(A) study on multi-cycle physics and economics considering end cycle optimization for a PWR

Abstract

Nowadays, license renewal of nuclear power plants is difficult due to the political, technical, and economical reasons, and the optimum end-cycle strategy has become an interesting and important research topic. In this thesis, commercial cycle optimization strategies considering permanent shutdown have been studied for a Westinghousetype PWR core. Both the conventional equilibrium cycle cores and end-cycle cores for permanent shutdown are considered and compared. Multi-cycle optimizations are mainly focused on the economics and neutronics analysis based on the commercial design criteria. In this work, all the neutronic designs and analyses are done with a licensed design code system (KARMA/ASTRA). A new hybrid strategy coupling 18- and 24-month, and ALPE (Automatic Loading Pattern search Engine) are also introduced to mitigate design challenges for equilibrium cycle cores and end-cycle cores. For the end-cycle optimization, various representative operational scenarios and fuel management schemes have been devised and analyzed. For each end-cycle operational scenario, detailed multi cycle LP (Loading Pattern) designs are performed and an annual total cost is evaluated to find the optimal one. Based on outcomes of the current study, an intuitive and powerful GUI program SCEF (SCEnario Final) system for end-cycles management are newly developed. In addition, a sensitivity study on the cost components for the economics analysis is performed. Finally, realistic optimum strategies applicable to commercial PWRs are introduced as reference results for improving competitiveness and reducing costs in operation.