Reference Material: Japan’s separated plutonium inventory (as of Dec. 31 2020)
By Ban Hideyuki (CNIC Co-Director)
The amount of plutonium stored in Japan as of the end of 2020 has been announced by the Atomic Energy Commission. Significant changes include the amount of plutonium stored in the UK, which has increased by 620 kg. The THORP plant in the UK finished operations in 2018. The reason for the increase is that the calculation of the amount of plutonium in the reprocessing process has been completed and the last allocation has been made to the reprocessing contracting countries.
The decrease at the JAERI reprocessing plant is attributed to storage and disposal (unrecoverable amount), while the decrease at the plutonium fuel fabrication facility is attributed to nuclear loss and inventory differences. The decrease in the Rokkasho Reprocessing Plant is also explained to be mainly due to nuclear loss and inventory difference. Detailed breakdowns of increases/decreases are not shown here, but the categories are: 1) Retained waste; 2) Reclaiming retained waste; 3) Nuclear loss; 4) Measured discard; and 5) Material unaccounted for.