Pressure fluctuation analysis for charging pump of chemical and volume control system of nuclear power plant

Equipment Failure Root Cause Analysis (ERCA) methodology is employed in this paper to investigate the root cause for charging pump's pressure fluctuation of chemical and volume control system (RCV) in pressurized water reactor (PWR) nuclear power plant. RCA project task group has been set up at the beginning of the analysis process. The possible failure modes are listed according to the characteristics of charging pump's actual pressure fluctuation and maintenance experience during the analysis process. And the failure modes are analysed in proper sequence by the evidence-collecting. It suggests that the gradually untightened and loosed shaft nut in service should be the root cause. And corresponding corrective actions are put forward in details.