Radiological Impact due to Atmospheric Releases of the Source Term for F-D, Unit 1, Using HOTSPOT Code

Term CalculationsDetermining of radioactive release during Fukushima accident has depended mainly on the measurements of the concentrations of radioactive iodine and cesium in the air around the plant after the accident by Tokyo Electric Power Co. (TEPCO).Then, a reverse method was used to predict the amount of radioactive ABSTRACT This paper concentrated on the calculation of atmospheric releases of the radioactive materials originating from Fukushima Daiichi Nuclear Power Plant (F-D) accident, unit 1, which were calculated by Tokyo Electric Power Company (TEPCO) and the Egyptian atomic energy authority (EAEA).HOTSPOT Code, Gaussian plume model, was used to calculate the dose rate distribution resulting from the plume air submersion and ground shine of radioactive deposits on the soil surface.The results showed that the maximum dose rates resulting from air submersion and ground shine are 0.03 and 0.005 Sv/h at distance of 0.27 Km from the reactor.The deposition density for I-131 and Cs-137 in some locations around F-D, NPP were calculated also using HOTSPOT code and the results show good agreement with the measurements of the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT).The results also were compared with the deposition calculations of National Oceanic and Atmospheric Administration (NOAA), and Institute for Radiological Protection and Nuclear Safety (IRSN). Radiological Impact due to Atmospheric Releases of the Source Term for F-D, Unit 1, Using HOTSPOT Code