Wüest M. 51 Wykes M. 82 Yamaguchi M. 17 Ybarra G. 129 Yubero F ...

JUNE 27 TUESDAY MORNING
WS-18-TuM-OR.10 A NEW PROCEDURE AND DEVICE FOR THE STUDY OF HY-
DRIDING PROCESSES FROM THE INNER SURFACE OF NUCLEAR FUEL CLAD-
DINGS. M. Díaz a , J. S. Moya a , J. L. Sacedón a* a Instituto de Ciencia de Materiales de Madrid
(CSIC), Cantoblanco, Madrid-28049, Spain. B. Remartínez b , S. Pérez b . b TEMAT Iberdrola, Pº
Virgen del Puerto, Madrid-28005, Spain
A new method and UHV equipment 1,2 that allows the study of the hydriding process of fuel claddings
from the inner surface is described. The hydriding is performed by heating the cladding in an
ultra-high vacuum chamber while hydrogen flows inside the tube. The external H 2 partial pressure,
the tube electrical resistance and the power dissipated by the reaction are measured throughout the
process. These measurements at different hydriding stages are complemented with an optical microscopy
analysis of the claddings give insight into the main physical processes 1 . As a consequence a
description of the hydriding first stages is provided. The method allows the measurement of the incubation
and failure times and the total energy dissipated by the hydriding reaction. In addition, useful
information about the kinetics of the hydriding process is obtained from external H 2 partial pressure
vs hydride rim thickness plot
This method has been applied to test the durability and reliability against the hydriding reaction of
commercial fuel claddings of zirconium alloys with different compositions and thermal treatments.
An additional study of the variation of Vickers hardness and elastic modulus with the stoichiometry
and thickness of the zirconium hydride rim formed inside this type of claddings has been carried out
by nanoindentation and XRD measurements. From these results it is possible to obtain some conclusions
about the mechanical stress distribution induced by the hydriding process and its influence in
the failure of these industrial elements.
1 Patent No.: US 6,873,672 B2
1 Patent No.: WO 2005/076286 A1
1
J. L. Sacedón, M. Díaz, J. S. Moya, B. Remartínez, J. Izquierdo, Journal of Nuclear Materials, 327 (2004) 11-18.
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