The UK’s Office for Nuclear Regulation (ONR) on 7 April closed the second and remaining regulatory issue (RI) for Hitachi-GE’s UK Advanced Boiling Water Reactor (UK ABWR) design.

The ONR, the Environment Agency and Natural Resources Wales said in March that they expect to complete the generic design assessment (GDA) for the plant in December. The RI concerned Hitachi-GE developing and delivering a suitable and sufficient probabilistic safety analysis (PSA) for the UK ABWR. ONR said it was content that Hitachi-GE had provided sufficient information “to meet the intent of RI-ABWR-0002”, noting that the RI had represented “a serious regulatory shortfall”. It added: “Hitachi-GE presented a resolution plan to address the issue, which is now completed.

The regulators are satisfied that Hitachi-GE has delivered a comprehensive UK ABWR PSA submission, including consideration of internal events and hazards, for the reactor, used fuel pool and other facilities. This is considered a positive step forward as Hitachi-GE continues to progress through ONR's step 4 of the GDA process.” Hitachi's UK subsidiary Horizon Nuclear Power plans to build two UK ABWRs at the Wylfa Newydd site in north Wales and two more UK ABWRs at Oldbury in western England. Horizon announced this week that it had submitted its site application to build and operate the two Wylfa Newydd units.