Sizewell C FAQs

Nuclear is needed because it is the only proven technology that can deliver always-on low carbon power at scale.

Nuclear will help to balance a future energy system dominated by variable renewables like wind and solar which depend on the weather. 

Nuclear has lower carbon emissions than most other energy technologies and delivers a lot of electricity from a small land footprint. It will help reduce our reliance on energy imports. 

Some projections suggest 20-30GW of nuclear capacity could be needed by 2050. That’s the equivalent power generated by Hinkley Point C (under construction in Somerset) plus five to eight additional power stations of the same size.

The UK's 8 nuclear power stations currently provide around 17% of our electricity. 

The existing fleet has generated 2000 TWh since the first power stations began operating in 1976. They have saved approximately 700 million tonnes of CO2 compared to gas-fired power. 

All but one of those power stations will close by 2030 so it’s important that new projects are developed to supply ‘baseload’ low carbon electricity in the future.

According to the Committee for Climate Change, the net zero target will require a fourfold increase in low-carbon electricity from today’s levels. 

Wind and solar will play the biggest role in meeting that challenge, but we can’t rely on them alone. Other technologies will have to help keep the lights on when the sun doesn’t shine and the wind doesn’t blow.

We need a lot more renewables to get to net zero, but we need nuclear alongside renewables.  Nuclear reduces the cost and challenge of dealing with intermittent generation.  
 

• The National Grid, the UK’s electricity system operator, explains that nuclear power will continue to be a key generation source on the road to net zero in 2050. 
• The Prospect trade union explains why new nuclear is essential to beating the climate crisis.
• The Energy Systems Catapult’s Innovating to Net Zero report set out a range of possible pathways for how the UK can achieve net zero emissions by 2050 – in the centralised ‘Clockwork’ pathway, nuclear provides up to half of total electricity generation.
• The UK’s independent Climate Change Committee also modelled pathways to decarbonisation which showed the need for new nuclear power stations – see their latest Carbon Budget for details.
• This modelling has informed the UK government’s Energy White Paper, which emphasises the role of nuclear in the low-carbon energy mix.
• Internationally, the IPCC has produced a range of pathways of how the world’s economies can limit global heating to 1.5C, with different assumptions about technological and social changes. All call for more nuclear.
• And the International Energy Authority’s roadmap to net zero by 2050 calls for nuclear alongside solar, wind, hydro and bioenergy. Also check out the IEA’s paper on nuclear power in a clean energy system.
• The United Nations Economic Commission for Europe (UNECE) says international climate objectives will not be met if nuclear power is excluded.
   

Sizewell C is the only new nuclear project which can start construction in the next few years.

It is the only project which is ready to deliver the lower financing and construction costs that come through replication.  

Other nuclear designs are being developed but it will be several years before those projects obtain the required regulatory approvals and contracts to begin construction. 

Achieving net zero requires an unprecedented build rate and means we need to deploy approved designs that are available today.   

Sizewell C will sustain jobs and skills in the nuclear industry until other projects are more fully developed.  
 

Even though nuclear power stations have a high upfront capital cost, a balanced energy mix which includes nuclear will lower costs for consumers.  

Government analysis shows it is cheaper for consumers to have nuclear in the energy mix than to try to run the electricity system on renewables alone. That’s because renewables like wind and solar energy are intermittent. Building enough solar or wind farms with storage to meet demand on calm or cloudy days would be extremely costly.  

EDF estimates suggest that with 20GW of nuclear capacity in 2050, consumers would pay almost £5bn less each year in an energy system using technologies that are available today.

The think-tank, Energy Systems Catapult, says trying to meet Net Zero without nuclear could put the target at risk and make the shift to a low carbon economy more expensive. 
 

In October 2021, the Government introduced legislation to allow new nuclear projects to be financed using the so-called RAB (Regulated Asset Base) model. 

RAB is a funding arrangement for large infrastructure projects which reduces costs for consumers.

It’s a tried and tested method which has already been used to finance around £180bn of UK infrastructure. 

By attracting a pool of investors and allowing them to share some project risks with consumers, the RAB model helps to reduce financing costs. Lowering the cost of finance has a much bigger impact on what consumers pay than construction costs. 

Government says that overall consumers are expected to save more than £30bn over the projects lifetime on each new large-scale nuclear power station compared with existing funding mechanisms.

Because Sizewell C is a copy of Hinkley Point C, construction costs will be lower and the project faces less risk.

Greater confidence about construction and risk-sharing means the project can attract lower-cost financing from pension funds, insurance companies and other investors. 

Sizewell C is the only nuclear project which can deliver lower construction and financing costs that come from replication.  
 

Under a RAB model, consumers pay a small contribution during the construction of the power station through their energy bills. This avoids the build-up of interest on investor loans which would ultimately lead to higher costs. The Government estimates consumers will pay on average less than £1 per month during construction.  

Consumer payments and returns to investors will be regulated during the construction and operation of the power station. This will ensure the returns to investors are fair and that consumers are getting value for money. 

Lowering financing costs has a much bigger impact on consumer bills than changes in construction costs. This means that even if there are increases in construction costs, the effect on consumer bills will be limited.

Sizewell C will have no impact whatsoever on the supply of water to homes and businesses in East Suffolk.

Sizewell C has a clear plan for providing all the water the project needs during construction.

In the first 9-12 months of construction, water will be supplied to site using water tankers. After that, water will be supplied using a desalination plant which will draw its water from the North Sea. Northumbrian Water has committed to providing a permanent supply to the project and is aiming for this to be in place by the late 2020s. Should this not become available until later, the desalination plant could continue to operate throughout the construction phase.

Our original proposals did not envisage the need for a desalination plant. We have been consulting with the water utilities for some time and our original planning application set out plans to supply the project using a permanent water main.  

Towards the end of the planning process, Northumbrian Water indicated there was a risk that the mains supply might not be able to provide the full amount of drinking water needed in the early years of construction. To make sure there is no risk to the local supply and to ensure the project has adequate water, we have decided to use desalinated water from the sea.

The change in advice from Northumbrian Water came towards the end of the examination of our planning application. It was important that we listened to this new information and adapted our plans accordingly.

No. We have agreed to cap the number of HGVs to and from the main development site each day. HGV movements will be strictly monitored to make sure the total number of journeys remains within agreed limits. We will accommodate the journeys made by the water tankers by rescheduling other deliveries to the site. 

More details about our transport policy and HGV limits can be found in the 'Local Communities' FAQ below.

The assessment that we submitted as part of our planning application, which was based on a set of worst-case assumptions, showed that the desalination plant would have a negligible impact on the project’s overall emissions.

Northumbrian Water have confirmed their commitment to supplying Sizewell C’s long-term requirements for drinking water. While this will not come from a transfer main, good progress is being made to identify other options and these are now being considered. These include a water transfer system, larger local desalination and new reservoir infrastructure. 

NB: Cooling water used for generating electricity is provided through the power station’s own sea-water intake system.

Desalination plants supply several nuclear power projects globally but it is not an option we are considering for Sizewell C. We are confident that Northumbrian Water will be able to meet the project’s long-term water needs through the sources that it is in the process of identifying. Any proposal to use a permanent desalination plant during the operational phase would require further detailed assessments.

All sources of energy generation produce some form of by-product or waste. Nuclear is the only generating technology which takes full responsibility for managing its waste.  

Radioactive waste and spent fuel from nuclear power stations are well controlled and safely managed to reduce any risk to people or the environment. 

By contrast, air pollution which includes waste emissions from fossil fuels kills around 7 million people each year.

Nuclear is one of the safest ways of generating electricity. A recent report by Our World in Data concluded that "fossil fuels are the dirtiest and most dangerous, while nuclear and modern renewable energy sources are vastly safer and cleaner."

A study by climate scientist James Hansen found that by replacing fossil fuels, nuclear energy had prevented around 1.8 million air pollution-related deaths.

The EPR reactor design used at Sizewell C will include shielding, barriers and materials so that it generates much less radioactive waste than existing UK nuclear power stations. 

Radioactive waste is broken down into three categories to classify it in terms of risk level:

• Low Level Waste (LLW):  around 95% of radioactive waste at Sizewell C. No shielding is needed during handling and it can be disposed of immediately. 
• Intermediate Level Waste (ILW): around 5% of radioactive waste will be ILW. It requires some shielding during handling, torage and disposal.
• High Level Waste (HLW): around 0.25% of radioactive waste will be HLW. This requires long-term cooling and shielding. Spent fuel can be treated either as HLW (requiring long-term cooling and shielding), or it can be reprocessed to provide fresh fuel for existing and future nuclear power stations. 

Before Sizewell C can begin construction, it needs to demonstrate to the environmental and safety regulators that the volume of waste has been minimised, and that it will be managed safely. 

• HLW and spent fuel will be packaged in concrete casks in an interim storage facility on the Sizewell C site. The casks use shielding which will reduce the radiation to a level that poses no risk to the workforce, public or the environment. The shielding is so effective that it is safe to touch the outside of the casks. The casks can be stored on site indefinitely or moved to a Geological Disposal Facility.  An interim storage facility is already used for waste and spent fuel at Sizewell B.  
• ILW will be packaged in stainless steel drums and stored in a shielded facility made of concrete. This is the same approach used at other nuclear sites and allows the radiation to reach a level that poses no risk.   
• LLW will be promptly removed and taken to the UK’s Low-Level Waste Facility at Drigg in Cumbria.
   

Interim spent fuel store at Sizewell B. Most radioactivity from a nuclear power station comes from spent fuel. This is often stored in casks which are safe to work around and even touch. 

An expert report into waste management by Ove Arup & Partners for EDF concluded that:

• Nuclear is the only form of power generation that takes full responsibility for waste management.
• Quantities of waste are significantly less than other forms of power generation
• Once packaged, radioactive waste is essentially benign.
• Safe and secure long-term solutions for radioactive waste exist and have done for some time.

In June 2021, the European Commission concluded that Sizewell C would not pose a radiological risk to the health of Member State Populations. In addition, the Commission confirmed that Sizewell C had adequate arrangements for the management of Radioactive Waste and Spent Fuel.

Government policy is to build a GDF in the future which will contain most of Sizewell C’s waste and all its spent fuel. 

Working groups in Copeland and Allerdale in Cumbria have been set up to discuss having a GDF in their area.  

If the GDF does proceed then the waste from Sizewell C would only represent around 1-2% of the volume of materials disposed of there.  

Although a site for the GDF has not yet been confirmed, this does not mean waste or spent fuel from Sizewell C will pose a risk to the environment. 

The methods that are being used to store waste on an interim basis today could be extended indefinitely without any harm to human health or the environment. 
 

Hinkley Point C and Sizewell C will be the first UK power stations to include the future costs of waste and decommissioning in the price of their electricity. 

Nuclear is the only form of electricity generation which includes the price of waste management in this way. 

The technical plan for waste management and the funding arrangements (collectively known as the Funded Decommissioning Plan) must have Secretary of State approval before construction can begin. 
 

Decommissioning of Hinkley Point C and Sizewell C will be much quicker than for the older UK Magnox and AGR power stations.  

The Hinkley and Sizewell sites will largely be returned to a green field about 20 years after they stop operating.

The only facilities that will remain will be relatively small temporary spent fuel storage and packaging facilities which will close 30 years later.