A study of online maintenance practices at US nuclear plants

This paper discusses the insights gained from a study of the online maintenance (OLM) practices at selected US nuclear power plants. OLM has been practiced extensively in the US to shift some of the outage work to be performed during power operations. By reducing the outage work scope and performing more OLM, nuclear power plants can significantly reduce generation loss resulting from planned maintenance during outage. This is becoming increasingly important in a deregulated, competitive market environment for electric power supply. The workweek concept and rolling schedule are some of the aspects of OLM that makes the performance of OLM easier to implement. The scope of OLM, however, has to be carefully reviewed to ensure that reliability improvements resulting from OLM are not offset by extended unavailability of the safety systems or other undue operational risks.