Providing safety of reinforced concrete containments is one of the main challenges of the nuclear industry. This is because:
• Concrete degradation, decreasing compressive, tensile and yield strengths, macro- and micro- cracks, fatigue cracks, de-bonding reinforcement, spallation and porosity reduce the fracture toughness, change the magnitude and orientation of the main stresses, and decrease the load-carrying capabilities of structures.
• Dehydration of cement stone, due to temperature, radiation, leaching of calcium hydroxide from the concrete, sulfate attack, alkali-aggregate reaction and subsequent swelling, is evaluated currently by traditional local NDE methods with low accuracy.
• Revealing corrosion location and determination of its type and danger level in reinforced or pre-stressed concrete containments is not performed on a regular basis.
• Movement of soil under the containment base is evaluated only when there are visible indications of damage.
The situation is even worse because existing Non-Destructive Inspection (NDI) methods provide limited information and are not suitable for revealing, identifying and assessment of flaws in structural elements of nuclear power plant containments. To solve the above-mentioned problems, the authors have created and successfully used for different applications the Quantitative Acoustic Emission Non-Destructive Inspection technology (QAE NDI). The results of the investigations presented below demonstrate the capabilities, advantages and limitations of QAE NDI technology for revealing, typifying, and assessing flaws and age-related degradation in nuclear power plant containments.
2010. Vol. 12, no 1
Nuclear power plants, Containments, inspection, Quantitative Acoustic Emission Non- Destructive Inspection method