Reference Material: Japan’s separated plutonium inventory (as of Dec. 31, 2021)
The Atomic Energy Commission has released the amount of Japan’s plutonium stockpile as of the end of 2021. The decrease in the United Kingdom is thought to be due to nuclear loss. The main reason for the decrease in France is that the plutonium was processed into MOX fuel and exported to Japan. The export destination was Takahama Unit 4, and the amount was 629 kg, as shown in the stored plutonium. 198 kg of plutonium at the Ikata Unit 3 has been irradiated; calculations show that there is a difference of 1 kg, but this is explained as ‘retained waste.’
The decrease at JAERI’s reprocessing plant is also due to ‘retained waste’ (unrecoverable amount), and the decrease at the Plutonium Fuel Fabrication Facility is due to nuclear loss and material unaccounted for (inventory difference). The decrease at the Rokkasho Reprocessing Plant is explained as nuclear loss and material unaccounted for (inventory differences). The categories of increases/decreases are: 1) Retained waste; 2) Reclaimed retained waste; 3) Nuclear loss; 4) Measured discard; and 5) Material unaccounted for.