Japan, US renew nuke pact amid Japan plutonium stock concern
Japan’s stockpile of plutonium causes jitters as pact is renewed
Japan and the U.S. have extended their nuclear pact as Tokyo pledged to work to reduce its plutonium stockpile to address Washington's concern. The 30-year pact agreed upon in 1988 has allowed Japan to extract plutonium and enrich uranium for peaceful uses even though the same technology can make atomic bombs. Without either side requesting a review, the pact was extended Tuesday with an option by which it can be terminated by either side giving six months' notice. The new condition, however, makes Japan's nuclear program more susceptible to U.S. policy. Foreign Minister Taro Kono told reporters that Japan must reduce the stockpile to keep the pact in place stably.
Reducing Japan’s plutonium stock
But in the 21 years between 1995, when a sodium leak at the Monju reactor forced a shutdown of operations, and 2016, when the government formally decided to scrap the facility, Japan's plutonium stockpile increased threefold.
"If the government is to continue its nuclear fuel recycling program, it will be insufficient to only revise its plutonium usage plan," Sakata said. "The only option available will be to show the world through specific results that it is serious about not holding surplus plutonium."
Under the elusive nuclear fuel cycle policy, plutonium extracted from spent fuel removed from nuclear reactors is to be converted into plutonium-uranium mixed oxide (MOX) fuel to be used either in fast-breeder reactors or in conventional nuclear plants. But Monju, the nation’s sole fast-breeder reactor and once deemed a prototype for a dream technology for this resource-scarce country because it produces more plutonium than it consumes as fuel, remained mostly idle after it reached criticality for the first time in 1994. It suffered a sodium coolant leak and fire in 1995 and a subsequent series of other problems, until the decision was made in 2016 to finally pull the plug for good.
The use of MOX fuel in conventional reactors, deemed a substitute way to consume the plutonium stockpile, has also not proceeded as expected. The government earlier planned to have MOX fuel used at 16 to 18 reactors across the country by 2015. But the restart of nuclear power plants idled in the wake of the 2011 meltdowns at Tokyo Electric Power Co.’s Fukushima No. 1 plant remains slow. Only four of the nine reactors that have so far been brought back online are capable of using the costly MOX fuel, and only in small amounts.
While the consumption of plutonium as reactor fuel stagnates, the reprocessing of the spent fuel to extract plutonium has also hit a snag. Completion of a reprocessing plant in Rokkasho, Aomori Prefecture — on which more than ¥2 trillion has already been spent — has been delayed for years due to a series of technical glitches. But once completed, the reprocessing plant supposedly will be able to produce up to 8 tons of plutonium annually, raising the specter of further increasing the stockpile of unused plutonium if its use does not pick up.