Friday, May 18, 2012

Setting the Record Straight on the Spent Fuel Pool at Fukushima Daiichi Unit #4

At the end of April, former Department of Energy official Robert Alvarez sounded the alarm about the safety of the spent fuel pool at Fukushima Daiichi Unit #4 (click here for his piece from the Huffington Post). Here at NEI, we've long been familiar with Alvarez's position on the disposition of  used nuclear fuel, and it's safe to say that not only do we disagree with his assessment, we also believe that it is needlessly alarmist.

We're not the only ones who have said that, something that's become abundantly clear in recent weeks as independent bloggers have decided to take on Alvarez on their own initiative. The first to step to the plate was Dan Yurman of Idaho Samizdat:

One of his (Alvarez's) favorite rhetorical strategies is to total up the mass of material at a nuclear site and then make the assumption that all of it will blow up through some mysterious and unspecified mechanism spewing its contents far and wide. This is a great stuff for a B- movie on the SciFi channel, like an imaginative idea for a script of Mega-Shark meets Atomic Octopus, but it doesn't match reality.
Yurman was quickly followed by Rod Adams over at Atomic Insights. Rod even went so far as to record his own video rebuttal:
But the crescendo came earlier this week on Wednesday when a group of bloggers, headed by Will Davis at Atomic Power Review, debunked Alvarez's claims very thoroughly over at the ANS Nuclear Cafe:
These articles are highly deceptive. The occurrence of a cataclysmic release of radioactive material as surmised is hinged upon the occurrence of so many statistically impossible events that it is certain to be a practical impossibility. Since the assertions continue to gain a wider audience, however, it is necessary to examine them and make a realistic assessment of their likelihood.
Please take the time to read the rest right now. Once you finish that, be sure to stop by The Neutron Economy for a great followup piece.

3 comments:

EL said...

Readers might want to consult Brookhaven National Labs Study:

http://www.osti.gov/bridge/purl.cover.jsp?purl=/510336-qmwPBP/webviewable/

Case 3 in Brookhaven scenario looks at pool drainage after one year of offloading: "The lowered decay heat does not cause rapid oxidation, however the assemblies reach high temperatures and 50 percent of the fuel rods in the pool fail, resulting in a gap release" (3.7).

The accent scenario in this case (3H) results in contamination of 25 square miles of land, as many as 20,400 cancer fatalities over time, and property damage up to $34 billion (in 2011 dollars). The Brookhaven study concludes "critical decay times of about 17 months" (3.2) for first timing scenario ("Hot Fuel in the Spent Fuel Pool), and timing risk of cladding failure and gap release is highly dependent on "reactor type, assembly burn-up, and racking geometry" (which none of the sources above detail for Fukushima).

Perhaps it's worth looking at credible sources … rather than YouTube videos of grad students looking to "ignite" zirconium cladding with a blow torch (and succeeding in significantly damaging the rod)?

Brian Mays said...

"Readers might want to consult Brookhaven National Labs Study: ... The accent scenario in this case (3H) results ..."

Wow! There is so much wrong with this that it is difficult to know where to begin.

"... in contamination of ... [blah blah blah] ... The Brookhaven study concludes 'critical decay times of about 17 months' (3.2)"

All of these figures that you cite are for a Pressurized Water Reactor (PWR). The reactors at Fukushima are Boiling Water Reactors (BWR's). Perhaps you do not understand the difference?

Well, the difference matters. For example, the critical decay time given in the report for a "representative BWR" is only 7 months, not 17 months. The freshest spent fuel in the fuel pool at unit 4 has now been out of the reactor for 18 months.

The cost and fatality figures that you cite are almost meaningless. The Brookhaven study assumed "a large city of 10 million" between 30 and 50 miles from the accident. Although Tokyo is larger than this, it is about 150 miles away, not 50. The study also assumes a uniform population distribution of 1000 persons per square mile within 30 miles, which is over twice the population density of Fukushima Prefecture (before the accident). Furthermore, about half of the area of the 30-mile region around the damaged reactors has a population density of zero, since it consists of the Pacific Ocean.

Next, you conveniently took figures from the high estimate case (3H) and ignored the low estimate case (3L). That's just being dishonest. There's no other way to put it.

Finally (and possibly most importantly), your quote, "the lowered decay heat does not cause rapid oxidation, however the assemblies reach high temperatures and 50 percent of the fuel rods in the pool fail, resulting in a gap release" is not a conclusion of this study, it's an assumption!

Before you go quoting figures for death tolls and property damage you need to put forward a convincing argument that the assumptions on which such figures are based are reasonable. This is where you have failed most egregiously.

I agree with you that it's worth looking at credible sources, but to get anything meaningful from them you have to know what you're looking at. It is obvious to me, from what you have written, that you do not.

Anonymous said...

I just heard a talk by Mr Alvarez at Brookings Institute in DC. Needless to say he regurgitated his alarmist/ hyperbolic non sense. He is a hack and has no credible credentials to back up his analysis. He has no engineering degree, and his biggest claim to fame was to help file a lawsuit for Nuclear reactor overexposure victims - laudable but not a source of technical credibility. When I confronted him facts all he could do is recite DOE history.