Abstract
Small Modular Reactors (SMRs) are characterized by high safety, small size, and modular construction. In this paper, an integrated design of a small nuclear reactor, with thermal power of 200 MW and fuel enrichments below 5%, is designed and analyzed to study the burnup behaviour and reactivity coefficients. The core has been simulated by using the transmission neutron Monte-Carlo program Serpent. The results establish that the core is able to provide an 18-month operating cycle. Comparisons of different enrichments and loading patterns are carried out to explore potential future improvements. The relationship between the refuelling cycle length, geometric size of the core, fuel enrichment, arrangement of the burnable absorber and operating power is demonstrated. It is also confirmed that the SMR design has a sufficient negative feedback coefficient to ensure nuclear safety.