A construction update by client EDF Energy confirmed revised project completion costs of between £21.5bn and £22.5bn – an increase of £1.9bn to £2.9bn on previous estimates.
EDF said the exact increase “depends on the effectiveness of action plans to be delivered in partnership with contractors.”
The client added: “Cost increases reflect challenging ground conditions which made earthworks more expensive than anticipated, revised action plan targets and extra costs needed to implement the completed functional design, which has been adapted for a first-of-a-kind application in the UK context.”
Main contractor the BYLOR joint venture between Laing O’Rourke and Bouygues has successfully delivered the nuclear island “common raft known as J-0.
Its completion in June was a major milestone which prompted a detailed review of the project’s costs, schedule and organisation.
The review also confirmed that the risk of previously announced delays of 15 months and nine months to the completion of the main Unit 1 and 2 structures had “increased”.