PREDICTING THE GAS PHASE CHEMISTRY INSIDE THE NEXT-GENERATION RTG

摘要

Recent reports indicate that the Next-Generation RTG may he a vacuum system, meaning that the thermoelectric cavity of the RTG will be exposed to the complex chemistry of the fuel during storage. A benchmarked model that was used to predict the chemistry produced by CeO_2 under "RTG-like" conditions was modified so that it could predict the chemistry produced by the ~(218)PuO_2 RTG fuel. Confidence in the accuracy of this modified model is high. Preliminary calculations using the PuO_2 model were performed using inputs that are within realistic boundaries for a Next-Generation RTG. Results indicate that the quantity of CO produced by the fuel is large (i.e. -2%), and that it will not be possible to prevent CO production through standard fuel processing procedures. Some CO_2 production also occurred, but the quantities were small (i.e. ~17 ppmv). Designs for any Next-Generation RTG should account for the presence of these gases.