核电厂冷源系统是核电工程的重要组成部分，对保障核电厂安全运行具有重要意义。近年来，我国滨海核电厂发生多起冷源取水口海生物堵塞事件，对核电厂的安全性与经济性造成不利影响。根据我国滨海核电厂冷源安全研究成果，结合核安全监管要求与工程实践经验，对冷源取水口海生物堵塞事件的原因与对策进行分析，进一步提高核电厂的安全性与经济性。“,”The cold source system of a nuclear power plant, as important part of a nuclear power project, is of great significance to guarantee the safe operation of a nuclear power plant. In recent years, there have been some cases of marine organism blockage at cold source intake at coastal nuclear power plants in China, which has adversely affected the safety and economy of nuclear power plants. According to the research result of cold source safety in coastal nuclear power plants in China and in compliance with the requirements of nuclear safety regulatory control and the engineering practice experience, the causes of, and countermeasures against, marine organism blockage at cold source intake are analyzed to further improve the safety and economy of nuclear power plants.