NEW NUCLEAR BUILD APPROVAL FRAMEWORKS

1. Introduction

The New Nuclear Build Approval Framework in the United Kingdom is a multi-layered legal system governing whether a new nuclear power station may be designed, located, constructed and operated. Unlike an ordinary electricity project, nuclear development requires approval under planning law, nuclear safety law, environmental law, security regulation and radioactive-waste controls.

The principal institutions include the Secretary of State for Energy Security and Net Zero, Office for Nuclear Regulation (ONR), Environment Agency (EA) or Natural Resources Wales, and the Planning Inspectorate. The framework aims to reconcile energy security and low-carbon generation with stringent requirements concerning nuclear safety, environmental protection and public participation.

2. Generic Design Assessment

An important preliminary mechanism is the Generic Design Assessment (GDA). Through GDA, the ONR and environmental regulators assess a proposed reactor technology independently of the particular site on which it may eventually be constructed.

The assessment examines matters including nuclear safety, security, safeguards, radioactive waste and environmental protection. Successful assessment can result in regulatory conclusions confirming the acceptability of the reactor design. However, GDA does not itself authorise construction. Site-specific licences, permits and planning approvals remain necessary.

In 2026, regulators also began implementing reforms intended to streamline reactor-design assessment, including greater use of judgments reached by trusted overseas regulators while retaining UK safety standards.

3. Nuclear Site Licence

Under the Nuclear Installations Act 1965, an operator must obtain a nuclear site licence from the ONR before carrying out prescribed nuclear activities.

ONR examines whether the proposed site is suitable, whether the applicant is organisationally capable and whether adequate arrangements exist to manage nuclear hazards. Importantly, receiving the licence does not automatically authorise nuclear-related construction; separate ONR regulatory permission may still be required before relevant construction begins.

The licence therefore establishes continuing regulatory control throughout construction, commissioning, operation and eventual decommissioning.

4. Development Consent and Planning

Large nuclear generating stations generally fall within the Nationally Significant Infrastructure Projects (NSIP) regime established by the Planning Act 2008. In England, nuclear generating infrastructure exceeding 50 MW normally requires a Development Consent Order (DCO) from the Secretary of State. Different thresholds apply in Wales.

The planning assessment considers matters such as land use, ecological impacts, water resources, transport, community effects and national energy policy. Nuclear regulatory questions remain principally within the specialist jurisdiction of ONR and environmental regulators.

5. Environmental Permitting

A new nuclear project must additionally obtain appropriate environmental permits. In England these are principally administered by the Environment Agency.

Environmental regulation addresses matters including radioactive substances, water discharges, waste management and environmental impacts. Accordingly, approval of the reactor technology or granting of development consent does not eliminate the need for separate environmental authorisation.

6. Case Law – Together Against Sizewell C Ltd v Secretary of State

Case Name/Citation

R (Together Against Sizewell C Ltd) v Secretary of State for Energy Security and Net Zero [2023] EWCA Civ 1517

Facts

The Secretary of State granted a DCO for the construction, operation, maintenance and decommissioning of Sizewell C nuclear power station in Suffolk. The claimant challenged the approval, particularly concerning the proposed station's long-term potable-water supply and its implications for protected European sites.

Legal Issue

The central issue was whether the Secretary of State had unlawfully failed to conduct an appropriate assessment of the effects associated with the permanent water-supply arrangements under the Conservation of Habitats and Species Regulations 2017.

Judgment

The Court of Appeal dismissed the challenge and upheld the relevant approach to the Sizewell C development consent decision.

Legal Principle / Ratio Decidendi

The case demonstrates that the identification of the legally relevant “project” and connected environmental effects depends upon proper application of the statutory planning and habitats-assessment framework. Courts supervise legality but do not simply substitute their own infrastructure assessment for that of the lawful decision-maker.

Significance

Sizewell C illustrates how nuclear approval decisions remain vulnerable to judicial review, particularly where environmental assessment, habitats protection and connected infrastructure are disputed.

7. Integrated Regulatory Approach

A nuclear project therefore cannot proceed through a single approval. The developer must coordinate reactor-design assessment, nuclear licensing, DCO planning, environmental permitting and subsequent construction permissions.

The framework deliberately separates responsibilities. Planning authorities assess whether development is acceptable in the public interest, while specialist nuclear regulators determine whether demanding safety, security and environmental standards are satisfied.

8. Conclusion

The UK's new nuclear build framework combines strategic energy planning with independent specialist regulation. The Planning Act 2008 provides the major-project consenting route, while the Nuclear Installations Act 1965 establishes nuclear site licensing and continuing ONR supervision. GDA provides early scrutiny of reactor technologies, while environmental permits address site-specific environmental consequences. The Sizewell C litigation confirms that major nuclear approvals are also subject to judicial review, ensuring that national energy objectives remain constrained by statutory environmental and administrative-law requirements.