Development of a new simulation software system to evaluate radiation doses and facilitate decontamination tasks in reactor buildings (The 12th International Conference on Radiation Shielding (ICRS-12) and the 17th Topical Meeting of the Radiation Protection and Shielding Division of ANS (RPSD-2012)) -- (Empirical Methods and Applications)

Exploring a reasonable way to decontaminate the reactor buildings at the Fukushima Daiichi Nuclear Power Plant, a new simulation system calculating the doses originated in the contamination on the surface of structures was developed. This simulation system, called “RaF-MAP (Radiation Field MAP)”, calculates doses based on built-in attenuation data conducted using MCNP5 within a short time. This paper describes the system principle of RaF-MAP, verification by comparing with doses conducted with existing code, and a comparison with the measured doses in the reactor building at Fukushima Daiichi Nuclear Power Plant. In addition, this paper shows how RaF-MAP contributes to decontamination tasks, by presenting procedures to use RaF-MAP and the dose-reduction effect provided by the hypothetical decontamination operations.