Integrated Scheduling of Maintenance Workers and Activities for Nuclear Power Plant Subsystem

Abstract

Maintenance is regarded as one of the effective methods to enhance the reliability of nuclear power plant (NPP) system. The existing research works on NPP maintenance optimization mainly focus on the preventive maintenance (PM) scheduling, with the common assumption that activities are performed at scheduled time. Though the straightforward asset management brought by PM scheduling, its inflexibility could result to either unnecessary maintenance activities or undiscovered failures. On the other hand, due to the budget limit it's inappropriate to neglect the shortage of maintenance workers and the missed plans caused by it. In this research, an integrated scheduling of maintenance workers and activities for NPP subsystem is considered. Effective age is used to determine the performed maintenance activities while measuring its effectiveness. To deal with this problem, a mathematical model is established with the objective of minimizing the total cost. Maintenance starting time, workers and activities of each component over the scheduling horizon are regarded as decision variables. The proposed model is applied to an NPP feed water subsystem and solved by specially designed genetic algorithm.