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The plant in Rokkasho in northern Japan was out of action for six months from the end of 2008 due to problems in one of its vitrification facilities, a furnace that mixes high active liquid waste with molten glass to seal radioactive waste in steel canisters that can safely be buried in the ground.
Attempts to restart the plant failed last November as problems with the glass melting process persisted. Then in January, 150 liters of high-level liquid radioactive waste leaked from pipes in the vitrification cell, forcing Japan Nuclear Fuel Ltd. to postpone operations until August.
The problems at Rokkasho, especially with extracting plutonium from spent nuclear fuel, are a blow to Japan’s nuclear fuel-cycle program, whose goal is to reprocess and re-use recoverable resources from spent nuclear fuel to produce fuel for its power plants. In fact the commitment to a domestic program to increase energy and reduce nuclear waste by reprocessing spent fuel led to the creation of Japan Nuclear Fuel Ltd.
At full capacity, the Rokkasho plant can process 800 tons of spent fuel and extract eight tons of plutonium from it annually. Japan currently has over 40 tons of plutonium, but only around 5.5 tons is kept in Japan, with the rest at reprocessing plants in France and Britain.
The main issue for Japan is the storage of spent fuel, since agreements with regional governments do not permit it to indefinitely hold it at nuclear power plants. Sending it to reprocessing plants like Rokkasho would help overcome this problem. So the technical snags at Rokkasho are a big concern.
Isami Kojima, president of JNFL, said at a press conference last month, "We have much work to do but we don't think that the melting furnace is defective merchandise." Kojima is intent on not postponing operations at Rokkasho beyond August, although according to a source at the plant, it is almost impossible to get the plant up and running within this year.
Since November 2007, when the glass melting furnace was first tested, every attempt to fix a problem has seen another arise. First, operations were suspended because of damage to the machine that welds the lids onto the waste canisters. Then the outlet of the furnace was found blocked due to the accumulation of platinum within the liquid waste at the bottom of the furnace. Attempts to deal with this accumulation failed when the nozzle through which the glass was supposed to flow could not be heated, blocking the glass. Later, operations had to cease when stirring rods inside the furnace were found bent due to heat and the fuel load.
Although the Rokkasho plant was originally built using technology from France, the vitrification process was developed at Japan's Tokai Reprocessing Facility. "If things go wrong, the reprocessing plant could be halted for more than three years," said a source at the plant, on condition of anonymity, who admitted that problems would not be resolved any time soon.
Hiroaki Koide, an assistant professor at the Kyoto University Research Reactor Institute, endorses the same viewpoint. "The furnace of the Rokkasho plant cannot deal with the problem of the platinum group. Although JNFL has to design a new one after casting aside both the troubled A furnace and the unused B furnace, which is the same design as A, it is not sure that even the new one would work well," he said.
Japan was banned by the United States from producing nuclear weapons after World War II. But it has pursued developing nuclear power for civilian use in order to be energy self-sufficient. Although it is the world’s third-largest producer of nuclear power after the United States and France, it still lags behind in the area of reprocessing technology.
"The failure to produce vitrified waste with domestic technology shows that Japan's reprocessing technology is 10 to 20 years behind Europe and the United States," Koide said.
The source at the Rokkasho plant agrees with Koide. "We have to accept that we were too optimistic from the beginning," he said. He also said that JNFL should change its policy, whatever it takes, to solve the difficulties with the current furnace at Rokkasho.
One possible solution would be to use French technology, but the Japanese government is bent on developing its own technology and unlikely to choose that option. If the plant suspends operations for more than three years, as the source at Rokkasho suggests, then the situation will be more serious as Japan's nuclear power policy is premised on reprocessing spent nuclear fuel at the plant.
"If the Rokkasho plant cannot accept spent fuel due to its long-term closure, then electric companies that run out of storage space will have to shut down their nuclear power in turn," the source said.
According to the Federation of Electric Power Companies of Japan, out of the 19,240 tons of total storage capacity available in Japan for spent nuclear fuel, 60 percent is already used up. It is believed that the storage capacity at the Fukushima No.1 and No. 2 power plants, operated by the Tokyo Electric Power Company, will be used up within two to three years.
Although an interim storage facility for spent nuclear fuel in Mutsu city is expected to start accepting fuel in 2012, the schedule is unclear. A government safety review has been prolonged because of an active fault running near the site.
Japan also must deal with the attitude of its main ally, the United States, toward its nuclear activity. Unlike former U.S. President George W. Bush, who promoted the idea of reprocessing facilities, President Barack Obama is against it.
Late last month he announced that the United States would not build any reprocessing facilities or a reactor to burn the plutonium extracted by reprocessing facilities. Obama also officially announced that the country would abandon a project to construct a nuclear repository at Yucca Mountain in Nevada, even though over US$10 billion has been invested in research since 1994.
Obama’s decision has disappointed many nuclear power countries that face problems associated with the storage and reprocessing of spent nuclear fuel. Still, Japan is unlikely to give up its reprocessing policy. It has both nuclear power plants and a reprocessing plant that can produce plutonium, the basic ingredient for nuclear bombs.
"For Japanese policymakers, it is a matter, of course, of keeping open the option of producing nuclear bombs. This is the reason Japan has been fastidious about the reprocessing, which comes at a high cost and is unsafe," Koide said. "It is impossible for Japan to back away from the reprocessing policy."
