Study on In-Service Inspection of Nuclear Fuel Assembly Failure Using Ultrasonic Plate Wave

Area of Science:

• Nuclear Engineering
• Materials Science
• Non-Destructive Testing

Background:

• Nuclear fuel rods are sealed in zirconium alloy cladding for protection.
• Damage like thinning, corrosion, or cracking can lead to coolant ingress and fuel assembly failure.
• Current inspection methods face limitations in underwater, radioactive environments.

Purpose of the Study:

• To propose a novel inspection method for detecting nuclear fuel rod failures.
• To enable in-service inspection by identifying coolant presence within fuel rods.

Main Methods:

• Utilizing ultrasonic plate waves to detect coolant presence or absence inside fuel rods.
• Developing an inspection model and process algorithm for in-service applications.
• Establishing and analyzing the relationship between ultrasonic signals and scanning position.

Main Results:

• Ultrasound field simulations and experimental validation confirmed the method's effectiveness.
• The proposed technique successfully detected failed nuclear fuel rods within entire fuel assemblies.
• Inspection was effective even for internal rods and unaffected by the near-field region.

Conclusions:

• The novel ultrasonic plate wave method offers an effective solution for detecting nuclear fuel rod failures.
• This non-destructive technique addresses limitations of current methods in challenging nuclear environments.
• The method allows for reliable in-service inspection of fuel assemblies.