For over 40 years, Bouygues Travaux Publics has been using its expertise to serve the development of the nuclear energy sector. From the construction of the very first power plants in France to the latest generation of reactors (EPRs) and the development of future technologies such as small modular reactors (SMRs), the history of Bouygues Travaux Publics is one of a pioneering builder contributing to the development of this decarbonised energy.
Today, as an acknowledged leader in civil engineering for these infrastructures, the Group has developed a unique know-how geared to these projects, which require a heightened degree of safety, planning, cost control and constant vigilance. EPR projects are a perfect example of this combination of demanding standards and excellence, and of Bouygues Travaux Publics’ capacity for innovation.
These projects, of rare complexity, call for recognised expertise in project management, safety and technical skills. But nuclear power is not just about energy production. Bouygues Travaux Publics is proud to be taking part in projects that mobilise nuclear civil engineering technology to serve other equally essential objectives, requiring us to imagine, design and build custom-made structures that are often unique.
Earthworks and civil engineering for the EPR
On the Flamanville site in the Manche department, Bouygues Travaux Publics carried out the civil engineering works for EDF on the first third generation pressurised water reactor (EPR) in France. This cramped site, measuring 100 metres on each side and located between the cliffs, the sea and the first two reactors of the existing power plant, is home to some 10 buildings, including the power room and the reactor building. This exceptional construction site is particularly noteworthy for the specific features of the construction of a dual enclosure shell: a structure 54 metres in diameter and 60 metres high, "lined" with an inner steel liner capable of withstanding the pressure resulting from a core meltdown, and topped by a 240-tonne dome installed by one of the largest cranes in the world. The power room houses a 1,600-megawatt turbine. To meet the most stringent nuclear safety requirements, the building notably incorporates two new items of equipment: a core catcher, which can contain the reactor core in the event of a meltdown, and a plane-protection shell that can withstand the impact of an airliner.
Construction of two nuclear reactors
To the south west of Bristol, England, is the site of the first nuclear power station built on British soil in 20 years. When its two new-generation reactors are commissioned, this gigantic project involving extraordinary feats of organisation and methods for its construction will supply 7% of the country’s electricity consumption and power nearly 6 million homes. This project, commissioned by the British government from NNB, a company majority owned by EDF Energy, was entrusted to Bouygues Travaux Publics, in partnership with Laing O’Rourke within the Bylor consortium. It brings together structures of rare complexity, condensing all the developments in the sector in terms of technicality and safety. To optimise the project and better manage construction deadlines, Bylor relied in particular on the prefabrication of heavy concrete elements. Some of these massive elements require the mobilisation of the SGC250 "Big Carl", the largest land-based crane in operation, capable of lifting slabs of up to 1,100 tonnes, up to a reach of 100 metres.
Construction of nuclear reactor buildings
Areva awarded Bouygues Travaux Publics the civil engineering contract for the nuclear island of the world’s first EPR, including the reactor buildings and fuel and its protection systems. On the shores of the Baltic Sea in western Finland, where winter temperatures can drop to -28°C, the number 3 reactor at the Olkiluoto power plant now stands as a technical and engineering feat. This fortress of imposing dimensions has an outer shell of reinforced concrete 1.80 metres thick and an inner containment structure of pre-stressed concrete 1.30 metres thick, lined with a steel sealing skin.
Construction of a thermal electric power plant
In Lagos, the capital of Nigeria, Bouygues Travaux Publics was awarded the contract, as part of a consortium, to build the Egbin thermal electric power plant, the largest in the country, on a 30-hectare site. The plant, which is fuelled by natural gas and heavy fuel oil, comprises six 220 MW units, with a total capacity of 1,320 MW. Each unit is a complete power plant in itself with a steam production unit and a power generation unit and is thus able to operate independently. The works consisted of the design and construction of all the structures, covering all the specificities of civil works, including the civil engineering part of the infrastructure. Bouygues Travaux Publics also supervised the installation of peripheral industrial equipment, including a cooling water pumping station and water production and storage systems.
Construction of the R1 workshop at the La Hague reprocessing plant
In the 1980s, Bouygues built numerous workshops for COGEMA (now known as ORANO) in the UP2 and UP3 units of the nuclear fuel reprocessing plant at La Hague, in the Manche department. Once the first stage of transfer and storage of these used fuels in the pool has been completed, the elements are transported to a first series of workshops, R1 and T1. In these automated workshops, the operations of cutting the fuel elements and dissolving the nuclear material are carried out remotely. The R1 workshop was built by Bouygues in 1987. The works consisted of the execution of the civil engineering with the construction of two blocks comprising 11 levels founded on a 2.60-metre general slab and comprising biological walls of more than one metre with dense reinforcement. The teams had to face a major challenge: the fact that the workshop site was surrounded on all sides by other buildings.
Building annexed to the R2 and T2 workshops at the La Hague reprocessing plant
As part of the replacement of the evaporators needed to concentrate the fission products, Bouygues Travaux Publics carried out the civil engineering works for two semi-underground structures designed to house them. These annexes to the workshops are part of the spent fuel reprocessing chain and are located after those at the head of the plant, consisting of the R1 and T1 workshops. The spent nuclear material is dissolved in nitric acid, then the uranium and plutonium are extracted by a chemical process. The remaining part is made up of "fission products", transferred to the R2 and T2 workshops, where they are concentrated by means of evaporators that heat them in order to evaporate the acid, which is recycled. The work was carried out in a very constrained environment: a construction site on an operational ORANO site and in cramped spaces requiring complex manoeuvres.
Civil engineering works for the Synchrotron in Grenoble
On a peninsula between the Drac and Isère rivers stands a strange circular structure: the ESRF-Synchrotron, the world’s most powerful particle accelerator. Conceived in 1988 and financed by 11 countries, it hosts some of the most important research programmes in X-ray science and counts
four Nobel Prize winners among its users. The Synchrotron is a super generator of X-rays: they are produced by accelerating electrons to the speed of light. Bouygues Travaux Publics was chosen for its construction. The structure consists of a linear accelerator complex and its storage ring with a circumference of 850 metres and a diameter of 300 metres. Around there are dozens of laboratories where experiments are carried out.
Construction of the proton therapy equipment bunker-like basement
In the heart of London, Bouygues UK and Bouygues Travaux Publics were chosen by NHS England to build one of the world’s proton therapy centres. Hosted by University College London Hospital, the centre will use a cutting-edge technique that can target cancers with extreme precision, thereby minimising damage to surrounding tissue. While medical innovation is at the heart of the project, the construction aspect is not to be outdone: consisting of five levels underground and six above ground, the centre was the subject of the largest excavation in the British capital, involving a 3,600 m2 dig at depths of 22 metres to 28.5 metres, in an extremely constrained urban environment. The underground installation of a state-of-the-art proton therapy facility imposed heavy constraints in terms of radiation shielding: this was ensured by the thickness of concrete walls and slabs ranging from 1.80 metres to 4 metres, as well as by steel plates 1.40 metres thick.
Civil engineering and secondary works for the Megajoule nuclear test simulation centre
South of Bordeaux, the town of Le Barp is home to an extraordinary building, the Laser Megajoule, an exceptional research tool managed by the French Atomic Energy and Alternative Energies Commission (CEA). It is one of the main elements of the programme designed to ensure the continuity of France’s nuclear deterrent after the definitive cessation of nuclear tests in real conditions: 240 laser beams seek to trigger a nuclear fusion reaction. This implies a high degree of precision, which required a very sophisticated level of construction, to the nearest tenth of a millimetre, on a plot of land known for its complexity. Three Bouygues Construction companies, including Bouygues Travaux Publics, were responsible for the civil engineering and secondary works. Located in the centre of the building, the experiment room is surrounded by two halls housing the laser beams. To meet the high stability requirements, the building’s foundations were designed to prevent vibrations that could be caused by certain geological phenomena. Diaphragm walls were built to a depth of nearly 30 metres.
Construction of eight Ultimate Diesel Generator units
Following a post-Fukushima nuclear safety audit, EDF launched an action plan to deal with major accident situations. The resulting improvement programme includes the construction of Ultimate Diesel Generators (UDGs) for all of the 58 reactors in the French nuclear network. Bouygues Travaux Publics was awarded a civil engineering package for eight units on three major sites: Flamanville (50), Paluel (76) and Penly (76). The principle is to have an additional power supply in case of failure of the two external power supplies and the two existing internal power supplies. This last-resort power source makes it possible to further secure the power supply for refrigeration of the fuel deactivation pool. In addition to the thickness of the walls and the density of the reinforcement used in the nuclear industry, the need for robustness required the construction of buildings on earthquake-resistant blocks (at Paluel and Flamanville), the setting of the lower floor above the reference flood level, and a metal structure equipped with anti-tornado and anti-projectile nets to protect the external equipment.