UK regulators question Westinghouse's target date for AP1000 GDA

28 November 2016

UK regulators expect to complete the Generic Design Assessment (GDA) process for Hitachi-GE's UK Advanced Boiling Water Reactor (UK ABWR) as scheduled, in December of 2017, but doubt the GDA for the Westinghouse AP1000 will be done by March as previously stated.

In its quarterly GDA report for May to October 2016 issued recently, the Office for Nuclear Regulation (ONR) also said it had met "a number of times" in the period with General Nuclear Systems as the potential GDA Requesting Party (RP) for China General Nuclear's HPR1000 design.


Horizon Nuclear Power - established in 2009 and acquired by Hitachi in November 2012 - plans to deploy the UK ABWR at two sites - Wylfa Newydd, which is on the Isle of Anglesey, and Oldbury-on-Severn, in South Gloucestershire.

Of the UK ABWR, ONR said: "Our delivery confidence for this project is green/amber, which means that successful delivery remains probable, however constant attention from both Hitachi-GE and the regulators is required to ensure that risks do not materialise into major issues threatening delivery. Hitachi-GE shares our view of delivery confidence. Overall we are confident that completion of the GDA by the end of December is achievable."

ONR's "intensive assessment" of the design continues, it said, and with a year remaining in its anticipated schedule it is "moving towards finalising any significant safety case issues and identifying any final matters that may require additional work and/or design enhancements". 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 is continuing to carry out its assessments and starting consultation on its findings so far on 12 December. Natural Resources Wales (NRW) is also working towards this consultation. The Environment Agency and NRW considers that a statement of design acceptability (SoDA) in December 2017 is achievable, ONR said.


NuGeneration (NuGen), the UK joint venture between Japan's Toshiba and France's Engie, plans to build a nuclear power plant of up to 3.8 GWe gross capacity at Moorside, in West Cumbria using AP1000 nuclear reactor technology provided by Westinghouse Electric Company, a group company of Toshiba.

Of 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. 122. 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 noted the results of Westinghouse's revised management arrangements for the UK GDA project. "The improved oversight is helping to progress matters and to secure and maintain the resource it needs to deliver the project. Overall submissions are improving, however there are instances where further revisions are needed to meet regulatory expectations."

There are concerns about the volume of work still to be assessed in the remaining time, it 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 became the first reactor design to complete the GDA process and receive a Design Acceptance Confirmation (DAC) from the ONR and a Statement of Design Acceptability from the Environment Agency 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 £18 billion ($28 billion) 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 is a joint venture between CGN and EDF, developed to deliver the Bradwell project in Essex. ONR said: "Our interactions have focused on ensuring that the RP 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."

Researched and written
by World Nuclear News