Nuclear Desalination and the Economics of Nuclear Power

By Andrew Reimers and Brittany Speetles

Concerns about global warming and water scarcity have motivated many researchers to consider the potential for nuclear desalination, i.e., integrating a desalination plant with a nuclear power plant, as a means of producing drinkable water. There are numerous benefits to integrating a desalination plant with a nuclear power plant such as carbon-free electricity, low-marginal cost of generating electricity compared to fossil fuels, and a consistent power supply, unlike intermittent renewable electricity sources like wind and solar. Nearly 46 percent of the world’s nuclear power capacity is within fifty miles of a coast according to data from the World Nuclear Association. In the U.S., several nuclear power plants are located near the coasts in states such as California and Florida where large-scale desalination plants have been constructed in the last decade. Thus, for locales with existing nuclear power plants and sufficient demand for desalinated water, nuclear desalination is an attractive option.

Nuclear desalination also has the potential to improve the economics of nuclear power. For example, nuclear desalination could help shield nuclear power plants from low electricity prices because some of the power generating capacity could be used for running the desalination plant instead of being sold into the electricity market below cost. Another possible benefit of nuclear desalination is that uranium could be extracted from concentrated brine more cost-effectively than extracting uranium from seawater, reducing the cost of nuclear fuel. First-order estimates of these benefits, however, suggest that they are likely to be marginal at best.

Regarding the extent to which nuclear plants can be shielded from low electricity prices, even the largest desalination plants in the world do not use enough electricity to make much of a difference. For example, the average power-generating capacity of nuclear power plants within fifty miles of a coast is approximately 2265 MWe, but the largest seawater reverse osmosis plant in the world, the Sorek plant in Israel, only requires around 75 MW to operate at full capacity assuming a specific energy consumption of 3.05 kWh for each cubic meter of freshwater produced by the plant.

In addition to high-purity water, another output of a desalination plant is concentrated brine. Extracting uranium from concentrated brine would likely be more cost effective than extracting uranium from seawater, but it would still be more expensive than conventional uranium production or importing uranium from abroad. Thus, extracting uranium from concentrated brine might only appeal to countries that are intent on having more direct control over their nuclear fuel cycle. For example, seven out of twenty-one countries with nuclear power plants near the coast have to import at least a fraction of their uranium. Even if uranium extraction from concentrated brine were more cost effective than conventional uranium production or importing uranium, this strategy would have a limited impact on the overall economics of running a nuclear power plant. Nuclear fuel is already a relatively minute percentage of the cost of nuclear power compared to other power generation technologies, and raw uranium is only a fraction of the cost of nuclear fuel.

Researchers should continue to investigate nuclear desalination as an economic means of augmenting global water supplies with minimal environmental impact. Nuclear desalination is a particularly attractive concept compared to powering desalination plants with fossil fuel or intermittent electricity sources. Even so, a summary analysis of some of the proposed ways in which nuclear desalination could improve the economics of nuclear power indicates that such benefits are likely to be marginal at best.


Andrew  ReimersAndrew Reimers is a Ph.D. candidate in the Webber Energy Group at the University of Texas at Austin and an energy systems modeling intern at the National Renewable Energy Laboratory. His research focuses on thermodynamic and economic analysis of power generation and water treatment systems. Andrew blogs about current events related to energy and water at andrewreimersblog.com.

 

 

Brittany SpeetlesBrittany Speetles is a mechanical engineering student at the University of Texas at Austin and a researcher in the Webber Energy Group. Her research involves solar energy, desalination, and food waste management.

 

7 thoughts on “Nuclear Desalination and the Economics of Nuclear Power

  1. Kyle

    What about using a seawater distillery to condense steam from the reactors turbines? It would have to be a very big distillery to consume gigawatts of thermal power. You could use fresh seawater in combination with electric cooling to condense the distillery steam and let the hot brine leave.

  2. Katy Huff

    This message is for Steve Nesbit (commented above). Future potential high temperature reactor designs would have an advantage over other technologies ( because the heat would be high quality and you could use heat-driven desalination efficiently.) For current reactors, though, a watt is indeed a watt! Personally, I think the promise is in making nuclear ‘fake load follow’. Nuclear is increasingly competing with load-following peaking generation sources which are more adaptable to the penetration of renewables into the grid. If a nuclear plant could offload some electricity to desalination during times of the day when the sun is out (and therefore when nuclear baseload isn’t helping the grid…) that would help the economics of nuclear. That is, nuclear plants could avoid charges for overgeneration. Using a peaking natural gas plant for desalination doesn’t do anything for the natural gas industry. But using desalination to avoid putting electricity on the grid when the sun is out… that could help nuclear fit better on the gird.

  3. Steve Nesbit

    I am curious if there is anything about nuclear energy that makes it especially attractive for desalination. If we are talking about providing the electricity that powers the pumps, valves, etc., of a desalination plant, then there would not seem to be any special reason to use nuclear power. You would make the same choice to provide 75 MWe for desalination as you would to provide 75 MWe for anything else. Once it hits the grid, a watt is a watt. Am I missing something?

  4. Fred Giffels

    We have been suggesting this approach to several of our client’s over the past few years. Our NOMES data base tracks Nuclear Desalination and the Economics of Nuclear Power
    What is needed is a closer detailed look at the real cost issue which is life cycle cost. Some of the new SMR’s maybe a perfect match for the large desal units and help the USA produce clean water-Issues to address will include past and current Project management cost and schedule overruns of USA Commercial Nuclear fleet, the D’s anti nuclear positions, and of course a comprehensive RISK and mitigation assessment.

  5. Earnestine Johnson

    I would be very interested in continuing to hear of the progress of nuclear desalination. I was involved for a few years in the initial development of a desalination plant as the raw water source at Calvert Cliffs when Units 3 and 4 were being considered actively. Zero discharge discussions were cursory. This provides a whole new direction.