SUPERCRITICAL CARBON DIOXIDE BRAYTON CYCLE CONTROL FOR A NUCLEAR POWER PLANT: LOAD FOLLOWING AND DECAY HEAT REMOVAL

摘要

The supercritical carbon dioxide (S-CO_2) Brayton cycle offers efficiency and economic benefits as a power converter for advanced reactors by taking advantage of the property variation behavior of supercritical CO_2 near the critical point. That particular property variation behavior at the same time presents challenges for cycle control and transient analysis. The Plant Dynamics Code (PDC) has been developed at ANL to address these challenges and to provide an analysis to develop a control strategy for the cycle. The PDC has been coupled to the SAS4A/SASSYS-1 Liquid Metal Reactor analysis code system for the analysis of liquid metal-cooled reactors, such as Sodium Cooled Fast Reactors (SFRs). A SFR plant under load following and transition to the decay heat removal mode is analyzed with the PDC and SAS4A/SASSYS-1. The S-CO_2 cycle and reactor controllers are optimized to achieve a favorable system response at all stages, as demonstrated by the transient simulation of the plant. The S-CO_2 cycle is shown to be capable of operating from 100% power to as low as at least 1% reactor power in the decay heat removal mode.