MONITORING

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 ensures the durability of the post-tensioning and therefore helps mitigate the risk of a ‘loss of coolant accident’ (LOCA).

Monitoring is key for the preservation of the structure and for efficient maintenance operations. Using instrumentation to capture data on a structure helps optimize the scheduled maintenance and any repairs needed. It also allows the development of a computer model for the detection of structural defects, thereby improving safety and reducing financial risks.

Strict requirements governing nuclear structures mean that inspection and maintenance are well defined by international codes such as those produced by ASME.

VSL is highly experienced and certified to carry out the necessary inspections involving post-tensioning and associated concrete works.

VSL has access to all the specialized equipment that is required for the maintenance and inspection works. The company has developed a range of equipment that incorporates in-situ data logging to capture and record:

• all of the key parameters associated with the installation of large tendons; and
• the information required to ensure ‘traceability’ and durability of the components.

A global package tailored to the needs of the client and the specifications of the structure, including:

• the definition of the monitoring and inspections needs and the associated hardware;
• the integration of the system components: load cells for permanent monitoring, corrosion sensors for the post-tensioned tendons, instrumentation to check for any vessel deformation, etc.;
• engineering assistance for the integration of these systems into monitoring packages, including the acquisition and management of the monitoring data;
• assistance for an add-on rental service to provide online access to the data;
• an inspection and maintenance regime in line with international codes.