MULTISCALE SIMULATIONS OF HIGH TEMPERATURE NUCLEAR FUEL ELEMENTS

THE BENEFITS OF NUCLEAR POWER ARE BECOMING MORE ATTRACTIVE AS DEMANDS FOR CLEAN RENEWABLE ENERGY SOURCES INCREASE. AS CURRENT NUCLEAR POWER PLANTS AGE RESEARCHERS ARE SEARCHING FOR WAYS TO DESIGN AND BUILD MORE EFFICIENT NUCLEAR REACTORS. NUCLEAR FUEL ELEMENT DESIGN AND PERFORMANCE ARE PIVOTAL TO THE FUTURE OF NUCLEAR FUELS. FUELS WITH HIGH TEMPERATURE CAPABILITY ARE POTENTIALLY SAFER (STABLE AT HIGHER TEMPERATURES) AND MORE ENERGY EFFICIENT. A MULTISCALE MODELING APPROACH WAS SUCCESSFULLY PIONEERED FOR LIGHT WATER REACTOR (LWR) FUELS TO SIMULATE PERFORMANCE IN A PROTOTYPICAL ENVIRONMENT USING MARMOT (MESOSCALE) AND BISON (MACROSCALE) CODES; HOWEVER LWR FUELS OPERATE AT LOW TEMPERATURES. FURTHER DEVELOPMENT OF THESE CODES TO MODEL HIGH TEMPERATURE FUELS COULD PROVE BENEFICIAL FOR THE NUCLEAR POWER AND AEROSPACE INDUSTRIES BY PROVIDING AN AFFORDABLE METHOD TO PREDICT FUEL PERFORMANCE. 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 HIGH-PRESSURE HYDROGEN AT ELEVATED TEMPERATURES. THERE ARE CURRENTLY NO FACILITIES IN THE US THAT ARE CAPABLE OF PRODUCING THE REQUIRED ENVIRONMENT. THE PI PROPOSES TO START THE DEVELOPMENT OF AN INNOVATIVE MULTISCALE FUEL ELEMENT MATERIALS MODELING APPROACH CAPABLE OF PREDICTING THE PERFORMANCE OF HIGH TEMPERATURE FUELS AND REDUCING THE NEED FOR EXCESSIVE TESTING. DEVELOPING THESE MULTISCALE MODELING TOOLS WILL LEAD TO INCREASED CAPABILITY FOR THE NUCLEAR POWER INDUSTRY NASA AND ACADEMIA.