An Improved Steady-State and Transient Analysis of the RSG-GAS Reactor Core under RIA Conditions Using MTR-DYN and EUREKA-2/RR Codes

Steady-state and transient analysis of reactor core under Reactivity-Initiated Accident (RIA) conditions are important for reactor operation safety. •e reactor dynamics are in„uenced by neutronic and thermal-hydraulic aspects of the core. In this study, steady-state and transient analysis under RIA conditions of the RSG-GAS multipurpose reactor was carried out using MTR-DYN and EUREKA-2/RR programs. Neutronic calculations were performed using a few group cross-sections generated by Serpent 2 with the latest cross-section data ENDF/B-VIII.0. Steady-state conditions were carried out with a nominal power of 30MW, while transient under RIA conditions occurred because the control rod was pulled too quickly while the reactor operated. •ese transient RIA conditions were performed for two cases, during start-up with an initial power of 1W, and within power range with an initial power of 1MW. •ermal-hydraulic parameters considered in this study are reactor power, the temperature of the fuel, cladding, and coolant. •e calculated maximum fuel temperature at a steady state is 126.02°C. Meanwhile, the calculated maximum fuel temperature during RIA conditions at the initial power of 1W and 1MW are 64.38°C and 137.14°C, respectively. •ere are no signiŸcant di¡erences in thermal-hydraulic parameters between each used program. •e thermal-hydraulic pa rameters such as the maximum temperature of the coolant, cladding, and fuel under this postulated RIA condition are within the acceptable reactor operation safety limits.