| After four decades of experience with pressurized water reactors, a new generation of nuclear plants are emerging. These advanced designs employ passive safety which relies on natural forces, such as gravity and natural circulation. The new concept of passive safety also necessitates improvement in computational tools available for best-estimate analyses. The system codes originally designed for high pressure conditions in the presence of strong momentum sources such as pumps are challenged in many ways. Increased interaction of the primary system with the containment necessitates a tool for integral analysis. This study addresses some of these concerns. An improved tool for integral analysis coupling primary system with containment calculation is also presented. The code package is based on RELAP5 and CONTAIN programs, best-estimate thermal-hydraulics code for primary system analysis and containment code for containment analysis, respectively. The suitability is demonstrated with a postulated small break loss of coolant accident analysis of Westinghouse AP600 plant. The thesis explains the details of the analysis including the coupling model. |
