Monday, 23 January 2012: 1:45 PM
Estimation of Transport and Deposition of Caesium From the Fukushima Accident Using a Regional Chemical Transport Model
Room 338 (New Orleans Convention Center )
A powerful tsunami generated by the earthquake occurred at eastside of Japan on March 11, 2011 caused serious damage to several reactors of the Fukushima Nuclear Power Plant #1 (37.42N, 141.04E) on their cooling system. Explosive release of radionuclides, such as iodine 131 and caesium 137 was occurred for several days. The Nuclear Safety Commission of Japan estimated that 150 PBq of iodine 131 was released into the atmosphere by this accident. This value is expected to be about 8% of iodine 131 released at Chernobyl accident. We have implemented wet deposition, dry deposition, and the radioactive decay of iodine 131 and caesium 137 into a regional chemical transport model WRF/Chem (Weather Research and Forecast model / Chemistry) to estimate the budget of total deposition of radionuclides into the land and ocean. As the release of radionuclides was caused by the complex of each reactor's explosion, 11 tagged-tracers were introduced to evaluate each event. The results demonstrate that radionuclides have been mainly depositted through the wet deposition. The ammount of total deposition has been estimated to be 0.14 TBq into the ocean, and 0.19 TBq into the land.