REACTOR CONTROLLABILITY OF 3-REGION-CORE MOLTEN SALT REACTOR SYSTEM — A STUDY ON LOAD FOLLOWING CAPABILITY

摘要

This paper reports the result of a unsteady analysis under the case of heat removal change and discusses the load following capability of the 3-region-core MSR system by using a numerical model developed by the authors. In the analysis, the "reactor- slaved-to-turbine" control technique which is recently utilized in the PWRs is applied to the 3-region-core MSR control. The following results were obtained in this study. 1. In the range of heat removal change (Q_c/P_0) 50 to 150%, the reactor can follow the steam turbine load autonomously. Furthermore, the stabilization times of all of the reactor parameters such as temperature, neutron ux es, delayed neutron precursors and reactor power are within 1000s approximately. 2. Fuel salt inlet temperature in the all of the cases of heat removal change uctuates immediately after the heat removal change; subsequently, it converge to the initial inlet temperature, 833K. 3. In the case of heat removal change Q_c/P_0=150%, fuel salt inlet temperature is below the solidi cation point of the fuel salt. Thus, in this case, we have to raise the inlet temperature by using other reactor control techniques like control rod manipulation and fuel salt o w control. 4. At the case of heat removal change Q_c/P_0=50%, temperatures, neutron ux es and delayed neutron precursor densities are decreased caused by the heat removal change. However their local elevations and drops are not occurred. From these results mentioned here, the 3-region-core MSR system has high nuclear and thermal safeties and good load following capability. Furthermore, the "reactor-slaved-to-turbine" control technique which is utilized in the PWRs is effective reactor control technique for the 3-region-core MSR system.