A new class of material has been synthesized and demonstrated feasible at the laboratory level, as a potential integral neutron and gamma shield for the Kilopower Project and other small fission reactor technologies under development. The new material will have a competitive mass and volume-to-shielding effectiveness and offer a superior stable integral form as compared to the current best available technology discrete combinations - Lithium Hydride or B4C and Tungsten or Depleted Uranium. In the Phase II effort, optimization of the forming method will be completed, with an eye towards manufacturability of large geometry shields. Radiation exposure testing of material samples will continue/expand from the Phase I testing that was completed, and be performed at the actual levels of the expected reactor environment. Post-irradiation characterization will be performed on the samples for durability assessments. Nuclear simulation models will be further optimized from the Phase I level, to guide the design of the shield geometry using the integral material. By the end of the Phase II, a full-scale prototype shield section will be designed, manufactured, and delivered to NASA for hardware integration purposes.
The new material being developed will be immediately applicable to the Kilopower Project, as well as other future fission power generation programs under development, such as Nuclear Thermal Propulsion. The ability to have an integrally combined neutron and gamma shield will enable NASA shielding component designers to realize freedom of design not possible with the best available technology in current material combinations.
The new shield material being developed has significant potential beyond spaceflight applications, including terrestrial fission reactor shielding, spent fuel casket shielding, medical and industrial radiation shielding. The non-nuclear application opportunities for this new class of material include high volume industrial wear and cutting parts.