With the Environment Agency describing Suffolk as “seriously water stressed” – will there be enough water for the nuclear power station Sizewell C without impacting the region? Dr Stephen Mannings, Sizewell C environment consents manager, explains.

The UK government has given the green light to start work on Sizewell C, a new nuclear power station on the Suffolk coast. The two-unit reactor will generate affordable, low-carbon energy for six million homes over the next 60 years.

One of the primary resources needed to ensure that the nuclear power station works is water. But how will the water be managed, and where is it going to come from?

East Anglian Daily Times: Dr Stephen Mannings with Alde Valley Academy students on a field trip to Aldhurst Farm, the Sizewell C nature reserve in LeistonDr Stephen Mannings with Alde Valley Academy students on a field trip to Aldhurst Farm, the Sizewell C nature reserve in Leiston (Image: Sizewell C)

Dr Stephen Mannings, environment consents manager, says that Sizewell C is a critical piece of infrastructure to meet the government’s net-zero objectives by 2050.

“We need to decarbonise our electricity and Sizewell C will make a massive contribution towards that goal, while providing energy security and value for customers.

“Suffolk is a highly water-stressed area,” Stephen acknowledges. “So, meeting demand for Sizewell C was always going to have its challenges. But it’s not just a matter for Sizewell C. Water supply is a regional issue that needs a regional response to support growth, adapt to climate change and leave more water in the ground and in our rivers to protect the environment.”

It’s the job of the regional water companies to support this and develop plans for the future. Sizewell C’s long-term demand will be supplied by Northumbrian Water, which trades locally as Essex & Suffolk Water. Its draft water resource management plan has just been published for consultation, which identifies two credible options to supply Sizewell C that will even provide a surplus. 

East Anglian Daily Times: The schemata for Sizewell CThe schemata for Sizewell C (Image: Sizewell C)

One of the main drivers for construction water is lubricating the tunnel boring machines that will churn through rock under the sea to create the cooling water intakes and outfalls three kilometres offshore.

“We’ve set ourselves very ambitious targets for reduction and re-use," Stephen says.  “At least 70% of the water needed in this process will be recycled.

“Our water strategy includes construction of a bespoke temporary desalination plant within the construction site. This gives us security of supply during the construction phase of the project, without drawing off the local water distribution network.”

Desalination is little-known in the UK but is a tried and tested technology that’s been used successfully for decades in places such as the Middle East.

Sizewell C is in negotiations with Anglian Venture Holdings to build and operate this plant. It will be powered by low-carbon electricity from the existing Sizewell B nuclear power station and will produce up to 4 million litres of potable grade water a day.

The reactor will be connected to a vast network of water-filled pipework that is used to create electricity. This pipework is arranged in closed loops, called primary and secondary circuits, in which the water is constantly recirculated.

Nuclear energy produced in the reactors is used to heat water to produce steam. This drives turbines to produce electricity in generators. Once the steam has done its job it is converted back into liquid in the condensers, where the waste heat is picked up by seawater abstracted off-shore, which is immediately discharged back to sea.

“Impacts on the marine environment, including fish, have been minimised,” Stephen says.

Water also serves an important safety function, as it cools the reactors.

“Think of it as two sides of the same coin,” says Stephen. “Potable grade water fills the closed pipework that serves the reactors and seawater cools the condensers. Sizewell C’s operational demand for potable water will be two million litres per day. That may sound a lot, but Sizewell C will supply low-carbon electricity to six million homes, which puts it into perspective.”

This represents a small portion of the total potable water demand for Suffolk.

“We know this is a water stressed area,” Stephen adds. “Which is why we’ve got a clear and sustainable strategy for managing water. Every drop is accounted for and local people around Sizewell can rest assured that we will have no negative impact whatsoever on their supply but hope to make a positive contribution to the availability of water.”

For more information, please visit sizewellc.co.uk

Sizewell C pledges to:

  • Minimise disruption to local communities during construction.
  • Invest in local employment, education and skills.
  • Support the growth of the local economy.
  • Not impact on the supply of water to local residents by a single drop.
  • Transport 40% of construction materials by rail and sea.
  • Respect the Suffolk heritage coast.
  • Support the Suffolk coast tourism sector through a tourism fund.
  • Provide a comprehensive 24/7 on-site occupational health service for workers.
  • Require all workers to sign a Worker Code of Conduct and enforce it.
  • Enhance the economic, social and environmental wellbeing of local communities through a community fund.