The UK Office for Nuclear Regulation (ONR) expects to complete the Generic Design Assessment (GDA) process for Hitachi-GE's UK Advanced Boiling Water Reactor (UK ABWR) in December 2017 as scheduled, but said in its latest quarterly report that the GDA for the Westinghouse AP1000 is unlikely to be completed by the previously expected date of March. ONR also said it had met "a number of times" in the reporting period with General Nuclear Systems as the potential GDA Requesting Party (RP) for China General Nuclear's HPR1000 design.

Horizon Nuclear Power, which was set up in 2009 and acquired by Hitachi in November 2012, plans to construct the at Wylfa Newydd on the Isle of Anglesey, and Oldbury-on-Severn in South Gloucestershire.

ONR said its “delivery confidence” for the UK ABWR GDA was “green/amber, which means that successful delivery remains probable”. However, it added that “constant attention from both Hitachi-GE and the regulators is required to ensure that risks do not materialise into major issues threatening delivery”. There are technical issues outstanding and a large volume of work remaining, it added, but Hitachi-GE "continues to respond well and at this juncture we consider the project stable overall, and are confident in Hitachi-GE's projected completion date of December 2017".

The period covered by the report included closure of Regulatory Issue RI-01 (identification and justification of source terms), which represents the completion of new analyses and clarity on the hazard. This is a "commendable achievement" by Hitachi-GE, ONR said, and will help Horizon in the future stages of the project.

The Environment Agency (EA) is continuing its assessments and will begin consultation on its findings on 12 December. Natural Resources Wales (NRW) is also working towards this consultation. Both EA and NRW considers that a statement of design acceptability (SODA) in December 2017 is achievable, ONR said.

As to the AP1000, ONR said: "Our delivery confidence for this project is amber/red, which means that successful delivery of the project is in doubt with major risks or issues apparent in a number of key areas.AP1000”.  NuGeneration (NuGen), a UK joint venture between Japan's Toshiba and France's Engie, plans to build a NPP of up to 3.8GWe gross capacity at Moorside, in West Cumbria using AP1000 nuclear reactor technology provided by Toshiba-owned Westinghouse Electric Company. ONR said: “We acknowledge that Westinghouse has made progress since the start of the year and its commitment is welcome; however there are only five months remaining and a very large amount of assessment to complete with issues still emerging. We will undertake a project deep dive at the end of this year, when we expect to have a clear view on the viability of completion and closure at the end of March 2017."

ONR added: "Westinghouse has submitted first revisions of documents in all areas and multiple revisions in some areas. However, there are technical issues arising from our assessments and in some areas, the compression of the schedule is a significant challenge to us."

The UK EPR design was the first to complete the GDA process and receive a Design Acceptance Confirmation (DAC) from the ONR and a SODA from the EA in December 2012. Under a deal agreed in October last year, China General Nuclear (CGN) will take a 33.5% stake in EDF Energy's GBP18bn ($28bn) project to construct Hinkley Point C, in Somerset, which will comprise two Areva EPR units. In addition, the two companies will develop projects to build new plants at Sizewell in Suffolk and Bradwell in Essex, the latter using Chinese reactor technology – the HPR1000.

General Nuclear Systems, a joint venture between China General Nuclear and EDF, was set up to deliver the Bradwell project in Essex. ONR said: "Our interactions have focused on ensuring that the RP [Requesting Party] is ready to commence the GDA and has met the 'pre-requisites' identified in our 'Guidance to Requesting Parties'. Our view is that the potential RP is in a good position to commence GDA, and we await a request from Government to commence the process."