Preliminary design and front-end fuel cycle assessment of 200 MWt marine molten chloride fast reactor

• A preliminary design of a 200 MWt Marine Molten Chloride Fast Reactor (MMCFR) was developed. • Long-lived core design with Partial Fuel Change (PFC) mechanism. • Using Constant Replacement scheme in PFC mechanism lowers fuel consumption by 20%. • Reactivity swing is maintained below 5% throughout burnup using burnable absorber. • Control drum worth sufficient to shut down the reactor until end of cycle. The molten Chloride Fast Reactor (MCFR) emerges as one of the advanced nuclear reactor designs for use in a nuclear marine propulsion. This paper delineates the preliminary design of a 200 MWt Marine MCFR (MMCFR) intended as a propulsion for zero-carbon large container ship, focusing on the neutronic analysis and fuel cycle assessment. The MMCFR employs eutectic 66NaCl-34UCl 3 as the fuel with 19.55 wt% enriched uranium as the initial fuel contained in a BeO-reflected core, operated as a long-lived core and batchwise refuelling to simplify reactivity control and refuelling mechanism in a constrained space. As the MMCFR is designed with a compact core and large initial reactivity, the innovative Partial Fuel Change scheme is proposed to optimise fuel consumption and reduce the strain in the front-end fuel cycle, with Constant Mol or Constant Replacement scenario. Initial reactivity is suppressed using burnable absorber (BA) rods and control drums are used to control the reactivity and core shutdown. Neutronic and depletion calculations for the MMCFR design were performed using Serpent-2 code and ENDF/B-VII.0 library. The optimum front-end fuel cycle was obtained to be Constant Replacement scenario with lowest uranium consumption. Meanwhile, excess reactivity can be maintained below 5% throughout operational time by using BA and control drum, whilst temperature coefficient of reactivity (TCR) is sufficiently negative, ensuring the MMCFR fulfils the safety criteria.