Environmental monitoring for discharge of low level liquid waste from the Tokai Reprocessing Plant to the marine environment; Evaluation for influence of released radionuclides in the marine environment from the hot-test to the end of contract based reprocessing

Takeishi, Minoru ; Nakano, Masanao ; Kokubun, Yuji ; Kono, Takahiko  ; Maejima, Kyoko*

The Tokai Reprocessing Plant (TRP) was designed for commercial Light Water Reactor (LWR) power station as the first reprocessing plant in Japan. The TRP had been processed over 1000 tons of spent fuels up to 2006 through the hot test operation since 1977 and the routine operations since 1981. Almost of radioactive materials in the liquid waste were removed out by the process using multiple evaporators. However, low level liquid effluents were discharged to the sea through a long pipeline after confirmation of concentration of radionuclides beneath the limits by the Safety regulation of the TRP. The environmental monitoring had confirmed whether an unexpected release caused an influence to the environment. The environmental monitoring for seawater, sea sediments and marine products such as fishes, shellfish and seaweeds had been carried out offshore the Tokai-mura since 1977. This report reviewed comprehensively the all data obtained marine environmental monitoring since 1977.