Status of standard data on shielding calculation in standard committee of the Atomic Energy Society of Japan

In radiation shielding calculations, fluence-to-dose conversion coefficients are necessary to estimate dose rate. This standard gives effective dose conversion coefficients based largely on the ICRP recommendations in 1990. However, original values based on research conducted in Japan have been retained primarily with respect to the extension of energy range and multigroup-wise data. The gamma-ray buildup factor is defined by the ratio of gamma-ray dose included scattered gamma-ray contribution to dose of unscattered gamma-ray which has no experience of collision from source point to evaluation point. 20 years have passed since publication of standard data by the standard committee of America Nuclear Society at 1991, the extension of data is needed for the evaluation of effective dose and ambient dose equivalent in the shielding calculations, and the codes were also advanced for the evaluation of buildup factors. In the new report, buildup factors obtained by the Invariant Embedding (IE) method and its Geometrical-Progression (GP) fitting formula parameters appeared for 28 materials.