Sizewell A

10 Site area (Hectares)
110 Station lifetime output of electricity (TWh)

Current phase: C&M Preparations

Sizewell A is located near Leiston in Suffolk and is a twin reactor site. The site became fully operational in 1966, and shut down on 31 December 2006. Over 40 years of safe, compliant generation the site produced 110 TWh of electricity. The site has now completed defuelling with the final flask of spent fuel leaving site on Wednesday 6 August 2014.

Key near term activities

The key activity for the site has been working steadily towards completion of defuelling which was achieved in 2015. The site is currently focusing on enabling demolition work in preparation for care and maintenance preparations.

It is also undertaking project works to enable its transition into decommissioning such as the electrical and control and instrumentation overlay projects. The site will also continue its ongoing efforts to ensure that systems and structures remain fit-for-purpose and use a process called  “configuration control” to create opportunities for future deplanting and demolition work as resources and funding are available.


  • The site completed defuelling well ahead of schedule and a month before the target date set by the Department of Energy and Climate Change.
  • As a result, the site has safely and successfully removed over 99 per cent of of the radiological hazard.


Small and Medium Enterprises (SMEs) are a key link in our supply chain and Magnox is committed to supporting the SME agenda for growth.

Opportunities for contracts and ways to become a supplier are set out in the main Suppliers pages of this website.


Site Stakeholder Groups (SSG) are long-established at each of the Magnox sites and provide an opportunity for stakeholders to find out more about the work being undertaken there.

Independently-chaired, the SSG meets regularly to examine our work, as well as that of the Nuclear Decommissioning Authority (NDA) and regulators. The SSG’s membership includes local councillors, non-governmental organisations and other interested stakeholders.

If you would like to apply for socio-economic funding please visit:

Community Events

6th July 2017

Sizewell Site Stakeholder Group AGM - 6 July 2017- rescheduled from 15 June


Saxmundham Market Hall, 29 High Street, Saxmundham, IP17 1AF, 6.30 for 7pm

Meeting Documents:

Associated Documents:

28th September 2017

Sizewell Site Stakeholder Group Meeting - 28 September 2017


Sizewell Sports and Social Club, King George's Avenue, Leiston, IP16 4JX

Meeting Documents:

Associated Documents:

View all reference documents

Contact Secretariat:

Tracey Finn, Secretariat, Tel: 01728 633809
Dungeness A Site, Romney Marsh, Kent, TN29 9PP.

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