Horizon Nuclear Power, a wholly-owned subsidiary of Hitachi, plans to build the 2.7GW Wylfa Newydd nuclear power plant in Anglesey, Wales, UK.

Estimated to cost £20bn ($26bn), the proposed two-reactor nuclear power plant (NPP) will be located in a site adjacent to the Magnox Wylfa nuclear power station, the world’s oldest commercial nuclear power station, which was decommissioned in 2015.

Wylfa Newydd will be one of the new nuclear plants to be built in UK since 1995, after Hinkley Point C NPP, which has been under construction since 2017.

It will also be UK’s first nuclear power facility to use the Generation-III Advanced Boiling Water Reactors (ABWR).

Anglesey council approved site clearance for the nuclear plant in September 2018. Horizon Nuclear Power hopes to begin construction on the project by 2020 and produce first power in 2025.

The plant is expected to produce enough low-carbon electricity to power five million UK households and account for approximately 6% of the country’s electricity needs, over 60 years of its estimated project life.

Wylfa Newydd nuclear project development history and details

E.ON UK and RWE Npower created a 50:50 joint venture company called Horizon Nuclear Power in January 2009 to develop new nuclear power stations in the UK.

Horizon Nuclear Power acquired the Wylfa Newydd project site in the same year and signed the planning performance agreement (PPA) with Isle of Anglesey County Council in October 2011.

Hitachi acquired Horizon Nuclear Power in November 2012 to become the owner of Wylfa Newydd as well as Oldbury nuclear project site in South Gloucestershire.

Horizon Nuclear Power applied for the nuclear site license for Wylfa Newydd in April 2017. UK nuclear regulators approved the advanced boiling water reactor (ABWR) design for use in the UK in December 2017, after four years of generic design assessment (GDA) process.

The project received key environmental approval from the European Commission in June 2018.

Application for the Wylfa Newydd Development Consent Order (DCO) was formally accepted for consideration by Planning Inspectorate of the UK Government in June 2018.

Wylfa Newydd plant make-up

Wylfa Newydd nuclear power station will consist of two Hitachi-GE 1,350MW UK advanced boiling water reactors (ABWR).

Each generating unit will comprise a 44m-high reactor building with a 70m to 80m-high emission stack of on its top, a turbine building housing steam turbine generators, a control building situated between the reactor building and turbine building, a heat exchanger building located close to the seawater intake, and a filter vent building.

The power station’s common facilities to be shared by the two units will include the radioactive waste building, water treatment facilities, emergency response facility, administration building, maintenance and workshop building, and a marine off-loading facility (MOLF).

Power transmission

Each generating unit at Wylfa Newydd will have step-up transformer near o the electrical generator, from where the electricity will be fed to the national grid via 400kV transmission lines connected to the existing National Grid substation adjacent to the plant site.

Financing for Wylfa Newydd nuclear power project

The Wylfa Newydd nuclear power project is proposed to be developed through a tripartite investment structure with Hitachi, the UK government, and state-backed Japanese entities as equal investment partners.

Horizon Nuclear Power, Hitachi, and HM (Her Majesty) Treasury signed a co-operation agreement under the UK Infrastructure Guarantee Scheme (UKGS) to promote external financing for the Wylfa Newydd project, in December 2013.

The UK government expects to negotiate a strike price for the electricity generated by Wylfa Newydd at £15 ($19.92) per megawatt-hour, which is much lower than the deal negotiated for Hinkley Point C.

Contractors involved with Wylfa Newydd nuclear power project

Hitachi-GE, a joint venture of Hitachi (80%) and General Electric (20%), was awarded the front-end engineering and design (FEED) contract for the Wylfa Newydd nuclear reactors in May 2013.

A special consortium named Menter Newydd was formed by Hitachi Nuclear Energy Europe, Bechtel and Japan Gas Corporation in 2016 to provide engineering and design support for the project.

Menter Newydd is also engaged in construction planning and project preparation under an early contractor engagement (ECE) contract.

Elliott Group, with the help of DU Construction, was responsible for the Wylfa Newydd site office extension, which was completed in 2017.

Bechtel was selected as the project manager for the Wylfa Newydd nuclear power plant in August 2018.

Hitachi Nuclear Energy Europe appointed Atkins, KBR, and UK-based engineering firm Wood as construction partners for the project in October 2018.

Atkins will be engaged for civil engineering design for the nuclear island, while KBR will work on project controls and Wood will provide architect engineering services.

Wylfa Newydd advanced boiling water reactor (ABWR) design

ABWR is a generation III+ reactor representing the latest design improvements on conventional boiling water direct cycle reactors, which pass the steam generated inside the reactor directly to the turbine for power generation.

The most significant design improvement is the provision of ten reactor internal pumps (RIP), which are directly mounted to the bottom of the Reactor Pressure Vessel (RPV) to supply coolant to the reactor core. The inclusion of RIPs eliminates external recirculation piping loops and pumps in the containment of a conventional BWR.

Further, the ABWR design includes 205 electro-hydraulic Fine Motion Control Rod Drives (FMCRD) mounted on housing welded to the pressure vessel bottom head, unlike the hydraulic locking piston system used in traditional BWR. The use of FMCRD enhances system reliability and plant operation and eliminates the possibility of Rod Drop Accident (RDA).

The ABWR design was approved in the UK in December 2017.