Korean nuclear power plants (NPPs) have various radiation protection programs to attain radiation exposure as low as reasonably achievable (ALARA). In terms of ALARA, this paper provides a comprehensive overview of administrative dose control for occupationally-exposed workers in Korean NPPs. In addition to dose limits, administrative dose constraints are implemented to resolve an inequity of radiation exposure in which some individuals in NPPs receive relatively higher doses than others.

more »

... tional dose constraints in Korean NPPs are presented in this paper with the background of how those values were determined. For pressurized water reactors, 80% and 90% of the annual average limit for an effective dose, 20 mSv/y, are set as the primary and secondary dose constraints, respectively. Pressurized heavy water reactors (PHWRs) have also established the primary and secondary dose constraints corresponding to 70% and 80% of the effective dose limit, and additional constraints for tritium concentration are provided to control internal exposure in PHWRs. Follow-up measures for exceeding these administrative dose constraints are also introduced compared to exceeding the dose limits. Finally, analysis results of dose distributions show how the implementation of administrative dose constraints impacted the occupational dose distributions in Korean NPPs during the years 2009 to 2018. Korean NPPs have established administrative dose constraints by optimization process to achieve goals of both keeping radiation exposure at low levels and not providing an excessive economic burden to NPP operation. The constraints are applied to all Korean NPPs with the same conditions since all Korean NPPs belong to Korea Hydro & Nuclear Power (KHNP), the state-run NPP operator in Korea. This paper not only introduces the occupational dose control system, focusing on dose constraints dedicated to Korean NPP operation but also shows how administrative dose constraints are implemented in practice.