Authors:
VenkatRao Mallipudi
;
Stéphane Valance
and
Johannes Bertsch
Affiliation:
Paul Scherrer Institut, Switzerland
Keyword(s):
Dry storage, Zircaloy, Creep, Hydrogen, Hydride.
Related
Ontology
Subjects/Areas/Topics:
Application Domains
;
Energy and Power Systems
;
Materials
;
Mechanical Sciences: Fluid Dynamics, Solid Mechanics
;
Simulation and Modeling
;
Simulation Tools and Platforms
Abstract:
During dry storage of used nuclear fuel, creep is the most likely degradation mechanism for the zirconium alloy fuel cladding. The cladding integrity during dry storage depends on the internal fuel rod pressure, the temperature, the amount of oxidation, irradiation hardening and the content of hydrogen which has been taken up during in-reactor operation. In this paper, the effect of hydrogen on the creep behavior of zirconium alloy cladding material was investigated at the temperature of 400°C. Depending on temperature, hydrogen can be found in the material under the form of solid solution and/or precipitated hydride. To capture this phenomenon, a numerical mesoscale model of the hydrogenated material has been built using the Finite Element (FE) method. The numerical setup explicitly describes the hydrides as an inclusion in a hydrogenated matrix. The matrix creep behavior follows combined Norton-Bailey creep rules whereas the hydrides are considered to be elastic material. The creep
law was defined in FE Code ABAQUS using the user subroutine CREEP. The comparison of predicted creep behavior obtained from FE showed good agreement with the results reported in literature. Particularly, our model is able to seize the competition between the creep strain rate enhancement induced by hydrogen in solid solution and its reduction due to precipitated hydrogen.
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