Fukushima: spent fuel pools & Hiroaki Koide

http://neic.usgs.gov/neis/bulletin/neic_c00096wb_h.html
The page shows recent historical seismicity in the vicinity of Fukushima since 1973. Large earthquakes, like the great Tohoku event on 11 March, 2011 are few and far between, and so far have happened offshore.

Granted, I agree that I don't believe in a collapse of the SFP either. But this kind of thinking, to stop at the "the probability is so low that it will never, ever happen during our lifetime" point, is exactly what brought us in this kind of mess in the first place. Nobody thought about consequences of a station wide SBO. The possibility was obviously there, but nobody wasted even a thought about it just because this even seemed so unlikely that thinking about it properly would be a waste of time.

You made your point that his fears of a collapse are unreasonable but that a very minor possibility for this to happen is there. So extend your explanation to this very unlikely case. Everything else would be dispersing salt in his eyes.


No offense, but I think your answers are symptomatic for at least the public stance of the nuclear industry as a whole. "The accident can't happen. Period. Therefore there is no need to evaluate possible consequences. If someone does he's unreasonable since, as already stated, the accident can't happen."

There are a lot of panic laden posts around the internet at the moment referring to a "mass extinction event" if the unit 4 spent fuel pool collapses.

I was going to include a few links but the forum wont let me (less than 10 posts). Just search this quote for example: “If they are MOX fuel, containing six percent plutonium, one fuel rod has the potential to kill 2.89 billion people.”, a statement widely quoted, originating from Christina Consolo (who I note is a photographer, not a nuclear scientist.)

Most of the reports refer to how cataclysmic it would be if there are MOX fuel assemblies in that storage pool, but none of them say whether there actually are. Do we know whether there is any MOX fuel in the unit 4 pool? Is a mass extinction event really a possible outcome here?

Thanks.

-Intended to the mass point system, as a result of the time history response analysis against basic earthquake ground motion, shear strain occurred on remaining seismic wall below 5th floor was estimated 0.17 * 10-3 (Ss-1 and Ss-2, EW direction, 1st floor) at maximum and the value fall much below 4 * 10-3 which is the standard value. Therefore we evaluate it has adequate security (Fig4).

-As a result of seismic safety evaluation by 3 dimension FEM analysis (Fig5), combining with earthquake load occurred by basic earthquake ground motion Ss and other load, the maximum strain of rebar is 1230 * 10-6, Therefore we evaluate it has an adequate margin against 5000 * 10-6 the plastic limit strain which is the standard value. And regarding out-of-plane shear force at the minimum part was 800 (N / mm) against 1150 (N / mm) which is the standard value, therefore we estimate it has the adequate safety.
http://www.tepco.co.jp/en/press/corp...s/110528e1.pdf page 2

“If they are MOX fuel, containing six percent plutonium, one fuel rod has the potential to kill 2.89 billion people.”, a statement widely quoted, originating from Christina Consolo (who I note is a photographer, not a nuclear scientist.)

TOXICITY

Plutonium never was “the most toxic substance known to man”, as has so often been asserted by its detractors. It is indisputably very toxic but in a different way from more familiar poisons such as cyanide or botulin. In the worst imaginable circumstances plutonium lodged in the body might cause cancer 20 years later. Cyanide can kill in minutes.

What was perhaps the world’s most exclusive club comprised a handful of Americans who became contaminated in accidents with plutonium in the scramble to make the first plutonium weapons. All were young white males who had been working under laboratory conditions acknowledged to have been “extraordinarily crude” in 1944-5, on one of four chemical processes: purification, fluorination, metal reduction and recovery. The kinds of accident they suffered included chemical burns by plutonium salt solutions. Members were enrolled by medics at Los Alamos because they were judged to have experienced the highest exposures to plutonium of all people engaged in the Manhattan Project. The chosen 26 were excreting the highest levels of plutonium in their urine. In 1952, when the club was formed, each was estimated to be contaminated with between 0.1-1.2µg of plutonium.

Most of the men left Los Alamos soon after the war ended and scattered throughout the USA. Three of them continued to work with plutonium. Four had been involved with three or more accidents with the stuff. The medics traced all 26 in 1952-3 and carried out their first follow-up of medical studies. Thereafter they were given a complete medical examination about every five years. Two decades later, in 1971-2, 22 of them returned to Los Alamos for a more complete study of their plutonium body burden, with two more opting for their own doctors instead of Los Alamos’s. One had died.

By 1979, when George L Voelz and his colleagues published their 32-year medical follow-up of club members, two had died: the first from a heart attack in 1959, aged 36; and another from a road accident in 1975, aged 52. The surviving 24 had suffered no cancers other than two skin cancers “that have no history or basis that relate them to plutonium exposure”, they reported. They found the diseases and physical changes in club members were “characteristic of a male population in their 50s and 60s”. The mortality rate of the club was about 50% of the expected deaths among white American males at that time.

The moral of this story is not, of course, that plutonium is good for you, but that it’s nowhere near as deadly as it’s been cracked up to be. Admittedly, the club members were above-average intelligence – college students or chemical engineering graduates in their early-20s who had been called up for the US Army and drafted to Los Alamos. Many returned to college after the war. Within a few years almost all were in supervisory, administrative or professional positions where they were no longer exposed significantly to any toxic chemicals or radioactive materials. Nine never smoked. Four had reached their sixties, one 69.

Voelz, speaking in 1999 after his retirement, recalled that he’d arrived in Los Alamos in 1952 for a year of in-plant training in industrial medicine and was intrigued with all the concern for protecting and following people exposed to plutonium. “I had never heard of plutonium until I got to Los Alamos”. The club had already been started. Describing the exposures of the 26, Voelz noted: “The work during World War II was done in ordinary wood frame buildings with openfaced chemical hoods”. Some work, such as weighing and centrifuging, was actually done outside the hoods”. Club members expressed no serious fears or concerns about their exposures to plute. “They are interested in hearing the results of our studies and have been fully cooperative through these many years”. He stressed the importance of a close rapport and kept in touch personally with letters and presentations, encouraging them to call if they had any questions – as any good club might do. None ever filed claims for compensation.

Today there are over 1200 plute-contaminated people under constant medical observation, with no detectable effects so far, Eric Voice, a British scientist who worked with plutonium at Harwell and Dounreay, told me in the summer of 2004. In retirement in 1992 Voice participated in several experiments, in one of which plutonium citrate solution was deliberately injected into several volunteers, for biomedical researchers to follow the patterns of plute excretion and movement of plute in blood, tissues, liver and bones. These metabolic experiments used short-lived plutonium isotopes. Twelve years later he’d reached the age of 80 and accumulated no fewer than 15 reports of results and deductions about these experiments published in the professional press. Is getting plutonium inside the body more dangerous than any radioactivity we already have inside us? No, Voice asserted, the radium in the world around us is twenty times more dangerous than the same mass of plutonium. “And there is no evidence that any human on Earth has ever died or suffered any health consequences whatever from plutonium radioactivity”.

Eric Voice died in September 2004 from motor neurone disease. An obituary in the Daily Telegraph recounted how in one experiment “Voice was one of a dozen guinea pigs who inhaled trace amounts of plutonium isotopes of the sort found in nuclear reactors. Measurements were then made tracking the progress of the substances through the body. The study was designed to find out how to treat people in the event of a nuclear accident”. He had lived for another five years after the UKAEA declared in 1999 that all of its guinea pigs were still alive and healthy.


Author Info:
David Fishlock, Traveller’s Joy, Copse Lane, Jordans, Buckinghamshire HP9 2TA, UK