Japan has decided to reduce its plutonium stockpile, in line with its principle of possessing only the amount necessary for peaceful use, the country’s nuclear panel said Tuesday, while failing to give a numerical target.
The Japan Atomic Energy Commission also said in the revised policy guideline that plutonium production at the planned Rokkasho reprocessing plant should be limited to the amount required to fuel the country’s nuclear reactors.
The revision to the 2003 plutonium-use policy came amid international concerns about a stockpile increase and uncertainty about the recycling policy on spent nuclear fuel following the 2011 Fukushima disaster.
In its updated policy, the panel said “recent circumstances surrounding the use of nuclear energy not only in Japan but also in the world” have been taken into account, while pledging to cooperate with the international community to work toward nuclear nonproliferation.
The commission, however, did not specify a cap on the amount of plutonium allowed to be possessed nor a deadline for curbing the stockpile.
Some countries, including the United States, which has allowed Japan to extract plutonium and enrich uranium for decades, are seen as concerned about its increasing stockpile of plutonium.
On July 17, Japan and the U.S. extended a bilateral nuclear agreement beyond its initial 30-year period that has served as the basis for Tokyo’s push for a nuclear fuel recycle policy.
Japan had a total of 47.3 tons of plutonium at the end of 2017, up from 46.9 tons the year before, which is enough to produce about 6,000 nuclear warheads.
Most of the total, or about 36.7 tons, was stored overseas — 21.2 tons in the U.K. and 15.5 tons in France. About 10.5 tons are kept within the country, according to the government.
The panel said the country will aim to keep its stockpile from rising further by taking a series of measures, including the steady curbing of plutonium stored overseas.
Despite the latest pledge, it remains to be seen whether the amount of plutonium can actually be curbed once the Rokkasho fuel reprocessing plant starts operating, nuclear experts say.
The plant in Aomori Prefecture is now expected to be completed in the first half of fiscal 2021 following repeated delays. When fully operational, it is designed to extract about 8 tons of plutonium per year through the reprocessing of up to 800 tons of spent fuel.
Resource-poor Japan has been pushing for a fuel cycle policy. Spent fuel from nuclear reactors is reprocessed to extract uranium and plutonium, which is then recycled into fuel called mixed oxide (MOX) for use in fast-breeder reactors or conventional nuclear reactors.
But most of the country’s nuclear reactors remain offline amid safety concerns and public opposition, and the prospects are dim for active MOX fuel use. Currently, only four nuclear reactors can burn it.
In a setback for nuclear fuel recycling, the government decided in 2016 to scrap the trouble-plagued Monju prototype fast-breeder reactor.