With more nations embracing nuclear energy as a zero carbon emission power source, researchers are drafting blueprints on how to harness that power in the fight to beat water scarcity.
Scientists think that nuclear-powered desalination plants could help bring potable water to drought stricken communities, accordint to a report by the BBC.
According to the United Nations, communities on every continent are currently experiencing water scarcity. Northern Mexico is currently experiencing historic water shortages. Low water levels in Iraq are straining harvests. East Scotland is currently on a high water scarcity alert. And right now, India is experiencing a deadly water crisis that affects the country every summer.
In the United States, 32 percent of contiguous states were affected by “severe to extreme” drought, as reported by the National Drought Report. Earlier this month, BBC called the events in the western US, “a once-in-a-lifetime drought.” Climate-intensified water scarcity is one of the most prevalent problems across the globe, and nuclear power desalination plants might pose a solution.
Desalination plants help supply fresh water by removing salt from seawater. When only 2.5% of the planet’s abundance of ocean and sea water is drinkable fresh water, the demand for desalination is high. The demand for fresh water is expected to exceed the existing sustainable water supply by 40% by 2030 as reported by the U.S. Intelligence Community Assessment of Global Water Security. This is projected to be the result of a trifecta: population growth, scaling industrialization, and climate change.
However, desalination plants are one of the most expensive ways of creating safe drinking water and are an extremely energy-intensive process. However, powered by nuclear reactors, floating vessels equipped with desalination plants could travel to islands and coastlines affected by drought, bringing them not only safe drinking water but power.
Energy droughts are a common occurrence with water scarcity. Lower water levels in reservoirs can reduce the energy generated by hydroelectric dams. Typically, high temperatures accompany droughts, as seen particularly in California and the southwest US, affecting the energy supply chain and drastically increasing the likelihood of wildfires with the potential to impact energy infrastructure.
The blueprint of nuclear desalination plants is not new, however. For two decades, the General Conference of the International Atomic Energy Agency has stressed the idea. Additionally, in 2019, Forbes reported that 1,500 nuclear-powered desalination plants might be able to save the world from desertification.
At the time of the Forbes publication, only 15 of the world’s thousands of desalination plants were powered by nuclear plants. One of these is California’s small Diablo Canyon plant, which will be closing in 2025 because of both environmental protocols and lack of money. However, like the 20,000 desalination plants worldwide, these plants are on the shore as opposed to offshore and mobile.
Despite crackdowns on the system, amid California’s energy crunch, the power plant could be saved, as reported by The Guardian. Researchers at Stanford and the Massachusetts Institute of Technology examined new opportunities for the plant. Among them was nuclear desalination.
"You could have them moving around on an intermittent basis, filling up tanks," Mikal Bøe, chief executive of Core Power, told BBC, speaking on the idea of offshore nuclear desalination plants. Core Power is a UK-based company, focused on advanced nuclear technology. The company has come up with a design for a nuclear-powered desalination plant.
Of the traditional desalination plants that currently are in operation, the majority exist in Saudi Arabia, the United Arab Emirates, and Kuwait, with some in the US, UK, China, South Africa, Brazil, and Australia. Almost all of these plants are onshore, however, some engineers say that it would be more effective and cheaper if they were positioned offshore, so water could easily be pumped abroad. Core Power wants to make that happen.
The idea would be to use a vessel similar to a small container ship, but with stacked containers on board filled with desalination technology. At the heart of the ship would be a nuclear reactor to power it all, providing the vast amount of power needed.
The floating nuclear desalination plants would vary in levels of power output, from five megawatts, up to around 70. With just five megawatts of nuclear power, it could provide 14 Olympic swimming pools worth of fresh water a day. That is 9,246,021.8 gallons of water.
How does it work?
So how do desalination technologies work? It’s all in osmosis. To remove salt from saltwater, treated seawater is pushed across a semipermeable membrane at high pressure via desalination technology.
These minerals are removed by osmosis, the movement of molecules in liquid across membranes, leaving freshwater and a separate, particularly salty water called brine. Desalination technologies are capable of treating water outside of seawater.
They can also treat brackish groundwater and surface water. It can also treat domestic and industrial wastewater and develop it into useful products as developed by MIT. The caveat is that most desalination systems in the world use fossil fuels to power them.
While this technology has evolved over the years, floating desalination systems remain extremely rare.
Nonetheless, at the beginning of this year, Saudi Arabia inaugurated the first of three floating desalination plants. The plant is the largest ever built, and is set to provide energy to several cities across the country’s southern grid.
Floating plants could be the future of energy and water. However, they might not all be nuclear. A company called Oisann Engineering has developed a system called Waterfountain.
Although the company declined to give BBC too much detail regarding the intricacies of its technology, the company claims its innovation vastly reduces the environmental impacts of traditional desalination. Waterfountain utilizes a decades-old mechanism known as subsea desalination, through various designs from large ships to small buoys.
"[The technology] was never commercialized because you still need subsea pumps to facilitate taking the water to the surface," the company’s chief administrator, Kyle Hopkins told BBC. "We removed the pump."
The system takes advantage of the pressure on the seafloor and uses a low-pressure reverse osmosis system to move water around, using less energy than a pumping system would use. The system also employs a pipeline that runs from the water to the shore and may hire gravity to assist with the water’s flow to further cut costs, as mentioned by Hopkins. He calculates that this system may be approximately 30 percent more energy-efficient than a traditional onshore desalination facility. Currently, the company has a miniature version of its design in the works and hopes to initiate the first commercial installation in the Philippines in 2023.
What are the challenges?
However, floating desalination plants are not without their drawbacks. BBC illustrates that while these designs are “promising,” according to Raya Al-Dadah, head of the Sustainable Energy Technology Laboratory at the University of Birmingham, there are still challenges such as “pumping the desalinated water ashore and in finding a workforce with both offshore experience and desalination expertise,” BBC wrote.
In addition to public acceptance, a 2020 research book on the coupling of nuclear reactors and desalination plants, says that they will produce marine, coastal, atmospheric, and socioeconomic impacts, the most prevalent of which will be brine discharge.
The bottom line is that humanity needs more water systems. Nevertheless, as companies begin to blueprint and establish their plants, the environmental effects must be considered. After removing the salt, desalination plants leave the highly salinated brine behind. The resulting water that is already produced by today’s desalination plants could be toxic to marine life. The authors write that there are multiple solutions to brine discharge that are feasible and applicable through state-of-the-art technologies.
Kyle Hopkins told BBC that the expected byproduct of Waterfountain is not salty enough to be classified as brine. As outlined by The Explorer, by using reverse osmosis technology, Waterfountain reduces the environmental impact of traditional desalination.
While Waterfountain is not nuclear, unlike other desalination projects, it does not require any chemicals, and according to The Explorer, most of its components can be recycled or reused. In comparison to Core Power, Waterfountain is projected to produce between 2,641,721 and 7,925,161 gallons of water a day. The high end of the projection is enough for 40,000 homes to have almost 200 gallons a day.
Right now Core Power’s nuclear design is still solely a design. However, the firm hopes that within a decade it will be in commercial operation. The need is there.
At present, in California, the standard approach to relief efforts is flying and trucking bottled water to places that need them, Greg Pierce, co-director of the University of California Los Angeles Luskin Center for Innovation, told BBC.
It’s inefficient and costly. According to Forbes in 2019, California would need 30 desalination plants to ameliorate future water crises. In combination with water conservation measures, water recycling, and rainwater treatment, floating desalination plants 一nuclear or subsea一may be the final piece to solving the water crisis puzzle.