Development and simulation of a numerical model for evaluating the accumulation potential of tritium released from Fukushima Daiichi Nuclear Power Station in edible seaweed along the Fukushima coast

Since August 2023, treated water containing tritium, a hydrogen radionuclide, has been discharged into the coastal Pacific seawater facing Japan, and this discharge is planned to continue for a few decades for gentle release under controlled tritium concentrations in the treated water. This study evaluated the potential accumulation of tritium in edible seaweed on the Fukushima coast under the release conditions of the treated water. The maximum concentration of organically bound tritium (OBT) accumulated was estimated at 10 Bq L −1 (combustion water equivalent concentration) under the continuous release of treated water meeting Tokyo Electric Power Company Holdings' proposed permissible upper-limit tritium concentration of 1500 Bq L −1 . The maximum OBT concentration in seaweed was estimated at <0.1% of the OBT food guideline proposed by Food Agricultural Organization/World Health Organization. This suggests that the release of treated water will not significantly impact the safety and sustainability of the fishery industry.