Nuclear Power Plant Structural Health Monitoring
Over the last few years, the nuclear power industry has developed dramatically in order to respond to a worldwide increasing demand for economic and sustainable energy. New nuclear power stations set the standards for safer and longer lifetime (60 years) plants, requiring the highest level of monitoring system based on reliable and durable sensors. Therefore, the monitoring system offers quite unique challenges that the Testindo Group has addressed successfully since 1960.
Indeed, different threats might affect the function of the containment building:
- Concrete deformation due to internal swelling mechanisms
- Rebar corrosion
- Losses in the pre-stressing due to concrete creeping
- Collapse of soils under the raft of the nuclear island, which can have consequences on the displacement of the structure and load distribution over the raft
- Seismic activity, which can compromise structures
- Increase of pressure / temperature inside the building due to accidents (meltdown of the reactor, pipeline leakage, etc.)
The Testindo Group’s monitoring system gives real-time data on the condition of the concrete containment and its steel liner, ensuring the leak-tightness, using traditional sensors (vibrating wire) and fiber optic sensors.
By studying different parameters, the In-Service Inspection Instrumentation (ISI) allows the evaluation of the mechanical behaviour and integrity of the containment at different phases:
- During construction
- During the acceptance (pressure) test and periodic tests during the life of the plant
- During the operating time of the plant
Benefits of the Testindo Group's Integrated Nuclear Power Plant Health Monitoring Solutions
4 - Reduces costs The implementation of a Testindo Group monitoring system with high accuracy, reliability and robustness can decrease the insurance premiums allocated for refunding possible liabilities and damages on people, properties and environment caused by any major accidents.
5 - Help preventive and proactive structure management Allows the control of budgets and unforeseen unavailabilities:
- Diagnose and forecast the mechanical integrity of containment and, therefore, to prevent and anticipate potential failures and unavailabilities
- Plan maintenance operations due to unexpected structural degradations
- Have a realistic view of the residual life of the structure and identify the needs for investment, if necessary
- Justify the extent of the plant lifetime, if needed.
Local Strain: Concrete embedded extensometer
Distributed Strain: Distributed deformation of steel liner / concrete structure
Average Strain: Long base extensometer
Displacement: Joint openings, existing crack opening
Distributed Temperature: Temperature distribution in concrete
Local Temperature: Air / Concrete temperature
Tilt : Global tilt / Rotation / Verticality of containment walls
Load : Force in pre-stressing cables
3D Movement: Global movements of the building
Pipeline Corrosion: Water cooling pipelines
Pipeline leakage: Water cooling pipelines