Off-site Dose Assessment during the Operational States of APR1400

Abstract

Normal operation and anticipated operational occurrences (AOOs) of nuclear powerplants (NPPs) involves periodic or continuous release of solid, liquid, and gaseous radioactiveeffluents to the environment. In this study, gaseous and liquid effluents of Shin Kori unit 3, oneof Advanced Power Reactor 1400 (APR1400) in Korea, were analyzed from 2016 to 2018 in orderto ensure compliances with regulations of Nuclear Safety and Security Commission (NSSC)for radioactive effluents releases. Meteorological data from Ulsan city area was applied forgaseous effluents. Doses for 80 km radius from the site, exclusion area boundary (EAB) and lowpopulation zone (LPZ) were considered. Doses to age groups and 14 body organs were studied viavarious pathways for gaseous and liquid effluents. Three computer codes were used; XOQDOQfor atmospheric dispersion and deposition, GASPAR for gaseous effluent doses and LADTAP forliquid effluents doses. Wind stability classification showed 2016 to be calmer than 2017 and 2018implying higher overall depositions and subsequent doses. Highest air beta and gamma absorbeddoses at EAB were 0.04 mGy·yr-1 and 0.003 mGy·yr-1, respectively, which were sufficiently lowerthan NSSC limits of 0.2 mGy·yr-1 and 0.1 mGy·yr-1, respectively. Children doses were highestat EAB and LPZ. Child effective dose at EAB was 0.02 mSv·yr-1 and skin equivalent dose was0.051 mSv·yr-1 which were below NSSC limits of 0.05 mSv·yr-1 and 0.15 mSv·yr-1, respectively. Effective dose from liquid effluents was highest to children at 0.01 mSv·yr-1 and equivalent dosesto any internal organ was 0.08 mSv·yr-1 for gastrointestinal lower large intestine which werebelow NSSC limits of 0.03 mSv·yr-1 and 0.1 mSv·yr-1, respectively. Consumption of invertebratesand algae were found to contribute highest doses. This study showed regulatory compliances ofgaseous and liquid effluents for Shin Kori unit 3 during its normal operations and anticipatedoperational occurrences.