Horizon Nuclear Power plans to deploy the UK ABWR at nuclear power stations located in Wylfa in Anglesey, and Oldbury in South Gloucestershire.
In the third phase of GDA, the ONR concluded that Hitachi-GE made sufficient progress to move into the final assessment stage.
Hitachi-GE Hitachi Europe licensing general manager Ken Sato said: "GDA is rightly a thorough and rigorous assessment – challenging scrutiny from the regulators is to be expected and welcomed."
The GDA allows the UK nuclear regulators to assess the potential suitability of a nuclear reactor design for development, considering safety and environmental impact.
ONR plans to complete the final assessment stage in December 2017.
Following completion of final assessment process, the Environment Agency’s and Natural Resources Wales (NRW) will undertake environmental assessment as part of the GDA process.
The environmental assessment is scheduled to commence in October 2016.
The deployment of the new reactor, however, is subject to securing all relevant permissions by the operators for the site including a Nuclear Site License and environmental permits.
Sato added: "The ABWR is the only generation III+ reactor which has entered operation anywhere in the world, and has been delivered on-time and on-budget."
Horizon Nuclear Power engineering director Mark Lunn said: "This is an important step forward for our Wylfa Newydd Project and keeps us firmly on track to start generating in the first half of the 2020s."
Image: Illustration of UK Advanced Boiling Water Reactor. Photo: courtesy of Horizon Nuclear Power.
