A story from BBC News on the potential for nuclear powered de-salination plants:

There are communities on every continent running short of water, according to the United Nations. Unfortunately, although our planet is swathed by oceans and seas, only a tiny fraction of Earth’s water – about 2.5% – is fresh, and demand for drinking water is projected to exceed supply by trillions of cubic metres by 2030.

Desalination plants, which remove the salt from seawater, could help supply the fresh water needed.

However, these plants are considered among the most expensive ways of creating drinking water- as they pump large volumes across membranes at high pressure, which is an extremely energy intensive process. One radical solution could be using floating vessels equipped with desalination systems.

Powered by nuclear reactors, these vessels could travel to islands, or coastlines, struck by drought, bringing with them both clean drinking water and power.

“You could have them moving around on an intermittent basis, filling up tanks,” says Mikal Bøe, chief executive of Core Power, which has come up with design for this type of desalination plant.

There are already around 20,000 desalination plants worldwide, almost all of which are onshore. The majority are located in Saudi Arabia, the United Arab Emirates and Kuwait, with others in countries including the UK, China, the US, Brazil, South Africa and Australia, to name a few.

But some engineers say it could be cheaper to position this desalination technology offshore, where the seawater can be more easily pumped aboard. For decades, engineers have dreamed of building floating, nuclear powered desalination systems.

Core Power want to use a vessel very much like a small container ship, but stack containers on board filled with desalination technology. The nuclear reactor would then lie at the heart of this vessel providing the huge amount of power needed.

The firm’s floating nuclear desalination vessels could have varying levels of power output, from five megawatts, up to around 70, Mr Bøe adds. At five megawatts of nuclear power, it could pump out 35,000 cubic metres – or 14 Olympic swimming pools’ worth – of freshwater every day.

To take the salt out of saltwater, desalination technology pushes treated seawater across a semi-permeable membrane at pressure. Osmosis, the movement of molecules in liquid across such membranes, removes the minerals, leaving freshwater and a separate, particularly salty water called brine.

There are different versions of this technology and it has become increasingly more efficient over the years. But floating desalination systems remain relatively rare. Saudi Arabia, however, has just taken delivery of the first of three desalination barges, the largest ever built. So, can floating desalination plants take-off?

Oisann Engineering, which has developed a system called Waterfountain, hopes so. The company has various designs, from large ships to small buoys, but they all work on the same principle, explains chief administrative officer, Kyle Hopkins. However, the big difference is that instead of using nuclear power, they would all use what’s called subsea desalination, a decades-old technology.

The full news story from the BBC can be read here.