Development of SPEEDI-MP, comprehensive simulation system for circulation of environmental pollutants, 8; Application of atmospheric models to the environmental assessment of the Rokkasho Reprocessing Plant

Terada, Hiroaki  ; Nishizawa, Masato; Nagai, Haruyasu  ; Chino, Masamichi; Sasaki, Koichi*

SPEEDI-MP has been developed for comprehensive prediction of migration of radionuclides in the atmosphere, ocean, and terrestrial region. In this study, we made attempt to distinguish the contributions to observed air dose rate between natural and artificial radionuclides from the reprocessing facility in Rokkasho, Aomori during the period when the increase of dose rate by precipitation was observed. For the purpose, two atmospheric dispersion models of SPEEDI-MP were applied, which were an Eulerian model for natural radionuclides and a Lagrangian particle model for artificial radionuclides. Simulation period is 10 September 2007. The data used for the model calculation and comparisons with the calculations are Grid Point Value (GPV), AMeDAS from Japan Meteorological Agency, and Kr release amount, meteorological observations near the stack and environmental monitoring data around the facility from Japan Nuclear Fuel Limited (JNFL).