Tue Mar 15th, 2011 at 09:28:03 PM EST
After the last diary reached 300 comments, time for a new diary
Migeru came upon a an interesting report that discussed similar problems to that which are being experienced in the storage pools at the Fukushima plant. Specifically with BWR reactors.
More interestingly he found the US regulators response, which appears to say that doing anything about this was too expensive as it was far too unlikely to happen.
Post repeated below.
US Nuclear Regulatory Commission: Fact Sheet on NRC Review of Paper on Reducing Hazards from Stored Spent Nuclear Fuel
[editor's note, by Migeru]
The NRC staff has reviewed the paper, "Reducing the Hazards from Stored Spent Power-Reactor Fuel in the United States," April 21, 2003, Robert Alvarez, et al., (published in Science and Global Security, spring 2003) and concludes that it fails to make the case for its central recommendation.But, anyway, that was an unexpected bonus from my google search for the title of the Brookhaven paper:
The paper suffers from excessive conservatisms throughout its cost benefit evaluation. Therefore, the recommendation for an accelerated program of complex and costly measures does not have a sound technical basis. In the United States, spent fuel, in both wet and dry configurations, is safe and measures are in place to adequately protect the public.
... For example, the authors' analysis of societal costs is based on a 1997 Brookhaven National Laboratory study which was performed for a reactor site location that represents an extremely high surrounding population density and is not representative of an industry average.
In estimating fuel damage, the paper again makes reference to past NRC studies which conservatively assumed bounding pool configurations for cooling analysis and conservatively assumed the extent of radiation release. In the 1997 Brookhaven National Laboratory (BNL) study, "Severe Accidents in Spent Fuel Pools in Support of Generic Safety Issue 82," (NUREG/CR-4982), it was assumed that 10-100% of the cesium-137 was released to the atmosphere. Similarly in NUREG-1738 the base case assumed the release of 75% of the total cesium-137 inventory. The assumption of such a large release in NUREG-1738 was a large conservatism which was tolerable for the purposes of that study. However, it is neither a realistic estimate nor an appropriate assumption for a risk assessment of security issues where realism is needed. Ongoing research to address these issues includes more detailed realistic analyses of the thermal response of fuel to loss of water scenarios and more detailed, realistic analyses of the radionuclide releases for those scenarios where adequate cooling is not maintained. Based on preliminary analyses, we conclude that spent fuel in pools is more easily cooled even in the event of a complete loss of water. Further, preliminary analysis indicates that previous NRC estimates of the quantities of fission products released were high by likely an order of magnitude. Earlier NRC studies used large conservatisms, in generic calculations, with simplified modeling.It's remarkable to see a regulator report arguing that the purpose of risk assessment is to convince yourself that the risks are as small as you can get away with.
The reason I was looking for the Brookhaven 1997 paper is that it was mentioned by the New Yortk Times: In Fuel-Cooling Pools, a Danger for the Longer Term
A 1997 study by the Brookhaven National Laboratory on Long Island described a worst-case disaster from uncovered spent fuel in a reactor cooling pool. It estimated 100 quick deaths would occur within a range of 500 miles and 138,000 eventual deaths.
The study also found that land over 2,170 miles would be contaminated and damages would hit $546 billion.
That section of the Brookhaven study focused on boiling water reactors -- the kind at the heart of the Japanese crisis.
European Tribune - Japan: New Open Thread
European Tribune - Japan disasters open thread
European Tribune - Japanese Earthquake Diary