TOKYO -- Japan is laying out plans to reduce its plutonium stockpile in response to international pressure, but the move would force difficult decisions regarding a power industry built around the nuclear fuel cycle.
The government will draw up guidelines aimed at reducing its supply as early as this month and report on its efforts to the International Atomic Energy Agency. The measures will include a cap on Japan's reserves.
Japan extracts plutonium from spent nuclear fuel to reuse in reactors, but the highly radioactive element can also be employed in atomic weapons. The country possessed about 46.9 tons of plutonium at the end of 2016, most of which, 37.1 tons, is being stored temporarily in France and the U.K. for reprocessing.
Cooperation among power companies will be a cornerstone of the government plan. Most of Japan's nuclear capacity remains offline following the 2011 Fukushima Daiichi disaster, and big utilities, including Tokyo Electric Power Co. Holdings and Chubu Electric Power, have yet to restart reactors capable of "pluthermal" power generation, which uses mixed-oxide fuel containing plutonium and uranium.
This has led to excess plutonium piling up inside and outside Japan as spent fuel continues to be recycled. The government envisions having these utilities transfer their plutonium to peers that can use it now, such as Kyushu Electric Power, whose pluthermal-capable Genkai No. 3 reactor is online.
"As nuclear power plant operators, we do not possess any plutonium without a specified purpose," said Satoru Katsuno, chairman of the Federation of Electric Power Companies and president of Chubu Electric. Steady progress is being made on pluthermal power, he added.
But having utilities hand over plutonium to peers may be easier said than done. Power companies in principle recycle only their own waste, in light of potentially costly concerns such as liability in the event of an accident involving fuel from elsewhere, a senior utility executive said.
And transferring mixed-oxide fuel to another company's plant could spark protests by local residents. The utilities will consider this issue, Katsuno said, noting that they have relationships with the municipalities situated near nuclear plants.
"Our priority is restarting our own reactors" to use up excess plutonium, rather than sending it elsewhere, said Hokkaido Electric Power President Akihiko Mayumi.
The government guidelines will also call for minimizing the plutonium produced by Japan's Rokkasho reprocessing facility. Tokyo plans to let the plant recycle only as much fuel as is needed for pluthermal generation.
But Japanese power companies have together invested more than 2 trillion yen ($18 billion) in Japan Nuclear Fuel, which operates the Rokkasho facility. Should it become unprofitable, the foundation of Japan's nuclear fuel cycle policy would be shaken.
Yet pressure from the international community -- particularly the U.S., whose deal with Japan has made it the only nation without nuclear weapons allowed to reprocess spent fuel -- has left Tokyo with little choice but to whittle down its plutonium stockpile.
American ally Saudi Arabia is said to be seeking permission for a facility like Japan's to help wean itself off oil as well as to compete with regional rival Iran, which it suspects of pursuing its own nuclear program. South Korea also requested a similar arrangement when it negotiated a revised nuclear deal with the U.S. in 2015. China, meanwhile, has voiced concern that Japanese plutonium could be diverted for nuclear weapons.
The U.S. is well aware of Japan's strict oversight of its plutonium supply, a diplomatic insider said. But the administration of President Donald Trump is still leaning harder on Tokyo to cut back. As Washington prepares for serious denuclearization talks with Pyongyang after Tuesday's meeting between Trump and North Korean leader Kim Jong Un, it must rethink Japan's unique exemption.
The Trump administration is more worried about nonproliferation than Barack Obama's, the diplomatic source said.
Tokyo hopes its new guidelines will garner support from the international community. "If we take any more time to cut our plutonium supply, the international criticism will intensify," a Japanese government insider said. "We'll make clear that we plan to reduce it so that we're not unjustly suspected."