Waste Disposal Assessment of HYLIFE-II Structure

Initial scoping analysis indicates that by using Type 304 stainless steel (SS), most of the vacuum vessel's structural mass in the HYLIFE-II inertial fusion energy power plant conceptual design could be disposed of by shallow burial. And, if all the structural components are mixed together and treated as one solid entity, all of it could be disposed of by shallow burial. Two other types of SS assessed, manganese-modified Type 316 SS and prime candidate alloy (PCA), were found to require disposal by deep geologic burial of most of the structural mass. The presence of niobium and molybdenum in manganese-modified Type 316 SS and PCA was found to dominate the generation of long-term wastes that contribute to the shallow burial index, and their presence should be avoided.