Nuclear Technology / Volume 177 / Number 2 / February 2012 / Pages 285-292
Technical Paper / Radiation Measurements and General Instrumentation
Speckle interferometry is an optical technique able to measure and to image displacement of surface. An original setup is used to investigate the measurement of a deformed cylinder as a feasibility study. This shape allows us to determine the capability of this technique to measure nuclear fuel rod cladding. Indeed, in a nuclear reactor, the fuel rod undergoes different physical phenomena that induce dimensional changes in the cladding. The aim of this study is to quantify the amplitude of local ridges appearing on the outer cladding surface due to the "hourglass shape" assumed by the pellets under irradiation.
Because of the environmental constraints imposed by testing, an optical measuring device will be used to experimentally characterize mechanical strain induced by the interaction between the cladding and the fuel pellets. The aim of this paper is to examine the experimental feasibility of speckle interferometry using model samples.
An experimental setup based on the speckle interferometry technique was therefore implemented to measure local deformation in nuclear fuel cladding. Different experiments on model samples have shown that this technique is well adapted to the measuring range, shape, and condition of the surface as well as the working distance.