Japan's Spent Fuel and Plutonium Management Challenges

Japan’s spent fuel management and fuel cycle programs are now at a critical stage. Its first commercial-scale reprocessing plant, at Rokkasho Village, will soon start full-scale operation.
Japan's commitment to plutonium recycling has been maintained since the introduction of nuclear power to Japan and has been explicitly stated in its Long Term Program since 1956. Under Japan's nuclear regulatory requirements, utilities must submit evidence that their spent fuel will be reprocessed before they load the fuel. They also commit to their local communities to ship spent fuel from the reactor site to reprocessing plants "soon" (without any time period being specified, however). Therefore, there has been no choice for utility companies but to make reprocessing contracts.

Despite the clear cost disadvantage of reprocessing compared with direct disposal or storage of spent fuel, the latest Framework for Nuclear Energy Policy published in November 2005 by Japan's Atomic Energy Commission (JAEC) did not change the policy that spent fuel must be reprocessed. The Rokkasho reprocessing plant therefore started active testing on March 31, 2006.
The financial risk to Japan’s nuclear utilities from operating the Rokkasho plant has been significantly reduced by the establishment of a “reprocessing fund” that is, in effect, a tax on all Japan's electric-power consumers – not just consumers of nuclear-power – to pay the costs. The risk has not been eliminated entirely, however. Losses due to accidents or operational problems will probably not be covered by the fund.
Since 1977, Japan has separated a total of 7 tons of plutonium in Japan. In addition, during the 1970s, Japan's utilities made reprocessing contracts with BNFL (in the United Kingdom) and COGEMA (in France) which have resulted in the separation of a total of 41 tons of plutonium out of which only 2 tons have been returned to Japan. Japan's stockpile of separated plutonium held at home and abroad totaled 43 tons at the end of 2004.1 Japan's cumulative consumption of plutonium has been only 5 tons to date and its future consumption rate is still uncertain. But once the Rokkasho reprocessing plant starts its operation, Japan will separate about 8 tons of plutonium annually. There is every reason to postpone this reprocessing until Japan has dealt with its backlog of separated plutonium.

Japan's utilities, however, are under pressure to deal with their accumulating spent fuel. According to Government and industry estimates, some nuclear power plant (NPP) storage pools will be filled up by the end of 2006. This is the main reason given for starting operation of the Rokkasho reprocessing plant. In addition, because the Rokkasho plant, even operating at full capacity, will not be able to keep up with the projected discharges of spent fuel, Japan's utilities have decided to build an interim away-from-reactor (AFR) spent-fuel storage facility (which has been allowed since 1998). This facility will be built in Mutsu city at Aomori prefecture and is projected to start operation in 2010.

Our analysis shows that, with optimum use of available at-reactor and away-from-reactor storage capacity, there would be no need for reprocessing until the mid 2020s. There would be sufficient spent fuel storage capacity up to 2025 (low spent-fuel burn-up case) or 2028 (high burn-up case). With an additional 30,000 tons of AFR spent fuel storage capacity (the equivalent of six more Mutsu type facilities but potentially at a smaller number of sites or even all at Mutsu) reprocessing could be avoided until 2050.
But, the political obstacles to such a no-reprocessing strategy would be severe. Transfers of spent fuel among NPP sites and the siting of additional AFR storage facilities would be opposed by local authorities. Also, because Japan Atomic Power Company (JAPC) has the exclusive rights to the PWR spent fuel storage capacity at Mutsu, storage pools owned by some other utilities could be filled up by 2014, while the Mutsu storage capacity for PWR remained unfilled.

Similarly, some BWR sites at-reactor pools would fill up by 2019, since the Mutsu storage capacity of 4,000 tHM owned by Tokyo Electric Power Company (TEPCO) is not scheduled to be completed by then. And, if the Rokkasho plant does not operate as planned, its spent fuel storage capacity will likely be filled by 2020.

Japan's recovered plutonium is to be recycled in Light Water Reactor (LWR) mixed-oxide (MOX) fuel and in Japan's Fast Breeder Reactor (FBR) R&D program. Due to delays in the MOX and FBR programs, however, Japan has accumulated a large stockpile of separated plutonium. If the Rokkasho plant goes into full scale operation in 2007, Japan’s plutonium stockpile will likely grow to more than 70 tons by 2020 from 43 tons in 2005. Deferring operation of the Rokkasho plant with optimal spent-fuel storage, at least until the plutonium stockpile had been worked down to the minimum required level, would minimize international concern about Japan's plutonium stockpile. We recommend postponing the full scale operation of Rokkasho for about a decade, and we found this feasible even under the current spent fuel storage management planning. This would give Japan sufficient time to re-consider plutonium and spent fuel management.