Demonstration of Continuous-Energy TSUNAMI-3D Methodology on a Molten Salt Reactor

Abstract

The ability to perform continuous-energy sensitivity and uncertainty calculations was recently added to the SCALE package as part of the TSUNAMI-3D code. This methodology was tested to calculate temperature coefficients for a molten salt reactor along with their uncertainties due to nuclear data, at different points in a fuel cycle. A burnup script was written using KENO and ORIGEN to deplete the fuel salt and add make-up fuel to maintain criticality. The CLUTCH methodology in TSUNAMI-3D was used due to its low memory footprint and good performance. The resulting uncertainties in temperature coefficients were found to be around 0.15 pcm/K for the fuel and 0.25 pcm/K for the graphite moderator. Uncertainties due to scattering converge poorly, but their true values appear to be very small so it is reasonable to omit the scattering contributions to the total uncertainty.