Research On The FMEMA Method For The Reactor Coolant Pump

The reactor coolant pump (RCP) is a key equipment of Nuclear Power Plants,whose main function is to drive the coolant and maintain the integrity of pressure boundary of the primary loop. Therefore, it's important to maintain RCP's reliability.Failure mode analysis is the basis of all reliability work. However, Failure Mode, Effect and Criticality Analysis (FMECA) method is insufficient for RCP reliability analysis,and need to be improved.As a sub-mission of the project of reliability research for the shaft-sealed RCP of a 1000MW Nuclear Power Plant, a new method named Failure Mode, Effect and Maintainability Analysis (FMEMA) is proposed in order to implement the reliability analysis for RCP. Considering the RCP's structural and functional features, and the need of maintainability analysis,FMEMA method and form for RCP's failure mode analysis were designed based on FMECA method.And the FMEMA software was developed to store, track and query the data.Firstly, in order to deal with the disadvantages of FMECA method, the paper put forward some solutions. Designers could classify the agreed analysis level based on the actual situation; the interface failure mode was taken as a system failure of higher-level analysis object. A comprehensive analysis method of maintainability in RCP was given out in terms of maintenance method, maintenance time, maintenance environment and maintenance accessibility; it's required to consider maintainability when evaluating the severity of failure modes. Then it introduced the FMEMA process and related forms of RCP in detail.Secondly, according to the principles of software engineering, this paper developed an FMEMA software based on the requirement analysis, database design and human-machine interface design. The software could be used to track and query the FMEMA information in design stage.Finally, the FMEMA data of a pump body were used to verify the availability and convenience of the FMEMA software.The results showed that the 1 st static ring and the 1st ring were the key parts of RCP's pump boby,and most of the failure modes with high-harmfulness were interface failures.