黑洞社区

Doubts have been raised over whether the escalating cost of earthworks at the Hinkley Point nuclear site is the biggest single reason for the scheme blowing its budget by as much as 拢3bn.

Last month French power giant EDF said the cost of the scheme had gone up by 拢1.9bn-拢2.9bn because of 鈥渃hallenging鈥� ground conditions 鈥渨hich made earthworks more expensive than anticipated鈥�.

The price tag of the job is now up to 拢22.5bn, although the firm says it is still on schedule for Hinkley to generate power in 2025.

But one former employee of a Hinkley contractor who worked on the scheme before leaving his role, told 黑洞社区 the idea that groundworks were responsible for the bulk of a near 拢3bn cost overrun was unconvincing.

• Read: Hinkley Point C running up to 拢2.9bn overbudget
• Analysis: Why have costs gone up at Hinkley Point C?

A Kier-Bam joint venture has been carrying out work at the site, with the team鈥檚 contract rumoured to be now nearer 拢300m rather than the original 拢203m, while further groundworks activity has been wrapped up in the main civils job undertaken by Bouygues-Laing O鈥橰ourke and the large 鈥渕arine works鈥� given to Balfour Beatty.

But the source said: 鈥淭he entire civils package was only in the region of 拢3bn. You鈥檇 have to double that. It must be more than groundworks.鈥�

He attributed the increase to general construction cost inflation and high labour costs alongside a failure to take account of the specific requirements of nuclear construction 鈥� such as the high grade of concrete.

鈥淭here are very few people in the industry who鈥檝e worked on nuclear power station projects before,鈥� he said. 鈥淎nd everyone was warned repeatedly it was going to be much more difficult, but nobody believed us.鈥�

In a statement, EDF said ground investigations before starting showed 鈥渨eathered rock in places, with a number of faults鈥� adding that as work progressed 鈥渋t became apparent that the extent of the faulted zones was more extensive than envisaged.

鈥淚n addition, the areas of highly weathered rock degraded quickly, despite tight controls in terms of the maximum duration it could be exposed prior to blinding with concrete. These issues have led to additional excavation, additional ground nailing and additional substitution/replacement concrete.鈥�

The scheme has required excavating 2.3 million m³ of rock across a site the size of 240 football pitches.