Frequently Asked Questions

What we get asked the most about

On this page, we’ve put together some myth-busting facts and responses to the most common questions we get asked.

If you have a question that isn’t answered below, you can send it to us via our contact form.

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  • The need for nuclear
    • Why do we need nuclear?

      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 COcompared 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.

    • Why can’t we just use renewables to get to Net Zero?

      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.

    • What do others say about nuclear?
    • Why do we need to build Sizewell C?

      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.

  • Funding Sizewell C
    • Isn't nuclear expensive?

      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.

    • How will Sizewell C be funded?

      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.

    • Why is RAB a suitable model for Sizewell C?

      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.

    • What does RAB mean for consumers?

      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.

  • The EPR design
    • Why will Sizewell C be using the EPR design?

      EPRs – originally known as European Pressurised Water Reactors – are a type of Pressurised Water Reactor (PWR).

      The UK EPR design being used for Sizewell C is the same as at Hinkley Point C in Somerset. Making a copy means we can lower construction and financing costs.

      The EPR is a good choice for Sizewell C. It is a proven technology which is already operating at Taishan in China.

      It is a major evolution of previous PWR designs and means Sizewell C and Hinkley Point C will be among the safest and most efficient nuclear plants ever built.

      The UK EPR meets the most stringent safety and environmental standards. It will use less uranium and produce almost a third less long-lived radioactive waste compared to other water reactors in operation today.

      As part of the Generic Design Assessment (GDA), the UK EPR design underwent years of evaluation by the Office for Nuclear Regulation and Environment Agency.

      850,000 hours of engineering studies were undertaken as part of the rigorous four-year design approval process.

    • Why have other EPRs been delayed?

      EPR projects in Finland (Olkiluoto) and France (Flamanville) have been affected by cost and schedule overruns because they were restarting the industry after a long gap in nuclear construction. Skills and experience had been lost.

      In addition, those projects began construction before the detailed design had been completed. This meant complex alterations had to be carried out once construction was underway.

      Construction at Hinkley Point C began in 2016. The project is making good progress and is benefiting from experience at other EPRs. Improvements in construction between the first and second reactor units are demonstrating the value of replication.

      Two EPRs at Taishan in China began successful commercial operation in 2018 and 2019. Taishan 1 is currently shut down for maintenance after minor damage to a very small number of fuel rods. It’s not unusual to experience minor issues with fuel in the early life of a reactor.

      Sizewell C will be the 7th and 8th EPR units in the world and will benefit from a large body of experience from construction and operation of the rest of the EPR fleet. The project will have a stable design, an experienced workforce and supply chain, and a well-tested schedule. We will have a very good understanding of project risks and how to mitigate them.

  • Carbon emissions
    • Will Sizewell C be too late to help get us to Net Zero?

      No. Sizewell C will start making a substantial contribution to net zero emissions from the moment it starts generating in the early 2030s. It will be pushing fossil fuels off the electricity grid and avoiding around 9 million tonnes of carbon emissions each year.

      Sizewell C will not only help to decarbonise the electricity mix, but it will also help to lower emissions in other sectors, like transport and heating.

    • Won't there be lots of carbon emissions during construction?

      The carbon emissions over Sizewell C’s full lifecycle will be lower than for nearly every other generating technology.

      All large infrastructure projects, including solar and wind farms, produce carbon emissions during construction. Although there will be emissions during the construction of Sizewell C, these pale in comparison to the carbon that would be emitted if a fossil fuel plant was generating instead.

      By replacing a carbon-emitting gas plant, it will take just 4-5 months of operation for Sizewell C to avoid the same quantity of emissions that were produced during its construction.

    • How will Sizewell's emissions compare with other low-carbon technologies?
      lifecycle carbon assessment graphic. it says, "Sizewell C will have lower lifecycle carbon emissions than wind and solar. All three technologies will be essential in helping to achieve net zero

      The Intergovernmental Panel on Climate Change (IPCC) found that lifecycle carbon emissions for nuclear are comparable with wind, and lower than all other technologies.

      A peer-reviewed Lifecycle Assessment (LCA) for Sizewell C shows that emissions will be half the level attributed to nuclear and offshore wind by the IPCC.

  • Water supply
    • What impact will Sizewell C have on local water supplies?

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

    • How will Sizewell C’s water be supplied during construction?

      A new permanent water supply for the power station will be completed in the early 2030s. Until then, the water needed for construction will come from a temporary desalination plant on the main development site. It will be one of the first things we build and will be located away from Sizewell Marshes SSSI and Sizewell beach.

    • Why do you need to use a desalination plant?

      East Anglia is one of the driest regions in the country and has been classified by the Environment Agency as a Serious Water Stressed Area. Climate change and a growing population mean water supplies are likely to come under greater strain in future unless action is taken.

      Seawater desalination is a tried and tested system which supplies drinking water to millions of people in drier parts of the world. By building a plant at Sizewell C, we will gain new skills in a technology which is going be used more widely in the UK.

    • Won’t the tankers bring extra pressure to bear on local roads?

      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.

    • Won't operating the desalination plant produce carbon emissions?

      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.

      Not only will our project reduce carbon emissions, but we will also help to address the threat of water shortage caused by global warming. An improved water supply is one of the many ways Sizewell C will bring change for the better to the East of England.

    • How will Sizewell C be supplied once the power station is operating?

      Once it is operating, the power station will use less than 0.1% of the total water forecast to be needed in the East of England while generating low-carbon electricity for around 6 million homes. It is one of hundreds of East Suffolk businesses which will need a new permanent water supply in the 2030s.

    • Is Sizewell C intending to establish its own permanent desalination plant?

      Desalination plants supply several nuclear power projects globally but it is not a permanent option we are considering for Sizewell C.

      To accommodate the overall increase in demand in the region, the local water companies will build either a water recycling plant in Lowestoft or a new reservoir in North Suffolk. Once the new source (or combination of sources) is chosen, Sizewell C will help to pay for a mains pipeline to bring the water to the Leiston area.

      The new mains pipeline will supply not just the power station but the wider community as well. As a result, by the mid-2030s the
      area around Sizewell C is expected to have more water than it needs.

  • Nuclear Waste
    • Doesn’t radioactive waste make nuclear a harmful technology?

      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.

    • What are the radioactive by-products from nuclear generation?

      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.
    • How will Sizewell C deal with its radioactive waste and spent fuel?

      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.

    • What about plans for a Geological Disposal Facility (GDF)?

      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.

    • How will waste management be paid for?

      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.

    • When will Sizewell C be fully decommissioned?

      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.

  • Local communities
    • How will you minimise the impact of construction?

      We are taking a wide range of measures to minimise the impact of construction on local communities. We made eleven pledges to the local community when we applied for a DCO in May 2020 and have taken measures to honour these.

      In the Deed of Obligation signed with Suffolk County Council and East Suffolk Council in October 2021, we agreed a £250m package to mitigate the effects of construction. It also provides funds to enhance the local environment and to support local employment and skills initiatives.

      An additional £400million will be spent on physical developments to avoid, limit, mitigate or compensate for the impacts of construction. This includes £175million for road infrastructure, rail improvements, a permanent beach landing facility and additional ecology work around the Associated Development sites. These will all provide a long-term benefit to East Suffolk.

      Measures we are taking to reduce the impact of construction include:

      • Up to 60% of construction materials will be transported to site by rail and sea, significantly reducing the number of HGVs on local roads.
      • Park and ride sites will allow commuters to use buses and will minimise traffic on local roads.
      • A freight management facility will allow us to carefully schedule deliveries to and from the construction site.
      • Bypass roads and a rail extension will be built to meet increased demand from the project.
      • Sizewell C will remove any unnecessary infrastructure following construction, restoring the land in the process, whilst leaving all useful road and rail enhancements in place.
      • Measures to reduce noise include screening, use of quieter working methods and a noise mitigation scheme for properties significantly impacted.
      • A Tourism Fund has been established to ensure any potential effect on local tourism does not have economic consequences. There is little evidence to suggest that Sizewell C will have an impact on tourism in the surrounding area.
      • We are exploring the use of alternative fuels (such as hydrogen and electricity) for buses, HGVs, and other construction equipment that will be used on the site.
      • Lighting will be managed to limit light spill on the surrounding environment, reducing the impact on local species.
      • Dust management plans will be implemented to control and minimise dust emissions.
    • How will you protect the local environment?

      Please visit the environment page to see how we plan to increase local biodiversity by 19%.

    • How can you build Sizewell C in a rural area with poor transport links?

      We know we have a responsibility to local communities and to the Suffolk Heritage Coast to build Sizewell C in a way which causes as little disruption as possible.

      In response to local feedback, we have improved our transport strategy and have increased the amount of material that will be delivered to site by sea and rail from 40% to 60%.

      Nevertheless, building Sizewell C will require moving substantial volumes of construction material.  To do this in as sustainable a way as possible, we will follow these principles:

      • Reduce the volume of material that needs to be moved away from the Sizewell C site by using it as fill or for landscaping.
      • Where material must be delivered to the Sizewell C site, we will try to move it by sea or rail where practicable.
      • Where delivery by road remains necessary, we will use defined routes for HGVs and systems which can monitor, manage and control the number and timing of HGV movements.
    • How many HGVs will it take to build Sizewell C and for how long can we expect them?

      Because we have increased the amount of material that can be delivered to site by sea, we have been able to cut the number of HGVs which will be on the roads.

      On the busiest days at the busiest time phase of construction, we expect a maximum number of 700 HGV movements (350 each way).

      On average, we expect 500 HGVs during the busiest phase of construction (250 journeys each way).

      It is important to note that the number of HGVs on the roads will change during specific phases of construction.
      At the start of construction, there will only be a few additional HGVs on the official HGV route, building up to a peak of 700 HGV movements (350 HGVs each way) at the busiest times.

    • Why can’t you just transport all the material by sea and rail?

      We have been able to source more of our required material from areas with good rail and sea connections.  This has given us the ability to reduce the total amount of material being moved by road to around 40%.

      However, some material is just not suitable for transportation by sea and rail, both in terms of where it comes from or its characteristics.

    • What other measures are you taking to manage local traffic?

      The following infrastructure improvements are among the many measures we will put in place to manage or reduce local traffic:

      • A two-village bypass for Farnham and Stratford St Andrew.
      • Sizewell Link Road from the A12 south of Yoxford to a location close to the main site entrance.
      • Southern Park and Ride in Hacheston with 1250 car parking spaces for workers from North Essex, Ipswich and South Suffolk.
      • Northern Park and Ride at Darsham with 1250 car parking spaces for workers from Norfolk, Lowestoft, Great Yarmouth and other locations in North Suffolk.
      • Freight Management Facility for 150 HGVs on the Old Felixstowe Road near the A12/A14 junction.
      • Highway junction improvements
      • Green Rail Route from the Saxmundham-Leiston branch line to the construction site, allowing freight to be delivered to site by rail.
      • Beach Landing Facilities: a permanent BLF for very heavy items and a temporary BLF for use in advance of peak construction.
  • The Sizewell Coast
    • Why is the Suffolk coastline the right place to build Sizewell C?

      The land to the north of Sizewell B was identified as a suitable site for a new nuclear power station by the Government over a decade ago.

      Electricity has been safely produced from nuclear power at Sizewell for over half a century. Siting Sizewell C next to Sizewell B reduces the environmental impact from construction and the site can benefit from nuclear licencing and a grid connection.

      All nuclear plants in the UK are located near the sea so that water can be used in the power station cooling system.

    • Won’t the power station be at risk because of coastal erosion?

      No. Extensive investigations have been undertaken by experts to establish that the Sizewell C site is stable.

      Parts of the Suffolk coastline are experiencing erosion, but Sizewell is located on a more stable section of land, between two hard points and the offshore bank of sediment known as the ‘Dunwich – Sizewell Bank’.

      Sizewell A has stood on the same part of coastline since 1966 and Sizewell B has operated since 1995. In more than half a century, neither of those power stations has seen any flooding or significant coastal erosion.

      The Government’s Centre for Environment, Fisheries and Aquaculture Science (CEFAS) is based in nearby Lowestoft and has comprehensive data for coastal change on the East Coast going back to the 1800s. The data show that this part of the coast has been very stable.

    • Won’t rising sea levels threaten the power station?

      No. Sizewell C will be built on a platform standing approximately 7 metres above today’s mean sea level and will be protected by a sea defence structure that will be more than 14 metres above mean sea level. These and many other measures incorporated into the design of the power station will protect it from the sea.

      The sea defence will be adaptable and could be raised in future if sea level rise turns out be greater than current predictions. Based on current forecasts, any adaptation would not be needed until 2140 and only under the most extreme climate change scenario.

      We have performed thousands of hours of flood risk modelling using the highest plausible estimates for sea level rise in the Sizewell area. Our assessments show that the power station and access road will be built to withstand a 1-in-10,000-year storm and 1-in-100,000-year surge events.

      Although extreme storm events could result in some sea water coming over the sea defence and pooling around the site, it would drain away in a matter of hours. This is predicted, planned for, and reflected in the design of the entire Sizewell C site.

      Drones are flown over the Sizewell beach each month and photograph every 3cm square of the coastline, producing 3D maps of any changes. Radar and tide gauges will also allow us to monitor sea conditions and levels at Sizewell throughout the lifetime of the power station. If there are any unexpected developments, we will take action to address them.

      Read the 2021 Sizewell Coastal Defences report here and the draft Coastal Processes Monitoring and Mitigation Plan (CPMMP) here.

    • Will Sizewell C have a detrimental impact on fish?

      Sizewell C will not have a significant effect on fish populations. Sea water is needed to operate the cooling system of the power station, but a fish return system and specially designed heads on the sea intake pipes will minimise the impact on fish.

      Government scientists at CEFAS say there is no scientific evidence that the rates of impingement at Sizewell C will have a significant effect on population sizes.

      Fish populations produce vast numbers of young each year. The species which will be most affected by the power station will be sprat and herring but the losses are expected to be just 0.01% of the adult population each year. That’s a tiny fraction of the population size and of the natural variation in the numbers of adult fish from year to year.


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