The Office for Nuclear Regulation has approved first structural concrete for the ‘technical galleries’ of the power station.

These are a series of underground reinforced concrete structures to be located beneath the site and some above-ground structures, connecting services such as cooling water and electricity to the two reactor units and other structures.

Up to now the on-site construction activities have been limited to preparatory and enabling works, including the construction of several concrete batching plants and aggregate stores.

Following First Nuclear Safety Concrete, the site workforce will grow rapidly to several thousand.

Mike Finnerty, Director of ONR’s new reactors programme said: “Our consent for the first nuclear safety concrete at Hinkley Point C is a key regulatory milestone marking start of construction of the first nuclear power station since Sizewell B in Suffolk.

“We have carried out extensive assessment of EDF’s safety case and preparedness for this important step at Hinkley Point C.

“However, this does not give consent for all elements of construction. We will continue to regulate NNB Generation Company – a subsidiary created by EDF Energy -activities and have implemented a number of hold-points to ensure we have full regulatory control over the various construction and commissioning stages through to start of operation.”