24.03.2025
Equans uses its expertise in ventilation and air conditioning to support Sizewell C
Designed as a replica of the Hinkley Point C (HPC) nuclear power station, the Sizewell C project marks a strategic step forward in speeding up and optimising the construction of new nuclear power plants. To achieve this ambition, Nigel Cann, joint managing director of Sizewell C Ltd. and Pierre Hardouin, managing director of Equans France, signed a key contract in London last February for the supply of the heating, ventilation and air conditioning (HVAC) systems for this future power plant located in Suffolk, in the United Kingdom.
A contract that builds on the success of HPC
Drawing on its experience on the HPC project since 2015, Equans France, via its entity Axima Nucléaire, has demonstrated its ability to meet the technical and industrial challenges of HVAC systems in nuclear environments.
The new Sizewell C contract aims to reproduce, as far as possible, the HVAC systems already being deployed for installation at Hinkley Point C.
By limiting adaptations to the strict minimum, this strategy considerably reduces the need for engineering, while facilitating team coordination and supply chain optimisation.
CGI of how the Sizewell C nuclear power plant would look (credit: la Sfen)
Replicate for faster progress and cost control
By replicating the designs and qualifications validated for HPC, Sizewell C optimises its costs and controls its completion times. Unlike HPC, which required long-term engineering and validation work, Sizewell C uses tried and tested solutions, thus limiting the need for adjustments and the risk of late modifications.
Thanks to this approach, which has already resulted in significant savings on the Sizewell C project, Equans France will ensure the progressive delivery of over 20,000 classified pieces of equipment between 2026 and 2031. The experience gained on HPC has also allowed Axima Nucléaire to refine its methods to design and qualify equipment more efficiently. More than one million hours of engineering, involving over 150 specialised engineers and design office technicians, had been dedicated to developing solutions adapted to the requirements of the nuclear industry, using 3D models and seismic calculations.
This expertise will be directly applied to Sizewell C, enabling faster and better controlled execution. In a similar vein, extending the validity of HPC qualifications to Sizewell C also makes it possible to significantly speed up production of equipment, most of which is custom-made and requires long lead times.
80% of the equipment will be ordered and delivered before construction even starts, thus ensuring smoother project deployment. This anticipation is made possible by the standardisation of the project: more than 90% of the buildings on which Axima Nucléaire will be working will be identical to those at HPC, thus limiting the need for adjustments and facilitating delivery coordination.
Ready-to-use equipment thanks to lessons learned from HPC
HVAC systems, which are essential for the safety and security of nuclear power plants, maintain suitable thermal conditions for sensitive equipment and for staff, and play a role in the dynamic containment of the facilities to avoid any risk of uncontrolled releases to the outside world.
Their long and demanding qualification process guarantees their resistance to extreme conditions, such as earthquakes, fire, radiation, explosions or air crashes.
Essential to the plant's operational safety, these systems help prevent accidents and protect the environment. Sizewell C will be able to capitalise on certifications already obtained at HPC by Equans France, thus helping to control lead times and associated costs.
Axima Nucléaire will also play a key role in the production of the equipment, drawing on its workshop in south-eastern France, which specialises in the manufacture of specific refrigeration and ventilation equipment. The Equans France entity will produce a range of custom-made equipment, meeting the strict safety and seismic resistance requirements of the nuclear sector.
In total, over 600 pieces of equipment will be manufactured in-house for this project, including local cooling units, air handling units and electrical cabinets. This equipment will play an essential role in thermal management, ventilation and control of critical air flows within the facility.
A strong commitment to the UK's energy transition
This contract is fully in line with the UK's energy transition dynamic. With its two EPR reactors, Sizewell C will produce 3.2 GW of low-carbon electricity, i.e. a sufficient amount to supply around six million UK homes. By reinforcing nuclear energy production, this project will play a key role in securing the country's energy supply while actively contributing to reducing carbon emissions.
The Sizewell C project is a great demonstration of how replication can offer significant time and cost savings for nuclear power infrastructure. It puts us in a uniquely strong position to deliver a project that will play a significant part in the UK’s low carbon future, delivering 7% of the UK’s energy needs. The experience gained at Hinkley Point C is a major advantage, and partners like Equans, which have already proven their HVAC skills there, play an essential role in the standardisation and optimisation of equipment essential to plant safety.
Julia Pyke et Nigel Cann, joint managing directors of Sizewell C Ltd.
“ This project is an extension of our achievements at HPC and a strategic step to prepare for the arrival of the future EPR2 reactors in France. By capitalising on experience gained and on the standardisation of equipment, we are consolidating our expertise and that of our supply chain, thus ensuring a gradual, controlled ramp-up. With Sizewell C, we are contributing to a deep transformation of the European energy model. Industrialising nuclear construction means guaranteeing a more reliable, safer and more competitive energy supply, in support of the energy transition. ”
