A level-1 PSA based systemic approach to optimal technical specifications of safety systems in nuclear power plants

Abstract

Level-1 PSA provides an integrated picture of the plant safety, incorporating all the design features, operational failure data, operational practices and maintenance information. The nuclear power plant operations are governed by the Technical Specifications, which specify Surveillance test frequencies, amongst other limiting condition of operations. With the detailed plant safety assessment having been conducted using the state of the art methodologies of PSA, there is a potential for evaluating the impact of varying the Testing frequencies on the plant risk and cost metrics. However, the complexity of the study is so vast that any optimization within the PSA framework, with change of input variables parametrically, is not feasible. In this paper, a multi-objective approach to optimization of surveillance test frequencies of two systems is studied using genetic algorithms, with inputs taken from the Level-1 PSA study of the 540 MWe Indian Pressurized Heavy Water Reactor.