Visual inspection plays a key role in the safety of nuclear facilities. It allows for the assessment of equipment condition, the detection of potential anomalies, and the planning of maintenance operations. Conducted from the very first checks on critical components – reactors, steam generators, primary and secondary circuits, and containment systems – it directly helps limit radiological risks and ensures compliance with regulatory requirements.

Specific Challenges of the Nuclear Environment.

Inspections in this sector must account for several major constraints:

• Confined spaces: vessels, containment areas, technical galleries.
• Irradiated environments: brief interventions with limited exposure.
• Harsh conditions: low visibility, humidity, high temperatures.
• Restricted access: requiring remote cameras, robotic arms, or teleoperated probes.

Objectives of Visual Inspection.

The main goal is to verify the structural and functional integrity of critical components to prevent any failure that could compromise safety. The defects targeted include:

• Surface or internal cracks: caused by thermomechanical stress and extreme temperature gradients, especially in pressurized zones.
• Localized corrosion: stress corrosion cracking, pitting or intergranular corrosion, often found on alloys exposed to aggressive environments.
• Plastic deformation and delamination: which can weaken welds and composite materials.
• Microleaks: typically found at joints, fittings, or pressurized components, often linked to thermal fatigue or assembly defects.

Limitations and Challenges.

Visual inspection in nuclear environments faces several challenges:

• Accessibility: some critical areas are unreachable without robotic assistance.
• Radiation and heat: require specialized equipment and strict planning to limit human exposure.
• Partial detection: underlying defects (corrosion, internal cracks) may not be visible through direct inspection alone.

How Video Borescopes Enhance Nuclear Inspections.

Next-generation video borescopes help overcome these constraints while improving inspection quality and traceability:

• Reduced Radiation Exposure
  Long, remotely operated probes allow operators to avoid entering irradiated zones.
  
• Inspection of Confined Areas
  Articulating heads and flexible probes reach spaces inaccessible to human operators: vessels, exchangers, technical galleries.
  
• Efficiency in Harsh Environments
  Equipped with high-resolution sensors and powerful LED lighting, borescopes deliver clear images despite humidity, heat or poor lighting. Some models also help detect thermal anomalies due to overheating or cooling failures.
  
• Regulatory Traceability
  Built-in photo/video recording and editing features simplify the creation of detailed reports, essential for safety audits and regulatory communication.
  
• On-site Responsiveness
  Compact and portable, video borescopes can be deployed quickly for scheduled or corrective interventions, without the need for heavy equipment.

✅ Operational benefits.

• Faster technical decision-making.
• Improved coordination with engineering teams (EDF, Orano, Framatome…).
• Reduced maintenance downtime.

Conclusion.

As a key non-destructive testing method, visual inspection remains a cornerstone of nuclear maintenance. Its effectiveness depends on tools tailored to extreme environments. When combined with other techniques (ultrasound, radiography, eddy currents), it supports a comprehensive approach to safety and performance. With the help of video borescopes, inspection teams can act quickly, document findings accurately, and contribute to the overall safety of nuclear facilities—while minimizing risks to both personnel and the environment.