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ICRP International

Conference on Recovery After Nuclear Accidents

Radiological Protection Lessons
from Fukushima and Beyond

December 1 - 18, 2020

Y. Endo, Y. Uezu, T. Takase, K. Yamaguchi, H. Tsukada

Updated: Dec 11, 2020

Studies on the Effective Dose for Public Calculated by Air Dose Rate

Y. Endo, Y. Uezu, T. Takase, K. Yamaguchi, H. Tsukada (Japan Atomic Energy Agency, JAEA)


After the Fukushima Dai-ichi Nuclear Power Station (1F) accident, the Ministry of the Environment decided that the additional annual dose in a high exposure situation (less than 20 mSv y-1) reduced to less than 1 mSv y-1. The additional annual dose is calculated from ambient dose equivalent, however the relationship among air kerma, ambient dose equivalent and effective dose seems to be identically by many organizations. In addition, conversion coefficients from air kerma and ambient dose equivalent to effective dose have been considered to change with elapsed time because the half-lives of 137Cs and 134Cs are differen