As the pressures of water security become more acute around the world, the significance of desalination as means of ensuring potable water supplies has never been greater. But with the expected growth of global desalination capacity comes a problem: processes remain heavily reliant on fossil fuels. According to the Global Clean Water Desalination Alliance, global installed desalination plants emit some 76 million tons of CO2 per year, an amount expected to reach around 218 million tons by 2040.

Clear alternatives do exist, namely ambitions and projects for desalination via renewables. Still, with emissions and water security high on the global agenda, another solution presents itself in the form of nuclear-powered desalination.

It’s not a new idea — it’s well documented as a feasible, reliable and efficient solution for process integration with desalination technologies of several flavors. A key strength of nuclear power plants (NPPs), aside from technical maturity, is their capacity to supply either thermal or electrical energy, or both, to respective desalination processes, at varying scales.

“We can think of nuclear-powered desalination in terms of two main applications. One is to serve make-up water resources for the plant; the other is to produce potable water. Both applications have already been demonstrated,” said Ibrahim Khamis from the International Atomic Energy Agency (IAEA) department of nuclear energy.

Precedent notwithstanding, Khamis explained that “nuclear-powered desalination of potable water isn’t currently widespread or deployed at large scale.”

A notable exception was the now-offline Aktau plant in Kazakhstan. A flagship nuclear desalination plant pioneered by the Russian nuclear industry, Aktau was commissioned in 1967 and operated for 40 years, supplying Aktau’s population (over 150,000 people) and industry with fresh water.

A few examples of nuclear-powered desalination in operation do exist. “Only recently we’ve moved from a few thousand cubic meters daily production to tens of thousands cubic meters daily production being built — it’s scaled up but not greatly,” said Claus Mertes with leading desalination consultancy DME on the state of global nuclear desalination.

He continued: “India, Pakistan, Iran and China already have nuclear-powered desalination capacity, although not at the scale that nuclear power could easily achieve — say 1 million cubic meters per day. We currently see plants with 10,000-15,000 cubic meters daily production using multi-effect distillation with thermal vapor compression (MED-TVC), reverse osmosis (RO) or multi-effect distillation (MED) processes. These plants are in operation today, and several have plans to increase production capacities.”