Fukushima Update–Three Meltdowns and Cooling Pool #4 in Peril

by Matthew Payne on June 12, 20113 comments

 

Fukushima Schematic; The Fuel Storage Pool is #5 (c/o Wikipedia)

Folks in the establishment media seem far more interested in congress-critters crotch shots or the violence in Syria (Yemen, not so much. . .), but some retrospectives at the three-month mark of the Fukushima FUBAR have been published and some clarity is possible on these events.  The first major point of clarity is that the nuclear accident at Fukushima Daiichi was and is catastrophic.  It is not even close to being “contained.”  All three stricken reactors at Fukushima, not simply unit 1, suffered complete core meltdowns and breaches of core containment. (H/t to My Philosophy at DailyKos).  Japanese papers are reporting on a leaked report by the IAEA which states,

The findings of the report, which has been given to the International Atomic Energy Agency, were revealed by the Yomiuri newspaper, which described a “melt-through” as being “far worse than a core meltdown” and “the worst possibility in a nuclear accident.”

What the IAEA found was that a full meltdown occurred in all three stricken reactors with loss of core containment as the molten fuel ate through its containment.  Simply put, melted nuclear fuel has dropped through the base of each reactor’s pressure vessel and is pooling at the bottom of the outer containment vessels.  These vessels, especially at reactor 1, are almost certainly breached themselves and unless the nuclear pile can be cooled, one can expect whatever limited containment they are offering to be compromised as well.  TEPCo’s confident prognostications that it would achieve “cold shutdowns” of these reactors by October no longer sound very achievable, especially since its method of “water entombment” is not effective on the mass of “cottage-cheese” melted fuel at the bottom of these containment vessels. 

Second, since cooling the melted cores is not possible with the reactors’ cooling systems (and there are leaks), whatever water is being doused on these toxic piles is pooling in the reactor’s underground structures.  And the capacity of those structures to hold this highly toxic water is quickly becoming compromised.  Already, unlike Chernobyl’, significant levels of radiactive isotopes have been measured in Fukushima’s groundwater (about 240 times permissable amounts of radioactive Strontium–probably leaking from conduits at Reactors 1 & 2).  Much emphasis was put on a French purifying unit that was delivered on Friday.  Unfortunately, that unit, with a capacity to reduce the radiation contamination of 1,200 tons a day, is already overdue and now experiencing technical difficulties.  With the rainy season upon Fukushima and the plant having already deliberately dumped 500 tons of highly contaminated water and 14,000 tons of lightly contaminated water, there are growing fears that the radioactive water could flow into the ocean, which has already experienced ten times the radioactive contamination that the Baltic did after the Chernobyl’ events.  It was hoped to established temporary holding facilities for the water, but these tanks will not be finished before July and August.  The estimate is that the plant as a whole is holding 100,000 tons of highly radioactive water in its basements, conduit alleys and other areas–so long-term storage is a very large challenge.

The trifecta of doom is completed by the cooling pool of unit 4 (which contrary to all sense and engineering expertise was put on the fourth floor of the reactor building).  The cooling pool building looks like it’s been hit by a howitzer and the spaghetti of mangled pipes and wires has made it extremely difficult for workers to stabilize the pool–they certainly won’t be rebooting the pre-existing coolant system.  It is not at all a minor point that the pool is on the fourth floor since there is a strong danger that the floor could literally fall out from under the pool.  TEPCo workers are attempting to shore up the floor with temporary struts but an aftershock or any other structural event could simply cause the fuel in the pool to “melt through” as well, or lose containment and catch fire.  Given the presence of MOX fuel at Fukushima 4, this cooling fuel has high levels of plutonium and may, in fact, have gone critical.  There are much too high levels of Iodine 131 (a radioactive isotope with a brief half-life) compared to Cesium-137 (which has a half-life of thirty years) to not evoke serious concern.  All attempts to cool the fuel have thus far failed and the temperature of 80 degrees Celsius may indicate some of fuel has melted down and nuclear fission is occurring.  If the fuel rods are exposed through lack of coolant or fall through the floor, very, very bad things would follow.  Despite the news focused on the three meltdowns, if another catastrophic event were to occur my bet would be on this cooling pool. 

For folks who make soothing cooing sounds about how such a loss of a coolant system couldn’t happen here (better designs, more professional, more regulation, yadda yadda), it just did.  The cooling pool at Ft. Calhoun Nuclear Plant in Nebraska (earlier threatened by floods) was knocked out for thirty minutes by an electrical fire.  Fortunately, the coolant system was rebooted in about 30 minutes, not the 88 hours it would have taken to expose the fuel.  This time the redundancies in the system were not compromised and the nearly one-hour long fire did not threaten the plant’s safety systems.  Still, one should ask oneself, why are we playing Russian roulette with storing highly toxic fuel in places where floods and earthquakes occur?  

The best the Japanese government can do in this situation is to normalize the unthinkable.  Rather than evacuate the large town of Date, it has decided to give radiation badges to 8,000 school children.   Including kindergartners.  Presumably, once they’ve reached their yearly dose (originally proposed to be twenty times that of an atomic plant worker), they should. . . what?  Only play indoors?  Get lead-lined Dr. Denton’s?

We have seen this normalization of the unthinkable in everything from sucking up seas to setting people’s drinking water on fire.  Now the only country to have ever lived with the devastating effects of direct nuclear attack is getting use to the idea that its school children should wear dosimeters. 

The earless bunny making the rounds as a new folk symbol of Fukushima is doubtless a random mutation, but it makes a powerful symbol of the accident.  With Prime Minister Nato Kan essentially having failed a vote of no-confidence due to his inability to hear how anxious the Japanese are on this issue (or maybe he only had ears for the empty assurances of TEPCo?), is that bunny the only creature deaf to the story of Fukushima?

3 comments

Art Jones on July 16, 2012 at 2:45 am. Reply #

#4 pool cooling reported to have failed about July first, one would expect some follow-up report regarding the expected meltdown with the continued absence of cooling. What is the status now of the #4 cooling pool, July 16, 2012? Thank You.

Art Jones on July 16, 2012 at 2:47 am. Reply #

Has #4 cooling now melted down?

Matthew on July 16, 2012 at 7:19 am. Reply #

Art, you are right to be concerned. The cooling system of the #4 cooling pool did go off line on July 1st but was rebooted the next day. The temperature of the water only reached 109 degrees fahrenheit (43 C), but clearly this is a worrisome development, even though TEPCo downplays it. Hopefully, something more stable is constructed soon.

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