InterTest The Scope Blog in-service inspection methods & tools

As the need for clean and renewable energy continues to rise, the importance of maintaining the robustness and safety of nuclear power plants cannot be overstated. A key component of these preventive measures is routine in-service inspection (ISI). Remote visual inspection (RVI) tools and non-destructive testing (NDT) solutions are integral to the ISI process in the nuclear and power generation industry. The following article covers the common practices and inspection equipment used in nuclear power plants.

Overview of ISI

ISI forms an integral part of the safety and preventive maintenance protocols in nuclear power plants. These inspections help identify and evaluate any anomalies or degradation, enabling timely preventive repairs or mitigation measures. The frequency and specifics of inspections may vary depending on numerous variables such as the plant design, operating conditions, and regulatory requirements.

Types of ISI

Visual Inspections: The most basic ISI, visual inspections help identify any obvious, visible issues such as leaks, corrosion, or physical damage.

Corroded Pipe joint that requires visual inspection

Image: a corroded pipe joint that requires visual inspection.

Internal Surface Inspections: This primarily involves the examination of welds and other high-stress areas susceptible to fatigue and damage. Surface inspections are sometimes smaller on inside critical part internals. For example, an oribital weld on the inner diameter of a pipe would require a surface inspection.

Orbital Weld on inner Diameter of pipe requiring visual surface inspection

Image: an oribital weld on the inner diameter of a pipe that requires a surface inspection.

Volumetric Inspections: These in-depth inspections are conducted to detect flaws or changes within a material or component that are not visible on the surface. Examples include internal integrities of joint and orbital welds and pipes. These anomalies are critical to discover in volumetric inspection because they would not otherwise be found until component or structure failure occurs.

Example of pipe undergoing Volumetric testing NDT-InterTest

Image: A pipe joint undergoing NDT

Inspection Technology & Equipment

The technological advancements have revolutionized the way nuclear facility inspections are carried out. The following tools are some of the crucial pieces of equipment that prove useful in ISI:

Smart Devices with Cameras - Most nuclear power facilities do NOT allow the use of personal cellular smart devices on sites, but approved safe and smart devices that have workplace connectivity may be used.

rugged smart device

Image: rugged smart device

A photo or video of a larger, visible issue is useful documentation so long as the image has good resolution, exposure, and clarity. A good benchmark is at least a 12MP camera sensor that can capture still images and 1080p (full HD) video.

Specialized RVI Tools - There are a range of RVI tools that specialize in certain types of inspections that are critical for ISI. RVI tools include, but are not limited to, extendable pole cameras, rugged pan-tilt-zoom cameras, and video borescopes. These types of specialized vision equipment conduct visual inspections of hard-to-reach areas, like the XtendaCam HD AIR for inspecting building or equipment structures high off the ground level.

 XtendaCam HD AIR

Image: XtendaCam HD AIR for hard-to-reach structure inspections in ISI

Pan-tilt cameras, like the VISIOPROBE 45 mm Pan and Tilt Stainless Steel Camera, can be used to inspect large container or pipe internals. 

VISIOPROBE PTZ stainless steel camera

Image: VISIOPROBE Pan and Tilt Stainless Steel Camera 


Video Borescopes: Also considered RVI tools, video borescopes allow for internal surface inspections of components such as pipes and tanks. Their flexible and articulating abilities make for increased maneuverability and precision. Video borescopes, like the Yateks USA Video Borescopes, offer unique visual inspection of extremely hard to reach areas during ISI. 

Yateks B+ Portable Borescope

Image: Yateks B+ Portable Series Video Borescope


Non-Destructive Testing (NDT) equipment: NDT techniques are widely used to analyze the integrity of materials and structures without causing any damage. NDT sensors and probes use ultrasonic testing, radiographic testing, and magnetic particle testing methods among others.

ultrasonic probe system is an example of NDT equipment

Image: an ultrasonic probe system is an example of NDT equipment.

In-service inspections are crucial for ensuring the safe and efficient operation of nuclear power plants. With the right practices and cutting-edge inspection tools, nuclear power operators can maintain an exceptional safety track record, making nuclear energy a viable option in the quest to meet the world's burgeoning energy needs.

Stay tuned with InterTest for the latest updates and equipment requirements for nuclear plant inspections, or contact us to solve your remote vision application today.