Nuclear energy, classified as a clean energy source, enjoys extensive application in numerous countries worldwide. In recent years, the growth rate of marine organisms has accelerated, resulting in the formation of large aggregations of marine organisms and other large congregations that have the potential to obstruct the cold source water intake system of nuclear power plants. The safety situation about the cold source is of significant concern. This paper presents a summary of water intake safety events at nuclear power plants around the world in recent years. It also analyzes the current status of comprehensive prevention and control technology for disaster-causing floating bodies at nuclear power plants’ water intakes. The analysis is based on the latest developments in global nuclear power technology. This study provides a comprehensive overview of the advancements in fine offshore monitoring and early warning systems, passive interception techniques for open channel dredging, the evolution of active defense measures, the development of composite water intake open channel structures, bubble curtain interception methods, cutting and grinding techniques, and the subsequent transportation of marine organisms. Nevertheless, shortcomings remain in the water intake safety of nuclear power plants. These include an inadequate design basis for water intake open channels and sewage interception networks, as well as deficiencies in marine organism early warning and monitoring equipment and layout. Furthermore, the issue of sea ice represents a novel challenge confronting the nuclear power industry in coastal regions situated at high latitudes. Therefore, it is essential to undertake research and implement improvements to the comprehensive technology used to prevent and control water intake safety in nuclear power plants. It is imperative to provide robust backing for the long-term advancement of nuclear power technology.