The British government is offering the support in loans and other ways to cover a large proportion of the cost of the project and Hitachi will make a decision as early as this week on whether to go ahead, Kyodo reported, citing an unidentified source close to the matter.
The offer is to ease concerns about rising costs, which have increased to 3 trillion yen, Kyodo said.
A Hitachi spokesman declined to comment when contacted by Reuters.
The Kyodo report also cited unidentified observers questioning whether the government would be able to carry out the offer, due to parliamentary opposition.
The British government last week played down another media report that said it will guarantee loans for the construction of the two reactors in Wales.
Britain is seeking new ways to fund nuclear projects after criticism over a deal awarded to France’s EDF (EDF.PA) to build the first nuclear plant in Britain for 20 years, which could cost consumers 30 billion pounds.
Hitachi’s Horizon plans to construct at least 5.4 gigawatts of new nuclear capacity at two sites in Britain – the first at Wylfa Newydd in Wales, and a second at Oldbury-on-Severn in England.
Reporting by Aaron Sheldrick and Kiyoshi Takenaka; Editing by Christian Schmollinger