Concrete containment structures are critical components of nuclear plants; they ensure the structure remains air-tight in the event of any leakage of coolant and prevent contaminated particles being released into the atmosphere. The design, construction and maintenance of such structures requires specialist expertise to guarantee their stability and safety. VSL offers a diverse range of solutions to meet this requirement; they can be combined to create bespoke packages or applied as standalone services for nuclear containment construction.
It is often necessary to carry out specialist ground improvement works before starting construction of nuclear power plants, to improve the ground’s shear strength, stiffness, and permeability and reduce the risk of liquefaction in areas of potential seismic activity.
Nuclear power plants involve the construction of complex structures and deep basements. Specialist knowledge and experience in deep foundations is necessary to safely undertake such large-scale excavations and transfer heavy loads into the ground.
Concrete cut-off walls built below ground level can be used to help prevent any groundwater movement, improving ground stability, and also to contain liquid pollutants, preventing contamination of the surrounding area.
In environmentally-sensitive areas, horizontal directional drilling (HDD) is the technique of choice for installation of a wide range of underground networks such as water, electricity, optical fibre, and so on.
The construction of nuclear facilities often requires temporary support for heavy loads and the construction of working platforms on congested sites. This is where there is an important role for earth-retaining walls, both temporary and permanent. The latter can serve as a long-term risk mitigation and protection measure against natural disasters or industrial hazards.
Nuclear containment structures, in particular those for pressurised water reactors, are designed to withstand high internal pressures to prevent such as those that might occur in an exceptional event, for example a LOCA (‘loss of coolant accident’). In such circumstances, the post-tensioning provides structural integrity to the containment vessel, and ensures that it is leak-tight.
Heavy lifting can be used to overcome constraints inherent in the construction of nuclear containment structures when:
At locations exposed to the possibility of seismic events or vibration, it is crucial to consider such threats at the design phase so that the asset is protected from structural damage and, of course, the population is safeguarded. Dampers and specialist bearings are very effective in mitigating vibrations, and enhancing the stability, durability and safety of the structure.
Regular monitoring and inspections must be carefully planned and carried out right from the start of the construction phase of a nuclear containment structure. This safeguards the durability of the post-tensioning system and confirms that it will comply with safety standards in any ‘loss of coolant accident’ (LOCA).