An Advanced Reverse Osmosis Technology For Application in Nuclear Desalination Facilities

The lack of adequate supplies of clean, safe water is a growing global problem that has reached crisis proportions in many parts of the world. It is estimated that 1.5 billion people do not have access to adequate supplies of safe water, and that as a result nearly 10,000 people die every day and thousands more suffer from a range of debilitating illnesses due to water related diseases. Included in this total is an estimated 2.2 million child deaths annually. As the world's need for additional sources of fresh water continues to grow, seawater and brackish water desalination are providing an increasingly important contribution to the solution of this problem. Because desalination is an energy intensive process, nuclear desalination provides an economically attractive and environmentally sound alternative to the burning of fossil fuels for desalination. Nevertheless, the enormity of the problem dictates that additional steps must be taken to improve the efficiency of energy utilization and reduce the cost of water production in order to reduce the financial and environmental burden to communities in need. An advanced reverse osmosis (RO) desalination technology has been developed that emphasizes a nontraditional approach to system design and operation, and makes use of a sophisticated design optimization process that can lead to highly optimized design configurations and operating regimes. The technology can be coupled with a nuclear generating station (NGS) to provide an integrated facility for the co-generation of both water and electricity. Waste heat from the NGS allows the use of 'preheated' feedwater into the RO system, improving the efficiency of the RO process and reducing the cost of water production. Because waste heat, rather than process heat, is used the desalination system can be readily coupled to any existing or advanced reactor technology with little or no impact on reactor design and operation and without introducing additional reactor safety considerations. Analyses of nuclear desalination systems employing this advanced RO technology under a variety of seawater feed conditions have consistently shown that the cost of potable water production can be reduced by as much as 15-20% relative to systems designed in a more traditional manner. Demonstration testing has been carried out using a trailer mounted system producing up to 150 m3/d of potable water. Experimental results from the demonstration testing are behaving as expected based on the analytical performance models, validating the advanced design concept and confirming that the performance improvements indicated by the analyses can be achieved in operating systems. Further demonstration testing is planned using a 1000 m3/d containerized system, currently under design, coupled to an existing nuclear power reactor. (authors)