title: Laser ultrasonics detection of an embedded crack in a composite spherical particle.
abstract: Laser ultrasonics was applied to the manufacturing control of the integrity (no failure) of coated spherical particles designed for High Temperature Reactors (HTR). This control is of major importance, since the coating of the nuclear fuel kernel is designed to prevent from the diffusion of fission products outside the particle during reactor operation. The SiC layer composing the coating is particularly important, since this layer must be an impenetrable barrier for fission products. The integrity of the SiC shell (no crack within the shell) can be assessed by the ultrasonic vibration spectrum of the HTR particle, which is significantly changed, compared to the reference spectrum of a defect-free particle. Spheroidal vibration modes of defect-free dummy particles with a zirconium dioxide (ZrO(2)) core were observed in the 2-5MHz range. A theoretical analysis is presented to account for the observed vibration spectra of defect-free or cracked HTR particles.
authors.affiliation: Laboratoire de Physique de l'Etat Condensé, UMR CNRS 6087, Université du Maine, Avenue Olivier Messiaen, 72085 LE MANS Cedex 9, France.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Amziane
authors.forename: Mohamed
authors.initials: M
authors.lastname: Amari
authors.forename: Denis
authors.initials: D
authors.lastname: Mounier
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Breteau
authors.forename: Nicolas
authors.initials: N
authors.lastname: Joly
authors.forename: Julien
authors.initials: J
authors.lastname: Banchet
authors.forename: David
authors.initials: D
authors.lastname: Tisseur
authors.forename: Vitalyi
authors.initials: V
authors.lastname: Gusev