Information regarding three new environmental permit applications for the proposed Sizewell C power station site, Sizewell, Suffolk, IP16 4UR

Closed 25 Sep 2022

Opened 4 Jul 2022



NNB Generation Company (SZC) Limited applied for 3 environmental permits to operate Sizewell C. We want your views on our proposed decision and draft permits.


The Environment Agency is the independent environmental regulator for the nuclear industry in England. It makes sure that nuclear power stations meet high standards of environmental protection. 

Any company that wants to operate a nuclear power station will have to show that it can build, commission, operate and decommission it safely and securely, whilst protecting the environment and managing radioactive waste. 

EDF nominated Sizewell as a potential site for a new nuclear power station. EDF’s new nuclear build company, NNB Generation Company (SZC) Limited, is proposing to construct a twin reactor nuclear power station at a location immediately north of the existing Sizewell A and B power stations. The proposed new power station is known as Sizewell C.

The Sizewell site is located on the east coast of the United Kingdom, approximately 1.5km north-east of the town of Leiston in the county of Suffolk. 

Find out more about our work at Sizewell C (SZC) at:

Permit applications and our proposed decision

In May 2020, NNB Generation Company (SZC) Limited applied to the Environment Agency for 3 environmental permits to operate Sizewell C. We consulted on these applications from July to October 2020. We have come to a proposed decision on whether we should issue these permits, and if we do what conditions they should include.

The permits are to:

  • dispose of and discharge radioactive waste
  • operate standby power supply systems using diesel generators
  • discharge cooling water and liquid effluent into the North Sea

Our proposed decision is that we should issue all 3 permits. Our Habitats Regulations Assessment conclusions support our view. We consider that the limits and conditions in the permits are suitable to protect people and the environment.

We’re inviting your comments on our proposed decisions, draft permits and supporting documents. Where relevant, we can use these to help inform our final decisions on the permits.

We welcome everyone’s views, for example from:

  • the public
  • the energy industry
  • academics with an interest in nuclear power, energy or the environment
  • non-governmental organisations
  • any other organisation or public body

Scope of consultation

Advice about what aspects and issues we can and cannot take account of is provided below:

We can take account of:

  • relevant environmental regulatory requirements and technical standards
  • information on local population and sensitive sites
  • comments on whether the right process is being used for the activity, for example whether the technology is the right one
  • the shape and use of the land around the site in terms of its potential impact, whether that impact is acceptable and what pollution control or abatement may be required
  • the potential for the land around the site to have an effect on air quality and what pollution control may be needed
  • information that we have not been made aware of in the application, or corrections to incorrect information in the application

We cannot take account of:

  • anything outside the remit of the Environmental Permitting Regulations, such as the proposed location of the site, which is done by the local authority via land use planning
  • whether a site should have a formal designation under the Conservation of Habitats and Species Regulations or other conservation legislation
  • whether the activity should be allowed or not as a matter of principle. For example we will not consider whether nuclear power generation is an appropriate process or whether alternative methods of generating electricity should be used instead
  • land use issues, or sustainability challenges, even if it is argued that changing the location of the activity would improve its environmental performance
  • the impact of noise and odour from traffic travelling to and from the site
  • the legally defined process we follow to determine a permit
  • comments about the government’s energy policy

How to comment

We have published the following documents for you to consider:

On this page

  • Consultation public summary document (covering RSR, WDA, Comb, HRA)

On the water discharge activity consultation page

  • draft permit for water discharge
  • Sizewell C water discharge activity consultation document (proposed decision document)

On the radioactive sources activity consultation page

  • draft permit for radioactive substances
  • Sizewell C Radioactive substances activities consultation document (proposed decision document)

On the combustion activity consultation page

  • draft permit for combustion activity
  • Sizewell C combustion activity consultation document (proposed decision document) On this page

On this page

  • independent dose assessment report - we commissioned an independent assessment of the impact of radioactivity on members of the public, plants and animals using the proposed discharge limits.
  • habitat regulations assessment report - covers all 3 permits
  • SSSI assessment – covers all 3 permits

On the water discharge activity consultation pages

  • review of the Water Framework Directive compliance assessment

On the radioactive sources and water discharge activity consultation pages

  • An updated NNB GenCo (SZC) Company Manual

On the radioactive sources activity consultation page

  • Letter from the Environment Agency to Public Health England requesting advice.
  • Letter from Public Health England to the Environment Agency providing the requested advice
  • Letter from the Environment Agency to NNB GenCo (SZC) confirming information provided by it to the Environment Agency.
  • Letter from NNB GenCo (SZC) to the Environment Agency regarding the learning from the issue at Taishan Unit 1

On the combustion activity consultation page

  • Request for further information dated 01/03/21
  • Response to request for further information regarding commissioning and fuel oil. 24/03/21

Schedule 5 notices

We requested more information from NNB GenCo to help us make decisions about the permit applications. We do this by issuing a legal notice called a Schedule 5 specifying the further information we need from them and the date by which it must be provided. We took this information into account in coming to the proposed decisions on the permit applications. Schedule 5 notices and any responses received as a result of those notices are placed on the Public Registers.

We have published all the schedule 5s below

On the combustion activity consultation page

  • Schedule 5 Notice dated 21/05/21 for combustion activity
  • Schedule 5 Notice response – Site Condition Report. 14/06/2021
  • Schedule 5 Notice response - Air Quality Assessment. 22/06/21
  • Schedule 5 Notice response – Air Quality Management Plan. 22/06/21
  • Schedule 5 Notice response – BAT and Cost Benefit Assessment. 23/06/21

On the water discharge activity pages

  • Schedule 5 Notice No.1 dated 02/10/20 for information requests (IRs) 1(a) to 1(f)
  • Schedule 5 Notice No.2 dated 18/01/21 for IRs 1(a) to 13 (c)
  • Schedule 5 Notice No.3 dated 15/03/21 for IRs 1 to 5(b)
  • Schedule 5 Notice No.4 dated 23/04/21 for IRs 1(a) to 5
  • Schedule 5 Notice No.5 dated 18/10/21 for IRs 1(a) to 1(i)
  • Schedule 5 Notice No.6 dated 19/10/21 for IRs 1(a) to 6
  • We received multiple responses from NNB GenCo (SZC) to each of the information requests within the six Schedule 5 Notices, which are provided on the water discharge activities consultation page

Next steps following this consultation

Our determination of NNB Generation Company (SZC) Limited’s 3 permit applications continues and we have not yet reached any final decisions. We will complete our determination, including carefully considering all relevant comments made during consultation and will produce final decision documents that: 

  • set out our decisions about whether environmental permits should be issued to NNB Generation Company (SZC) Limited
  • summarise the consultation responses and issues raised
  • set out our views on those issues

We will publish our final decision in early 2023.



  • Anyone from any background


  • Water quality
  • Permits
  • Nuclear
  • Environmental permitting
  • Installation
  • Radioactive substances regulations