Thermographic Imaging of Nuclear Fuel Rods

A method has been demonstrated for imaging details of the fuel-cladding gap region in nuclear fuel rods. The method exploits the geometry-sensitive variation in fuel-cladding gap conductance. After rapid electric resistance heating of the cladding tube by discharge of a capacitor bank, those regions of cladding cool first that have narrow fuel-cladding gaps. The cladding surface temperature is recorded by an infrared camera with a cathode ray tube display . Potential is seen for the measurement technique as a research tool and as a receiving inspection method.