Hitachi is scrapping its U.K. nuclear power efforts, which include the Wylfa Newydd nuclear plant on Anglesey in North Wales and the Oldbury-on-Severn site in South Gloucestershire. As a result, the company will write off around $5.5 billion of its investment, which was expected to total around $28 billion.

Horizon Nuclear Power was formed in 2009 by E.On and RWE to develop new nuclear power stations in the U.K. It was acquired by Hitachi in November 2012 for around $900 million. The company planned to build at least 5,800 MW of new nuclear power generating capacity at the two sites. The Wylfa Newydd plant was planned to provide around 6% of Great Britain's electricity.

The plants would have used advanced boiling water reactor (ABWR) technology, which according to the company is a "Generation III+" design that has been used in Japan. The plants each had been expected to employ around 850 people when in operation.

The company said it had been unable to conclude financing and associated commercial arrangements for the projects.

The U.K. ABWR was developed and offered in the U.K. by Hitachi-GE Nuclear Energy Ltd. The venture was formed in 2007 and was 80% owned by Hitachi and 20% by GE. From April 2013 to December 2017, the U.K. ABWR was assessed by the U.K. Office for Nuclear Regulation, Environment Agency and Natural Resources Wales. After the review, the project was approved to move to the site licensing stage of development.

The first proposed nuclear plant was Wylfa Newydd, next to the former Magnox Wylfa nuclear power station. The second site was near Oldbury-on-Severn, next to the former Magnox Oldbury nuclear power station.