Japan's Plutonium Stockpile Expected to Remain at 44.4 Tons by End of 2025

Japan's Cabinet Office reported to the Japan Atomic Energy Commission (JAEC) on August 5 that Japan's plutonium stockpile is expected to be 44.4 tons by the end of 2025, unchanged from the end of the previous year.

By source, domestically sourced plutonium stockpile is expected to be 9.9 tons, while overseas-sourced plutonium stockpile is 34.5 tons. The overseas-sourced plutonium mainly comes from separated plutonium formed after Japan entrusted its spent fuel reprocessing operations to the United Kingdom and France.

The report shows that in 2024, Kansai Electric Power Company (KEPCO) processed 1.3 tons of plutonium stored in France into mixed uranium-plutonium oxide fuel, namely MOX fuel, resulting in a decrease in overseas-sourced plutonium stockpile. Subsequently, after this batch of MOX fuel was shipped to Units 3 and 4 of the Takahama Nuclear Power Plant in Fukui Prefecture, the corresponding quantity was counted into the domestically sourced plutonium stockpile, increasing the domestic source by 1.3 tons.

Affected by the above stockpile transfer, Japan's total plutonium stockpile remained unchanged, still maintained at 44.4 tons.