In this paper the applicability of breed-and-burn to molten salt reactors is investigated first on a cell level using a modified neutron excess method. Several candidate fuel salts are selected and their performance in a conceptual three-dimensional reactor is investigated. | Breed-and-burn fuel cycle in molten salt reactors EPJ Nuclear Sci. Technol. 5 15 2019 Nuclear Sciences B. Hombourger et al. published by EDP Sciences 2019 amp Technologies https epjn 2019026 Available online at https REGULAR ARTICLE Breed-and-burn fuel cycle in molten salt reactors Boris Hombourger 1 2 Jiˇri Kˇrepel 1 and Andreas Pautz 1 2 1 Paul Scherrer Institut Nuclear Energy and Safety Division Laboratory for Scientific Computing and Modelling 5232 Villigen PSI Switzerland 2 Ecole Polytechnique F ed erale de Lausanne Laboratory for Reactor Physics and Systems Behavior 1015 Lausanne Switzerland Received 1 April 2019 Received in final form 1 July 2019 Accepted 12 August 2019 Abstract. The operation of a reactor on an open but self-sustainable cycle without actinide separation is known as breed-and-burn. It has mostly been envisioned for use in solid-fueled fast-spectrum reactors such as sodium-cooled fast reactors. In this paper the applicability of breed-and-burn to molten salt reactors is investigated first on a cell level using a modified neutron excess method. Several candidate fuel salts are selected and their performance in a conceptual three-dimensional reactor is investigated. Chloride-fueled single-fluid breed-and-burn molten salt reactors using enriched chlorine are shown to be feasible from a neutronics and fuel cycle point of view at the cost of large fuel inventories. 1 Introduction problematic due to maximum cladding fluence limita- tions. The stringent requirements on the neutron economy Currently the vast majority of existing reactors is com- needed for breeding implies it has mainly been considered posed of reactors operating on an open uranium fuel cycle for implementation in sodium-cooled fast reactor SFRs that on the one hand cannot achieve net breeding of but also in other fast reactors. fissile material and on the other hand have limited dis- However implementing some form of BNB cycle in charge burn-ups up to