On the development of a combined beam, sensitivity and measurement quality indicator for the neutron radiography of fuel pins

A radiographic quality indicator for nuclear fuel has been designed that combines the features of a beam purity indicator, a sensitivity indicator and a measurement indicator. This Combined Quality Indicator-Fuel (CQIF) consists of six-10 mm diameter by 4 mm long fuel pellets contained in a zirconium tube. The pellet diameters give five thickness variations between adjacent diameters of between 1/2% to 4%. The gaps between the pellet diameters and the zirconium tube are controlled by aluminium shims of thickness 50 μm to 200 μm. Linear gaps are represented by five aluminium shims of thicknesses 12.5 μm to 200 μm, placed between the adjacent pellets. Spherical voids are represented by three shallow holes, from 0.5 mm to 2 mm diameter, each with the depth equal to its diameter. Cylindrical voids are represented by a second set of holes, 4 mm deep, which vary from 0.5 mm to 2 mm in diameter. (Auth.)