Neutronics Analysis of a Water-Cooled Blanket with a Be 12 Ti Reflector to Enhance Tritium Breeding

This paper presents a neutronics analysis of a water-cooled solid breeder (WCSB) blanket designed to improve the tritium breeding ratio (TBR) through the incorporation of a reflector. The reference model is based on the WCSB blanket of the Double-Null Korean Fusion Demonstration Reactor (DN K-DEMO). In the modified design, rib structures are introduced to ensure structural integrity under high-pressure water coolant conditions (15.5 MPa). Parametric studies were conducted to evaluate the effects of the Li2TiO3-to-Be12Ti ratio in the tritium breeding zone, the reflector thickness, and the cooling channel dimensions. The results demonstrate that the modified WCSB blanket, consisting of 14% Li2TiO3 in the breeding mixture, a 10-mm vertical reflector, and a 15-mm horizontal reflector, achieves a global TBR of 1.068, thereby satisfying the self-sufficiency requirement (TBR > 1.05).Neutronics simulations were performed using MCNP6 with the FENDL-3.1d and ENDF/B-VIII.0 libraries. Furthermore, thermal analysis using ANSYS CFX confirmed that all blanket materials remain within their allowable temperature limits.