Risk identification and early warning of disaster-causing organisms in the cooling water intake area of a coastal...

Nuclear power plant cooling water safety is a critical issue for plant security and development. In recent years, incidents of cooling water intake blockages caused by massive accumulations of marine organisms have occurred frequently, resulting in significant economic losses and safety hazards. Based on biological survey data collected during four seasonal cruises (spring, summer, autumn, and winter) in 2009-2010 and historical data, this study analyzed the composition, spatio-temporal distribution, and potential risks of disaster-causing marine organisms in the intake area of a coastal nuclear power plant in northern China. Using a multi-level fuzzy comprehensive assessment model, ten species were identified as posing an "extremely high" risk: Paralia sulcata, Calanus sinicus, Ampelisca cyclops, Alpheus japonicus, Haustorioides magnus, Apohyale grandicornis, and Pleurobrachia globosa. Among these, A. cyclops, A. japonicus, H. magnus, A. grandicornis, and P. globosa were prioritized as key monitoring targets due to their body size and biomass. The risk organisms exhibited clear spatio-temporal patterns: spring and autumn were the critical risk windows, and abundance was higher nearshore than offshore. Given the mismatch between routine ecological monitoring and sporadic disaster-causing species, a dual-track approach combining seasonal monitoring of local dominant risks with horizon-scanning for "abnormalized" threats is recommended. An inventory of risk organisms and a seasonal outbreak calendar were established, providing a scientific basis for cooling water safety monitoring at nuclear power units.