Office for Nuclear Regulation

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Wylfa Newydd

ONR activity

Horizon Nuclear Power has confirmed its intention to apply for a nuclear site licence to construct and operate two Hitachi-GE Advanced Boiling Water Reactors (ABWR) at Wylfa Newydd on Anglesey.  Horizon cannot commence nuclear safety related construction until it has been granted a licence by ONR, and received permission to do so under a condition attached to the licence.  Legal conditions placed by other governmental and regulatory bodies must also be met.

The UK ABWR design is currently undergoing assessment as part of ONR's Generic Design Assessment (GDA) process.  As part of ONR's licensing assessment, we are considering Horizon's plans for adapting the generic design to local conditions at the Wylfa site - for example the geology and interactions with the adjacent nuclear site - and for developing a site-specific safety case.  We are also focusing on Horizon's development of its organisational capability to discharge the obligations associated with holding a nuclear site licence.  This means that we seek confidence that Horizon is putting in place appropriate governance arrangements, resources, competencies and arrangements to manage its activities safely and securely.

ONR has developed a strategy for engaging with Horizon covering the period through until receipt of the formal site licence application. The strategy sets out how we will plan and manage our work and the areas that we will focus on during this initial period.

Current status

July 2016

Horizon has advised ONR that its nuclear site licence application for Wylfa Newydd will be deferred until Quarter 1 2017.  Following a number of key appointments, including a Chief Executive Officer; Horizon has conducted a review of its organisation and project delivery arrangements to ensure that they are fit for purpose to take the project forward.  Horizon wishes to ensure that the licence application accurately reflects these changes. ONR has been kept informed about these changes and will review them during our continuing dialogue with Horizon.  We note Horizon’s current intention to maintain its target licence grant date of around April 2018 and we are confident that we can complete our assessment of the application within this timescale, subject to a good quality licence application, informed by continued early ONR engagement.  

Throughout Horizon’s reorganisation we have continued to engage with the company as it develops the capability and arrangements that it needs to apply for a licence for the Wylfa Newydd site.  However, the level of interaction has slowed in some areas whilst Horizon implements its changes.  We expect dialogue to resume to give us confidence that Horizon is progressing towards completion of a suitable licence application by its revised target date.

At this stage, our principal aim continues to be to provide constructive advice and challenge to Horizon which enables it to understand regulatory expectations and establish the infrastructure expected of a nuclear site licence holder.   When the site licence application is received we shall commence formal assessment of the application.  That process will culminate in a recommendation to the ONR Chief Nuclear Inspector as to whether a nuclear site licence should be granted to Horizon.

ONR's interactions with Horizon are structured in accordance with an intervention strategy for Wylfa Newydd, covering the period until receipt of the formal site licence application .  The strategy identifies a number of key areas or "cornerstones" that we are focusing on during this initial period. The cornerstones cover licensing and legal matters; site activities and licence condition compliance arrangements; design and safety case; security; and organisational capability.  These cornerstones are in turn sub-divided into a number of topic areas to enable efficient and effective engagement between the two parties at a more detailed level.  ONR’s lead for each topic area is seeking confidence that Horizon is developing suitable strategies, resources and arrangements to progress each area in a timely manner and, where appropriate, has started to implement these arrangements.    

A key area of focus for ONR remains Horizon's development of the organisational structure, resources, competencies and management arrangements that it needs in order to become a nuclear site licence holder.  As noted above, Horizon has refocused its organisation to establish a more project-oriented structure and made a number of key appointments, including a Chief Executive Officer.  ONR has engaged with Horizon to understand how it proposes to develop its corporate structures, governance and processes, in particular the creation of a functioning site licensee company Board and the embedding of processes that can be adequately demonstrated through the site licence assessment period. We continue to monitor closely the development of the site licence company governance structures and will seek assurance in advance of the licence application being submitted that they will meet our expectations.

As we move forward, ONR will continue to work with Horizon to understand how it proposes to develop its EPC (engineer, procure, construct) contract arrangements.  A key expectation of ONR is that Horizon is able to demonstrate that it has the right level of oversight and control of decisions and actions that may affect safety.

With regard to design and safety case, Horizon continues to support Hitachi-GE's work as part of the GDA of the UK-ABWR design.  We welcome this and have been pleased by the establishment of a joint safety case office involving Horizon and Hitachi-GE staff.  This is a collaborative working arrangement between Hitachi-GE and Horizon Nuclear Power to deliver Hitachi-GE’s GDA and Horizon’s site specific safety case objectives, while preserving obligations and governance arrangements for both organisations. The learning that the engineering team gain should help Horizon to understand and take ownership of the design and the site-specific safety case.  This approach should also help Hitachi-GE to understand site-specific design and safety case requirements. 

Throughout our interactions, we have developed, and will continue to maintain, constructive, open and effective working relationships with Horizon.  We remain satisfied that ONR advice is being carefully considered by Horizon as it works towards finalising its nuclear site licence submission pack.  We are working closely with HSE, which has responsibility for conventional safety until the site licence is granted, and are also maintaining close working relationships with Natural Resources Wales to ensure that safety, security and environmental matters are addressed in a transparent and consistent manner. 

Publication of reports

ONR is committed to being an open and transparent body. We have already published ONR's intervention strategy for pre-licence application engagement and will publish on this website the following material:

Useful links