ConSpare helps power up Hinkley Point C with ‘nuclear concrete’

View of Bylor's three concrete batching plants, including a GGBS Silo at Hinkley Point C. Image courtesy of EDF Energy 2017

In a partnership with highly regarded concrete specialists, ConSpare have helped advise and supply equipment needed to produce some of the finest nuclear-grade concrete in the world for EDF Energy’s Hinkley Point C: the first of a new generation of power stations to be built in the UK.

Hinkley Point C will provide 25,000 jobs over the lifetime of the project. Once operational, it will employ 900 people and generate seven per cent of the UK’s low-carbon electricity.

Because of the nature of the Hinkley Point C project, the concrete used to construct it was required to be of high quality – ‘nuclear concrete’ is the term that’s been coined to describe it. It is being produced by Derbyshire’s Hanson Aggregates on behalf of project contractor Bylor, a joint venture of construction giants Bouygues and Laing O’Rourke.

To achieve nuclear concrete, a precise mix is followed in every batch of concrete made. Each batch must comply with extremely stringent quality standards laid down by the Office for Nuclear Regulation.

The journey towards nuclear concrete began in 2013, and it took three years of development, testing and refining to get to the point where concrete of the required quality was being produced on a consistent basis.

Hinkley Point C is said to be one of the most complex and challenging construction projects the industry has seen, as precision is required to create concrete to the highest of specifications.

ConSpare has been involved in supplying concrete know-how, equipment and ongoing logistical spare parts support to major construction projects for over 30 years. Past projects include the Channel Tunnel, DP World London Gateway and Crossrail.

When plans to build Hinkley Point C nuclear power station began, ConSpare were contacted by concrete batching plant manufacturers D and C Engineers, and asked to help design mixing and batching equipment that could cope with the demands of a project of this size.

Making concrete involves a series of different processes, all of which are interdependent upon each other. It was determined that three concrete batching plants with Teka TPZ 4500 planetary mixers, connected to Walter mixer washout systems to remove residue, were needed to achieve the levels of concrete production to complete the development.

This model incorporates a unique counter-rotational mixing action suited to the quality demands being placed on the equipment.

Dust containment during the mixing process was a challenge facing the team at Hinkley Point C. D and C Engineers therefore used ConSpare CDX mixer dust extraction systems to filter displaced air and retain cement dust within the mixing process. This creates a safer working environment and helps prevent waste, reducing environmental impact.

Another challenge was to ensure the concrete formulation mix was correct. Bylor had to identify the right raw materials to achieve the highest quality standards. All the limestone is crushed to a specific grade, then washed and stored onsite in 57,000-tonne aggregate bays. All sand is stored in huge weather-protected aggregate storage bays.

As a result of this partnership to create ‘nuclear concrete’, the production of the best concrete possible on a consistent basis is now, according to ConSpare, available. Steve Peterson, ConSpare’s Engineering Director, said: “I’m proud that we were able to contribute and help deliver nuclear concrete from day one, once production started proper.

“What we’ve provided in conjunction with D and C Engineers is a concrete production system that is one of the most accurate facilities of its type in the world, it is safe, efficient, effective and requires minimal maintenance.

Though, according to Steve “it was extremely challenging to get right”, he stated “we were convinced that we could provide all the equipment needed to create nuclear concrete from one source which, coupled with our experience and our innate understanding of the entire concrete production process, meant that we would be able to produce what is probably the finest-grade concrete the industry has ever seen.”

Peter Abel, Chief Materials Engineer at Bylor, said: “To do nuclear quality concrete, everything has to pull together. Everything must work.

“The ethos of Team Concrete has set and maintained a high standard of work. There’s a real sense of pride on the plants. The teams really look forward to us coming to site, so they can tell us how their plant is performing, both technically and operationally.

“The focus and attention to constituents, batching start-up surveillances, continuous feedback and improvement, and overall batching consistency has delivered both the best operational batching plant in the UK but also production trends that really set the standard.”