disaster" that could be many, many times worse than Chernobyl. Dr Helen Caldicott raised the possibility of cataclysmic loss of life and suggested the emergency could be far more severe than Chernobyl."

These two experts are not totally at odds, there is in fact only a small difference.

The Lahey analysis seems the most realistic description of the situation. The Chernobyl reactor was running at 10 times the full power output rating when it exploded, whereas the Fukushima plants are all "shut down" (meaning control rods are in place) and only producing a small percentage of full power rating. It's also worth noting that the Chernobyl reactor was much bigger, about the size of all four troubled Daichi plants added together. Further, the burning graphite moderator at Chernobyl contributed a huge amount to the pollution problem, something which is not possible at Fukushima as their reactors are water moderated not graphite moderated. So a Chernobyl-type explosion seems very unlikely. But technically it is not impossible. Lahey has written off the mega-explosion scenario ("no danger"), based on a very low probability.

Whereas Caldicott has decided to sensationalise this low probability using the words "the possibility of cataclysmic loss of life". Her words were chosen carefully: she didn't say it was probable, or likely, but "a possibility". Whilst this may be more accurate (there is a finite possibility), the way it is stated I think makes the risk sound much higher than it really is.

Either way it is going to leave one hell of a mess to deal with. The highly radioactive water in the trench outside unit #2 clearly indicates both partial meltdown of the fuel and a breach in containment (no doubt caused by the explosion in the suppression pool that happened a while back) - you don't need an expert to work that out! The challenge at the moment is having to put more water in to keep the remaining fuel cool, vs causing the trench to overflow. They clearly haven't got a facility on hand to store thousands of tons of highly radioactive water. And if they put more water in, then eventually it is going to escape somewhere. Putting concrete at the other end of the trench can only be a temporary stopgap, sooner or later the water will find another way out and head towards the sea......

As I see it, the only option is to pump the radioactive water in the trench back into the reactor. That is, recirculate it for cooling until they have time to figure out how to store it safely. At least then, the level would not go up. But how to pump it out of the trench and back into the reactor is another challenge, given its radiation levels...

Edited March 30, 2011 by JulianLS

[atsiii]

http://news.xinhuanet.com/english2010/video/2011-03/30/c_13804909.htm

BEIJING, March 30 (Xinhuanet) -- As Japan struggles to recover from the devastating earthquake and tsunami, another strong tremor, at a magnitude of 6.4, struck off the coast of Fukushima late Tuesday. Luckily, no damage was reported from the beleaguered area.

I'm back in BKK... finally: good internet.

6.4 and thankfully no additional damage! Pretty lucky. I reiterate a rhetorical question I previously posed: what happens if--with everything currently going on/wrong--Fukushima was hit with yet another unexpected disaster? Another strong quake? Another small to mid-sized tsunami? A huge fire? Would that push us over the tipping point and result in a truly catastropic event? What are the odds? Impossible?

Edited March 30, 2011 by atsiii

[atsiii]

http://online.wsj.com/article/SB10001424052748704471904576229854179642220.html

TOKYO—Workers at Japan's Fukushima Daiichi nuclear complex positioned sandbags and concrete barriers around drains leading from the plant Tuesday, setting a last line of defense against highly radioactive water that has flooded reactor buildings and threatens to spill into the ocean.

At the same time, Japanese officials said Tuesday they would keep dousing the plant's stricken reactors with water—a course of action that could raise those water levels further. At the heart of the day's moves lies a calculated choice between bad and worse: To meet their goal of keeping reactors cool enough to forestall catastrophe, officials appear willing to risk letting some highly radioactive water spill out of vents that are positioned some 50 to 70 yards from the sea.

Underscoring the ongoing risks of contamination to the Pacific Ocean water near the plant, officials announced Wednesday morning that radiation in seawater spiked again in a sample taken Tuesday to the highest level yet, hitting 3,355 times the legal limit.

[JetsetBkk]

<snip>

" Dr. Helen Caldicott called the situation in Japan an “absolute disaster” that could be many, many times worse than Chernobyl. Dr Helen Caldicott raised the possibility of cataclysmic loss of life and suggested the emergency could be far more severe than Chernobyl."

Dr. Who?

Praying for meltdown: The media and the nukes

Science and the public lose out with TV's Hollywood disaster film obsession

Comment Sensationalism has always been part of the popular media - but Fukushima is a telling and troubling sign of how much the media has changed in fifty years: from an era of scientific optimism to one where it inhabits a world of fantasy - creating a real-time Hollywood disaster movie with a moralising, chivvying message.

Not so long ago, the professionals showed all the deferential, forelock-tugging paternalism of the dept of "Keep Calm And Carry On". That era lasted into the 1960s. Now the driving force is the notion that "We're all DOOMED – and it's ALL OUR FAULT" that marks almost every news bulletin. Health and environment correspondents will rarely be found debunking the claims they receive in press releases from lobby groups – the drama of catastrophe is too alluring. Fukushima has been the big one.

The Fukushima situation has yet to cause any measurable radiological health effects, and workers at the site were far less hard hit by the quake, tsunami and related events than just about anyone in the disaster zone, but nonetheless the nuclear story rapidly eclipsed the tens of thousands killed directly by the quake. TV's reaction to the crisis shows how at odds it is with a more rational audience, those who know something about radiation, its consequences, and the human body's capacity to absorb it and recover from it. The crisis for the media is that thanks to the internet, we can now all bypass these conduits for superstition and stupidity.

http://www.theregister.co.uk/2011/03/29/tv_news_goes_hollywood/

Edited March 30, 2011 by JetsetBkk

[JulianLS]

I reiterate a rhetorical question I previously posed: what happens if--with everything currently going on/wrong--Fukushima was hit with yet another unexpected disaster? Another strong quake? Another small to mid-sized tsunami? A huge fire? Would that push us over the tipping point and result in a truly catastropic event? What are the odds? Impossible?

Well, obviously it could cause things to get worse. All of the progress they have made with backup pumps and re-wiring the electricity might be trashed by another tsunami. And it is possible that a big earthquake could knock out what few systems are currently working - in particular, the emergency systems for injecting water into the reactor cores would be the biggest worry. If those went out, and the cores became exposed again, then further explosions due to either hydrogen, and/or steam pressure, would become a distinct possibility (as we saw soon after the original quake). But still it is likely to be less catastrophic than Chernobyl proportions, where the (very much bigger) reactor was running at full blast (well, actually 10 times full blast just before it blew), with next to no control rods, and where the resultant graphite fire continued for some time afterwards. A huge fire would seem less likely, they shouldn't be too many combustible materials around. Apart from the fuel rods themselves that is..... and any hydrogen they might produce on contact with water. At least there is no graphite to worry about....

And of course another tsunami would wash all that highly radioactive water into the sea.... that would be pretty bad...

Let's hope it doesn't happen, eh?

[atsiii]

The Japanese government is considering new measures to stem radiation fallout from the troubled reactors at the Fukushima Daiichi nuclear plant, including covering them with cloth, Kyodo news reported on Wednesday. Top government spokesman Yukio Edano said the authorities are looking into "every possibility" to rein in the crisis at the plant, which was damaged by a powerful earthquake and tsunami on March 11. The special cloth would reduce the amount of radioactive particles being released into the atmosphere.

Another measure under consideration is to collect contaminated seawater near the plant in a tanker. The water is reported to contain radioactive iodine at 3,355 times the legal limit. Prime Minister Naoto Kan said the government is on maximum alert as efforts continue to try to prevent major nuclear fallout.

http://en.rian.ru/world/20110330/163280916.html

[atsiii]

...in particular, the emergency systems for injecting water into the reactor cores would be the biggest worry. If those went out, and the cores became exposed again, then further explosions due to either hydrogen, and/or steam pressure, would become a distinct possibility (as we saw soon after the original quake). But still it is likely to be less catastrophic than Chernobyl proportions, where the (very much bigger) reactor was running at full blast (well, actually 10 times full blast just before it blew), with next to no control rods, and where the resultant graphite fire continued for some time afterwards. A huge fire would seem less likely, they shouldn't be too many combustible materials around. Apart from the fuel rods themselves that is..... and any hydrogen they might produce on contact with water. At least there is no graphite to worry about....

And of course another tsunami would wash all that highly radioactive water into the sea.... that would be pretty bad...

Let's hope it doesn't happen, eh?

Thanks, Julian. I guess my biggest concern, aside from the reactor cores, is the #4 cooling pool. This pool contains not only spent fuel rods, but also all 548 current fuel rods from #4's core--that were loaded into the pool last November or December for core maintenance. If anything happened to suspend the cooling of this pool (and it is not yet clear if the integrity of the pool has been compromised and whether or not it's leaking), then there is more than enough "hot fuel" here to boil off its water within days and subsequently ignite. Needless to say--this pool like all cooling pools--has no containment structure around it and is open to the atmosphere.

While I use the prospect of another major event as the basis of my question, my concern is that it may not take another large scale event to inhibit the ability to cool this pool (and the others!). If, for example, significant contamination were released from one of the nearby breached reactor cores, emergency crews could not get close enough to the pool to cool it--even though they may be able to keep water circulating to the cores.

What thinks ye?

Edited March 30, 2011 by atsiii

[Chopperboy]

Wednesday and the president of the plant's utility company was hospitalized, as setbacks accumulated in Japan's nuclear crisis.

Masataka Shimizu, president of Tokyo Electric Power Co., has not been seen for nearly two weeks after appearing at a Tokyo news conference two days after the March 11 earthquake and tsunami that hobbled the Fukushima Dai-ichi plant's cooling systems and set off radiation leaks.

Shimizu, 66, was taken Tuesday to a Tokyo hospital after suffering dizziness and high blood pressure, TEPCO spokesman Naoki Tsunoda said.

There had been much speculation about Shimizu's health since he disappeared from public view, with company Vice President Sakae Muto appearing instead at news briefings. TEPCO officials had been deflecting questions about Shimizu's health, saying he had been "resting" at company headquarters.

[elcent]

it's pretty much just the beginning of a new more dangerous stable phase (that's what they always saying, "stable") simply due to the location near the sea and so many other factors.

As things are unfolding, Tepco chief Masataka Shimizu has been sent to hospital due to stress and heart issues.

[elcent]

Edano: Cover may be used to stop radiation

Japan's top government spokesman says the government and experts are considering whether to cover the reactor buildings at the Fukushima Daiichi nuclear plant with a special material, to stop the spread of radioactive substances.

Chief Cabinet Secretary Yukio Edano told reporters on Wednesday the experts are also examining the use of a tanker to collect irradiated water at the plant.

Edano said a variety of options are being studied to minimize radioactive contamination in areas around the plant, and to prevent health hazards.

He said working-level discussions are underway on the new measures and a political decision will probably be sought at some stage.

He said the whole situation is not at a point where he can responsibly say when the reactors will be brought under control. He said it will likely take a considerable amount of time before the fuel rods in the reactors and spent fuel pools cool down and stabilize.

Edano said monitoring for plutonium contamination may be extended to areas outside the plant compound since trace amounts of the element were found in soil on the plant grounds.

Edano said consumption and shipping restrictions on farm products will be lifted once their safety is consistently confirmed.

Wednesday, March 30, 2011 12:56 +0900 (JST) http://www3.nhk.or.j...lish/30_18.html

COVER: > That may give some air to breath, but at the end it will be just dealying, apart from being very expensive.

What about the ground water/sea water then?

The cores maybe melting through and the mass will be slipping down and down ...

Edited March 30, 2011 by elcent

[midas]

<snip>

" Dr. Helen Caldicott called the situation in Japan an “absolute disaster” that could be many, many times worse than Chernobyl. Dr Helen Caldicott raised the possibility of cataclysmic loss of life and suggested the emergency could be far more severe than Chernobyl."

Dr. Who?

Praying for meltdown: The media and the nukes

Science and the public lose out with TV's Hollywood disaster film obsession

Comment Sensationalism has always been part of the popular media - but Fukushima is a telling and troubling sign of how much the media has changed in fifty years: from an era of scientific optimism to one where it inhabits a world of fantasy - creating a real-time Hollywood disaster movie with a moralising, chivvying message.

Not so long ago, the professionals showed all the deferential, forelock-tugging paternalism of the dept of "Keep Calm And Carry On". That era lasted into the 1960s. Now the driving force is the notion that "We're all DOOMED – and it's ALL OUR FAULT" that marks almost every news bulletin. Health and environment correspondents will rarely be found debunking the claims they receive in press releases from lobby groups – the drama of catastrophe is too alluring. Fukushima has been the big one.

The Fukushima situation has yet to cause any measurable radiological health effects, and workers at the site were far less hard hit by the quake, tsunami and related events than just about anyone in the disaster zone, but nonetheless the nuclear story rapidly eclipsed the tens of thousands killed directly by the quake. TV's reaction to the crisis shows how at odds it is with a more rational audience, those who know something about radiation, its consequences, and the human body's capacity to absorb it and recover from it. The crisis for the media is that thanks to the internet, we can now all bypass these conduits for superstition and stupidity.

http://www.theregister.co.uk/2011/03/29/tv_news_goes_hollywood/

Perhaps its not that surprising you don't know who Helen Caldicott is

if you consider that any work by the author of this article is even worth mentioning ....

And what are Andrew Orlowski's credentials to be able to tell his readers that " The Fukushima situation has yet to cause any measurable radiological health effects "

Andrew Orlowski, Sloppy Journalist or Bold Faced Liar?

http://thomashawk.com/2005/07/andrew-orlowski-sloppy-journalist-or.html

Edited March 30, 2011 by midas

[Chopperboy]

Japanese Operator Says It Will Scrap Four Reactors at Plant - New York Times

[StreetCowboy]

Edano: Cover may be used to stop radiation

Japan's top government spokesman says the government and experts are considering whether to cover the reactor buildings at the Fukushima Daiichi nuclear plant with a special material, to stop the spread of radioactive substances.

Chief Cabinet Secretary Yukio Edano told reporters on Wednesday the experts are also examining the use of a tanker to collect irradiated water at the plant.

Edano said a variety of options are being studied to minimize radioactive contamination in areas around the plant, and to prevent health hazards.

He said working-level discussions are underway on the new measures and a political decision will probably be sought at some stage.

He said the whole situation is not at a point where he can responsibly say when the reactors will be brought under control. He said it will likely take a considerable amount of time before the fuel rods in the reactors and spent fuel pools cool down and stabilize.

Edano said monitoring for plutonium contamination may be extended to areas outside the plant compound since trace amounts of the element were found in soil on the plant grounds.

Edano said consumption and shipping restrictions on farm products will be lifted once their safety is consistently confirmed.

Wednesday, March 30, 2011 12:56 +0900 (JST) http://www3.nhk.or.j...lish/30_18.html

COVER: > That may give some air to breath, but at the end it will be just dealying, apart from being very expensive.

What about the ground water/sea water then?

The cores maybe melting through and the mass will be slipping down and down ...

Perhaps people should have to take a driving test before they are allowed to use a computer; the worry is that people might take posts such as the above seriously.

When I was a child, I worried about nuclear war and oil running out. Who would have thought that a more likely cause of the end of civilisation was the internet, and the uncontrolled spread of stupidity and ignorance?

Perhaps we should restrict the internet to harmless content such as pornography, and perhaps football scores...

SC

[Chopperboy]

Richard Lahey, who was head of safety research for boiling-water reactors at General Electric when the company installed the units at Fukushima, told the Guardian that he believed nuclear fuel had melted and burned through the reactor floor in unit number two.

That would expose the core to the atmosphere, risking more serious radiation leaks.

He told the Guardian: 'The indications we have, from the reactor to radiation readings and the materials they are seeing, suggest that the core has melted through the bottom of the pressure vessel in unit two, and at least some of it is down on the floor of the dry well.

'I hope I am wrong, but that is certainly what the evidence is pointing towards.'

The major worry is that the lava-like radioactive core will react with the concrete floor in Unit Two, sending radioactive gasses into the atmosphere.

Fortunately, though, the plant is flooded with seawater which will cool the material quicker than normal, reducing the amount of gas released.

http://www.dailymail.co.uk/news/article-1371375/Japan-nuclear-suicide-squads-paid-huge-amounts-claims-battle-lost.html?ITO=1490

[Chopperboy]

Workers at the stricken Fukushima nuclear plant are being paid vast sums of money to brave high radiation levels - as experts warn that the race to save the facility has been lost.

Subcontractors are reportedly being offered up to 100,000 yen a day (£760) - twenty times the going rate - but some are still refusing the dangerous work.

Radiation levels are still extremely high at the plant, with water around the reactors emitting a highly dangerous 1,000 milisieverts per hour.