‘Nuclear Fuel in a Reactor Accident’ — Peter Burns, Rodney Ewing, Alexandra Navrotsky, 2012: Seawater was injected into the three active reactors […] large amounts of salt may have deposited in the reactor cores. […] Nonuniform burn-up in a fuel pellet gives higher concentrations of 239Pu near the pellet edge [...] the major potential pathway for continued release of radionuclides is through flowing water. […] Many radionuclides form aqueous complexes that are soluble in water. Furthermore, water promotes dissolution of the rod/fuel matrix, which releases radionuclides [that] pose a much longer environmental hazard […] The radiolytic breakdown of water creates oxidants (e.g., hydrogen peroxide) that can accelerate the oxidative corrosion of fuel […] If the water is alkaline, soluble nanoscale uranyl peroxo cage clusters are likely to form and persist in solution. […] there is no reliable way of predicting dissolution rates of damaged fuel in water under the conditions of a nuclear accident, especially one like Fukushima Daiichi in which fuel is exposed to hot or boiling seawater […] an understanding of the factors that determine radionuclide release is central to taking appropriate and timely action in order to minimize impacts on the environment and human health. […] Water that interacts with damaged fuel will transport radionuclides that present both short-term and longer-term environmental risk […] potentially continuing for many years if the damaged fuel is not adequately isolated [...]
AAAS Science Podcast interview with Peter Burns about study: […] it’s the interaction of the water and the air with that that is going to control the release of radioactivity to the environment […] what’s different about Fukushima relative to the earlier events is the vast quantities of water that were pumped into the reactor cores […] that created a whole new release pathway for radionuclides out of the reactors into the environment. We don’t know how much radioactivity was released through the water flow, and we don’t know very much about how the water interacted with the fuel and other structure materials. […] we need to take very seriously the development of knowledge about how […] melted nuclear fuel […] interacts with the environment, especially water that we might use in an emergency to cool it. Studies that have been done to date really haven’t looked at the longer-term interactions of water and the atmosphere with these damaged materials. […] as it interacts with water or whatever over time – [fuel] has a potential to release radionuclides that have much longer half-lives and they pose a much longer environmental threat.
See also: Fukushima Nuclear Chief after 3/11: It will be like 'China Syndrome' film, fuel to melt away -- "We're imagining collapse of eastern Japan... going to be more than Chernobyl" -- "Could be Plutonium... all substances from fuel are going to be released"
Published: June 4th, 2014 at 2:44 pm ET