TOKYO (AP) — Japan's nuclear policy-setting panel on Tuesday approved revised guidelines on plutonium use, putting a cap on its stockpile and pledging to eventually reduce it to address international concerns, but without giving a specific timeline or targets.
The Japan Atomic Energy Commission's guidelines call for some government oversight to carefully regulate operation of the Rokkasho reprocessing plant in northern Japan when it starts up in three years so the amount of extracted plutonium doesn't spike.
Despite security concerns raised by Washington and others, the stockpile isn't decreasing due to difficulties in achieving a full nuclear fuel recycling program and slow restarts of reactors amid setbacks from the 2011 Fukushima disaster.
The guidelines, updated for the first time in 15 years, also urge Japanese utility operators to steadily consume plutonium reprocessed overseas, but does not elaborate on how that works out with additional plutonium from Rokkasho.
The guidelines say Japan's stockpile should not exceed "the current level."
Japan now has about 47 tons of separated plutonium — 11 tons at home, and 36 tons in Britain and France, where spent fuel from Japanese nuclear plants has been reprocessed and stored because Japan is not able to reprocess it into MOX fuel at home. The amount is enough to make about 6,000 atomic bombs.
Japan reprocesses spent fuel, instead of disposing it as waste, to extract plutonium and uranium to make MOX fuel for reuse, while the U.S. discontinued the costly program. Allowed under international safeguard rules, Japan is the only non-nuclear weapons state that separates plutonium for peaceful uses, though the same technology can make atomic bombs.
"A suspicion that Japan is stocking up plutonium is not undesirable from a nonproliferation perspective," commission chairman Yoshiaki Oka told reporters, explaining that a cap was set. "It is extremely important that we strictly control the plutonium stockpile and increase transparency."
Officials at the government and Japan Nuclear Fuel Ltd., which operates the Rokkasho plant, ruled out any risk of proliferation, citing tight safeguards and close monitoring by the IAEA.
JNFL said in a statement that it will keep up with its safeguarding and transparency to gain international trust.
The stockpile largely comes from overly optimistic projections that had relied on the Monju plutonium reactor, and its failure has forced Japan to resort to conventional light water reactors as the only realistic option to burn it.
Seven years after the Fukushima meltdown, five of the 38 workable reactors have restarted, but only three of them are approved as MOX compatible and together they consume just over 1 ton of plutonium annually.
The guidelines also urged the utility operators to increase their capacity to keep spent fuel in long-term storage until it's needed for reprocessing at Rokkasho. Spent fuel storage space is getting tight, a concern shared by many nuclear plant operators, but any plan to build additional facilities is a sensitive issue.
Japan has long denied any possible misuse of the material and reprocessing technology, and has pledged to not possess plutonium that does not have a planned use. But its failure to reduce the stockpile of separated plutonium doesn't look good, especially as the U.S. wants North Korea to get rid of its nuclear weapons and abandon reprocessing capabilities.
China has announced plans to build a similar reprocessing plant with France, while South Korea has expressed interest in reprocessing, raising a concern over future plutonium concentration in the region, experts say.