March 24, 2025
Equans supports Sizewell C with its expertise in ventilation and air conditioning
Designed as a replica of the Hinkley Point C (HPC) power plant, the Sizewell C project marks a strategic step forward in accelerating and optimizing the construction of new nuclear power plants. To make this vision a reality, Nigel Cann, Associate Managing Director of Sizewell C Ltd., and Pierre Hardouin, Managing Director of Equans France, signed a key contract last February in London for the supply of heating, ventilation, and air conditioning (HVAC) systems for this future power plant located in Suffolk, United Kingdom.
A contract that builds on HPC's success
Drawing on its experience with the HPC project since 2015, Equans France, through its subsidiary Axima Nucléaire, has demonstrated its ability to meet the technical and industrial challenges of HVAC systems in nuclear environments.
The new contract signed with Sizewell C aims to replicate, as closely as possible, the HVAC systems already being deployed at the Hinkley Point C facility.
By limiting modifications to what is strictly necessary, this strategy significantly reduces the need for engineering work, while facilitating team coordination and supply chain optimization.
3D model of the Sizwell C nuclear power plant (credit: SFEN)
Scale up to speed up operations and control costs
By building on the replication of designs and qualifications validated for HPC, Sizewell C optimizes costs and keeps construction schedules on track. Unlike HPC, which required extensive engineering and validation work, Sizewell C utilizes proven solutions, thereby limiting the need for adjustments and reducing the risk of late-stage changes.
Thanks to this approach, which has already generated substantial savings on the Sizewell C project, Equans France will ensure the phased delivery of more than 20,000 classified pieces of equipment between 2026 and 2031. The experience gained on the HPC project has also enabled Axima Nucléaire to refine its methods for designing and qualifying equipment more efficiently. More than one million engineering hours, involving nearly 150 specialized design office engineers and technicians, were dedicated to developing solutions tailored to nuclear industry requirements, using 3D models and seismic calculations.
This expertise will be directly applied to Sizewell C, enabling faster and more controlled project execution. In a similar vein, extending the validity of HPC’s qualifications to Sizewell will also significantly accelerate equipment production, most of which is custom-made and requires long lead times.
As a result, 80% of the equipment will be ordered and delivered even before construction begins, ensuring a smoother project rollout. This foresight is made possible by the project’s standardization: more than 90% of the buildings on which Axima Nucléaire will work will be identical to those at HPC, thereby limiting the need for adjustments and facilitating the coordination of deliveries.
Equipment Ready for Use Thanks to Lessons Learned from HPC
Essential to the safety and security of nuclear power plants, HVAC systems maintain appropriate thermal conditions for sensitive equipment and personnel and contribute to the dynamic containment of the facilities to prevent any risk of uncontrolled releases to the outside environment.
Their qualification—a long and demanding process—ensures their resistance to extreme conditions such as earthquakes, fires, radiation exposure, explosions, or plane crashes. Essential to the safe operation of the plant, these systems help prevent accidents and protect the environment.
As a result, Sizewell C will be able to leverage the certifications already obtained by Equans France at HPC, thereby facilitating the management of associated timelines and costs.
Axima Nucléaire will also play a key role in equipment production, drawing on its facility in Isère, which specializes in the manufacture of specialized refrigeration and ventilation equipment. The Equans France division will produce several custom-made pieces of equipment that meet the nuclear sector’s strict safety and seismic resistance requirements.
In total, more than 600 pieces of equipment will be manufactured in-house for this project, including terminal air handling units, air handling units, and electrical cabinets. This equipment will play an essential role in thermal management, ventilation, and airflow control within the facility.
A Strong Commitment to the UK's Energy Transition
This contract is fully in line with the United Kingdom’s energy transition efforts. With its two EPR reactors, Sizewell C will generate 3.2 GW of low-carbon electricity, enough to power approximately six million British households. By boosting nuclear power generation, this project will play a key role in securing the country’s energy supply while actively contributing to the reduction of carbon emissions.
The Sizewell C project is an excellent example of how replication can lead to significant time and cost savings for nuclear infrastructure. It puts us in a particularly strong position to successfully deliver a project that will play a major role in the UK’s low-carbon future by supplying 7% of the country’s energy needs. The experience gained at Hinkley Point C is a major asset, and partners like Equans, which have already demonstrated their HVAC expertise there, play a key role in standardizing and optimizing the equipment essential to the plant’s safety.
Julia Pyke and Nigel Cann, Associate Managing Directors of Sizewell C Ltd.
“ This project builds on our previous achievements in HPC and represents a strategic step in preparing for the arrival of future EPR2 reactors in France. By building on the experience we’ve gained and the standardization of equipment, we are strengthening our expertise and that of our supply chain, thereby ensuring a gradual and controlled ramp-up. With Sizewell C, we are contributing to a profound transformation of the European energy model. Industrializing nuclear construction means ensuring a more reliable, safer, and more competitive energy supply to support the energy transition. ”
