Determination of the crack pattern of quenched zircaloy tubes

The quenching of LWR cladding is investigated in order to understand the behaviour of a LWR core during the injection of water in the course of a possible accident. A series of single tube tests is conducted in order to establish a data base providing information about the phenomena: oxide layer formation, cracking and hydrogen generation. Oxide layer formation and cracking after the experiments may be documented with a microscope and an image processing system. The hardware, the preparation methods and the software of this tube surface documentation system are described in the report. A number of tube surfaces have been examined. The class of penetrating cracks was found to be correlated with the oxide layer thickness. The density of these cracks was traced with programmed algorithms and by hand. The hand-generated crack nets are considered to be more realistic because interference from surface stains and different crack width are avoided by the human examiner. (orig.)SIGLEAvailable from TIB Hannover: ZA 5141(6013) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman