Area of investment and support

Low cost nuclear

Completed area of investment and support

This area is complete and will have no future activity.

The Low Cost Nuclear programme phase two was a research and development programme to further develop the UK small modular reactor power station concept to successfully pass the key regulatory milestone of Generic Design Assessment (GDA) Step two completion by 31 March 2025. It was led by Rolls-Royce SMR Ltd. with UKRI as delivery partner overseeing programme management on behalf of the Department of Energy Security and Net Zero, who were accountable for the project.

• Budget: Phase 2: £210 million grant from the UK government, matched by private sector funding of over £250 million.
• Duration: 2018 to 2025, the second phase started in November 2021.
• Partners involved: Innovate UK (delivery partner), Rolls-Royce SMR Ltd (single supplier), Department of Energy Security and Net Zero (funder)

The scope and what we're doing

The funding recipient, Rolls-Royce SMR Ltd, aimed to develop a compact, standardised nuclear power station product based around a UK-designed small modular reactor (SMR), using modern mass production methodology.

The low cost nuclear (LCN) programme was set up to deliver five objectives by March 2025:

• objective 1: to have fully completed step 2 Generic Design Assessment (GDA) by the end of the programme (March 2025)
• objective 2: to have developed, the SMR technical design and cost models to help with the investment proposition
• objective 3: to identify the supply chain and manufacturing strategy required by the Rolls-Royce SMR design and increase potential deliverability of any ‘fleet deployment’
• objective 4: to promote greater equality and diversity in the UK nuclear sector over the lifetime of the programme
• objective 5:
  • to utilise information generated by the LCN programme to support Department of Energy Security and Net Zero-led communications and engagement work on the awareness and public acceptance of nuclear energy
  • to track the communications impact of LCN
  • to provide detailed information on the project to inform government policy on SMRs

This challenge aligned with the Nuclear Sector Deal and UK government’s Advanced Nuclear Technologies framework, which can provide the supporting policy framework for encouraging new nuclear technologies.

Why we're doing it

To help the UK commitment to net zero, new sources of low carbon base power will be needed at an affordable cost to the consumer. Creating those future technologies and viable options is an important role for UKRI and government.

These small power stations are designed to create low-cost, low-carbon electricity for up to 60 years. Each unit, if built, will produce 470 megawatts of electricity each hour, which is enough to power 1 million homes, equivalent to a city the size of Leeds.

Past projects, outcomes and impact

We awarded £18 million in UKRI Challenge Fund funding to a UK-based consortium led by Rolls-Royce, with matched funding of £18 million from industry. This first phase was formally concluded on 30 June 2021 and successfully developed a concept design.

The second phase started in November 2021 and ended in March 2025. Rolls-Royce SMR successfully achieved GDA Step 2 in July 2024.

In June 2025, Rolls-Royce SMR was announced as the winners of the Great British Energy Nuclear competition, securing future investment in the technology.

The programme supported job creation and growth in the North of England. 62% of programme spend occurred in the Midlands (33%) and North of England (29%) with key hubs of activity in Derby, Sheffield, Manchester and Warrington.

Read UKRI low cost nuclear programme report.

Watch how the low cost nuclear challenge programme is transforming nuclear energy in the UK and beyond (YouTube).

Last updated: 8 May 2026