Consultation on the Nuclear Industry Association’s Application for Regulatory Justification of the ‘Rolls-Royce SMR’ designed by Rolls-Royce SMR Limited

Overview

We are seeking your views on an application for a regulatory justification decision on the ‘Rolls-Royce SMR’ (small modular reactor). This reactor is designed by Rolls-Royce SMR Limited and the application was made by the Nuclear Industry Association (NIA), the representative body for the civil nuclear industry in the UK.  

Justification is an early regulatory step that must be satisfied before a new type of nuclear reactor can be deployed in the UK. Justification determines the class or type of practice the proposed practice belongs to and provides a high-level assessment of whether that class or type of practice gives an overall benefit to society.  

Justification is the responsibility of Defra’s Secretary of State as Justifying Authority for nuclear energy. When we refer to Defra we are referring to Defra’s Secretary of State.  

The application and supplementary information from the applicant are presented as a single separate attachment, with the supplementary information presented after the application. Please read the application and supplementary information alongside this consultation document.  

This consultation will run for 8 weeks. The consultation opened on 6 October 2025 and will close on 1 December 2025.

Why your views matter

This consultation on the content of the application submitted by the NIA for a justification decision on the Rolls-Royce SMR reactor is an early part of the justification process. We are seeking views on:

• whether the proposed practice belongs to a new, or to an existing class or type of practice 

• whether the proposed practice is a suitably defined class or type of practice for a justification decision 

• whether the information in the application and supplementary information is suitable for Defra to make an appropriate assessment of the balance of benefits and detriments of the proposed practice 

The Justifying Authority will consider all responses to the consultation questions before producing a draft decision document for further public consultation. The draft decision document will give the Justifying Authority’s view on whether or not the Rolls-Royce SMR reactor should be justified in the UK and, if it should be justified, propose the most suitable definition of the class or type of practice.

This consultation is open to any organisation or individual and is likely to be of particular interest to:

• Regulatory bodies operating across the UK
• Nuclear operators
• Environmental and other non-governmental organisations
• Interest groups
• Trade associations
• Industry associations and suppliers
• Professional bodies of the nuclear industry
• Academia 
• Government organisations 
• Independent advisory bodies