Statutory Instruments
2026 No. 839
HEALTH AND SAFETY
ENVIRONMENTAL PROTECTION
The Justification Decision (Generation of Power by the RR SMR) Regulations 2026
Made
16th July 2026
Coming into force
17th July 2026
The Secretary of State makes these Regulations in exercise of the powers conferred by regulation 4(1) of the Justification Decision Power (Amendment) (EU Exit) Regulations 2019 (“the 2019 Regulations”)(1) and in accordance with the requirements of regulation 14(1) of the Justification of Practices Involving Ionising Radiation Regulations 2004 (“the 2004 Regulations”)(2).
The Secretary of State has consulted the persons required to be consulted under regulation 18 of the 2004 Regulations and such other persons as the Secretary of State considered it appropriate to consult, and has taken such steps as the Secretary of State considered appropriate to bring the proposed decision now contained in these Regulations to the attention of any person likely to be affected by it.
In accordance with regulation 5(3) of the 2019 Regulations a draft of these Regulations was laid before and approved by a resolution of each House of Parliament.
Citation, commencement and extent
1.—(1) These Regulations may be cited as the Justification Decision (Generation of Power by the RR SMR) Regulations 2026 and come into force on the day after the day on which they are made.
(2) These Regulations extend to the United Kingdom.
Interpretation
2. In these Regulations—
“ the RR SMR practice ” means the class or type of practice which is the generation of power from nuclear energy using uranium dioxide fuel of low enrichment in fissile content in a light water cooled, light water moderated thermal reactor designed by Rolls-Royce SMR Limited and where the specification of that reactor matches that set out in Annex 1 (pages 92 to 122) of the NIA Rolls-Royce SMR Application and Supplementary Information document which was the subject of the consultation paper published by the Department for Environment, Food and Rural Affairs on 6th October 2025 and titled “Consultation on the Nuclear Industry Association’s Application for Regulatory Justification of the Rolls-Royce SMR designed by Rolls-Royce SMR Limited( 3 )”.
Justification decision
3. For the purposes of regulation 14(1) of the Justification of Practices Involving Ionising Radiation Regulations 2004 the following positive justification decision(4) has effect—
(a)the RR SMR practice is justified(5); and
(b)any class or type of practice which is—
(i)a development of the RR SMR practice; and
(ii)so similar to the RR SMR practice that the balance of benefits and detriments from that class or type of practice does not materially differ from the balance of benefits and detriments for the RR SMR practice,
is justified.
Emma Hardy
Parliamentary Under-Secretary of State
Department for Environment, Food and Rural Affairs
16th July 2026
S.I. 2019/215. Regulation 4(1) allows the Secretary of State to make, by regulations, a positive justification decision.
S.I. 2004/1769, amended by S.I. 2018/430, S.I. 2019/24, and S.I. 2019/215. Justifying Authority for the purposes of this instrument is defined in regulation 6 of S.I. 2004/1769.
The NIA Rolls-Royce SMR Application and Supplementary Information document and the consultation paper can be found at: https://consult.defra.gov.uk/nuclear-justification/nuclear-rolls-royce-smr/. The page numbering (92 to 122) reflects the PDF page numbering rather than the document numbering.
Positive justification decision is defined in regulation 2 of S.I. 2019/215.
Justified is defined in regulation 2 of S.I. 2019/215.