Long-term variation of 90Sr and 137Cs in environmental and food samples around Qinshan nuclear power plant, China

Abstract

AbstractEnvironmental radioactivity monitoring in the surroundings of nuclear facilities is important to provide baseline data for effective detection in case of any radioactive release in the region. In this work, we report for the first time the long-term monitoring data of 137Cs and 90Sr in environmental and food samples around Qinshan nuclear power plant in 2012–2019. The distribution levels, temporal variations and source terms of 137Cs and 90Sr in the investigated samples were discussed. The annual effective dose (AED) for the local population from the ingestion of foods was also evaluated. Peak values of 90Sr and 137Cs concentrations and 137Cs/90Sr activity ratio were observed in total atmospheric deposition in 2016 and some water and food samples in the following years. This seems to be associated to an additional radioactive input, mostly likely from the operational release of a local facility. This demonstrates that 90Sr and 137Cs, especially the 137Cs/90Sr activity ratio, are sensitive indicators for detecting potential radioactive releases. Nevertheless, overall 90Sr and 137Cs activity concentrations measured during 2012–2019 in this work were at the background levels with average AED far below the internationally permissible limit and recommendation.