Subcooled boiling prediction on current fuel configuration of TRIGA 2000 reactor core by COOLOD-N2 code.

TRIGA 2000 reactor in Bandung is in operation for more than 50 years. Further, the current fuel configuration in the reactor core has been utilized since 1971. Since then, it has been found that numerous of the fuels still used today have burn-up varying from 20% to 40%. Under these conditions, the optimal core configuration that meets safety aspects is very limited, since the potential for local boiling caused by the heterogeneity of the core increases, due to burn-up level and also variations in fuel composition. Herein, both neutronic and thermal-hydraulic calculations were carried out to assess the scenarios that would lead to the possible occurrence of subcooled boiling. In this study, thermal-hydraulic calculations were performed using COOLOD-N2 to predict the subcooled boiling potential of the current TRIGA 2000 reactor fuel configuration, with a maximum axial and radial peak power factor of 1.34 and 1.826, respectively. Thermal-hydraulic calculations using COOLOD-N2 were carried out at the different level of power ranging from 100 kW – 1000 kW. According to the superheat temperature, it is found that the subcooled nucleate boiling condition was achieved at 200 kW for control rod withdrawal scenarios of 50% – 100%. [ABSTRACT FROM AUTHOR]