UK regulators – the Office for Nuclear Regulation (ONR), the Environment Agency and Natural Resources Wales on 14 December approved Hitachi-GE's UK Advanced Boiling Water Reactor (UK ABWR) as suitable for construction in the UK, completing the Generic Design Assessment (GDA). Following the five-year regulatory process, Hitachi’s UK subsidiary Horizon Nuclear Power hopes to build two ABWR units with a capacity of 2.7GWe at Wylfa Newydd on the island of Anglesey in Wales for startup by 2025. Horizon also plans two UK ABWR units for its site in Oldbury, Gloucestershire. The Wylfa units would be the first commercial boiling water reactors built in the UK.

Consideration will now be given to financing the Wylfa project following increasing criticism of the deal agreed between the UK government and EDF for the Hinkley Point C project. During a visit by UK ministers to Japan in December  2016, reports suggested that public financing may be a possibility.

Hitachi has so far invested spent GBP2bn ($2.68bn) on the development of Wylfa Newydd. Horizon Nuclear Power has indicated that it needs a financial support package to be in place by mid-2018 if development is to continue. Earlier in 2017 Horizon said: “We have always been clear that we are looking to bring other investors into Horizon. Based on the strengths of our project, we are in positive discussions with a number of parties, but we will not be commenting on the process while it is ongoing.”

Hitachi's UK ABWR began the GDA process in April 2013. The process entailed detailed assessments and submissions across 20 topic workstreams.

The GDA regulators said they were satisfied the reactor meets regulatory expectations on safety, security and environmental protection at this stage of the regulatory process. A reactor vendor, or the 'requesting party', has completed the GDA process when it receives a Design Acceptance Confirmation (DAC) from the nuclear regulator and a Statement of Design Acceptability (SoDA) from environmental regulators. ONR has now issued a DAC to Hitachi-GE, while the Environment Agency and Natural Resources Wales have issued a SoDA to the company.

The ABWR design is already licensed in Japan and the USA. Four units have been built in Japan, with two under construction in Taiwan, although the project has been placed on hold. ONR chief nuclear inspector, Mark Foy, said completion of the GDA is a significant step in the regulation of the overall process to construct this type of reactor in the UK.  "We are already working on our assessment of Horizon's site licence application and the development of the site-specific safety case to progress, in due course, the construction and operation of these reactors at Wylfa Newydd," he noted.

The first reactor design to receive a DAC and SoDA was Areva's European Pressurised Reactor (EPR) in December 2012, now beginning construction at Hinkley Point C. It was followed by the Westinghouse AP1000 in March 2017, planned for development by Toshiba’s NuGeneration at Moorside in Cumbria. However, following the bankruptcy of Westinghouse in March 2017, Toshiba is seeking to sell the project, and South Korea’s state utility Korea Electric Power Corp (Kepco) has been named as a preferred bidder. These developments could mean a new GDA to approve Kepco’s APR-1400 reactor design instead of the AP1000. The Hualong One design that General Nuclear Services (a subsidiary of EDF and China General Nuclear) plans to use at the Bradwell project began the GDA process in January 2017.

A new report by the Institution of Mechanical Engineers, Nuclear Power: A Future Pathway for the UK, released on 14 December said the UK government should implement an independent review of the GDA process to ensure that costs are not unnecessarily added and to enable more rapid approval of small modular reactors (SMRs). The report comes after several government announcements announcing support for next generation of nuclear technologies.

Photo: CGI view of Wylfa Newydd