Neutronic Analysis of SMART Reactor Core for (U-Th)O 2 and MOX Fuel Hybrid Configurations

The SMART reactor core has been analyzed for UO 2 , mix oxide fuel (MOX) fuel (PuO 2 with 3.0 wt% and UO 2 with 97.0 wt%), and (U-Th)O 2 fuel. The burnup, Doppler reactivity coefficient (DRC), effective multiplication factor ( k eff ), thermal neutron flux, power peaking factor (PPF), and moderator temperature coefficient (MTC) have been studied for (MOX), (U-Th)O 2, and UO 2 fuels. The MOX fuel has been introduced as a hybrid core, whereas (U-Th)O 2 fuel configuration has been studied as the homogeneous and heterogeneous configuration in the fuel assemblies. The k eff has also been assessed versus fuel temperature, burnup, and fuel cycle. The burnup of one complete fuel cycle has been compared for (MOX), (U-Th)O 2, and UO 2 fuels. The k eff has decreased monotonically between 500 and 700 K and was found to be 1.262, 1.149, 1.221, and 1.240 for UO 2 , MOX, homogenous (U-Th)O 2, and heterogeneous (U-Th)O 2 configuration of fuel, respectively. The most negative value of DRC has been found at 600 K, which is − 4.740 pcm K −1 , − 3.496 pcm K −1 , − 4.896 pcm K −1 , and − 4.8260 pcm K −1 , for UO 2 , MOX, (U-Th)O 2 homogeneous, and (U-Th)O 2 heterogeneous configurations at the temperature gradient of 300 K. The maximum PPF has been found as 0.926, 0.964, 0.912, and 0.9750 for UO 2 , homogeneous configuration of (U-Th)O 2, the heterogeneous configuration of (U-Th)O 2 and MOX fuel. The DRC and MTC became more negative at the end of the fuel cycle due to decreased burnup. The (U-Th)O 2 in both configurations has presented a titivated response compared to the reference core between 500 and 1000 K. The MOX fuel has shown less response than (U-Th)O 2 configurations because of the high resonance absorption coefficient of plutonium.