Sizewell C Nuclear Project Gets Final Green Light
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The UK government has officially approved the Sizewell C nuclear power station project, marking a new chapter in the long history of the Sizewell nuclear site in Suffolk.
This green light, given on 22 July 2025, sets the stage for a third station at Sizewell alongside its predecessors, Sizewell A and Sizewell B.
Below we explore the full history of these nuclear power stations from major milestones and staffing through to economic and social impacts.
Sizewell A (1966–2006): Magnox Beginnings and Decommissioning
Sizewell A was the first nuclear station at the site, housing two Magnox gas-cooled reactors.
It operated successfully for 40 years (1966–2006) and is now undergoing decommissioning.
Key milestones in Sizewell A’s history include:
- 1958 – Sizewell site selected for a new nuclear power station by the local council, and plans announced by the CEGB to seek construction consent.
- 1960 – The UK Minister of Power grants approval for Sizewell A to proceed (no public inquiry was deemed necessary).
- 1961 – Construction of Sizewell A begins on 1 April, undertaken by a BNDC consortium (English Electric/Babcock & Wilcox/Taylor Woodrow). Initial budgeted cost was ~£56 million (inflating to £65 million by completion).
- 1965–66 – Reactor commissioning: Unit 1 achieved first criticality in June 1965, and first grid connection on 21 January 1966. Unit 2 followed with first power on 9 April 1966. The station entered full commercial operation by September 1966.
- 1967 – Sizewell A is formally opened on 7 April 1967 by the Earl of Stradbroke, producing ~420 MW and generating ~110 TWh over its lifetime.
- 2006 – Sizewell A ceases generation on 31 December 2006, retiring the Magnox reactors.
- 2009 – Defuelling begins; used fuel removed to storage ponds.
- 2014 – Final spent fuel shipped off-site (Aug 2014), station declared fuel-free by Feb 2015.
- 2025 – Turbine hall demolished, marking major skyline change using innovative explosive techniques.
- Future – Residual structures remain in care-and-maintenance; full clearance projected by ~2077.
Sizewell B (1995–Present): Britain’s Only PWR and Extended Operation
Sizewell B is the UK’s only pressurised water reactor, the second station at Sizewell, featuring a 1,188 MWe PWR unit.
It continues to operate today and is slated for life-extension to 2055.
Key milestones in Sizewell B’s story:
- 1983 – Public inquiry into first UK PWR at Sizewell commences, lasting almost two years.
- 1987 – Plans approved by Secretary of State, paving way for construction.
- 1988 – Main construction begins 18 July; only one of four planned PWRs ultimately built.
- 1995 – First criticality and grid connection in Feb; commercial operation 14 Feb 1995, slightly under £2.03 billion (1987 money).
- 2006 – Post-review, new nuclear build agenda reinstated; Sizewell B remains newest UK reactor until 2010s.
- 2015 – Periodic safety review confirms safe operation for another decade (to 2025).
- 2022 – EDF announces 20-year life extension to operate until 2055, bridging energy gaps.
- 2025 – Nearly 30 years of operation; performance among most efficient in fleet. Life-extension plans progressing.
(Sizewell B currently licensed to 2035, pending life-extension upgrades that may allow 60-year operation, similar to US PWRs.)
Sizewell C (Planned): Twin EPRs and the 2025 Go-Ahead
Sizewell C will feature two French-designed EPR reactors (3.2 GW total), near-replica of Hinkley Point C, with construction starting after the 22 July 2025 Final Investment Decision.
Project milestones:
- 2009 – Sizewell identified as suitable for new nuclear in national policy statement.
- 2010s – EDF develops proposals; joint venture with CGN initially 20% stake; environmental consultations ongoing.
- May 2020 – Site license & Development Consent Order applications submitted; regulatory review begins.
- July 2022 – Development Consent granted by UK Secretary of State.
- Sept 2022 – UK government buys out CGN, invests £679 million (50% share) via RAB model.
- 2023 – Early site works continue; future equity and financing negotiations.
- 22 July 2025 – Final Investment Decision signed; £38 billion project equity: UK government 44.9%, Canada 20%, Centrica 15%, Amber 7.6%, EDF ~12.5%.
- July 2025 – Full construction begins; expected to supply ~6 million homes, target commissioning mid-to-late 2030s.
(Future milestones: first concrete, reactor installation, grid connection, 60+ years operation, final clearance next century.)
Workforce and Staffing Breakdown by Project Phase
Staffing across construction, operation, and decommissioning for all Sizewell stations:
| Station | Phase | Workforce (approx.) | Key Roles / Skills |
|---|---|---|---|
| Sizewell A | Construction (1960s) | Several hundred | Civil engineers, construction labourers, fitters, welders, project managers |
| Sizewell A | Operation (1966–2006) | More than 300 full-time staff | Reactor operators, maintenance technicians, electrical/mechanical engineers, safety inspectors, support staff |
| Sizewell A | Decommissioning (2007–present) | ~100 early, ~50 long-term | Decommissioning engineers, waste management, radiation protection, project supervisors |
| Sizewell B | Construction (1988–1995) | Over 10,000 total; 5,000 peak | Labourers to PhD nuclear physicists; contractors, steelworkers, pipefitters, electricians, engineers |
| Sizewell B | Operation (1995–present) | ~500 permanent + 200 contractors | Licensed operators, control room techs, maintenance engineers, safety & environmental specialists, apprentices |
| Sizewell C | Construction (2025–2030s) | ~10,000 jobs; 1,500 apprentices | Civil engineers, heavy equipment operators, welders, electricians, project managers, reactor installation engineers |
| Sizewell C | Operation (~2030s onward) | ~900 permanent staff | Reactor operators, engineers, chemists, safety & environment officers, security, admin/support |
Economic and Social Impact: Jobs, Training and Regional Benefits
The Sizewell projects have had a profound economic and social impact on East Suffolk, creating thousands of jobs and workforce initiatives.
Long-Term Employment: Sizewell A & B provided stable, well-paid roles. Sizewell A employed around 300 staff for decades; Sizewell B ~500 permanent, ~£40 million annual payroll. Many leaders began as local apprentices.
Construction Booms: Sizewell B construction (1987–95) peaked at >5,000 workers, many from outside Suffolk, boosting local housing, services, and supply chains. End-of-construction cycles informed Sizewell C planning.
Sizewell C Job Creation: ~10,000 jobs, 2,600 local East Anglia residents; agreements guarantee 500 jobs each for Ipswich & Lowestoft. Skills hubs, job fairs, and Young Sizewell C programs prepare workforce.
Skills and Training Initiatives: Apprenticeships at Sizewell B (~40–50). Sizewell C programs include post-16 Energy Skills College (2027), technical training, and career pipelines.
Local Supply Chain and Investment: Sizewell C expected £2 billion in Suffolk contracts; >£45 million awarded already. Benefits ripple across manufacturing, logistics, hospitality; funding for infrastructure & community programs.
Overall, Sizewell A–C showcase nuclear energy’s evolving role in UK economy and skills development; with Sizewell C’s 2025 approval, East Suffolk remains a nuclear powerhouse for decades.