Heat augmentation for process heating using light water nuclear reactors

Abstract

The urgent need for industrial decarbonization and the volatility in electricity prices have driven interest in utilizing Light Water Reactors (LWRs) for process heating applications. This study explores the feasibility of upgrading heat from LWRs to process heat levels ranging from 350 to 550°C using mechanical heat pumps, where steam from LWR's steam generator serves as a heat source. Steam compression and reverse Brayton cycles are evaluated, considering both simple and recuperated split compression and expansion configurations. A novel performance indicator, the corrected coefficient of performance (COPcor), was introduced to account for power production loss when extracting heat originally intended for power production. While several previous works considered upgrade of nuclear heat for selected specific application, the comprehensive approach of this work provides a complex and holistic overview of expected performance and technical feasibility over a range of possible application types and requirements. Our analysis is based on a pinch point approach and thermodynamic calculations. Furthermore, it demonstrates a theoretical maximum COPcor of 2.86, assuming a reference nuclear plant efficiency of 35 %. We conducted a comprehensive technical and thermodynamic assessment of the proposed systems, identifying performance and feasibility limits such as maximal system pressures and temperatures and return temperatures to the steam generator. Furthermore, we evaluated the economic viability of these heat pumps compared to electric heating by determining the minimum required COPcor values under various electricity prices and system costs. The findings indicate that while heat pumps utilizing nuclear heat can be economically feasible, their application is more viable for lower temperature lifts and specific industrial heating profiles. This study provides a comprehensive framework for understanding the potential and limitations of using LWRs for industrial process heating, offering valuable insights for future research and development, particularly in the context of technical feasibility and economic analysis.