A nuclear option for water

(As published in the Roanoke Times (Roanoke, Va.) in Sept. 2009)

J. Winston Porter

Porter is with Environmental Strategies in Leesburg and formerly was assistant administrator of the Environmental Protection Agency.

The problem of dwindling water supplies in the United States is becoming an increasingly critical one. It's not just happening in the Southwest, but beginning to show up in our own back yards in Virginia and elsewhere in the Southeast, where we've had an abundant supply of water for so long that we've taken it for granted.

Water scarcity is making it more difficult for farmers to grow crops and feed livestock, and it is creating competition among demands from industry, urban development and growing populations. The federal government estimates that at least 36 states will face water shortages within five years.

This is the junction to reconsider our approach to ensuring adequate water supplies. The experience of recent years shows that conservation, along with metering and recycling wastewater, is likely to fall short of what's needed to meet water requirements.

Using nuclear energy as a power source can be an important strategy for meeting our water needs. For more than a half century, the U.S. Navy has used energy from reactors on nuclear submarines to desalt seawater, supplying fresh water to crews who can be at sea for a month or longer.

The technology for nuclear desalination is straightforward. It uses waste heat to distill saltwater or electricity to separate freshwater from saltwater using reverse osmosis, a well-established membrane technology.

Currently, there are desalination plants in every state, though they usually obtain heat from burning oil or natural gas and most of the units are used for limited industrial purposes. The United States has more than 1,000 such units, supplying 8 percent of drinking water capacity in the country. A study by Argonne National Laboratory confirms that a nuclear plant that both generates electricity and provides energy for desalination would be more economical over its operating life than a similar plant using fossil fuels. And a nuclear cogeneration plant doesn't pollute the air or emit greenhouse gases into the atmosphere.

The National Research Council recently said that desalination of seawater offers the potential to substantially reduce water scarcity, particularly in water-scarce regions, in localities experiencing rapid population growth or where users are able and willing to pay for a high-quality, reliable new supply.

Other countries are making use of nuclear desalination to supply potable water for general use. Japan and India use reactors to augment freshwater supplies for cities, farms and industries. Nuclear desalination is being considered by countries in the Middle East, Europe and South America.

The International Atomic Energy Agency sees a real future for nuclear desalination around the world. It estimates that a mid-size 600-megawatt nuclear plant operating in a cogeneration mode would produce about 4 million gallons of water per day. To produce that amount of water would require about 20 percent of a reactor's electrical capacity. The IAEA said in a report that regardless of the type of nuclear reactor or its desalting capacity and site-specific conditions, nuclear desalination is by far economically the most interesting option compared to fossil fuels.

The U.S. Department of Energy should consider building a cogeneration reactor to demonstrate desalination. Freshwater produced at such a desalination unit could be shipped by pipeline to wherever its most needed. If we remember that water production is as essential as conservation, we will be better able to solve the problems of water shortages.

 

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Dr. J. Winston Porter is president of Environmental Strategies in Leesburg, Virginia and Washington DC. Formerly, he was an assistant administrator of the U. S. EPA with national responsibility for hazardous waste programs.