Sizewell C gets first on-site nuclear-grade concrete plant

On the Sizewell C site, the first concrete plant built to nuclear standards is already running. Heidelberg Materials UK installed it on site, and it is already producing concrete for a cut-off wall: a barrier designed to be watertight around the perimeter where the new nuclear power station will stand.

Nuclear work sets a higher bar than ordinary construction. Heidelberg says it is the first company in the UK certified to produce nuclear-grade concrete under BS EN 19443, a standard that applies ISO 9001:2015 to suppliers of products and services important to nuclear safety. The British Standards Institution describes it that way. The concrete for Sizewell C will be made to the same standard.

The wall is what makes the digging possible. It will allow approximately 4M m³ of earth to be excavated before the two 1.6GW reactor units can be built. The work is being carried out in collaboration with the Civil Works Alliance, formed of Balfour Beatty, Bouygues Travaux Publics, Laing O'Rourke and Sizewell C.

For the workforce, the change is in numbers. Heidelberg says it employed over 80 people at Hinkley Point C in Somerset at its height, and that at Sizewell this could reach 200. For the UK's nuclear programme, the company's major projects director, Sean Hunter, argues that its experience places Heidelberg 'uniquely' to help deliver the country's low-carbon energy infrastructure. The sources give no completion date for the reactors, so the timing of these gains is still open.

The same month, Amentum announced a £22.3M contract to design marine and tunnelling works for Sizewell C. These details come from the companies involved and from the standards body; no independent assessment of the plant's output is reported.