The Application of Risk Informed Method in Pressure Calibration Cycle Extending of RHR Systems SEBIM Valve

The stability of the SEBIM valve setting value can be validated based on the pressure calibration test during each refueling cycle. Depending on the feedback of other similar types of nuclear power plants, this test has been revised to two refueling cycles to execute for its excellent performance of SEBIM valves and has got satisfactory performance for several successive refueling cycles. Therefore, this paper will analyze and evaluate the feasibility of extending SEBIM valve setting value test period by employing risk-informed method. The results show that the performance of RHR system’s SEBIM valve is satisfactory; the increment risk is small and meets the quantitative risk acceptance criterion. Thus, the pressure calibration test of the RHR system’s SEBIM valve can be revised to execute for two refueling cycles.