Revealed: The water supply risks posed by Dutton’s nuclear plan

Opposition Leader Peter Dutton’s proposed nuclear plants will suck more water from nearby rivers than the coal plants they would replace, posing a challenge to maintaining drinking supply for local communities and irrigation for farms.

The federal government cites its own modelling to claim nuclear would use up to three times more water than the coal plants that are critical for the opposition’s pledge to help households with power prices and reach net zero emissions by 2050.

Opposition Leader Peter Dutton has pledged to build seven nuclear power stations across the country, which according to government data would use more water than the existing coal plants.Credit: Monique Westermann

A secure water supply is crucial for the communities the opposition has selected as sites for the seven nuclear plants it has pledged to build if it wins the election, due by May.

There is no water to spare in the local rivers that supply the coal plants the Coalition has selected to host a nuclear reactor, where state governments issue licences to manage the competing needs of residents, farming and environmental requirements.

Greater water consumption from nuclear energy could shrink the size of the agriculture sector. Introducing a government buyer into the market would also likely raise water prices for the farmers who remain and create tension between key Coalition voter groups.

For example, Lithgow’s Mt Piper coal power station about 140 kilometres west of Sydney, a site earmarked for a nuclear plant, is located in the Macquarie water catchment where cotton, wine grapes and grains are grown.

Departmental data released by Labor on Wednesday states the opposition’s seven nuclear plants would collectively use 500 gigalitres – roughly the same volume as Sydney Harbour – to generate the amount of power they plan to supply to the grid each year.

The seven coal plants earmarked to be replaced by nuclear use 168 gigalitres a year, generating 48-terawatt hours of electricity.

Credit: Matt Golding

Why does nuclear need more water than coal?

Coal and nuclear plants both use their heat source to boil water, make steam and spin turbines to generate electricity. This steam is cooled back to water (when most water loss occurs) and then re-used in the plant.

The opposition’s energy policy stipulates their nuclear plants would run at near full capacity every day of the year to recoup costs.

That means nuclear would need to draw on more water, far more often than some of the coal plants they replace, which run about 60 per cent of the time.

What do experts say?

The government cited an Australian National University study to make its claim that nuclear plants use 40 per cent more water than coal plants on average because their cooling processes tend to be less efficient.

ANU engineering professor Andrew Blakers said he stood by his findings.

“The key point is coal and nuclear and thermal power stations need water cooling,” Blakers said. “Solar and wind use vastly less because they don’t need any water for cooling.”

The World Nuclear Association, which was formed to promote investment in the technology, says water consumption of coal and nuclear is “very similar”. UNSW Nuclear Innovation Centre Associate Professor Edward Obbard said closed-loop cooling systems, which are used for nuclear and coal plants, would use comparable volumes of water.

Regardless of the dispute over nuclear energy water use compared to coal, Emeritus Professor Ian Lowe of Griffith University said Dutton’s nuclear plan would require more water than the existing coal plants because of how much they will be operating.

Lowe, an energy expert who advised the South Australian nuclear royal commission almost a decade ago, said nuclear plants use about 20 per cent more water than coal plants, on average, but would use even more under the Coalition modelling.

“If you are running at a 90 per cent capacity factor, then of course you’d be using more water for cooling,” he said.

What do politicians say?

The Albanese government is opposed to developing nuclear energy, which is banned under federal and state laws. It has committed to cut Australia’s greenhouse emissions with renewable energy.

Opposition energy spokesman Ted O’Brien said the government’s claims were “completely flawed” and said the opposition had not selected what types of nuclear plants it would build and could use more water-efficient systems, including “dry cooling”.

Modelling previously released by the opposition to argue their nuclear policy would result in cheaper energy prices than renewables was based on a water-cooled system.

“The Coalition has been clear that water security for communities and food production will be a priority in the comprehensive site characterisation studies at each location,” O’Brien said.

Environment Minister Tanya Plibersek said the opposition’s nuclear plan would “suck regional communities dry”.

“Where will the water come from and who will pay for it? Will farmers foot the bill? Or are they going to leave communities without a reliable drinking water supply? What happens during drought?” Plibersek said. The government also rejects the opposition’s cost claims.

Plibersek said the government is currently running a scheme to buy water back from irrigators, to put more flows back into the river for environmental health. Opposition water spokeswoman Perin Davey said this would also shrink the size of farm industries and “Plibersek needs to answer her own questions with regards to water buybacks”.

What do farmers say?

NSW Irrigators Council chief executive Claire Miller said “water is a very scarce resource” and all the available supplies around Lithgow and the Hunter Valley are committed to existing industries.

“Governments need to consider very carefully any industries coming in that increase the competition for that resource and what the impacts would be on other water users, including farmers.”

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