POST-TENSIONING

Nuclear containment structures, in particular those for pressurised water reactors, are designed to withstand high internal pressures when and if a ‘loss of coolant accident’ (LOCA) happens.

Applying high pressure to the inside surface of the containment structure causes tensile forces inside its walls, which can be resisted by the use of post-tensioning. As such, post-tensioning helps provide structural integrity to the containment vessel, and ensures that it is leak-tight.

This crucial technique makes a key contribution to the general safety of the structure. By making use of post-tensioning, owners and designers benefit from a safe and durable containment structure, reduced cost of maintenance, and design simplification while conforming to existing codes.

As a worldwide leader in post-tensioning, VSL offers high-grade systems and services, and can therefore fully optimise the impact of the technology within the overall structure.

VSL’s post-tensioning system complies with key international standards (including ASME, ETC-C, RCC-CW, FIB, PTI, ETAG) and can be supplied and implemented by local VSL teams. This ensures the project is completed to the highest level of safety with guaranteed quality, cost, and on-time delivery.

The design and build package can include:

• VSL’s involvement from the early stages of engineering the containment structure, with support for the design and detailing of the structure to take full advantage of post-tensioning;
• engineering for the post-tensioning;
• procurement of the post-tensioning system;
• development of the optimum construction methods;
• installation.

This initial package can be extended to include asset preservation and maintenance to guarantee the long-term safety and durability of the containment structure through:

• implementation of fire protection on the post-tensioned structure
• inspections & monitoring of the post-tensioning
• monitoring of the overall structure
• maintenance