Design and assessment of a molten chloride fast reactor

Abstract

In recent years a resurgence of interest in flowing fuel Molten Chloride salt Fast Reactors (MCFRs) has been observed. However, no such reactors have been constructed. There are few core designs available in the open literature, and typical nuclear safety assessment tools are felt to be inadequate for MCFR concepts. Upon reviewing MCFR designs several issues are revealed. For instance, there is a lack of consistent thermophysical properties utilized in proposed core designs. Spherical cores are typically considered, which opens up the possibility of recirculation zones containing fuel salt. There has been minimal consideration for core component lifetimes and how to keep the reflector cool during operation. As part of an effort to consider transients in a MCFR, a preliminary reactor design is developed. In this newly developed design, the core has constrained inlet and outlet flow paths and a replaceable reflector. The design is developed using the fast reactor codes DIF3D, PERSENT, GAMSOR, and MC2-3. Additionally, a heat exchanger sizing study is conducted for this system. The design developed reveals significant engineering challenges such as a large core and heat exchanger volume, inner reflector lifetimes on the order of five years, a lack of verified thermophysical properties, and an operational temperature range above that of any nuclear qualified materials.