Another Step Taken for Safe Disposal of High-Level Radioactive Waste

ON MAY 31, 2000, the Diet passed a law which enables the Geological Disposal Program to press ahead with plans to bury deep underground high-level radioactive waste produced as part of the spent fuel reprocessing operation.
As every country that relies to some extent on nuclear power generation must also address the need to dispose the radioactive waste that is created, the latest law takes Japan one step closer to that goal.

Disposal of High-Level Radioactive Waste

SPENT NUCLEAR FUEL can be reprocessed for reuse by recovering both the uranium 235 that has not undergone fission and plutonium created during the fission process. Because Japan is poor in energy resources, it must rely almost entirely upon imports to meet its energy needs. Recycling spent fuel thus makes eminent sense for Japan as it not only allows existing nuclear fuel to be used more efficiently but it also secures a reliable supply of nuclear fuel that is independent of imports.

High-level radioactive waste is essentially a liquid separated out during the reprocessing of spent fuel. This liquid contains a variety of substances that remain highly radioactive for a long period of time, so it must be stored well away from human habitation during the period radioactivity is retained. The Japanese disposal program calls for this waste to be vitrified (mixed with melted glass), then poured into secure stainless steel canisters and allowed to cool and solidify. Since vitrified waste gives off heat, the Japanese system is designed to hold it in surface cold storage facilities for 30 to 50 years then buried 300 meters or more underground.

Mandating Final Disposal Method

THE NEW DISPOSAL law stipulates that an implementing entity, under the approval and supervision of the Ministry of International Trade and Industry (MITI), be established to handle the geological disposal of vitrified waste. Japan's nuclear power companies are obligated to use this corporation and contribute to the cost of its services in proportion to the amount of vitrified waste they seek to dispose.The monetary contributions will be managed by a separate public corporation to be designated by MITI.

The law also mandates that a three-step selection process be instituted to establish a final disposal site. The first stage includes the identification of "general survey areas" that may be capable of providing for stable, long-term geological disposal. The second stage will narrow these sites down to "detailed survey areas" and the third stage specifies a "final disposal site" (see chart on the right).

Throughout the three-step process, the law requires that consultations be held at the prefectural, municipal and local community levels to give due weight to the views and concerns of citizens in the survey areas. Currently, the nuclear power companies are preparing to establish the implementing entity in October 2000. Once the entity has been set up and the three-stage selection process is complete, the disposal facility will be designed and then evaluated by the government so that it adheres to stringent safety standards. Current plans call for the facility to begin operations some time between the 2030s and mid-2040s.