The temperature in the Fukushima Daiichi Unit 4 spent fuel pool never exceeded 90 degrees C and the level in the pool never fell below the top of the used fuel that was stored there. The Chairman of the US Nuclear Regulatory Commission and the people who supported his testimony to Congress on the afternoon of March 16, 2011 were dead wrong.
He swore to the world that the pool was dry and the fuel was burning. His recommendation to evacuate all Americans who were within 50 miles of the facility caused intense embarrassment for one of America’s strongest allies and slowed the development of the only technology with the proven capability of supplying reliable power anywhere and everywhere on earth without releasing greenhouse gases. Jaczko’s testimony was the seed of a continuing campaign of misinformation about the conditions in the unit 4 spent fuel pool.
Chairman Jaczko’s announcement of the spent fuel pool fire and his evacuation recommendations were based on sketchy information, faulty logic, and poor assumptions about the physical behavior of simple materials like steel and water.
Those are the conclusions that should have been announced upon completion of a paper titled Study of Fukushima Daiichi Nuclear Power Station Unit 4 Spent-Fuel Pool. Instead, the research team of Dean Wang, Ian C. Gauld, Graydon L. Yoder, Larry J. Ott, George F. Flanagan, Matthew W. Francis, Emilian L. Popov, Juan J. Carbajo, Prashant K. Jain, John C. Wagner, and Jess C. Gehin completed their paper in December 2011 and submitted it to the peer review process for Nuclear Technology. That process involves no sense of urgency or understanding of the important political aspects of this particular topic.
The paper was accepted for publication in January 2012; the people who reviewed determined that it was accurate. There must be quite a queue of papers waiting for publication at Nuclear Technology; the paper has finally been published in the November 2012 issue of the journal and is available for subscribers or for individual purchase (for a bargain price of just $30.00) on the web. I suspect that it is fated to be greeted with silence instead of the loud acclaim I believe it deserves.
The paper authors have done little to draw attention to their important work, hiding their conclusions in dry scientific language full of acronyms and passive voice that requires reference to other sources for full understanding of what they are trying to say. Here is the abstract:
A study on the Fukushima Daiichi nuclear power station spent-fuel pool (SFP) at Unit 4 (SFP4) is presented in this paper. We discuss the design characteristics of SFP4 and its decay heat load in detail and provide a model that we developed to estimate the SFP evaporation rate based on the SFP temperature. The SFP level of SFP4 following the March 11, 2011, accident is predicted based on the fundamental conservation laws of mass and energy. Our predicted SFP level and temperatures are in good agreement with measured data and are consistent with Tokyo Electric Power Company evaluation results.
The quote below is one of the most important paragraphs in the paper. It provides support for my assertion on March 17, 2012 that Chairman Jaczko’s testimony was dangerously wrong and not based on physical realities.
It is interesting to make some simple calculations. For example, the SFP will daily lose 2 tons of water when the SFP temperature is at 40 C. The water loss would increase to 86 tons when the SFP temperature reaches 87.5 C, which means that such an evaporation rate would take away all the decay heat of SPF4 without reaching the boiling temperature. It should be pointed out that this analysis is very important to understand the SFP temperature data collected in SFP4. SFP4 would reach the equilibrium temperature within 2 days during the loss of SFP cooling with a total decay heat of 2.28 MW. We should not expect any observable changes in the SFP temperature over a short time (days to months) during a loss-of-cooling event since the decay heat change is small. We will discuss this later in the paper.
That information should be considered in all proposed regulatory actions to improve monitoring and cooling capabilities for spent fuel pools, but I suspect it will be ignored in the battle to create the most “conservative” models possible.
Here is the rather quiet conclusion from the Nuclear Technology paper.
… it is reasonably concluded that there would have been no large leakage in the SFP and no occurrence of fuel uncovery at any time.
The below statement helps to explain why this paper and its important conclusions have been soft peddled.
This manuscript has been authored by UT-Battelle LLC under contract DE-AC05-00OR22725 with the U.S. Department of Energy.
There is not usually much appetite among politically dependent funding sources for issuing clearly written materials that show that statements made by the heads of other agencies were completely wrong, especially when the person who made the false statement in the first place was backed up by the President and the Senate Majority Leader.
Are you getting the sense that I think there is a serious need for recalibration of the perceived risk to benefit ratio for nuclear energy? Not only are the benefits of an emission free, energy dense, reliable power source understated, but the hazards from the use of the power source have been hugely overstated. Nuclear energy is capable of rapid growth, important to the prosperity of billions of human beings, and extremely safe when handled with moderate care.