Assessment of Environmental Radioactivity Surveillance Results around Korean Nuclear Power Utilization Facilities in 2017

Results and Discussion: According to the result of the environmental radioactivity verification surveillance in the vicinity of nuclear power facilities in 2017, the anthropogenic radionuclides were not detected in most of the environmental samples except for the detection of a trace level of 137Cs, 90Sr, Pu, and 131I in some samples. Radioactivity concentration ratios between the anthropogenic radionuclides (137Cs/90Sr, 137Cs/239+240Pu, 90Sr/239+240Pu) were similar to those reported in the environmental samples, which were affected by the global fallout of the past nuclear weapon test, and Pu atomic ratios (240Pu/239Pu) in the terrestrial sample and marine sample showed significant differences due to the different input pathway and the Pu source. Radioactive iodine (131I) was detected at the range of < 5.6–190 mBq∙ kg-fresh–1 in the gulfweed and sea trumpet collected from the area of Kori and Wolsong intake and discharge. A high level of 3H was observed in the air (Sangbong: 0.688±0.841 Bq∙ m–3) and the precipitation (Meteorology Post: 199±126 Bq∙ L–1) samples of the Wolsong nuclear power plant (NPP). 3H concentration in the precipitation and pine needle samples showed typical variation pattern with the distance and the wind direction from the stack due to the gaseous release of 3H in Wolsong NPP.