Computations for Advanced Nuclear Fuels

Abstract

The objective of the project was to develop advanced computational techniques to improve the understanding of fission gas distribution and heat transfer in solid fuel under normal and accident conditions. To successfully implement an efficient and effective nuclear power strategy, it is essential to develop new fuels that can provide optimal performance over long periods of time. In this project, our aims were to make progress towards replacement of the empirical models used in existing fuel performance codes. Our specific objectives have been to develop understandings of phonon and molecular transport in nuclear fuels using both analysis and simulations. While we made progress in both the phonon and molecular transport areas, as the research progressed we concentrated much more on the first area. The challenges here alone turned out to be substantial. We explored a number of areas including full Chapman-Enskog solutions for the Phonon transport equation. After very considerable effort, we came to believe that some of the results reported in the literature cannot be viewed as converged, and substantial effort beyond what we could accomplish in the time frame we had will be needed to improve the results. We therefore focused on what was achievable and still useful, and we describe these efforts and results below.