New images reveal details about Last Energy’s Welsh micro reactor plans

Insiders from across the SMR sector often claim, always off the record, that Last Energy UK’s target to deploy its nuclear reactor design by 2027 is over-ambitious.

29 Jun, 2026 By Tom Pashby, https://www.newcivilengineer.com/latest/new-images-reveal-details-about-last-energys-welsh-micro-reactor-plans-29-06-2026/

New details about Last Energy’s plans for deploying four 20MW micro modular reactors (MMRs) at the proposed Llynfi Clean Energy Project in South Wales have been revealed in images shared on the Welsh Government’s planning portal.

The new details were uploaded along with related planning documents on 11 June as part of Last Energy UK’s notification to Welsh ministers of the company’s intention to make an application for a significant infrastructure project (SIP) under section 29 of the Infrastructure (Wales) Act 2024.

The documents show that the business, which is a subsidiary of the US-based Last Energy, plans to submit its SIP application in July 2026.

The proposals show that the company hopes to deploy four PWR-20 reactors, providing 20MW of electricity (MWe) or 83MW of heat (MWt).

Last Energy announced in October 2024 that it had gained control of the site and planned to complete construction by 2027.

The deployment of its PWR-20 micro nuclear reactors is part of the energy company’s Prosiect Egni Glan Llynfi project in Bridgend County. The firm refers to the project in English as the Llynfi Clean Energy Project and is proposed on the site of the former coal-fired Llynfi Power Station which was in operation from 1951 to 1977

At the time of the October 2024 announcement, the company said it estimated it would be making a £300M investment, £30M of which would benefit the local economy, excluding business rates collected by Bridgend County.

It also said it expected to create at least 100 local full-time jobs.

Last Energy UK CEO Michael Jenner spoke with NCE in November 2024, when he explained the rationale for the project and expressed his optimism for the development.

“We’ve spoken to local councils, and they’ve asked us, ‘leaving aside the nuclear project, how many roads do we need to widen? How many bridges do we need to strengthen?’ And we’re able to say ‘None’,” Jenner said.

The design of the micro-reactors features around 40 modules that can be fitted together on site.

“All of the parts of our unit are able to fit on the back of a normal HGV,” he continued.

“You don’t need any [infrastructure interventions]. You don’t need extra planning for anything else other than what’s happening on the site.”

In February 2025, the company became the first nuclear developer to enter the nuclear site licensing process with the Office for Nuclear Regulation (ONR) since Torness nuclear power station in 1978.

On 29 July 2025, the Office for Nuclear Regulation (ONR) announced that Last Energy UK had completed its preliminary design review (PDR).

Insiders from across the SMR sector often claim, always off the record, that Last Energy UK’s target to deploy its nuclear reactor design by 2027 is over-ambitious.

At the time of the July announcement, the ONR said it had “noted that Last Energy’s aspiration to receive a nuclear site licence decision by December 2027 could be achieved if Last Energy delivers the necessary submissions to the required standard and according to schedule”.

On 11 June 2026, the company posted a set of four documents on the Welsh Government’s planning portal. One was a ‘notification of proposed application’, another was an ‘Acceptance of Notification under Article 29 of the Infrastructure (Wales) Act 2024’.

The remaining two were images. One showed an outline of the site, and the other showed the ‘general arrangement during operations’.

The last image clearly features four reactors set within a ‘nuclear activity boundary’ next to the Llynfi River.

The other image has only one reactor present, but other features are more visible, such as the site boundary crossing over the river, plus a substation, a warehouse, a location marked as operations, a smaller location labelled as ‘sec booth’ and parking next to those.

Just outside of the nuclear activity boundary is an ‘electricity distribution site’.

The site location is described in the ‘notification of proposed application’.

“The Llynfi Clean Energy Project is proposed at the former Llynfi Power Station site, Llangynwyd, Bridgend, within Aberkenfig Ward,” it says.

“The project comprises four PWR-20 modular reactor units with associated plant, substation, buildings, security and access infrastructure.”

Later, a description of the development is provided. In addition to the basic information about the project, it says: “The site for the PWR-20 units, including mitigation and enhancement measures, equates to approximately 14 acres of land at Llynfi Power Station”, and this could power approximately 250,000 homes.

These systems will quickly reduce carbon emissions, helping us achieve urgent climate targets,” it adds.

“They will also enhance energy independence by furnishing industrial tenants with energy provisions that stabilise energy prices and reduce reliance on imported energy.”