Analysis of tritium levels in drinking water around Korean nuclear power plants and a proposal for radioactivity standards in drinking water

Many countries have established national guidelines for radionuclides in drinking water based on recommendations from the International Commission on Radiological Protection and the World Health Organization (WHO). However, the Republic of Korea lacks comprehensive radiological standards for all drinking water sources, only addressing saline groundwater under the Drinking Water Management Act (DWMA). This study aims to enhance radiological standards by analyzing radioactive effluent discharges from Korean nuclear power plants (NPPs), particularly focusing on tritium activity levels and evaluating annual effective doses. From 2015 to 2024, data indicated that tritium made up the majority of radionuclides discharged, with pressurized heavy water reactors (PHWRs) releasing about nine times more tritium than pressurized water reactors (PWRs) in gaseous effluents. These effluents can affect groundwater and surface water, making tritium essential for monitoring drinking water quality near NPPs. The highest tritium concentration found in drinking water near PHWRs was 19.64 Bq/L, corresponding to only 0.258 μSv/y of the public dose, with a dose limit of 1 mSv/y. The study recommends that Korea adopt a guideline level of 7000 Bq/L for tritium in drinking water, in accordance with WHO standards, and suggests revising the DWMA to set specific radiological guidelines.