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Fig. 4-6 Radioactive wastes from the dismantled JPDR Radioactive wastes were segregated by material type and level of radioactivity

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Fig. 4-7 Simple burial method Very low-level wastes were buried simply and safely without any artificial barriers.

The successful dismantling of the Japan Power Demonstration Reactor (JPDR) has been supported by development of a more reasonable protocol for waste disposal. During dismantling of nuclear reactor in some foreign countries, a scheme has been used to classify suspected radioactive waste as either radioactive or non-radioactive according to certain active level. Such waste classification was not possible in the case of JPDR, because there is a general rule that materials with any trace of artificial radioactivity be managed as radioactive. The radioactivity in JPDR materials was measured carefully prior to dismantling and the waste was segregated according to radiation levels. The radioactive waste totaled 3,700 tons, corresponding to 15% of the total waste weight, 24,440 tons. The ratio is higher than in any previous dismantling case in foreign countries. However, it should be noted that 1,670 tons out of the total 3,770 tons has only a trace level of radioactivity, and is therefore classified as very low-level waste (VLLW). The waste having the least concentration of radioactivity, mostly concrete debris, was packed in bags made of artificial resin and simply buried in a demonstration test site on the premises of Tokai Research Establishment. The disposal method differs from standard waste management practices in the past in which the waste was put into steel packaging and managed under strict guidelines. This more reasonable disposal method developed for the disposal of VLLW from the JPDR has the potential to replace more traditional methods. The demonstration disposal test was carried out under a carefully managed plan which included characterization and safety analyses for the disposal site as well as for transportation and operations. The test confirmed a safety and rationality of all procedures used. Data will continue to be collected on this waste management method. These data are expected to be valuable in preparing the Clearance Level For Radioactive Waste report, and for development of future waste disposal policies.

Reference M. Abe et al., Safety Demonstration Test for the Disposal of Very Low Level Concrete Waste, Dekomisshoningu Giho, 15, 50 (1996).

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