Description

ANS 6.6.1 – Calculation and Measurement of Direct and Scattered Gamma Radiation from LWR Nuclear Power Plants

ANS 6.6.1-2015 (R2020) defines calculational requirements and discusses measurement techniques for estimates of dose rates near light water reactor (LWR) nuclear power plants due to direct and scattered gamma-rays from contained sources on-site. On-site locations outside plant buildings and locations in the offsite unrestricted area are considered. All sources that contribute significantly to dose rates are identified and methods for calculating the source strength of each are discussed. Particular emphasis is placed on ¹⁶N sources as they are significant sources of direct and scattered radiation for boiling water reactors (BWRs). The standard specifically excludes radiation from gaseous and liquid effluents. The standard describes the considerations necessary to compute dose rates, including component self-shielding, shielding afforded by walls and structures, and scattered radiation. The requirements for measurements and data interpretation of measurements are given. The standard includes normal operation and shutdown conditions but does not address accident or normal operational transient conditions. The standard also applies to the gamma dose resulting from Dry Fuel Storage Facilities.

Keywords: shielding, radiation protection, light water reactor