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Determination of residual stresses around blisters in Zr-2.5%Nb pressure tubes

Santisteban, Javier R.; Steuwer, Axel LU ; Domizzi, Gladys and Peel, Matthew J. (2009) In Powder Diffraction 24(2). p.72-76
Abstract
We have used synchrotron X-ray diffraction experiments to measure the strain field introduced by a hydride blister grown on a section of a pressure tube from a CANDU nuclear reactor. After charging the tube section with a homogeneous hydrogen concentration of 300 wt ppm, the blister was produced by creating a small cold spot on its surface (similar to 200 degrees C), while the bulk was kept at a temperature of 338 degrees C over a period of 1008 h. The blister studied here is ellipsoidal in shape, with its long axis along the tube axial direction. The experiments were performed on the wiggler beam line ID15 at the European Synchrotron Radiation Facility (ESRF) using a polychromatic beam of high-energy X-rays (60 to 300 keV). Unlike... (More)
We have used synchrotron X-ray diffraction experiments to measure the strain field introduced by a hydride blister grown on a section of a pressure tube from a CANDU nuclear reactor. After charging the tube section with a homogeneous hydrogen concentration of 300 wt ppm, the blister was produced by creating a small cold spot on its surface (similar to 200 degrees C), while the bulk was kept at a temperature of 338 degrees C over a period of 1008 h. The blister studied here is ellipsoidal in shape, with its long axis along the tube axial direction. The experiments were performed on the wiggler beam line ID15 at the European Synchrotron Radiation Facility (ESRF) using a polychromatic beam of high-energy X-rays (60 to 300 keV). Unlike conventional X-ray diffraction, in this mode the scattering angle is fixed and the diffracted beam is discriminated on the basis of the photon energy. The results show that the blister is composed by two crystallographic phases (delta-ZrH and alpha-Zr), with volume fractions varying with position. The maximum stresses appear at the blister-matrix interfaces. Near the tube outer surface, we found large compressive stresses of (-450 +/- 90) MPa along the blister long axis, and tensile stresses (+320 +/- 90) MPa along the tube hoop direction. The main uncertainty in these stresses results from the uncertainty in the elastic constants of the hydride phase. Large strains and broad peaks were observed for this phase, which were explained by a rather low Young's modulus (35 GPa) for the hydride. The results are compared with finite element simulations found in the literature. (C) 2009 International Centre for Diffraction Data. [DOI: 10.1154/1.3139056] (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
hydride blisters, zirconium hydride, pressure tubes, residual stresses
in
Powder Diffraction
volume
24
issue
2
pages
72 - 76
publisher
International Centre for Diffraction Data
external identifiers
  • wos:000267522500016
  • scopus:68149120394
ISSN
0885-7156
DOI
10.1154/1.3139056
language
English
LU publication?
yes
id
bb878b24-323f-4a5a-9079-3920c46f0dbe (old id 1462938)
date added to LUP
2009-08-18 16:46:25
date last changed
2017-06-04 04:13:25
@article{bb878b24-323f-4a5a-9079-3920c46f0dbe,
  abstract     = {We have used synchrotron X-ray diffraction experiments to measure the strain field introduced by a hydride blister grown on a section of a pressure tube from a CANDU nuclear reactor. After charging the tube section with a homogeneous hydrogen concentration of 300 wt ppm, the blister was produced by creating a small cold spot on its surface (similar to 200 degrees C), while the bulk was kept at a temperature of 338 degrees C over a period of 1008 h. The blister studied here is ellipsoidal in shape, with its long axis along the tube axial direction. The experiments were performed on the wiggler beam line ID15 at the European Synchrotron Radiation Facility (ESRF) using a polychromatic beam of high-energy X-rays (60 to 300 keV). Unlike conventional X-ray diffraction, in this mode the scattering angle is fixed and the diffracted beam is discriminated on the basis of the photon energy. The results show that the blister is composed by two crystallographic phases (delta-ZrH and alpha-Zr), with volume fractions varying with position. The maximum stresses appear at the blister-matrix interfaces. Near the tube outer surface, we found large compressive stresses of (-450 +/- 90) MPa along the blister long axis, and tensile stresses (+320 +/- 90) MPa along the tube hoop direction. The main uncertainty in these stresses results from the uncertainty in the elastic constants of the hydride phase. Large strains and broad peaks were observed for this phase, which were explained by a rather low Young's modulus (35 GPa) for the hydride. The results are compared with finite element simulations found in the literature. (C) 2009 International Centre for Diffraction Data. [DOI: 10.1154/1.3139056]},
  author       = {Santisteban, Javier R. and Steuwer, Axel and Domizzi, Gladys and Peel, Matthew J.},
  issn         = {0885-7156},
  keyword      = {hydride blisters,zirconium hydride,pressure tubes,residual stresses},
  language     = {eng},
  number       = {2},
  pages        = {72--76},
  publisher    = {International Centre for Diffraction Data},
  series       = {Powder Diffraction},
  title        = {Determination of residual stresses around blisters in Zr-2.5%Nb pressure tubes},
  url          = {http://dx.doi.org/10.1154/1.3139056},
  volume       = {24},
  year         = {2009},
}