TEMPERATURE MAPPING OF TRIGA 2000 REACTORS AT 500 kW POWER WITH 105 CONFIGURATIONS OF PRE-RESHUFFLING AND POST-RESUFFLING FUEL

Abstract

The continuity of operation of the TRIGA 2000 reactor is thermohydraulically determined by the temperature of the fuel and the temperature of the primary cooling water in the reactor core. Currently, the operation of the TRIGA 2000 reactor at a power of 500 kW using a fuel 105 configuration in the core has caused boiling and the formation of bubbles in the reactor core, thereby reducing neutron moderation. The core of reactor is unable to achieve more power. One of the efforts that can be made to reduce the core temperature of the TRIGA 2000 reactor is by reshuffling the fuel inside the core, including using 105 fuels but shifting the position of the fuel to a different ring. In this research, thermohydraulic analysis has been carried out using the FLUENT program package for the configuration of 105 fuels in the pre-reshuffling and post-reshuffling core. Based on the results of the study, it is known that at 500 kW of power with a pre-reshuffling fuel configuration, there are positions for sub-cooled boiling in B3, B4, B5, B6, D4, D6, D8, D10, and D12. The hottest channel is at B5 with a maximum fuel cladding surface temperature of 126.41 °C, and a cooling water saturation temperature in the core of 112.4 °C. Meanwhile, for the post-reshuffling fuel configuration there is no position for sub-cold boiling in the core, where the maximum temperature is at B2 with the maximum fuel cladding surface temperature of 93.55 °C. Thus, it is concluded that the TRIGA 2000 reactor with a configurations of 105 post-reshuffling fuel can be operated at of 500 kW without boiling or at least not occurring sub-cold boiling.