Neutronic analysis of the new proposed configuration of CAREM-25 advanced small modular reactor with enriched thorium fuel

Small modular reactors (SMRs) have been considered as a serious alternative for large nuclear power plants (NPPs) to produce safer and cleaner energy in the context of global energy balance and climate change related to CO2 emissions for more than a decade. However, the high exploitation of uranium deposits around the world will make this substance rarer and even more expensive. Here, thorium is considered as a good alternative to be integrated into the nuclear fuel cycle to produce a stock of new fissile material, namely U233. The present work is considering the SMR model of CAREM-25 (Argentina), which is one of the leading SMR projects under construction in the world, to be loaded with new fuel made from thorium enriched with U233, considered with the same fractions used in the case of standard fuel made from enriched UO2. The neutronic analysis of this proposed model allowed us to produce and compare flux distribution and thermal output power for both configurations (UO2 and ThO2+233UO2). Under similar output power and initial reactivity, the new fuel appears to produce a more homogeneous flux.