NEW NUCLEAR PROJECTS (HINKLEY POINT C AND SIZEWELL C) LEGAL FRAMEWORKS

1. Introduction

The legal framework governing major new nuclear projects in the United Kingdom combines planning law, nuclear safety regulation, environmental protection, electricity-market regulation, financing law, waste management, and judicial review. Hinkley Point C in Somerset and Sizewell C in Suffolk are both planned as 3.2 GW European Pressurised Reactor (EPR) stations, but their financing structures differ substantially. Hinkley Point C principally uses a Contract for Difference (CfD), whereas Sizewell C is the first UK nuclear station being financed through the Regulated Asset Base (RAB) model.

2. Planning and Development Consent

Large nuclear generating stations qualify as Nationally Significant Infrastructure Projects (NSIPs) under the Planning Act 2008. Consequently, development generally requires a Development Consent Order (DCO) granted by the Secretary of State following examination through the national infrastructure planning regime.

The Sizewell C Nuclear Generating Station Order was granted in 2022. The DCO governs construction, operation, maintenance and eventual decommissioning and also contains a deemed marine licence.

National Policy Statements for energy infrastructure provide an important policy basis for determining whether nuclear development is justified and how environmental and infrastructure impacts should be assessed.

3. Nuclear Safety and Site Licensing

Planning consent alone does not authorise nuclear operations. Under the Nuclear Installations Act 1965, a developer must obtain a nuclear site licence from the Office for Nuclear Regulation (ONR).

ONR independently regulates nuclear safety, security, safeguards and relevant construction activities. Even possession of a site licence does not automatically permit every stage of nuclear construction; further regulatory permissions may be necessary. ONR continues to regulate construction and commissioning of the EPR reactors at both Hinkley Point C and Sizewell C.

4. Environmental Regulation

New nuclear projects require extensive environmental assessment. Relevant controls include Environmental Impact Assessment, habitats protection, radioactive-substances regulation, water regulation and marine licensing.

The Environment Agency therefore operates alongside ONR and the planning authorities. This creates a system of regulatory pluralism: planning authorities determine whether development should proceed, ONR focuses principally on nuclear safety and security, while environmental regulators control environmental discharges and impacts.

5. Financing: Hinkley Point C and Sizewell C

Hinkley Point C's financing framework uses a CfD, providing greater certainty over future electricity revenues while requiring the generator to sell electricity into the commercial market.

Sizewell C adopts a fundamentally different model under the Nuclear Energy (Financing) Act 2022. The RAB framework allows an eligible nuclear company to receive regulated revenues during construction as well as operation, reducing financing exposure but transferring part of construction-period financing to electricity consumers.

Following the government's July 2025 final investment decision, Sizewell C's RAB arrangements are implemented through its modified generation licence and regulated by Ofgem.

6. Case Law – R (An Taisce) v Secretary of State for Energy and Climate Change [2014] EWCA Civ 1111

Facts: An Taisce challenged development consent for Hinkley Point C, arguing that the UK should have undertaken transboundary consultation with Ireland concerning potential nuclear accident effects.

Legal Issue: Whether environmental assessment law required consultation with Ireland before consent was granted.

Judgment: The challenge was unsuccessful.

Legal Principle/Ratio Decidendi: Transboundary environmental consultation requirements must be applied according to the legally relevant assessment of likely significant environmental effects.

Significance: The case demonstrates how nuclear DCO decisions may be scrutinised for cross-border environmental consequences, while recognising the technical assessments underlying governmental decisions. The subsequent Supreme Court permission application was refused.

7. Case Law – Together Against Sizewell C Ltd v Secretary of State [2023] EWCA Civ 1517

Facts: Local campaigners challenged the Sizewell C DCO, particularly concerning whether a secure permanent supply of potable water had been adequately addressed in the habitats assessment.

Legal Issue: Whether the Secretary of State lawfully assessed the project's water-supply implications before granting development consent.

Judgment: The Court of Appeal dismissed the challenge, upholding the refusal of permission for judicial review.

Legal Principle/Ratio Decidendi: Infrastructure consent may lawfully rely upon future implementation arrangements where the decision-maker has adequately addressed the relevant environmental requirements and there is no legal necessity for every detailed solution to be finally fixed at the DCO stage.

Significance: The judgment demonstrates the interaction between planning discretion, habitats protection and infrastructure interdependencies in nuclear development.

8. Decommissioning and Waste

Under the Energy Act 2008, operators of new nuclear stations must establish an approved Funded Decommissioning Programme, ensuring arrangements exist for decommissioning and relevant radioactive-waste management costs. Sizewell C's financing framework expressly incorporates these long-term obligations.

9. Conclusion

Hinkley Point C and Sizewell C demonstrate the UK's multi-layered nuclear governance system. The Planning Act 2008, Nuclear Installations Act 1965, Energy Act 2008, Nuclear Energy (Financing) Act 2022, environmental legislation, DCO regime, ONR licensing and Ofgem regulation collectively govern development. The projects also illustrate an important evolution in nuclear financing—from Hinkley Point C's CfD model to Sizewell C's RAB model—while maintaining strong legal controls over safety, environmental impacts, public accountability, waste and decommissioning.