Current status of the project for re-evaluation of atomic-bomb survivor doses using a new computational voxel phantom series

Sato, Tatsuhiko   ; Funamoto, Sachiyo*; Paulbeck, C.*; Griffin, K.*; Lee, C.*; Cullings, H.*; Egbert, S.*; Endo, Akira   ; Hertel, N.*; Bolch, W.*

Owing to recent advances in computational dosimetry tools, it is desirable to update the dosimetry system for the atomic-bomb survivors, DS02. The DS02 system is based on adjoint Monte Carlo particle transport simulations coupled with stylized computational human phantoms. We therefore developed the J45 series of computational voxel phantoms representative of 1945 Japanese adults, children, and pregnant females, as a part of international collaboration project between RERF and several institutes in Japan and USA. Using those phantoms, we calculated organ doses in adults for 12 representative exposure scenarios having realistic particle energy and angular fluence, using the latest Monte Carlo particle transport codes, PHITS and MCNP. Those data were compared with survivor organ doses given by the DS02 system. It was found that overall impacts of introducing the new computational method in the dosimetry system are not so significant, less than 10% in most cases, except for organs whose calculation method or definition was changed such as colon and bone marrow. The current status of this international collaboration project will be presented at the meeting.