The optimized conceptual soluble boron free small modular reactor using solid pyrex and gadolinia rods

In this paper, the optimized Conceptual Small Modular Reactor using Solid Pyrex rods was studied for effective soluble boron free operation and long-term fuel cycle. The core designs have modeling of the current PWR-proven technologies except for a use of Pyrex rods. The loading pattern of fuel assemblies and fuel compositions are searched to achieve long cycle length of ∼4 EFPYs (effective full power year). And the effect of used Pyrex rods for low excess reactivity are analyzed in terms of core neutronics. The optimized core having Pyrex rods with various enrichment shows cycle length of ∼4.02 EFPYs and maximum excess reactivity of 848 pcm without degradation of the safety-related neutronic parameters. (Author)