Optimizing NSSS Power and Turbine/Generator Performance for Standardized Nuclear Power Plant Designs in Tropical Climates

摘要

The EPR was developed by AREVA as a standardized nuclear power plant design that could be deployed throughout the world. For the EPR to remain competitive on the worldwide nuclear energy market, standardization and high unit net electrical output are key features of EPR deployment. The first EPR, the only Generation III+ advanced reactor design that is currently being built, is being constructed at Olkiluoto, Finland. Many of the plant systems for this first-of-a-kind unit are optimized for the climate and heat rejection method (once-through cooling) used at Olkiluoto. Two such systems are the Nuclear Steam Supply System (NSSS) and the Turbine/Generator (T/G) system. To achieve the EPR's target net electrical output for tropical climates and various condenser heat rejection methods, design studies were performed that showed that the NSSS and T/G system designs developed for the Olkiluoto site conditions required modification. Tropical climates are more representative of the continental United States, and reflect sites with an average ambient temperature above 60 deg F. To optimize the EPR design for tropical climates, two sets of parametric studies were performed to determine the maximum NSSS power level that could be achieved, and to evaluate the effects of tropicalization on T/G performance for a range in condenser heat rejection methods (e.g., once-through cooling, natural draft cooling towers, etc.). These parametric studies explored a range of design considerations with four goals: (1) to maintain a highly reliable design, (2) to minimize changes to the Olkiluoto standardized design, (3) to optimize T/G performance for tropical conditions, and (4) to achieve the target net electrical output. This paper reports the results of these studies, and demonstrates how the net electrical output goal for U.S. EPR is met with tropical heat sink conditions and a range of condenser heat rejection methods.