Assessment of nuclear desalination in a small modular reactor using membrane distillation

Despite the proven feasibility and cost-effectiveness of nuclear desalination in small modular reactors (SMRs), the exclusive use of waste heat for this purpose remains virtually unexplored. This work investigates coupling an SMR (NuScale) to a direct contact membrane distillation (DCMD) desalination plant with heat recovery and feed recycle. Both the reactor waste heat and the low-pressure (LP) steam extraction from the reactor turbine were considered as heat sources. The DCMD hollow fiber module was modeled as a porous medium with satisfactory accuracy. Key parameters affecting system performance, identified through factorial analysis, include membrane porosity, module length, feed superficial velocity, and fiber inner radius. Single and multiobjective optimization analyses revealed the feasibility of producing up to 3,810 m³/d of water without any reactor power loss, and up to 8,832 m³/d, with a 2.28 MWe power loss, using steam extraction. DCMD demonstrated competitiveness, especially when the reactor’s primary purpose is electricity generation.