TOKYO -- Japan was in possession of a total of some 46.1 metric tons of plutonium at home and abroad as of the end of 2020, the Cabinet Office reported to the Japan Atomic Energy Commission (JAEC) on July 9. The amount represents an increase of about 0.6 tons from the previous year.
The JAEC had stated that the country would reduce its plutonium stockpile under guidelines revised in July 2018, and the amount in its possession had been on a downward trend since then. The reported increase was the first in three years.
Plutonium is extracted from spent nuclear fuel generated at nuclear plants, for the purpose of recycling. However, the international community has expressed concerns over Japan's large plutonium stockpile, saying it could be converted into nuclear weapons.
According to the Cabinet Office report, the latest increase in the nation's plutonium stockpile was due to the addition of roughly 0.6 tons that had been stored in Britain after being extracted from nuclear fuel but which had not been included in the stockpile due to delayed procedures. As the extraction of plutonium in Britain and France has been completed, Japan has no more unrecorded stockpiles, according to the report.
Plutonium is mixed with uranium to produce mixed oxide (MOX) fuel for use at nuclear power plants. However, none of the nuclear plants in Japan used MOX fuel in 2020. As a result, the domestic stockpile remained at the same level as the previous year, at roughly 8.9 tons.
If the nuclear fuel reprocessing plant operated by Japan Nuclear Fuel Ltd. in the village of Rokkasho, Aomori Prefecture, goes into full operation in fiscal 2023, Japan's plutonium stockpile will increase. However, only 0.6 tons of plutonium is expected to be extracted from spent fuel at the plant in fiscal 2023.
Meanwhile, the Federation of Electric Power Companies of Japan (FEPC), comprising major domestic power utilities, plans to consume 0.2 to 1.4 tons of plutonium per year between fiscal 2021 and 2023.
JAEC Chairman Mitsuru Uesaka commented, "The stockpile will be on a downward trend from here on."
In the wake of the nuclear meltdowns at the Fukushima Daiichi Nuclear Power Station, only four reactors capable of using MOX fuel have been restarted, including the No. 3 and No. 4 reactors at Kansai Electric Power Co.'s Takahama Nuclear Power Plant in Fukui Prefecture. While the FEPC aims to increase the number of such reactors to at least 12 by fiscal 2030, thereby consuming 6.6 tons of plutonium per year, there are no prospects of being able to activate other reactors or of local bodies and residents giving the green light for such a move.
(Japanese original by Ei Okada, Science & Environment News Department)