Evaluation of energy and economic efficiency in upgrading coal-fired power plants: Integrating HTGR reactors and turboexpanders for supercritical steam parameters

This study evaluates the energy efficiency and economic viability of modernizing coal-fired power plants by integrating high-temperature gas-cooled reactors (HTGRs) and turboexpanders to achieve supercritical steam parameters. The research employs an incremental methodology to analyze the potential benefits of this upgrade, focusing on the Joule and Clausius-Rankine cycles' integration. The study examines the impact of various operational parameters, particularly the helium outlet temperature from the turboexpander, on system performance and economic outcomes. Results indicate that the modernization can significantly improve overall plant efficiency, potentially reaching up to 41 %, which is substantially higher than conventional nuclear plants using PWR or BWR reactors. The economic analysis considers factors such as increased power output, operational costs, and potential revenue from additional electricity generation and avoided emissions penalties. The research highlights the importance of optimizing helium temperature and pressure to balance energy efficiency with investment costs. This modernization approach offers a promising pathway for enhancing the performance of existing power plants while addressing environmental concerns, potentially contributing to long-term energy security and sustainability in the power generation sector.