Published: June 30th, 2012 at 1:39 pm ET
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Subscription Only: Cooling system for Fukushima Daiichi No. 4 reactor suspended
Kyodo News
June 30, 2012
The cooling system for the spent fuel pool at the crippled Fukushima Daiichi power plant’s No. 4 reactor automatically suspended operation Saturday, Tokyo Electric Power Co. said.
The utility known as TEPCO has been unable to activate a backup cooling system for the pool and is looking into the cause of the trouble, officials of the plant operator said later in the day
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Published: June 30th, 2012 at 1:39 pm ET
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sending...
sound's like trouble, what are they going to do? What is the temp now? Hope they do not have the day off today.
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Hi norbu,
"The water temperature of the pool was 31 C at the time of the suspension at around 6.25 a.m."
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iwas worried about SP4 collapsing, but I suppose SP4 heating up and burning up in the air in an intact building is just as bad for us and the earth. What an unedning, always-threatening nightmare. We've got this Sword of Damocles hanging over our throats forever until it eventually slays us all.
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Challenges like this will be happening on a continuous basis for decades and decades. Cancer causing radiation will be spewing nonstop as well.
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18 hours since this happened. We know from previous times that the temperature increases at a predicted 0.5c but on average has actually been 1c per hour.
The temperature of the pool was 31c so now it should be between 40c to 49c. The safety limit is 65c which at a rate of 1c will be reached in 16 hours.
An educated guess is that if the temperature reaches 85c then the water will be boiling at the bottom and the fuel rods could start degrading. I'm not sure how long at 85c before there is any potential for the rods melting through the pool.
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Although there might not be any danger of a melt through unless there is very little/no water left in the pool. They did just recently put a cover on the pool, that would probably increase the rate of temperature increase and make air drops impossible.
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Right, with cover on can not get to it, how crazy.
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I remember the cover was put on by a crane in one piece. So I think it would be possible to remove it quite quickly, if necessary.
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I forgot it's just been placed on and not welded. One issue I can still see is the crane won't be able to lift off if it's windy because they big cranes aren't suited for winds over 20mph.
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Just great, not really, are they working to restore the cooling system? If it start's to melt how long before it reaches the common pool, or will it not cause a reaction between them?
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The bottom of the pool consists of 180 cm concrete, the side walls 140 cm, according to Tepco.
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will 5'10" of concreticus hold back all that heat?
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Let's not find out, I'd say
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I agree. Let's say they fix the cooling system.
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..um..what about the zirconium cladding..?
http://news.sciencemag.org/scienceinsider/2011/03/contention-over-risk-of-fire-fro.html
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A quote for the day:
“A lot of people think that Fukushima is behind us, in fact it’s ahead of us.” This was from Jean-Christophe Niel, head of ASN, the French nuclear safety authority.
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He's right, I'm afraid:
Kyodo says cesium was found in urine of 6.9% of children tested in Fukushima:
"A small amount of radioactive cesium was found in the urine samples from 141 infants and young children living in Fukushima Prefecture, where the crippled nuclear power plant is located, among 2,022 of those surveyed, a Japanese research group said Saturday.
Three urine samples contained more than 10 becquerels of cesium per kilogram, including a case with 17.5 becquerels. Ten becquerels or less of cesium was found in the samples of the other 138, the Yokohama-based Isotope Research Institute said.
The urine samples also contained about an average 64 becquerels of radioactive potassium."
http://english.kyodonews.jp/news/2012/07/166838.html
*is anyone testing their blood / bones???
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That's the first honest and intelligent thing that I have heard from a nuclear official since this disaster began.
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In the absence of any agitation, any vapour pockets/air bubbles clinging to the hot surfaces would provide localized insulation from cooling water contact, until those bubbles break free.
Heating and evaporation of cooling water would drive up dissolved solids content and make the remaining cooling water foamy.
Not sure how effective silicone based anti-foam solution would be in that case. Silicone based anti-foam would combine with dirt and become a fouling agent with high temperature stability. Silicone based anti-foam may also be quite insoluble in water after it's surfactant has been degraded by heat, reducing the efficiency of cooling water after circulation is reestablished.
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I find the choice of words curious. Maybe "suspended" sounds like they have some control, where "failed" does not?
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Gee, I wonder if the deconstruction of the Unit 4 building has anything to do with SFP recirculation loop shutting down again?
Vibrating debris and concrete dust would be enough to disturb the pool causing a mixing in the water to form a nice slurry to clog the pumps and overwork the electric drive motors and/or any inline filters.
I take it two pumping systems are down, the primary and the backup.
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That's a very good question.
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You have a spent fuel pool that has had a crane dropped into it, one or two fires, molten fuel at the bottom, and who know what kind of water put into it. There are all kinds of materials that pumps and values would not like at all. So having problems should be expected. In normal operation the water has almost zero impurities, and that is what it is designed for.
They can add water from somewhere even if both pumps are inoperable. It might not be filtered or high quality water, but they must have sources. This almost seems like a non story, because there are answers. Why are they passing out disturbing news when there is some kind of answer. As each day passes they appear to be bigger and bigger idiots. If I am wrong about another source of water then i have underestimated their idiocy.
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@chrisk9 – get used to their idiocy. I've been watching it daily since about 12/03/11.
They are criminally inept at tepco, the Japanese guberment is o different.
There are clear conflicts of interest between what is right for the people and the environment, and the profits of the mob.media.corp.guv
Tepco is the keystones cops and three stoogers wound into one, and the life of planet earth is in their foolhardy hands.
They need to be removed from the site and replaced by a responsible team of unbiased experts.
But the whole nuke industry is corrupt to the core. The jap.gov is corrupt. The media is corrupt and the USA guberment is extremely corrupt.
Now we have enenews, because many of us watched as these lying mongrels have brought us all closer to death. We need to fight and win the info war. And we need to stop the entire nuke industry. Else we are all dead. We probably are already, but justice needs to be delivered at the very least.
/end rant
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Even if there IS suitable water available, how do you propose they get it a hundred feet up in the air without using pumps? This is BAD.
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I no longer underestimate TEPCO's incomptence.
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Not to Worry! TEPCO … is looking into the cause of the trouble!"
Yikes.
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"then i have underestimated their idiocy."
don't feel bad, I seem to do it weekly….
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It would be a non-story if TEPCO didn't use Murphy's Law as their working motto.
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The one law we could always count on when I worked at these plants. Murphy's Law was in force daily. That and FUBAR.
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