Measurement of the power and temperature reactivity coefficients of the RTP TRIGA reactor

This paper presents the experimental results of the power and temperature coefficients of reactivity of the RTP TRIGA reactor at the Malaysian Nuclear Agency. The power coefficient of reactivity obtained was approximately −0.26 ¢ kW−1 (−1.81 × 10−5 kW–1), and the measured temperature reactivity coefficient of the reactor was −0.82 ¢ °C−1 (−5.77 × 10−5 °C−1) and −1.15 ¢ °C−1 (−8.08 × 10−5 °C−1) in IFE C12 and IFE F16, respectively. The power defect, which is the change in reactivity taking place between zero power and the power of 850 kW was ∼2.19 $. Because of the negative temperature coefficient, a significant amount of reactivity is needed to compensate for the temperature change and allows the reactor to operate at the higher power levels in steady state. Throughout this experiment, it is the temperature of the fuel that was measured, not the isothermal temperature coefficient (ITC), which comprises both moderator and fuel.