High Resolution Neutron Radiography and Tomography of Hydrided Zircaloy-4 Cladding Materials

Abstract

Hydrogen content and distribution in Zircaloy-4 cladding samples with controlled hydrogen concentrations up to 1100 ppm were studied using neutron radiography and computed tomography. Hydrogen charging was performed in a process tube that was heated to facilitate hydrogen absorption by the metal. A correlation between the hydrogen concentration in the hydrided tubes and the neutron intensity was established, by which hydrogen content can be determined precisely in a small area (55 µm × 55 µm). Image analysis was also performed to evaluate the heating rate and its correlation with the hydrogen distribution through hydrided materials. In addition to image analysis, tomography experiments were performed on Zircaloy-4 tube samples to study the local hydrogen distribution. A 3D reconstruction of the tube was evaluated in which an uneven hydrogen distribution in the circumferential direction can be observed.

H2 PERMEATION BEHAVIOR OF Cr2AlC AND Ti2AlC MAX PHASE COATED ZIRCALOY-4 BY NEUTRON RADIOGRAPHY

“…Hydrogen uptake in zirconium alloy can be studied quantitatively by means of neutron imaging as shown by various groups [5][6][7][8]. First neutron radiography investigations of the hydrogen permeability through Ti 2 AlC and Cr 2 AlC MAX phase coatings on Zry-4 are described in this paper.…”

In Situ Neutron Radiography Investigations of Hydrogen Related Processes in Zirconium Alloys

“…Neutron imaging is a powerful tool for the investigation of hydrogen in zirconium alloys because the macroscopic total neutron cross section of hydrides can be up to 2500% compared with one of the typical zirconium alloys applied as cladding material. Several groups worldwide applied neutron imaging for such investigations during the last years [4][5][6][7][8][9][10][11][12][13][14]. However, only few investigations were performed in situ.…”