Corroborating Channel Gap Probe Measurements with an Optical Profiler

Abstract

As nuclear fuel plates get irradiated, their thicknesses change. How the fuel plate changes with irradiation is a significant parameter that is an important factor in predicting fuel performance in new fuel systems. The channel gap probe (CGP) is used to indirectly infer changes in fuel plate thicknesses by measuring the gaps between the fuel plates contained within capsules after each irradiation cycle. Independent measures should be used to corroborate salient measurements such as changes in fuel thickness which help ascertain fuel performance. The use of traditional metrological tools to validate CGP measurements are not practical due to the capsule geometry. The accuracy of the CGP inserted within a capsule has not been verified. Since there is no 'gold' standard measurement to verify CGP measurements, an optical profilometer has been used to corroborate the CGP measurements. The optical profilometer has been able to corroborate the capsules channel gaps to within 0.025 mm for both ends of the capsule. The optical profiler is also able to measure plate thickness that matched micrometer measurements to within 0.033 mm. The profilometer is also corroborated with the CGP measurements.