Sensitivity to chlorine nuclear data in molten chloride fast reactors

Abstract

Moltex Energy is pioneering the Stable Salt Reactor – Wasteburner (SSR-W), a fast spectrum molten salt reactor fuelled with recycled spent fuel, selected to be built at Point Lepreau by NB Power. A fast neutron spectrum enables the burning of actinides in the generation of electricity, addressing the problem of spent fuel. Use of chloride salts yields a particularly fast spectrum, improving neutronic performance and waste reduction. However, given the lack of operating data for chloride fast reactors, it is important to understand the uncertainty in the relevant data, and the effect on reactor performance. In recent years chlorine data has been revised in the major international evaluated nuclear data libraries. This paper illustrates the sensitivity to these changes for the SSR-W, and to the uncertainty that still exists, in particular in the Cl-35 (n,p) reaction that dominates behaviour. Detailed full core models are used in a perturbative analysis to derive the effect on the main parameters. The resulting uncertainty is shown to be significant, which must be accounted for in design, but is also only one of several sources of uncertainty.