25 Juin 2013
A shipment of mixed-oxide fuel will arrive in Japan as early as June 27, part of the nation’s plutonium stockpile that is already equivalent to 5,000 Nagasaki-type atomic bombs.
The shipment, two years behind schedule due to the Great East Japan Earthquake in 2011, is expected to be used for plutonium-thermal (pluthermal) power generation, a key component of Japan’s nuclear fuel recycling program.
However, the fuel recycling program has been plagued by so many problems that the nation’s plutonium stockpile could increase further, heightening concerns in the international community about possible nuclear weapons proliferation.
The shipment from France is also creating headaches for Kansai Electric Power Co., which plans to use the fuel at its Takahama nuclear power plant in Fukui Prefecture, pending approval of its application to restart the No. 3 and No. 4 reactors there in early July.
Under pluthermal operations, mixed-oxide fuel, which contains plutonium extracted from spent nuclear fuel, is used in nuclear reactors.
A French company processed spent nuclear fuel from Kansai Electric into 20 mixed-oxide fuel assemblies, which contain an estimated 900 kilograms of plutonium. Kansai Electric has not disclosed how many of the fuel assemblies will be brought into the Takahama plant.
Japan currently possesses 44 tons of plutonium, according to the Atomic Energy Commission. Nine tons, including the latest shipment, are in Japan, while the remaining tons are in Britain and France, where spent fuel from Japan has been reprocessed.
The plutonium stockpile has grown exceptionally large for a non-nuclear power. Countries have been discouraged from possessing excess plutonium for fear of weapons applications.
The shipment to the Takahama plant is drawing particular attention because it will be the first mixed-oxide fuel to arrive in Japan since the earthquake and tsunami crippled the Fukushima No. 1 nuclear power plant on March 11, 2011.
Kansai Electric postponed the shipment of the mixed-oxide fuel after the disaster. But the utility has now been forced to accept it in the face of strong demands from France.
The timing of the shipment is undesirable for Kansai Electric, which is putting priority on reactor restarts, rather than resuming pluthermal operations.
“What is important is bringing nuclear reactors back online,” a senior Kansai Electric official said. “We want to avoid drawing criticism in the community now.”
Opposition to pluthermal operations from citizens and other critics is stronger in Kansai than in other regions. Kansai Electric needs a more detailed, time-consuming explanation to the local community than is required of other utilities.
Kansai Electric, which has relied heavily on nuclear power generation to supply its customers, has been desperate to restart idle reactors since incurring 243 billion yen ($2.4 billion) in losses in the year ended March.
Japan’s 50 nuclear reactors were taken offline following the Fukushima nuclear disaster. Only two--at Kansai Electric’s Oi plant--have been brought back online.
Four utilities plan to apply for restarting 12 reactors as soon as new nuclear safety standards take effect July 8.
Three of the reactors were involved in pluthermal power generation before the nuclear disaster: the No. 3 reactor at the Takahama plant, the No. 3 reactor at Shikoku Electric Power Co.’s Ikata plant in Ehime Prefecture, and the No. 3 reactor at Kyushu Electric Power Co.’s Genkai plant in Saga Prefecture.
While Shikoku Electric and Kyushu Electric plan to resume pluthermal operations if the restarts are approved, Makoto Yagi, president of Kansai Electric, remains noncommittal.
“We will make a decision based on changes in government policy and understanding of the local community,” Yagi said.
Another problem for the utilities is that pluthermal operations do not offer an advantage to the companies’ bottom line.
The import value of mixed-oxide fuel brought into the Takahama plant in June 2010 was 1.3 billion yen per ton, according to trade statistics and other sources. The figure is nearly five times as much as conventional uranium fuel due to costs to reprocess the spent fuel and transport it to and from France.
But electric power companies do not have the option of withdrawing from the government-led pluthermal program.
“We have no other choice because Japan needs to consume plutonium,” a senior official of the Federation of Electric Power Companies of Japan said.
The government originally planned to consume plutonium extracted from spent nuclear fuel in a fast-breeder reactor, but plans have remained stalled since sodium leaked at the Monju prototype reactor in 1995.
The government has since shifted its emphasis to feeding mixed-oxide fuel to conventional light water reactors.
Electric power companies had planned pluthermal operations at 16 to 18 reactors, but the number was limited to four reactors due to accident cover-up scandals and other reasons.
One of those reactors was the No. 3 reactor at the stricken Fukushima No. 1 plant that will eventually be decommissioned.
It will also be difficult to introduce pluthermal operations at new facilities.
Idle nuclear reactors will remain offline unless they meet the new safety standards. Some are expected to be decommissioned.
Japan’s plutonium stockpile is expected to increase because the government and utilities plan to start full-scale operations of a spent nuclear fuel reprocessing plant in Aomori Prefecture.
The Aomori prefectural government is demanding the reprocessing of all spent fuel as a condition for accepting used fuel at the plant.
Storage pools for spent fuel are quickly reaching capacity at nuclear power plants across the nation. If Aomori Prefecture refuses to accept spent fuel, nuclear plants will be saddled with overflowing spent fuel pools and will be unable to continue operations.
Direct disposal, or burying spent fuel without reprocessing, was considered under the previous Democratic Party of Japan government. But discussions have gone nowhere after the Liberal Democratic Party took over government in December.
(This article was compiled from reports by Toshio Kawada, Rintaro Sakurai, Shinya Takagi and Mari Fujisaki.)