Tritium concentration and diffusion in seawater discharged from Tokai reprocessing plant

Nakano, Masanao ; Kokubun, Yuji ; Takeishi, Minoru 

The tritium concentrations in seawater collected around the Tokai Reprocessing Plant (TRP) were measured for 10,800 samples in 30 years from 1978. The tritium concentration, dillution factor and diffusion situation were investigated. As a result, the tritium was occationaly detected due to the discharge from TRP. But it was considered to be the result of normal diffusion assumed in the safety assessment. It was confirmed that the tritium concentration was much lower than the concentration limit defined in the law and that it was not concern of environmental safety.