With an abundance of seawater and a lack of fresh water, scientists have a challenge — to create new drinking water supplies and to incorporate new technologies to do so. Among those now getting the attention is nuclear desalination and water treatment.
In a story in Phys.org, it says that scientists are looking to nuclear membrane desalination or hybrid technologies: “These methods should be combined with recycling and treatment of residues to a level that corresponds with environmental requirements.”
The majority of modern desalination technologies are based on distillation of thermal energy, it says. In the process of distillation, salt water is boiled, and produced steam leaves the system and is condensed as fresh water. If a nuclear reactor is used as the heat source, the method is called nuclear desalination, it adds.
What the membrane method does — what the scientists are working on — is to use “reverse osmosis.” That can also be used in combination with nuclear desalination.
The United Nations Foundation’s Global Water Challenge has said that about 1.1 billion people don’t have access to water and another 2.6 billion don’t have access to safe sanitation.
While desalination technologies are advancing, they still remain cost prohibitive. Experts say that it is at least five times more expensive to purify seawater than it is to treat fresh water.
A number of methods now exist to purify saltwater that include solar power and fossil fuels. But nuclear energy might be a more efficient method of removing contamination and saltwater because it can do so efficiently and on a large-scale basis without adding to concerns over global warming.
Desalination is also energy intensive.
Nearly 40 million cubic meters of desalted water are produced worldwide each day, says the International Atomic Energy Agency. Most of the facilities to do so are located in the Middle East and North Africa and they use fossil fuels to draw the steam or electricity they need to facilitate the process.
But as environmental concerns grow over greenhouse gas emissions and water needs rise, cleaner options that have large-scale applications are necessary. The need is paramount. The demand for drinking water grew six-fold in the 20th century and is expected to increase another 40 percent by 2025, according to the United Nations.
Nuclear energy is the most feasible method, the atomic agency adds. It points out that the technology of coupling nuclear energy and desalination plants already has taken hold in Japan and Kazakhstan, where commercial facilities have been operating since the 1970s. Altogether, the agency is working with 20 nations to advance nuclear science and desalination.
It is estimated that a 300-megawatt nuclear plant would be required to drive a desalination facility with a capacity of 1 million cubic meters of potable water a day. That’s enough water to support a population of between 3 or 4 million people. That same population would require between 4,000 and 6,000 megawatts of installed capacity to meet its electricity needs.