The facility will be the first of its kind in the UK.

The Welsh Government’s new ‘Global Centre of Rail Excellence’ – the first of its kind in the UK – is expected to be fully operational by 2025, bringing up to 300 jobs to the area.

It will be constructed at Nant Helen opencast coal mine, near Ystradgynlais, and Onllwyn coal washery and distribution centre, after Celtic Energy ends its operations at the mine later this year.

Under the plans, a 6.9 kilometre high-speed testing track and 4.5km low-speed high-tonnage testing track will be built at the Nant Helen site along with a dual platform station.

The facility will be connected to the main Brecon to Neath line, with signalling upgrades also planned as part of the project.

Plans for the Onllwyn site include a control centre, a research and development facility, maintenance sheds and staff overnight accommodation.

The site spans the Powys/Neath Port Talbot border and identical planing applications have been submitted to both councils.

A planning statement prepared by Ove Arup and Partners, on behalf of the Welsh Government, says the project will be “a catalyst for the creation of a rail technology hub in Wales”.

The first phase of the project – which includes the high tonnage test track and station – could open by 2023, with work to be completed on the latter two phases by 2025.

Arup says the construction is expected to support between 53 and 163 jobs, with 298 permanent direct and indirect roles to be created when the facility is fully operational.

The statement says: “This job creation is important in consideration of the cease of coaling operations at the Nant Helen Surface Mine in 2021 which currently support 170 jobs.”

It goes on to say the impact on the landscape, road and rail networks would not be “significant”, and the facility “would not cause unacceptable impacts in terms of noise, or any other type of pollution” on neighbouring residents.

The statement concludes: “The benefits of the proposed development are clear, the Global Centre of Rail Excellence (GCRE) would be a state-of-art facility, the kind of which does not currently exist elsewhere in the UK.

“It would not only serve to meet specific needs of the UK rail industry but also would result in transformational socio-economic impacts both at a national and local level in terms of job creation and education and training opportunities over the long term.

“GCRE has been developed collaboratively in consultation with industry experts, it is considered that it would be at the forefront of innovation to create a more sustainable, low-carbon rail network not only in the UK but internationally.

“The Nant Helen surface mine and Onllwyn washery site has been specifically chosen as the most suitable site within South Wales to accommodate such a complex development proposal, and it is considered that the proposed development demonstrates clear areas of special merit which would warrant the grant of planning permission.”

The applications will be decided in due course by Powys County Council and Neath Port Talbot County Borough Council.

Submission of the planning applications comes after the Welsh Government announced last month that it would loan £50 million to Powys County Council for the first phase of the project, which also received a £30 million pledge from chancellor Rishi Sunak in his spring budget.

A new GCRE company will be established to take the project from one that is government-led and supported by industry to one that is industry-led, and supported by government.

Nigel Brinn, director of economy and environment at Powys Council said: “We are fully committed to doing everything we possibly can to play our part in delivering this project of truly international significance.”