25 Septembre 2012
September 25, 2012
Methods and locations for the disposal of nuclear fuel remain unclear as the government maintains a directionless course over its nuclear policy, which is full of inconsistencies on eliminating nuclear power by the 2030s.
The government has mapped out its nuclear policy in a document on "innovative energy and environmental strategy," but it failed to clarify how spent nuclear fuel from power plants is to be disposed of.
The strategy referred to beginning research on burying spent fuel underground as a final disposal measure, but at the same time, said a project to reprocess spent fuel will continue.
Finding final disposal sites is certain to become more difficult as public distrust of nuclear power has been growing following the crisis at the Fukushima No. 1 nuclear power plant.
"It's impossible to win residents' understanding," said an official of the Nuclear Waste Management Organization (NUMO) after he learned the government called for research into burying the fuel in its new energy policy. The main pillar of the policy is zero dependence on nuclear power.
NUMO, a private organization, has been trying to find final disposal sites for spent fuel.
Currently, all spent fuel from nuclear power plants is reprocessed and plutonium and uranium are extracted from the fuel and recycled as plutonium-uranium mixed oxide (MOX) fuel.
The remaining highly radioactive waste is to be vitrified and permanently buried 300 meters or deeper underground.
The government also included in the current plan an option to dispose of spent fuel by directly burying it underground in anticipation of the future zero nuclear target.
However, if research to bury the fuel underground begins, this will surely increase the hurdles in finding final disposal sites.
If nuclear waste is buried before being reprocessed, the volume is expected to be about three times that of reprocessed waste, making it more difficult to secure disposal sites.
"There aren't many technical problems. The thing that's difficult is addressing the unease of residents who worry that recriticality may occur as [the waste] contains plutonium and other things," said Osamu Tochiyama, director general of Nuclear Safety Research Association's Radioactive Waste Disposal Safety Research Center.
In 2002, the government and NUMO said buried vitrified waste would not affect the environment although it would take several tens of thousands of years until radiation would reach natural levels.
That year, they started searching for potential final disposal sites. But the only local government that applied to be the site was Toyo, Kochi Prefecture. The town later rescinded its application and there has been no further progress on the issue.
"There has been no research to directly bury spent fuel underground, and it will take time to establish the technology. It's almost certain there will be more delays in finding sites," a NUMO official said.
Under the circumstances, a proposal submitted by the Science Council of Japan on Sept. 11 created a stir as it proposed new measures to dispose of spent fuel.
The proposal differs greatly from the current government plan, noting that it is difficult to anticipate the long-term stability of the Earth's strata.
"[We propose] temporarily storing spent fuel in a way that makes it possible to retrieve after several decades or hundreds of years. During that time we can study the stability of strata. We can also study appropriate measures to dispose of the fuel and look into ways to lower the risk of radioactive substances," the proposal said.
The council opted for temporary storage as it wants to find a solution by proceeding to discussions over the deadlocked nuclear waste disposal issue.
The council made this move as it feared there will be no space to store spent fuel that has been piling up toward the capacity of spent fuel pools at nuclear power plants.
If every nuclear reactor restarted operations, the pools are expected to reach capacity in an average of six years. The pools at the Tokai No. 2 nuclear power plant in Ibaraki Prefecture, the Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture and the Genkai nuclear power plant in Saga Prefecture are expected to reach capacity in about three years.
NUMO is perplexed by the council's proposal.
"The technology to safely bury [spent fuel] underground for several tens of thousands of years has been established. [We're embarrassed] to hear a proposal reversing the initial plan," a NUMO official said.
The Japan Atomic Energy Commission under the Cabinet Office, which asked the council to draw up a proposal, is also unsure how to handle the council's proposal.
Meanwhile, the government is looking to abolish and reorganize the commission that set the basic atomic energy policies.
The government's strategy and its many inconsistencies will cast further uncertainty over types and amounts of nuclear waste, adding another layer of confusion.