Leveraging Surplus Energy from Nuclear Power Generation for Seawater Desalination: A Case Study

Nuclear power plants represent a large, untapped supply of low grade waste heat that could be utilized for seawater desalination. These facilities convert only 33% of the thermal energy generated into electrical energy, with the remaining 67% disposed of as unwanted heat. If an appropriate partner processes can be identified, this thermal energy can be used to desalinate seawater, enhancing coastal water supplies without significantly increasing energy demand. To effectively leverage the waste heat, several desalination technologies were investigated, including reverse osmosis, forward osmosis, multi-effect distillation, multi-stage flash distillation, membrane distillation, and adsorption / desorption distillation. These technologies were studied as stand-alone processes and in combination with each other, ordered according to their unique advantages and disadvantages with respect to maximum achievable water recovery, energy utilization, tolerance of fluctuations in available energy, and susceptibility to scaling. Material and energy balances were used to model each potential combination in MATLAB in order to determine the quantity and quality of water that could be produced from a given amount of waste and prime energy. These results were used together with water-use data in southeastern Florida to estimate the cost and value of desalinating water alongside a 300-megawatt-thermal nuclear power plant at Turkey Point, Florida. All of these metrics, in addition to the ability of the system to handle intermittency in the availability of energy, were used to identify the best seawater desalination technologies for potential pairing with nuclear power generation in the future.