The UK Parliament’s Welsh Affairs Committee select committee said on 26 July that small modular reactors (SMRs) should be built at the site the decommissioned Trawsfynydd NPP and gave qualified support to the proposed 2,700MWe Wylfa Newydd NPP in North Wales.

The Commons Select Committee on Welsh Affairs, which launched an inquiry into nuclear power's future of in Wales in January, took six sessions of evidence from 33 witnesses. Members of the committee also visited the two main nuclear sites in Wales – Wylfa and Trawsfynydd – the sites of now decommissioned Magnox reactors.

"Nuclear power has a long history in Wales, supplying power to large parts of the nation and providing thousands of people with well-paying jobs," the report said. "Wales has played a key part in establishing the nuclear industry in the UK, having hosted two first generation nuclear reactors for the past half a century. However, the future for nuclear power in Wales is uncertain. Both the [Wylfa and Trawsfynydd] power stations are now closed, and therefore Wales no longer has any operational nuclear power plants."

Trawsfynydd, which had two 195MWe gas-cooled Magnox reactors, is on a 15-hectare site, on an inland lake in Snowdonia National Park in North Wales. In order to support the development of SMRs the government should move fast to make it clear what needs to be done for Trawsfynydd to meet these criteria and be designated as a site, the committee said. “That said, we are strongly of the view, based on the expert evidence we have received, that Trawsfynydd is a standout candidate for locating a first-of-its-kind SMR,” the committee said.

Trawsfynydd was not included on the list of approved sites for new nuclear construction drawn up by the government in 2009, due to its inland, national park location and small size. The MPs said that Trawsfynydd would be "an ideal site for a first-of-its-kind SMR", citing the availability of water from Trawsfynydd lake for cooling purposes, the existing grid connections, its history as a nuclear site and the fact it is currently owned by the government and is not earmarked for use by another nuclear developer.

The committee heard from the leader of Gwynedd County Council that such a development could help revive the economy in an area that was "bleeding young people" and suffered from low wages and poverty.About 250 people are currently involved in decommissioning work at Trawsfynydd, but most of these jobs are expected to be lost within the next decade.

In March the government launched a competition to find the best value SMR design for use in the UK. It received 38 expressions of interest and has identified 32 companies as eligible to take part in the first phase of the competition. Former energy minister Andrea Leadsom told the committee that the government was "looking at potential SMR sites and would take Trawsfynydd into consideration".

The process that will be used to identify suitable sites is expected to be set out in an "SMR roadmap" document later this year. Tom Mundy, UK managing director of NuScale Power, which has entered its SMR technology into the government's competition, said: "We welcome the publication of the Select Committee’s report and can see the potential in the Trawsfynydd site being considered for SMR deployment. NuScale is currently having discussions with Government as part of the ongoing SMR competition and siting is an important area of consideration."

As to the proposed Wylfa Newydd NPP, the Committee said it should be built only if the strike price (subsidy) is below that agreed for EDF's planned 3,200MWe Hinkley Point C plant. The committee report said nuclear is capital intensive compared with other energy technologies and the high cost, delays and uncertainty around EDF Energy's Hinkley Point C project have resulted in questions over the UK government's nuclear strategy. The UK should therefore aim to balance costs against energy security and environmental concerns. "We recommend that the government negotiate a strike price for Wylfa Newydd below that agreed for Hinkley Point C and seek a price that would be competitive with renewable sources, such as on-shore wind," the Committee said. "The government should not continue with the project if the price is too high."

The committee noted concerns of possible delays in the completion of Wlyfa Newydd construction, following the issues faced by Hinkley Point. Wylfa Newydd is scheduled to begin operation when the currently operating NPPs close in 2025. If there are any delays, "it would be difficult to replace this provision," the committee said.

"We recommend that the UK government devises a contingency plan for a delayed start to the Wylfa Newydd project. It will be essential to have a back-up plan to fill the gap in the energy supply in the case that Wylfa Newydd is delayed," it added. Although Wylfa developer, Horizon Nuclear Power, is looking to minimise delays, the committee said recent experience suggests the UK should not assume the project will stay on schedule.

"We believe that Wylfa Newydd can deliver value for money and deliver a significant portion of the country's future energy needs," the committee concluded. "To achieve this, the developers and the government will need to manage potential delays and bottlenecks, to keep costs down and the project on schedule."

The committee said it is surprised the government's plans for nuclear skills development in the UK does not have "a Welsh dimension". It recommends the UK government sets out plans to create a North Wales campus for the National Nuclear College, announced in May this year.