Environmental radiological monitoring around JNC Tokai works

Nakano, Masanao ; Isozaki, Tokuji; Takeishi, Minoru 

The regional environmental radiation monitoring and the dose calculation for the public were performed for the past 25-year operation of the Tokai Reprocessing Plant (TRP). For the environmental monitoring, various kinds of terrestrial and marine samples including air dust, surface soil, polished rice grain, leafy vegetable, milk, seawater, seabed sediments, fish, shellfish and seaweed were collected in the surrounding environment of the TRP. Radionuclides such as H, C ,Sr, I, Cs and Pu in the environmental samples were determined by radiochemical methods. However, they showed no significant short-term increase or long-term accumulation of radionuclides discharged from the TRP. Therefore, the public dose was evaluated by the mathematical models using the discharge data of radionuclides and the meteorological data. The estimated annual effective dose for the public was about 0.1% of the annual effective dose limit recommended by the ICRP.