WNWR 2019 — 4. RISKS FOR THE ENVIRONMENT AND HUMAN HEALTH
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be constantly monitored, continually cooled to remove decay heat, and chemically adjusted to ensure correct alkalinity levels. If cooling were to fail for any reason, the pools would fully evaporate within a few days and the fuel assemblies could ignite as their zirconium cladding would react strongly with oxygen in air.118 The same would occur if the pond waters were emptied for any reason, such as a breach of the walls of the pools caused by a terrorist attack. These problems grow worse over time by the fact that the lengths of time spent fuel stays in pools has been increasing and now routinely extend for several decades.
The continued practise of storing spent nuclear fuel for long periods in pools at most nuclear power plants worldwide constitutes a major risk to the public and to the environment. Spent nuclear fuel contains most of the radioactivity in the world’s nuclear waste, and consists of fission and activation products. In 2014, the US Nuclear Regulatory Commission (NRC) examined whether to require most spent fuel currently held in pools at nuclear power plants to be moved into dry casks and storage vaults. Such a move would reduce the likelihood and consequences of a spent fuel pool fire. It concluded that the projected benefits did not justify the estimated US$4 billion cost of a wholesale transfer.119 However, the NRC report was criticized for seriously underestimating the risk and consequences of a spent fuel fire: models of a potential accident at US nuclear fuel storage sites estimated very serious effects of hypothetical radionuclide releases.120 They contained maps illustrating the radioactive plumes across large areas of northeastern United States. The lead author, Professor Frank von Hippel, Princeton University, warned of drastic economic consequences: “We’re talking about trillion-dollar consequences.” 121 This risk not just affects the US but most countries that operate nuclear power plants, where increasing amounts of spent fuel are being left in cooling pools for increasingly long periods of time. The absence of robust proven technical solutions and the existence of political opposition to plans for nuclear waste facilities make this difficult situation even more problematic. The present situation poses considerable challenges for current governments and future generations. In the meantime, it is widely accepted that spent nuclear fuel requires well-designed storage for long periods to minimize the risks of releases of the contained radioactivity to the environment. Safeguards are also required to ensure that neither plutonium nor highly enriched uranium is diverted to weapons use.
4.5 RISKS FROM THE REPROCESSING OF SPENT NUCLEAR FUEL Two main means exist for managing spent nuclear fuel: long-term storage with the ultimate aim of direct disposal and reprocessing. This section discusses the latter method. In the 1950s and 1960s, during the Cold War, countries constructed reprocessing plants in order to create weapons with plutonium separated from spent fuel. 118 von Hippel, F.N. and Schoeppner, M. 2016, Reducing the danger from fires in spent fuel pools,
Science & Global Security, 24(3), pp. 141-173. 119 Barto, A. 2014, Consequence study of a beyond-design-basis earthquake affecting the spent fuel pool for a US Mark
I boiling water reactor, United States Nuclear Regulatory Commission, Office of Nuclear Regulatory Research. 120 von Hippel, F.N. and Schoeppner, M. 2017, Economic Losses from a Fire in a Dense-Packed US Spent Fuel Pool,
Science & Global Security, 25(2), pp.80-92. 121 Stone, R. 2016, “Spent fuel fire on US soil could dwarf impact of Fukushima”, Science, May 24, viewed 25 May 2019,
https://www.sciencemag.org/news/2016/05/spent-fuel-fire-us-soil-could-dwarf-impact-fukushima
