Ageing Management

Abstract

The internal environment of a marine nuclear power plant is normally a hydro-chemical environment with high temperature and the primary loop system and equipment are exposed to fast neutrons, while the external is the marine environment. Meanwhile, the operating conditions of marine nuclear power plants change frequently, and swing and seawater impact may occur during the operation of marine nuclear power plant. The physical and chemical effects of the environment such as irradiation, temperature, medium, vibration, and impact would lead to performance degradation of the nuclear power plant. Ageing refers to the process that the structures, systems and components of a marine nuclear power plant gradually deteriorate over time or service. The ageing has various forms, which are closely related to the material type of structures, systems and components and the environmental characteristics. The ageing forms of different structures, systems and components vary from each other. In general, the ageing of nuclear power plant mainly includes degradation in ductility and toughness, crack propagation, thickness reduction and pitting, etc. The ageing of structures, systems and components would lead to the decline of original design functions or even loss of function, to jeopardize the operational safety and service life of nuclear power plants.