Optimization of Plutonium-238 Production in the Advanced Test Reactor for Radioisotope Thermoelectric Generators in Deep Space Exploration Applications

Plutonium production for use in Radioisotope Thermoelectric Generators (RTGs) is becoming increasingly important in the United States due to several reasons. The plutonium stockpile originally purchased from the USSR has steadily decreased due to utilization in RTGs and the degrading quality of the specific plutonium isotope of interest in the stockpile: plutonium-238. With a half-life of 87.7 years, the quality has decreased since it was originally purchased just after the Cold War. The United States is aiming to produce high-quality 238Pu and become independent in space fuel production in the process. The high-quality plutonium combined with the currently available low-quality plutonium will produce usable fuel for future space explorations like the Mars 2020 expedition. This paper details the new models / methodologies investigated by Center for Space Nuclear Research (CSNR) to optimize 238Pu production in the Advanced Test Reactor (ATR). Increasing the 238Pu production at ATR will supplement the current production at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Labs in Tennessee to achieve the national goal of 1.5 2.0 kg 238Pu per year.