An emergency decision-making on a regional environmental contamination

When an environmental contamination occurs in a wide area, it is necessary to estimate the future influence by emergent environmental monitoring and rapidly take measures for it. This study aimed to support an emergency decision-making by constructing practical schemes with regards to the following three items in the dose limitation system recommended by ICRP; validity of intervention actions, optimization of protection and dose limitation. A framework of decision-making process was constructed to make clear the corresponding responsibility and the principle of intervention, to introduce stochastic techniques for estimating the environmental radiation shift and to reduce the social burden for the contamination. The results obtained by using this method were variable depending on the characteristics of subjects and regions applied. Therefore, it is needed to select an appropriate evaluation model and specific parameters suitable for the respective cases. (M.N.)