Accuracy of dimension measurements from neutron radiographs of nuclear fuel pins

Paper to be presented on 8.9.76 to the Eight World Conference on Nondestructive Testing in Cannes, France. A review is given of different methods used fordimension measurements from neutron radiographs and results are presented of an investigation performed, using unirradiated fuel pins with calibrated UO, pellet diameters and fuel-to-clad gaps.

Projection microscope, three types of travelling microdensitometers and an electronic image analyzer were used to measure diameters and gaps from neutron radiographs produced at Risø DRl and Studsvik (Sweden) R2 reactors, using different brands of X-ray films and transfer technique with 0.1 mm Dy foil.