Abstract: The ¹³⁷Cs activity concentration in seawater around Daya Bay, Yangjiang and Taishan NPPs, and from other coastal areas in Guangdong, is presented. And the impact of nuclear power liquid effluent discharge on seawater in the nearby area is analyzed. For Daya Bay Nuclear Power Station, the ¹³⁷Cs activity concentration in seawater was significantly higher than the background level due to abnormal emissions in the early days, which was then returned to the background level. The concentration of ¹³⁷Cs in the seawater around Yangjiang Nuclear Power Station varies from0.49 to 4.77 Bq/m³. The concentration of ¹³⁷Cs activity in seawateraround Taishan Nuclear Power Station ranged from <0.11 to 2.21 Bq/m³. The activity concentration of ¹³⁷Cs in seawater from other areas ranges from0.62 to 2.52 Bq/m³. The results show that the concentration of ¹³⁷Csin seawater in coastal waters of Guangdong fluctuates within the background level.

Key words: ¹³⁷Cs, Seawater, Coastal area, Guangdong