The Nuclear Regulatory Commission (NRC) identified a disturbing trend in the mid-80s—the number of safety problems caused by inadequate maintenance was increasing. In some cases, ineffective practices during routine maintenance such as replacing worn-out gaskets or lubricating rotating machinery resulted in equipment that had been operating satisfactorily breaking down soon afterwards.
The NRC undertook a public rulemaking process that culminated in the NRC issuing Section 50.65, “Requirements for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants,” to 10 CFR Part 50 on July 10, 1991.
This new regulation, commonly called the Maintenance Rule, did not require new maintenance methods or alter the frequency of preventative maintenance tasks. Instead, it required plant owners to develop programs that periodically evaluated the effectiveness of their existing maintenance activities to help assure that safety equipment remains able to perform safety functions.
The Maintenance Rule is the best thing the NRC has done during my nearly 40-year career in the nuclear power industry. The NRC identified an adverse trend indicating that maintenance efforts and the existing regulation governing them were not successfully achieving the desired outcomes.