Editorial
Japan must take cautious approach toward use of nuclear fuel
At the present moment, the unresolved problems surrounding the nuclear fuel cycle touted by the Japanese government as a major pillar of its nuclear energy policy far outweigh its benefits.
As a contributing player in achieving such a nuclear fuel chain, Japan's first so-called "pluthermal" fuel reactor began operations on Thursday at the No. 3 reactor at the Genkai Nuclear Power Plant in Saga Prefecture. Pluthermal generation involves burning MOX fuel -- made by blending plutonium extracted from spent fuel with uranium -- in standard light-water reactors. Implementation was delayed 10 years from its original plans.
While pluthermal generation has already been implemented in other countries, we urge that strict safety precautions be taken in Japan, as the program involves materials that have heretofore not been used as fuel in our reactors. Only when safety concerns have been addressed should we move forward with a review of the various challenges we hope to resolve with our nuclear energy policy.
The ultimate objective of Japan's nuclear fuel cycle is the use of fast-breeder reactors using plutonium extracted from spent nuclear fuel that has been reprocessed. Such reactors allow for the highly efficient reuse of materials, and have been lauded in the past as being a perfect solution for Japan, a nation with few natural resources.
However, fast-breeder reactors and reprocessing plants -- crucial to Japan's envisioned nuclear fuel cycle -- have been met with numerous stumbling blocks, and their future remains unclear.
Operations at the Monju fast-breeder reactor in Fukui Prefecture have been at a halt since a 1995 accident involving sodium coolant leaks. A series of problems since its reconstruction have significantly pushed back plans to reopen the plant. Various obstacles surrounding the Rokkasho reprocessing plant in Aomori Prefecture have also postponed the plant's completion.
Pluthermal generation was meant to take on a mere supporting role in Japan's nuclear fuel cycle. Its importance has increased as a result of the problems surrounding Monju, but the efficiency with which it can reuse materials is fairly low. Moreover, rods that are used to control fission in emergencies are said to be less effective than they are when using standard sources of fuel, requiring stricter safety measures.
Despite such costs, however, there is an important point to pluthermal generation, which allows us to use up pre-existing plutonium. Japan is in possession of around 28 tons of fissile plutonium that has been reprocessed both internationally and domestically. This stock must be reduced, as the material can be used to build nuclear weapons.
Implementation of pluthermal generation is planned for various plants across the country. One incident at any one plant, however, could affect operations nationwide. To start reprocessing of spent fuels under such circumstances means that there is a possibility that we will end up with an additional surplus of plutonium. There is no doubt that the selection of final disposal sites for the high-level radioactive waste that will remain after reprocessing will be no easy task.
Prime Minister Yukio Hatoyama has shown enthusiasm for nuclear energy as a means of achieving greenhouse gas reductions. However, only a limited number of countries maintain such a method, with even President Barack Obama freezing the U.S. nuclear fuel chain. Japan must take a flexible approach on the matter, assessing changing global dynamics concerning the use of nuclear fuel toward the goal of nuclear nonproliferation.
(Mainichi Japan) November 6, 2009