Reference Material: Japan’s Separated Plutonium Inventory (as of Dec. 31, 2023)

By Matsukubo Hajime (CNIC)

Starting with the plutonium management data released at the end of 2022, the Atomic Energy Commission has drastically changed the way it used to describe the situation at each facility and process in detail. At present, having combined data for Japan Nuclear Fuel and the Japan Atomic Energy Agency, the process is also now described in combination with the classification. Although there has been little movement at present, uncertainty will further increase as the Rokkasho Reprocessing Plant is completed and the pluthermal process proceeds at each nuclear power plant. In 2023, the Takahama Unit 3 reactor consumed 631 kg of plutonium (16 assemblies of MOX fuel). On June 12, 2023, the Federation of Electric Power Companies of Japan announced a Kansai Electric Power Company plan to transport around 10 tons of spent MOX fuel and around 190 tons of spent fuel from to France for reprocessing in the latter half of the 2020s. Further, as Kyushu Electric and Shikoku Electric Power Companies’ plutonium stocks held in France have all but run out, these companies also announced a plan to exchange plutonium held overseas by other Japanese power companies (1.7 tons of fissile plutonium, including 0.1 tons from Tohoku Electric, 1.0 tons from Tokyo Electric, 0.4 tons from Chubu Electric, 0.0 tons from Hokuriku Electric, and 0.2 tons from the Japan Atomic Power Company) with plutonium held in the UK (Shikoku Electric, 0.7 tons of fissile plutonium and Kyushu Electric, 1.0 tons) for use as MOX fuel by both companies (February 16, 2024).