MOX in Switzerland: Explaining an Uneconomic Fuel Choice

Harry Kim and Alan J. Kuperman

This chapter assesses Switzerland’s use of mixed-oxide (MOX) plutonium-uranium fuel in light water nuclear reactors (LWRs). Interviews were conducted in Switzerland, France, and Germany in 2018 with parliamentary officials, regulators, NGOs, nuclear power plant operators, and think tanks. The report assesses the history of MOX use in Switzerland, including its motivations, economics, operational performance, safety, security, public acceptance, and waste management. The report finds that Switzerland’s use of MOX fuel arose from the absence of a national nuclear waste-management policy, concern about global uranium reserves, and the desire to preserve a nuclear-weapons option. Performance of MOX fuel in Switzerland was acceptable but not without controversy. MOX fuel rods suffered cladding failure and leakage in the core, in 1990 and 1997, raising safety concerns and public unease about nuclear energy. The cost of fresh MOX to Swiss utilities was several times that of traditional low enriched uranium (LEU) fuel. Spent MOX fuel will require more canisters and space in Switzerland’s eventual geological repository than an equivalent amount of spent LEU. The Swiss experience demonstrates that the closed fuel cycle is more expensive than the once-through fuel cycle even if a country does not construct and operate plants for reprocessing spent fuel or fabricating MOX fuel. It also shows that closing the fuel cycle does not solve a country’s nuclear waste disposal challenge.