Effect of using various grades of plutonium in the protective liquid wall of an IFE type fusion reactor

摘要

One of the main issues in a fusion reactor is the need for the frequent replacement of first wall structures during its lifetime. In order to eliminate this problem completely, use of a protective liquid wall between the fusion plasma and solid first wall has been proposed by various researchers. One of the major fusion energy reactor designs is called HYLIFE-II, an inertial fusion energy (IFE) type reactor that also utilizes such a flowing liquid wall to extend the lifetime of the first wall to its lifetime. This study presents the neutronic analysis of the HYLIFE-II reactor using Li_2BeF_4 (Flibe) with various grades of plutonium as a flowing liquid wall. For this purpose, four different coolants containing Flibe with 0.5% or 1 % of weapon grade (WG) PuF_4 and Flibe with 0.5 % or 1 % reactor grade (RG) PuF_4 were considered. Main neutronic parameters: tritium breeding ratio (TBR), energy multiplication factor (M) and radiation damage at the first wall were computed with respect to the liquid wall thickness and coolant type. The highest TBR and M values were reached when the Flibe with 1 % WG PuF_4 was used in the liquid wall.