STUDY ON CLASSIFICATION METHOD OF EQUIPMENT BASED ON AVAILABILITY OF NUCLEAR POWER PLANT

Abstract

At present, the classification of nuclear power plant equipment mainly considers nuclear safety, and there is no equipment classification system aiming at economy. With the continuous development of the third generation of nuclear power plants are becoming higher and higher. As one of the most important economic indicators of a power plant, availability intuitively reflects the economic benefits of power plant operation. In this paper, a set of classification system based on availability is created, which classifies power plant equipment according to the influence of single equipment failure on the availability of power plant. By putting forward different technical management requirements for different equipment with different availability levels, the purpose of improving unit availability levels, the purpose of improving unit availability is achieved. This method is described from three aspects: identification of important equipment for nuclear power plant availability, classification of availability levels, and design management requirements for different availability levels. The equipment with important availability can be identified from the aspects of unplanned outage and planned outage through failure mode and effect analysis and critical path analysis of refueling overhaul. The classification of availability level is based on the identification of the important equipment of availability rate, which is divided into different levels according to the influence degree of equipment on availability rate, including immediate shutdown caused by equipment unavailability, power reduction or defense of unit in violation of operation technical specification, overhaul activity or extension of equipment maintenance time, reduction of redundancy and increase of shutdown risk. Finally, according to the different availability levels of equipment, relevant measures are taken to improve the availability of equipment from the aspects of design, manufacturing, operation and maintenance, quality assurance and so on, so as to achieve the effect of improving the availability and economy of the power plant. The equipment availability classification system is an equipment management system aiming at the economy of nuclear power plant, which covers the whole process from the initial design to operation management of the plant. The analytical approach adopted in this paper fills the gap in the hierarchical approach aimed at increasing availability. At the same time, the availability classification, as an economy-based equipment classification management system other than safety classification, is the basis of nuclear power plant performance monitoring, preventive maintenance implementation, corrective maintenance, equipment reliability improvement, and life/obsoleting management.