Japan's plutonium utilization plan delayed again

Masafumi Takubo

On 17 February 2023 Japan's Federation of Electric Power Companies (FEPC) announced a new Plutonium Utilization Plan. According to the plan, Japan's eleven nuclear utilities will load mixed-oxide (MOX) fuel containing an average of 0.7 tons plutonium annually during FY 2023-2025 (0.7 tons in FY2023, zero in FY 2024, and 1.4 tons in FY2025, all at Takahama #3&4 operated by Kansai Electric Power Company). For the following two years, FEPC projects 2.1 tons of plutonium will be loaded in FY 2026 and 1.4 tons in FY 2027 but the reactors to be used are not specified.

FEPC has projected since 2020 that "about 6.6 tons/year [of plutonium will be loaded] by FY 2030," but its plans for the "next three years" have been delayed consistently since then. The goal of loading 6.6 tons of plutonium per year, which is highly unlikely to be achievable, would match the projected separation rate of the Rokkasho Reprocessing Plant operating at full capacity. That would put Japan's total stock of separated plutonium on a plateau, but its stock in Japan would increase dramatically if the plutonium loaded in MOX came primarily from Japan's stock of separated plutonium in France. As of the end of 2021, Japan's total stock of separated plutonium was 45.8 tons: 36.5 tons in Europe (21.80 tons in UK and 14.76 tons in France) and 9.3 tons in Japan.

For background, see Japan's Rokkasho reprocessing plant, 25 years behind schedule, delayed again. For the history of MOX fuel shipments and use by Japan, see Mixed Oxide (MOX) Fuel Imports/Use/Storage in Japan.