Small Modular Reactors (SMRs) are nuclear power plants that are smaller in size (300 MW or less) than current generation base load plants (usually 1,000 MW or higher). SMRs are a relatively new technology for civil nuclear power generation. SMRs are modular, which means that much of the design and plant can be fabricated in a factory environment and transported to site. They are physically smaller, rely less on vast quantities of cooling water and are quicker to build.

This note considers the planning process for such projects and sets out the government's current strategy with regard to the development of SMRs.

Planning process

Almost all SMR proposals would be classified as “Nationally Significant Infrastructure Projects” (NSIPs), as they would have a capacity in excess of 50 MW. Any application for an SMR would therefore be subject to the Development Consent Order (DCO) application process under the Planning Act 2008.

However, some revisions to the Nuclear National Policy Statement (EN-6) (NPS) are likely to be required to support the government's developing policy – outlined further below – on SMRs. Whilst the NPS recognises the need for new nuclear power stations to meet the government’s targets for significant and urgent decarbonisation of the economy and enhanced security of supply, the NPS specifically relates to applications for development consent at eight named sites.

The NPS does state that if a DCO application is received for a new nuclear power station on a site not listed in the NPS, the Secretary of State should "have regard" to the NPS and EN-1 (Overarching NPS for Energy) as important and relevant considerations. However the NPS is still very restrictive, noting that the “government does not believe that there are any alternatives to the listed sites that are potentially suitable for the deployment of new nuclear power stations”.


A programme of government support for smaller reactors – which are quicker to build than conventional nuclear power stations and could be manufactured largely in the UK – has the potential to provide an attractive alternative to large scale projects. However, they produce much less power (a generating capacity of 300MW being roughly one tenth of the capacity planned at Hinkley C), which means that there will need to be more of them to generate sustainable energy.

They will also have to be built close to the communities they serve and SMR siting is likely to raise a whole new set of challenges and opportunities in terms of public engagement.

Updating the Nuclear NPS to reflect changing government policy on SMRs is not straightforward. In particular it will require a period of consultation and assessment of the environmental impacts of SMRs, which could take a number of years. Further the DCO process itself is not necessarily a short one. Although the time taken for examination and decision has been streamlined, developers are required to carry out pre-application consultation with the local community and other stakeholders as well as a comprehensive environmental impact assessment.

Therefore potential applicants should look to familiarise themselves with the legal process at this stage in order to develop realistic timeframes for delivery of future SMRs.

UK government and SMRs

In 2014, the UK government published a report[1] on SMR concepts, feasibility and potential in the UK. The report was produced by a consortium led by the National Nuclear Laboratory and concluded that there is an opportunity for the UK to regain technology leadership in the ownership and development of low-carbon generation and secure energy supplies through investment in SMRs.

Last year's Spending Review and Autumn Statement 2015 then announced that the Department of Energy and Climate Change (now the Department of Business, Energy and Industrial Strategy, or BEIS) would invest £250m in a nuclear research and development programme, which would include a competition to identify the best value SMR design for the UK.

In March 2016, the government called for expressions of interest in the aforementioned competition[2]. The objective of Phase One of the competition is to gauge market interest in developing, commercialising and financing SMRs in the UK. It will take the form of a structured dialogue between the government and participants.

Applicants are required to submit an Expression of Interest, with eligibility for the Phase One dialogue governed by criteria set out in the "'Eligibility Criteria Checklist, Expression of Interest and Declaration Document". Criteria include:

  • Capacity: the applicant must intend to propose (whether as a technology developer, utility, potential investor, funder and other interested party) a SMR design that has a single-unit electricity generation capacity of up to a maximum of circa 300MW
  • Modularisation: the applicant must intend to propose a SMR design for manufacture and assembly that will be able to achieve in-factory production of modular components or systems amounting to a minimum of 40% of the total plant cost (including the nuclear island, balance of plant and wider site civil engineering).

In parallel with Phase One of the competition, BEIS intends to develop an SMR Roadmap to set out the policy framework and assess the potential for one or more possible pathways for SMRs. The Roadmap will include details of the process that the government will use to identify suitable sites or types of sites and is intended to be published after the close of Phase One, in parallel with publication of plans for the next steps in the SMR competition.

The expected close of Phase One is "Autumn 2016".

[1] Small Modular Reactors (SMR) Feasibility Study, National Nuclear Laboratory (December 2014)

[2] SMR Competition Phase One: Expression of Interest and Declaration, DBEIS (March 2016)