PDF: Estimating the Potential Impact of Failure of the Fukushima Daiichi Unit 4 Spent Fuel Pool A Local Problem for Japan or a Global Mega Crisis?
Holophi Special Report
Paul C. Gailey, Ph.D., President & CEO, Holophi CH AG
Extreme opinions are being voiced about the risk of global catastrophe resulting from a possible collapse of the Fukushima Daiichi unit 4 spent fuel pool. These claims are appearing mostly among the public through internet media and other non-‐official channels. Officials sources remain largely mute on the subject or downplay the risks. This report provides an approximate bounding of the risks using available data. The results of this analysis suggest that a nominal release of 10% of the SFP 4 inventory of cesium and strontium would represent 3-‐10 times the March 2011 release amounts, substantially increasing risk levels in Japan and impacting marine life. Release of 100% of the SFP 4 inventory, or 30-‐100 times the March 2011 release amounts, could result in significant global impact.
Radioactivity releases from the Fukushima Daiichi reactors so far appear to have resulted from a number different processes. For example, the very low plutonium releases (possibly 100,000 times less than Chernobyl as a fraction of plutonium present), suggest that it resulted from shattering of fuel rods during the hydrogen explosions (Zheng et al., 2012). The prolonged fires at Chernobyl may have volatilized plutonium by heating. Although the unit 4 reactor does not use MOX fuel, plutonium is created as a by product of reactor operation and spent fuel is about 1% plutonium isotopes. Extensive studies have been performed to determine the rates and mechanisms of plutonium volatilization (Gelbard et al., 2003). The fraction of plutonium aerosolized can vary over a wide range depending on temperature, air flow, the presence of water vapor, and other factors.
h/t Enformable, Chris Harris
Published: June 27th, 2012 at 7:10 pm ET