Steady-state Thermal-hydraulic Analysis of the TRIGA 2000 Reactor Core when Using Configuration of 105 Fuels

Abstract

The continuity of the TRIGA 2000 reactor operation is determined by the fuel temperature and the primary cooling water temperature. Currently operating the TRIGA 2000 reactor using 105 fuel configurations it is difficult to reach 1000 kW of power, because the fuel temperature and primary coolant temperature in the core are high. It causes boiling and bubble formation in the reactor core, thus reducing neutron moderation in the core. The results of neutronic calculations on the configuration of 105 fuels in the core at this time, it is known that heat generation is focused into the center of the core, and some fuels have large power fluxes, so that some of these fuels produce high cladding surface temperatures as well and cause boiling. In this research, thermal hydraulic analysis has been carried out using the CFD program package for the configuration of 105 fuels in the core. Based on the results of research on the reactor operated at 500 kW power, the hottest channel is at B5 fuel with the power it generates of 9.43 kW, the maximum surface temperature of the fuel cladding is 126.41 °C, and the temperature of coolant wets 119.92 °C. This temperature has exceeded the saturation temperature of the reactor cooling water 112.4 °C, so that sub-cooled boiling is possible. This situation is in accordance with the conditions that occur in the operation of the TRIGA 2000 reactor, where at 500 kW power has begun to observe bubbles coming out of the reactor core. One effort that can be done to reduce the temperature of the TRIGA 2000 reactor core is to do reshuffling and increase the amount of fuel used.