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Very high radiation, little water in Fukushima No. 2 reactor

96 Comments
By Mari Yamaguchi

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96 Comments
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Ermmmmm.....okay.What does this mean? Is it safe for the folk leaving around outside the evacuation zone?

-3 ( +4 / -7 )

When will the J-government realize this is out of control and beyond their abilities. Is it not time to call in for international help?? Where is Captain America???

-8 ( +9 / -12 )

entomb it already, since there is hardly any water.

3 ( +7 / -4 )

Expand evac zone to 50 km just in case. Then build a launch pad nearby the facility. Build a rocket. Build robots to tear the buildings down and get the cores out. Have the robots put the cores in the rocket and shoot that thing straight into the sun. The sun will not even notice it.

Though this might not be very practical and probably way above the budget that the government and TEPCO are willing to spend. Having those cores of the planet and destroyed seems like a good idea to me.

-4 ( +6 / -9 )

Not to sound sarcastic or funny or anything but we really need international experts to say if Japan is safe or not.

20 ( +21 / -1 )

If anyone believes anything that TEPCO representatives have to say regarding Fukushima and it's reactors, I have some lovely beach front property for sale. Interested? It glows at night.

12 ( +14 / -1 )

A Melted core penetrates concrete at 2 inches per hour, No doubt containment is lost during blackout.

Bury it now, time is a wasting.

3 ( +6 / -2 )

Baseless rumours. Bah, humbug. If J- Inc. says it's safe, of course it's safe.

8 ( +10 / -2 )

Hey, what matters it's "in a state of cold shutdown", right? And why call it "fatally" high levels of radiation? Wouldn't "invigoratingly high levels" sound so much better? Low water levels? Doesn't that actually mean that less radioactive water is leaking out, right? Y'know, just putting out some ideas to Nakatacho here...

1 ( +7 / -5 )

Not to sound sarcastic or funny or anything but we really need international experts to say if Japan is safe or not.

Not to sound sarcastic or funny or anything as well, but which international experts would you suggest?

Not IAEA, I hope.

6 ( +9 / -2 )

IAEA will not help the people of Japan. A select few of questionable integrity yes, but not the general populace.

Samantha, it means that while the water is not boiling and spewing radioactive material into the wind, you want to avoid line-of-sight. But if the water levels go critically down and start to boil again (you will be notified months afterwards, I'm sure), the radioactive clouds will not stop at borders of evacuation zones arbitrarily designated by local economic policy.

10 ( +10 / -0 )

when they say it was save, they stopped pouring water in it?

-2 ( +1 / -3 )

Seems to me that it needs to melt down faster to end this silly stuff.

-10 ( +1 / -10 )

gaijinTechie- Thank you. If I were living anywhere near that plant, especially with kids, this latest news would most certainly raise my already beleaguered stress levels.

-1 ( +4 / -5 )

Yesterday the good prime minister said,

Noda said there was a need to establish procedures to quickly respond to emergencies

Well, here's another emergency. And the quick response is...?

I predict a government official will say, soon, that "there is no immediate health effect." Despite the meaning of 'fatally' in the rest of the world.

8 ( +8 / -0 )

the results don’t affect the plant’s “cold shutdown status” because it was never really shutdown.

1 ( +2 / -1 )

I don't understand the point of this story.

Water is low, due to an unknown leak, but the water temp is also low, so it's in "cold shutdown". High radiation in vessel, so no workers can get near it to determine where the leak is.

This story causes aggravation and frustration, because it is not clear to the layman what the hell you are talking about.

If there is an immediate danger here, say it clearly.

If it's business as usual; just keeping the nuclear fear on high alert, in keeping popular opinion with reactors staying off-line, please say so.

This is not a thing to play politics with.

15 ( +14 / -1 )

Reaperinc:

Then build a launch pad nearby the facility. Build a rocket. Build robots to tear the buildings down and get the cores out. Have the robots put the cores in the rocket and shoot that thing straight into the sun. The sun will not even notice it.

Yes, and if the rocket explodes mid-air, the rest of the world will be less forgiving and less patient with Japan. Sorry, but you're living on cloud cuckoo land.

8 ( +8 / -0 )

The worst thing is that, after a year of reading similar news articles about the nuclear crisis and its mismanagement by TEPCO, we tend to ignore them nowadays.

I still remember the announcement where the Japanese government claimed that the situation is going to be stabilized at the end of the year (2011). Three months have passed and we still read about leakages, detection of radiation, etc... At the beginning it was scary, then it got awkward, but now it's just ridiculous...

I am sorry to say so, but my only hope now is...nature and its ability to absorb any hazardous materials.

2 ( +3 / -1 )

So the temperature of the water in the containment vessel is 50 C, but is there actually any fuel in the water? I suspect there is very little as most of it has escaped and is probably working its way down to the water table.

2 ( +2 / -0 )

High radiation means that the fuel melted or otherwise is undergoing an uncontrolled reaction which there is no way of stopping-it is literally a time bomb .......

2 ( +4 / -2 )

Yet the government has declared the area in cold shutdown?

1 ( +2 / -1 )

The report said that the actual water level inside the chamber was way off the estimate.

Makes me wonder what other data is way of the estimate??

8 ( +8 / -1 )

Good point pamelot

Madness. Its never ending. The area around the plant should closed off for a very, very long time., no question about it. "cooling water up to only 60 centimeters from the bottom", where did it go?. And the other reactors.......they dont know.....cover-ups, lies, incompetence.

6 ( +6 / -0 )

Not to sound sarcastic or funny or anything as well, but which international experts would you suggest?

Not IAEA, I hope.

How about some from Iran? Or North Korea perhaps? Russia anyone?

They would probably be better than the comedy group running things now.

2 ( +3 / -1 )

No conclusion of any international team report with a clear final statement means unknown level of risks at least, fatalities to come hidden to public probably. By the way, I am a fire safety specialist accustomed to explaining risks to committees in my field. I would feel like raped everyday if living in that area of Japan. Apology for my honesty to tell this truth about risk management.

1 ( +2 / -1 )

Cold shutdown doesnt mean the whole thing is fixed/safe/whatever. People need to get that notion out of their heads. Cold shutdown means it is under 100 degrees; it is just a stage of the shutdown process (which is expected to take years). The plant is stable in the sense that there are no more massive explosions, but that doesnt mean Tepco can just pack up and leave (and as you can tell, they arent).

And UTrack, entomb it? Thats like putting deadlocks on your front door, but leaving the windows open. The fuel is going DOWN. Building a case over the top of the reactor does nothing to stop that.

3 ( +4 / -1 )

Yes but thats exactly what people do think - Cold Shutdown means everything is OK. This clearly is NOT the case. The Gov should stop worrying about mass hysteria and Chaos and just say that the situation is FAR from SAFE, the place is a no go area, nothing should be anywhere near there. They are doing what they can of course but they just need to make things clear and tell the truth

2 ( +3 / -1 )

"It doesn't match the data", or "It doesn't match the computer simulation". TEPCO is in over their heads.

3 ( +5 / -2 )

Hey original

There is enough of the right type of debris laying around to full up the reactor then encase it in cement. Like it was done in Chernobyl.

1 ( +2 / -1 )

The worst thing is that, after a year of reading similar news articles about the nuclear crisis and its mismanagement by TEPCO, we tend to ignore them nowadays.

Antonius_M - exactly. I can feel myself thinking 'oh God, not another story about TEPCO'. It's just a matter of time before we become all desensitized to news stories.

On a more positive note, a good friend of my sister's was one of the foreign experts called in to measure radiation levels outside the evacuation zone and he said that levels are perfectly safe. This is of course excluding the hotspots that pop up here and there. Anyway, that was a relief to hear it from a non-Japanese expert who has no reason to cover up anything.

2 ( +2 / -0 )

But, but, but... some city and government officials are telling people it is safe to go back to their homes. Does this mean they're wrong? Thumps head against the wall.

-9 ( +2 / -11 )

The Gov should stop worrying about mass hysteria and Chaos and just say that the situation is FAR from SAFE, the place is a no go area, nothing should be anywhere near there. They are doing what they can of course but they just need to make things clear and tell the truth

Seamus78 - I agree with you. If TEPCO wants any chance at all of improving its image in the future in the eyes of the Japanese public (which is not going to happen anytime soon!), then they need to start providing more accurate, honest details, not stories which contradict what they said at an earlier date. They can't sink much lower (barring bankruptcy) so honesty is evidently the best policy and tack they should take.

1 ( +1 / -0 )

OK, so there's only 60 cm of water in the container, and the melted fuel is covered. What about the 50% of the fuel that didn't melt?

1 ( +1 / -0 )

The reason there has not been much help from the international community is because no one has any idea how to deal with the situation at these plants...That IMO is the BIGGEST problem with nuclear generation.. The Governments and Companies that build them know vary well that there will be failures and that melt downs will happen but have yet too devise a workable plan to deal with melt downs... If the water level is as low as reported where did the water go? Is the all the fuel still contained in the vessel or has some escaped? How will the high levels of radiation be scrubbed from the existing cooling water in the vessel? How/when will anyone be able to build the equipment that will allow too even see what is happening in the reactors?? With all that is being reported and the lack of a realistic plan to rectify the problem, or at lhe very east insure the plants are indeed stable and safe, should people be moving back into areas so near these plants? And most importantly.Why would the Japanese Government be encouraging people to do so? these are all obvious questions that I am sure the people in Japan are asking but the government and media do not supply the answers because they themselves just do not know?

1 ( +3 / -1 )

Had this right from the start, from Day Zero. A complete shambles. Why has this never been approached from what it has always been: The worst case scenario. Appalling lack of concern for anything BUT money / reality.

4 ( +7 / -3 )

@Steve Mcgrew

Although I agree that there are still many unknown factors in handling nuclear, it's also a fact that the nuclear power management corporations have time and again ignored recommendations, hushed about certain mismanagement procedures, excessive charging and many other malpractices over the years.

The nuclear disaster last year may still have happened if the mismanagement practices were corrected ... but it may also have a much lesser damage and impact.

3 ( +3 / -0 )

Nothing to see hear. Go about your business - work, consume and obey. Keep smiling, everything else is a baseless rumor.

4 ( +5 / -1 )

There is enough of the right type of debris laying around to full up the reactor then encase it in cement. Like it was done in Chernobyl.

Problem is, this situation is not like Chernobyl. The scale might be the same but Chernobyl went UP and OUT, so they could just put a big sarcophagus over it to effectively stop it going up and out. FukuIchi isgoing DOWN (and also OUT). Even encasing the whole plant in cement would not stop the fuel that is going DOWN (Keep in mind that nuclear fuel can melt through concrete)

2 ( +4 / -2 )

They can't sink much lower (barring bankruptcy)

TEPCO is so protected by the government that they wouldn’t go bankrupt.

(Please correct me if I am wrong. Not sure if this law has been applied to TEPCO case) Japan's 1961 Act on Compensation for Nuclear Damage states the operator of a nuclear facility will not be responsible for any damage caused by their reactor if it was due to "a grave natural disaster of an exceptional character or by an insurrection." Either the government or the group of insurers are to provide 120 billion yen for liability coverage. The operator has to compensate for all the damage exceeding that amount unless the exception of a natural disaster is granted. If the operator is threatened with financial ruin then it can ask the government to assist.

[Mainichi Shimbun yesterday]

TEPCO plans to seek additional financial assistance from the government later this month to pay massive compensation. The state-backed Nuclear Damage Liability Facilitation Fund could be between 700 and 900 billion yen, raising the total amount of aid to over 2 trillion yen if approved by the government.

http://mdn.mainichi.jp/mdnnews/business/news/20120327p2g00m0bu084000c.html

0 ( +0 / -0 )

WTF, this is ridiculous. A year on and no semblance there was any contingency planning (plan A, plan B Plan C) no modelling, no scenario formulations, etc. The Ukranians might not have been good at finesse, but when they had to do something they did it. even it it was crudely encasing the whole thing in concrete.

This thing was not spewing the same levels of radiation as Chernobyl, they have had a year to try and do some whatiff scenarios, etc. and all they can say is that it looks like there is less water than anticipated and that there appears to be some leak?

WTF, is this amateur hour or something? I wouldn't expect them to have a solution the week or month after, but a year out and still look like a one legged man putting out a brushfire. That's serious disaster mismanagement. It's the worst kind of incompetence. It's not treason, but it should be.

7 ( +8 / -2 )

It can't be encased, unfortunately.

0 ( +1 / -1 )

Someone needs to come up with new terminology that reflects the reality of the situation. "Cold shutdown" means below 100 deg., and not shut down. So, 80 or 90 degrees, for example, is cold ??? And shutdown is not like when you turn the car engine off and take out the key, its like leaving the engine idling while you pop in the conbini.

And "hot spot" sounds like one bit of dandruff on your jacket. But there could be a thousand bits of dandruff almost whiting out your jacket and each one of them is a hot "spot"?? How many trees make a forest? How many snowflakes make a blizzard?

Mixed metaphors rule OK.

3 ( +3 / -0 )

@Original et al: No, after reactor number 4 exploded the Corium mass at Cheb was going down. The Soviets brought in a crack team of miners to dig under the plant. Initially the intent was construct a refrigeration apparatus, when they realized how bad it was, they still dug under the plant but filled it with concrete. This can be done. Encasing is a very real feasible approach and was very much considered at first and so should still be on the table.

http://www.aolnews.com/2011/03/18/if-cooling-fails-japan-may-bury-fukushima-nuclear-plant/

From Day Zero should have been so. Approached from what it is: Worst Case Scenario.

6 ( +7 / -1 )

"The probe also found that the containment vessel - a beaker-shaped container enclosing the core - had cooling water up to only 60 centimeters from the bottom, far below the 10 meters estimated when the government declared the plant stable in December."

This is why you don't declare something stable until you can VERIFY and state for a fact that it is actually so!!!

4 ( +6 / -2 )

jojo_in_japan

When will the J-government realize this is out of control and beyond their abilities. Is it not time to call in for international help?? Where is Captain America???

America?? WTF will the americans do what the japanese can't? you might not know, Japan is the world second biggest nuclear power producer, they don't need to be teached from america how they solve this problem. no one in the world had ever such a case before and for those who don't know, since the beginning of the disaster Hitachi and Toshiba were supporting Tepco. The comments here in this forum are so naiv, if you really just thought about all the politicians living with their familys in Tokyo, if you were just a little bit more intelligent, could it not be that especially these people who decide about Japan have biggest interest to make the very best to save their country? do you believe they would not care if their familys life were in danger? if Japan can't solve the problem, no one can do it. 90% of foreigners living in Japan just don't understand about the way Japan is handling this situation, and those people will never understand japanese's mentality. be thankfull such a tradegy does not happen in the usa, otherwise tousends of people there would have been killed because of panic, chaos and disorder.

0 ( +7 / -7 )

What if the fuel has melted through the containment and the measuring devices are only adjusted to measure to that depth.Assuming that the melted fuel has breached its containment and is in fact much deeper would explain the increasing temperatures and very high radiation levels

2 ( +3 / -1 )

@Michael: Calm down dear. Japan is NOT the world's second biggest nuclear power producer, certainly not now with ONE reactor online. Nor before. The US is the largest, France is second, Japan WAS third. The US did help, right from the offset and still --most probably-- is. They supplied coolant and logistics and more. Japan is NOT handling this situation. We DO understand the, who, where, why and what. The first causality was truth. Just like anywhere, because the Japanese, and this is a big secret --they are human. Just like the rest of the species on the planet. Nothing 'unique' 'different' or 'special', just human.

6 ( +8 / -3 )

m5c32

WTF, this is ridiculous. A year on and no semblance there was any contingency planning (plan A, plan B Plan C) no modelling, no scenario formulations, etc. WTF, is this amateur hour or something? I wouldn't expect them to have a solution the week or month after, but a year out and still look like a one legged man putting out a brushfire. That's serious disaster mismanagement. It's the worst kind of incompetence. It's not treason, but it should be.

Do you know how to manage the situation?? Why don't you write a mail to TEPCO or the japanese govrnment and tell them what they should do. Because they're just waiting and playing cards together.

2 ( +8 / -5 )

TEPCO is so protected by the government that they wouldn’t go bankrupt.

What happens when the govt goes bankrupt?

0 ( +1 / -1 )

@YongYang: i'm calm, don't worry. maybe you should know that the total sum paid by Japan for U.S. military bases in Japan reaches 7 billion dollars in 2011. 7'000'000'000 USD. OK? what the US supported to Japan was the minimum they had to do. and second, sorry i said wrong, since Toshiba has overtaken Westinghouse, Japan is the world second biggest builder of nuclear power plants. not the second biggest user of nuclear energy. Japanese are just human, however unique in the world is, over several centuries the japanese have been sensitized to such natural disasters and they are handling this situation as good as possible. if there was help from outside of Japan, japanese government would not hesitate to accept help.

-6 ( +7 / -12 )

I still say, let them down totally to the ground below and then they will head to the ocean.

-1 ( +0 / -1 )

They need powerful cranes(its not line of sight so its safe for operators), helicoptors/airships with telescopic lenses and containment vessels and a lot of patience- tear it apart piece by piece not specialised equipment - can be done now.

-1 ( +0 / -1 )

sounds like it is close to reaching the China syndrome.

0 ( +2 / -2 )

Just look at how poorly Americans have dealt with Katrina, Haiti, etc. And those are brain-dead simple compared to a nuclear emergency. Don't pretend any other country would be any less incompetent in this unprecedented situation.

2 ( +4 / -2 )

everyone just knows how to complain yet no solution. whats the point? u guys get a kick out of complaining?

0 ( +1 / -1 )

as far as I know there have been 2 previous incidents involving NPP's where meltdown has occured, Daiichi where 3 meltdowns happened last year need to be taken care of.

Originalusername,

the Soviets Did Indeed consider a melt through when dealing with Chernobyl.

0 ( +1 / -1 )

Zichi, where are you? I really want to hear your take on this news! Please!

2 ( +2 / -0 )

@Michael. I would tend to agree that most likely Japan does technically the best possible to cope with the post disaster situation (speculation based on my limited experience of living in Japan). The problem is that the facts are hidden and at best unveiled months after they happened. Thus yes you contain panic with this tactic, but you build stress because the "harmful rumors" become true. I tell you that 90% of the Japanese people I know who dare talking about this taboo thing do not understand either how Japan is dealing with that. The - totally founded - distrust against the N-Village (not only in Japan) has gone so far that nothing will be believed blind anymore. What is urgently needed is an M9.0 in the worldwide N-Village: TRANSPARENCY! (IMHO this will never happen unless massive, not big, massive protests happen worldwide. But against this financial, army and politic giant I am not expecting too much, unfortunately).

2 ( +2 / -0 )

there it goes, Reality rearing it's ugly head again.

1 ( +2 / -1 )

The people at TEPCO 'running the show' do not know what they are doing. Nothing they have modeled has come to be. Essentially nothing they have said has come to be. They have denied. They have LIED. They have been criminally obstinate with, 'We know best' when they do not. TEPCO has 'disowned' the radioactive isotopes contaminating Tohoku and Kanto, 'It is no longer ours'. They are in no way or measure the best technically, why would they be using a BWR1 for crying out loud IF they were? As for help, the Japanese are getting plenty of help. The water decontamination process, where did that come from? NOT domestic. US. A French-made installation which removes radioactive caesium and strontium. NOT Japanese. Where's all that technical prowess?

0 ( +3 / -3 )

Any reactor, even in a state of cold shutdown, or more accurately with the Fukushima NPP we should call it safe shutdown, will have high levels of radiation. We know that reactors 1-3 had meltdowns with the nuclear core melting its way through the bottom of the reactor vessels and into the surrounding larger containment vessel which is made from concrete and steel. We also know that the melted fuel has also burnt into the concrete base but probably no deeper than about 60 cm. The concrete base is a couple of meters thick.

The melted fuel that is left inside the reactor vessel and the melted fuel which escaped into the containment vessel must have enough coolant or water to keep it from heating again and to reduce the level of radiation.

There are three areas of concern with the No2 reactor. The suppression ring was damaged by the earthquake although that has been denied by TEPCO. The seal on the reactor lid has been leaking since 3/11. The radiation level inside the suppression chamber is probably the highest, 1.6 Sieverts/hr. TEPCO were unable to enter the No3 chamber because the door can't be opened which was damaged by the explosion.

The radiation level in reactor No1 has dropped but it still leaks a large quantity of water into the basement. The radiation in No3 is still high probably to spent fuel mixed in with the debris from the explosion.

Melted fuel has never been removed before. At Chernobyl and Three Mile Island, the melted fuel is still there.

The three points of interest would be the depth of water in the containment vessel, the internal temperature of the containment vessel and the pressure of the containment vessel. The reactor could be leaking from the suppression ring and the seal on the lid. The external level of radiation from those locations would be critical.

60 cm of water in the base of the N02 containment vessel is dangerously low which would also mean there's no water inside the reactor vessel which probably still has some core fuel? I would have thought the level of water in the containment vessel should be up to the top. TEPCO have been pumping water into it for months, 9 tons/hr, where has all the water gone? Probably leaking out of the suppression chamber.

TEPCO could think about taking the lid off the reactor so it could flood water into from the spent fuel pool located above it. But the radiation level is too high for workers to spend any length of time inside the reactor building. TEPCO will need to come up with a way of repairing the leak from the suppression ring.

Diagrams of the current state of the reactor.

http://4.bp.blogspot.com/-AGnHrxO_atI/T3CvR0_SJ5I/AAAAAAAADb0/HyGL82FVbOM/s1600/fukushimareactor2CV-March12.JPG

http://1.bp.blogspot.com/-rTKr__6REFs/T3IEc7mt-bI/AAAAAAAADcw/XRY6BD0LhRk/s1600/fukushimareactor2CV-March12Rad-1JPG.JPG

There's info on the TEPOCO site but I don't think anyone will gain much understanding from it.

http://photo.tepco.co.jp/en/index-e.html

In all my comments I have never been a pro TEPCO but I think it's dealing with a nuclear disaster which has no previous experience or knowledge base. They have done better over the past six months than during the first six months. I don't think there is any other company which could do it any better, whether Japanese or international. It's mostly a trial and error story.

14 ( +14 / -0 )

As always, many thanks for the informative post, Zichi-sensei!

4 ( +4 / -0 )

This will continue to be a major problem for many more months, if not years.

0 ( +1 / -1 )

Serrano

it will continue to be a major and very serious situation for t least 30-50 years. Until something final happens like the removal of all the spent fuel and a solution found for the melted fuel.

3 ( +3 / -0 )

I think it's safe to say Fukushima will be radiation free in the year of 2075

THE ONLY SAFE PROCEDURE FOR THE TIME BEING IS TO SEAL UP EVERYTHING WITH CONCRETE

1 ( +1 / -0 )

We need a comment from Johannes Weber who could give us the best insight to this latest event.

3 ( +3 / -0 )

sounds like it is close to reaching the China syndrome.

More like the Brazil syndrome

On a serious note, Hiroaki Koide, an assistant professor at the Kyoto University, made the following comment (TV Asahi June 16) "As far as I can tell from the announcements made by TEPCO, the nuclear fuel that has melted down inside reactors at the Fukushima nuclear plant has gone through the bottom of the containers, which are like pressure cookers, and is lying on the concrete foundations, sinking into the ground below. We have to install a barrier deep in the soil and build a subterranean dam as soon as possible to prevent groundwater contaminated with radioactive materials from leaking into the ocean." The high-ranking government official said that construction of an underground dam was indeed being prepared. But the project was in limbo due to opposition from TEPCO. The reason is funding. It would cost about 100 billion yen to build such a dam. Initially an announcement on the underground barrier was due to be made to the press on June 14, but it was put off until after TEPCO's general shareholders meeting on June 28.

http://mdn.mainichi.jp/perspectives/pulse/archive/news/2011/20110620p2a00m0na005000c.html

1 ( +1 / -0 )

Zichi has hit the nail squarely on its head.

The situation is a very difficult one to deal with. One feature, of course, which will help very considerably is that all the short-lived fission products, originally present at an intense concentration, will by now have decayed, so the heat that was being produced by their radioactive decay will no longer be produced. The fission products remaining are more longer-lived, therefore their rate of decay is slowing down - a continuous process - with the amount of heat being produced continuously falling. So there's a lot less heat to have to remove, now, and, just maybe (I cannot be sure), the natural conduction of heat through the steel core vessel to whatever it is in contact with is all helping to prevent the core from grossly overheating, despite the apparently low level of cooling water.

Although lots of fission products have decayed to zero amounts, none-the-less, those remaining will still be decaying and producing high intense ionizing radiations. Therefore does rates are going to remain high for a very long time.

There's nothing clearer than that the three major reactor incidents - TMI-2, Chernobyl-4 and Fukushima Daiichi - represent three quite different scenarios, none of which were predicted in advance. At least the Daiichi scenario, like TMI-2, has not been accompanied by a massive release of radioactivity as occurred at Chernobyl-4. None-the-less, what has been released into the environment will obviously cause concern for some years ahead.

I am not going to dare to form any judgement on how TEPCO have dealt with the accident. My only concern would be to make sure that never again, ever, allow vital back-up diesel generators at any of your nuclear plants to be located in basements which can be flooded. But for that disastrous example of engineering wisdom there would have never been a problem with the Daiichi reactors. Their auto-shutdown at the time of the earthquake went impeccably.

2 ( +2 / -0 )

THE ONLY SAFE PROCEDURE FOR THE TIME BEING IS TO SEAL UP EVERYTHING WITH CONCRETE

Wishfull thinking of the "Just make it go away!" sort. Capping the corium with concrete only hides a ticking bomb, metaphorically speaking. If the corium reaches the water table, to quote Egon from Ghostbusters, "It would be bad."

This measurement of water temperature is sketchy because if the corium HAS melted through the bottom of the containment vessel, then only a small portion of the fuel is contacted/cooled by the water. If you have a container that doesn't conduct heat well and fill it with water, then only expose a square centimeter of the water to 100+°C heat, the water will never boil because the heat source isn't large enough to offset the water's ability to shed energy.

2 ( +2 / -0 )

@mike23thurgood,

thank you for the comment. My level of nuclear engineering is nothing more than a layman's. I've been on a rapid learning curve since 3/11.

What you say about the emergency generators was pure engineering insanity but the problem goes further than that even had the generators had been located in position to continue working following the flooding from the tsunami, operators in the reactor buildings at the time of 3/11 stated they saw reactor cooling pipes being twisted and ripped off the walls by the force of the earthquake.

Later, engineer's who had worked at the plant, stated the cooling pipes had been incorrectly installed with insufficient welds on the joints to withstand a powerful earthquake.

Due to wide scale power outages the plant lost all external water supplies and there was no back up systems.

So, yes, the generators caused a set of problems but they would not have helped without water and cooling pipes to the reactors.

6 ( +6 / -0 )

Cold shutdown was not can not be achieved at any of the three units suffering meltdowns / melt throughs. A Corium mass sat on / eating through its concrete mat is not a viable state to define a reactor, which is needed for a cold shutdown. The announcement that it was was an appalling affront to honesty, a lie to the world. All this ad-hoc dead ending process is doing is creating more radioactive waste and lulling the easily fooled into a sense of false security. The catastrophe is STILL a Level 7. That's 3 Level 7s. Storage Pool No 4, well, that could take us to a new dimension, IF it collapses and one thing we HAVE to have learned is... That's right. Keep an eye on what is going on, will we get some truth? Exhale now, no point waiting. My thoughts, respect and thanks AGAIN to those working to save us still.

3 ( +4 / -1 )

Part of the TEPCO road plan is to remove the melted cores in about ten years but that isn't going to happen. To even achieve it TEPCO would have to build robots that could withstand the very high levels of radiation. The expensive probe they used has a life of 14 hours.

6 ( +6 / -0 )

Not to sound sarcastic or funny or anything as well, but which international experts would you suggest?

Those who fought in Chernobyl.

2 ( +2 / -0 )

It's the responsibility of all world nuclear organizations to rectify this situation. And they'll need to expedite the process, at any cost.

0 ( +1 / -1 )

Very nice TEPCO, so what is the radiation level? It is my understanding this radioactive water is leaking into the Pacific ocean? So how many rems per hour? 10 times lethal does does not say a lot.

3 ( +3 / -0 )

to tolerate the harsh environment and decommission the plant, a process expected to last decades.

How many decades we talking here, a couple hundred?

parts of the reactor building are accessible for a few minutes at a time - with the workers wearing full protection.

Exactly how much work can you get done in "a few minutes" wearing a space suit?

0 ( +0 / -0 )

TV: Radiation levels 10 times higher than experts hoped at Reactor No. 2 — No. 1 and 3 even worse

http://www.euronews.com/2012/03/28/latest-fukushima-probe-appals-experts/

1 ( +1 / -0 )

It is not the total amount but the half life. Just what is making up the radioactive soup? It is time TEPCO comes clean on this and tells us the truth about the accident. Just what are they covering up and why have no arrests been made? A person can get 3 years for a minor traffic accident with injury. TEPCO has not only caused injury and death but has made a good amount of Japan a no go zone.

4 ( +4 / -0 )

Did the math and said "holy cow pies Batman!" At 7k rems per hour it comes to 870 years to reach background. Seven minutes to get a lethal dose. The level is so very high it is mind boggling to me. Levels far higher than we used for after an atomic war. This is suppose to be "cold shutdown"?

2 ( +2 / -0 )

YuriOtani

and you still want to support nuclear energy so this is a price you must be prepared to pay.

7 ( +7 / -0 )

If the melted fuel has burnt into the concrete base which is more than one meter thick and the foundations which is several meters thick followed by bed rock I think TEPCO will never be able to extract it and will need to come up with a plan for dealing with it in situ. Probably, theyll try for 20 years before deciding it just cant be done.

America only promoted the use of nuclear energy so that it could build thousands of atomic bombs.

7 ( +7 / -0 )

"Very high radiation" means: more radiation in store, for all of us.

1 ( +1 / -0 )

How many centimeters today?

1 ( +1 / -0 )

With bits of remaining corium stuck to the side walls it will be difficult to cool every one of those glowing lumps. This would explain why one thermometer might show higher temps than another. Did we ever get a report on how it went after they presumably replaced the 'broken' thermometer?

Naturally they will continue to spray and spray, but nine tons of water a day washes down and out of the gaps, leaving an average of just 60cm in the bottom of the vessel. Unfortunately, increasing the amount of cooling water will also increase the amount of irradiated and polluted water leaking out of the bottom, so maintaining 'cold shutdown' will be a tricky balancing act in No 2.

1 ( +2 / -1 )

Excellent post nandakandamanda.

0 ( +0 / -0 )

zichi, this was an accident brought about by TEPCO. Suppose they should of envisioned such a quake. However until a replacement is found the atomic plants have to be operated. Surprising enough the fossil plants spread more death and suffering. How many people die a year in Beijing from the foul air?

My beef is that the government in Tokyo is paying lip service to the problem. Hoping it will go away...

-3 ( +1 / -4 )

YuriOtani

the standard of the coal fired plants in Japan are much more advanced than those in China. Many uranium miners in Australia have been fighting for years for compensation for the cancers they developed during their working lives.

The safety of nuclear plants in Japan can't be ensured not only following the nuclear disaster but also the failure of all the various atomic safety agencies.

5 ( +6 / -1 )

Accident wasn't brought about by tepco. Quakes and tsunami's are part of nature. And every nuclear catastrophe in history was set-off by different circumstances. The technology is unpredictable, and far too dangerous, as the facts show.

1 ( +2 / -1 )

TheBigPicture

ex PM Kan stated the nuclear disaster was a man made one!

3 ( +3 / -0 )

Nuclear, the the fuel of the past, and the waste of the future.

3 ( +4 / -1 )

UPI: Fukushima “at risk of a new meltdown” — Level of cooling water 29 feet lower than estimated

http://www.upi.com/Top_News/World-News/2012/03/29/Water-levels-low-in-Fukushima-reactor/UPI-64981333053826/?spt=hs&or=tn

NYTimes: Core damage at No. 2 worse than thought? Reactor water could be flowing directly into ocean or under plant — Risk of fuel melting again, says nuclear engineering professor

http://www.nytimes.com/2012/03/30/world/asia/inquiry-suggests-worse-damage-at-japan-nuclear-plant.html?_r=2&partner=rss&emc=rss

0 ( +0 / -0 )

Wide swaths of the Pacific coastline stretching from Honshu to Kyushu may be hit by tsunami over 20 meters high if a newly feared megaquake occurs in the Nankai Trough.

0 ( +0 / -0 )

Interesting articles, Utrack, especially the one in the NY Times. It says the reactors cracked in the quake/tsunami, because they were under increased internal pressure. (?)

Is this general knowledge here in Japan, and what exactly does it refer to, I wonder? Do Japanese engineers like to run their reactors at higher than worldwide pressures?

1 ( +1 / -0 )

Quote from above NY article: "But at Fukushima, the reactor vessels are known to have cracked, because they were overpressurized."

1 ( +1 / -0 )

Hmmmm... no, I do not think the reactor vessels were cracked. Corium leaked out round the holes through which fuel rods are inserted into the bottoms of the reactors.

As to 'overpressurization', perhaps they are alluding to the temporary build up of pressure that caused the hydrogen explosions?

There still seems to be some debate as to whether en explosion did or did not happen in No.2, and whether a hole was or was not created in the torus. Reading between the lines an internal event seems to have happened there, different from the other hydrogen explosions. A less overtly explosive noise was heard, but the reporting was vague, I remember, with some experts saying one thing and some another.

(Just trying to remember reports from a year ago. If any of this is off the wall, please feel free to comment, in the interests of truth! Thank you.)

1 ( +1 / -0 )

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