Core design studies for advanced burner test reactor

This paper describes the core design and performance characteristics of 250 MWt Advanced Burner Test Reactor (ABTR) designs. A phased approach was adopted with initial startup using conventional enrichment plutonium-based fuel and gradual transition to full core loading of transmutation fuel after its qualification phase. Reference core designs were developed for ternary metal alloy and mixed oxide fuels based on weapons-grade plutonium feed. The transuranics (TRU) transmutation fuel tests can be accommodated in the designated test assemblies, and if fully developed, core conversion to TRU transmutation fuel can be envisioned. For the startup core designs, the calculated TRU conversion ratio is 0.65 for the metal fuel core and 0.64 for the oxide fuel core. The metal fuel core requires an average TRU enrichment of 18.8% and has a TRU loading of 732 kg. Compared to the metal fuel core, the lower density oxide fuel core requires an average TRU enrichment of 21.8%, which results in a 780 kg TRU loading despite a ∼ 9% smaller heavy metal inventory. Alternative designs were also studied for a light water reactor spent fuel TRU feed and a low conversion ratio, including the recycle of the ABTR spent fuel TRU. Reactor performance characteristics were evaluated in detail, including equilibrium cycle core parameters, mass flow rates, power distributions, kinetic parameters, reactivity feedback coefficients, and reactivity control requirements and shutdown margins. (authors)