Development of Regionally Extended/Worldwide Version of System for Prediction of Environmental Emergency Dose Information:WSPEEDI, II. Long-Range Transport Model and Its Application to Dispersion of Cesium-137 from Chernobyl.

Abstract

As a part of a study to expand the computational region of SPEEDI (System for Prediction of Environmental Emergency Dose Information), a long-range atmospheric transport model of radioactivity was developed. This model computes air concentration, deposition, external γ-dose and internal dose due to inhalation. The model is applied to the simulation of dispersion of ³¹⁷Cs from Chernobyl over Europe and the calculated values of surface air concentrations and deposition were compared with those of measurements. In the comparison of surface air concentration, about half of the calculated value agreed with measured ones within an order. The degree of quantitative agreement was comparable to that of the model application for the dispersion in local complex terrain. This suggests that the proposed model has capability to assess the long-range transport and the consequence of radioactivity released into the atmosphere.