Utilization of the Thorium of the Holos-Quad Micro-Reactor Concept

In this study, the criticality and burnup analyses have been performed for Holos-Quad micro nuclear reactor as a thorium burner which has 15 ton reactor mass and 22 MWth full core geometry by using continuous-energy multi-purpose three-dimensional Serpent and OpenMC Monte Carlo particle transport code with ENDF/ B-VII data libraries. As nuclear fuel, reactor grade (RG) and weapon grade (WG) Pu mixed with ThO2 in different proportions have been used. Firstly, effective criticality for RG-Pu and WG-Pu for operation period have been determined. In addition, since each of the 4 subcritical power modules must be subcritical due to the structure of the Holos-Quad reactor, the criticality analysis of the power modules has been performed. The criticality, burnup and fissile fuel production of the Holos-Quad micro nuclear thorium-burner have been calculated with different fuel fraction depending on the fuel type. Finally, thorium mixed fuels with 35% WG-Pu or 75% RG-Pu would allow burn up levels of ~ 25 GWd/ton and ~15 GWd/ton with reactor operation periods ~3.5 years without fuel change, respectively.