Development of an evaluation program of internal dose using the latest models and data

Manabe, Kentaro; Takahashi, Fumiaki; Sato, Kaoru

Japan Atomic Energy Agency is developing a program using the latest models and data for estimation of internal dose compliant with the 2007 Recommendations of the International Commission on Radiological Protection (ICRP). Nuclear decay data, specific absorbed fraction data for adult males and females, and radiation weighting factors and tissue weighting factors have been published as the models and data compatible with the 2007 Recommendations. The program equips all the latest models and data, and can evaluate radiation weighted S coefficients. A test calculation was executed using the program for evaluation of S coefficients for self-absorption in the thyroid of adult males corresponding to the 2007 and 1990 Recommendations. The coefficient based on the 2007 and 1990 Recommendations was 1.3 10 Sv/decay and 1.6 10 Sv/decay, respectively, and the coefficient decreased 18%. This is because correction of the mass of organs considering their blood content was executed for self-absorption cases. We will report the development status of this program, and the results of test calculations and the study.