SYMPOSIA PAPER Published: 01 January 1994
STP23991S

Evolution of Microstructure in Zirconium Alloy Core Components of Nuclear Reactors during Service

Source

X-ray diffraction (XRD) and analytical electron microscopy (AEM) have been used to characterise microstructural and microchemical changes produced by neutron irradiation of Zr-2.5Nb, Zircaloy-2 and Zircaloy-4 nuclear reactor core components.

In many cases there is a clear relationship between the radiation damage microstructure and the physical properties of in-service core components. For example, the difference in delayed hydride cracking velocity between the inlet and outlet ends of Zr-2.5Nb pressure tubes in PHWR reactors can be directly correlated with variations in a-dislocation density and β-Zr phase decomposition. For the same tubes, the variation of fracture toughness has the same fluence dependence as dislocation loop density and, in addition, improvements in corrosion behaviour can be linked with decreases in the Nb concentration in the α-Zr matrix due to Nb precipitation during irradiation. For PWR and BWR reactors, the onset of “breakaway” growth in Zircaloy-4 guide tubes can be directly correlated with the appearance of basal plane dislocation loops in the microstructure.

Author Information

Griffiths, M
Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario
Chow, PCK
Atomic Energy of Canada Limited, Whiteshell Laboratories, Pinawa, Manitoba
Coleman, CE
Atomic Energy of Canada Ltd., Chalk River Laboratories, Chalk River, Ontario
Holt, RA
Atomic Energy of Canada Ltd., Chalk River Laboratories, Chalk River, Ontario
Sagat, S
Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario
Urbanic, VF
Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario
Price: $25.00
Contact Sales
Related
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Details
Developed by Committee: E10
Pages: 1077–1110
DOI: 10.1520/STP23991S
ISBN-EB: 978-0-8031-5262-5
ISBN-13: 978-0-8031-1488-3