A cost-benefit analysis of nuclear valve industry cooperative programs: examples taken from motor operated and air operated valves efforts

摘要

Over the past ten years, the NRC has challenged the nuclear industry to provide further assurance that safety related motor operated valves (MOVs) can function when subjected to design basis conditions. In Generic Letter 89-10 (NRC 89) and seven supplements, the US Nuclear Regulatory Commission (NRC) directed nuclear plant licensees to review and to document the design basis for safety related MOVs and to establish correct switch settings (limit and torque). In Generic Letter 95-07, the NRC directed licensees to evaluate all safety related power-operated valves to ensure that those valves identified as susceptible to pressure lockinng and thermal binding are capable of performing the intended safety function(s). In Generic Letter 96-05, the NRC staff directed licensees to address,more formally, periodic verification of the caapbility of safety-related MOVs to perform associated safety functions.