NASA S NUCLEAR THERMAL PROPULSION (NTP) PROJECT IS FOCUSED ON DETERMINING THE FEASIBILITY AND AFFORDABILITY OF AN NTP ENGINE FOR EXPLORATION OF MARS AND BEYOND. A KEY TECHNOLOGY CHALLENGE FOR AN NTP SYSTEM IS THE FABRICATION OF A STABLE HIGH TEMPERATURE FUEL. VERIFICATION OF NTP FUEL MATERIALS WILL REQUIRE SUBJECTING PROTOTYPICAL SAMPLES TO THE COMBINED EFFECTS OF RADIATION AND HIGHPRESSURE HYDROGEN AT ELEVATED TEMPERATURES. HOWEVER THERE ARE CURRENTLY NO FACILITIES IN THE US THAT ARE CAPABLE OF PRODUCING THE REQUIRED ENVIRONMENT. THE PI PROPOSES TO CONTINUE THE DEVELOPMENT OF INNOVATIVE MULTISCALE MODELING TOOLS TO PREDICT THE PERFORMANCE OF THE NTP FUEL REDUCING THE REQUIRED NUMBER OF TESTS. DEVELOPING THESE MULTISCALE MODELING TOOLS WILL LEAD TO INCREASED UNDERSTANDING OF CERMET FUEL PERFORMANCE AND WILL ACCELERATE THE CERTIFICATION OF THE FUEL. THE PRIMARY FOCUS OF THIS PROJECT WILL BE THE DEVELOPMENT OF A FUEL LOSS MODEL FOR UO2 CERMET FUEL THAT WILL LATER BE EXTENDED TO UN FUEL.