Nanoscale chemistry of Zircaloy-2 exposed to three and nine annual cycles of boiling water reactor operation — an atom probe tomography study
Journal article, 2022

Atom probe tomography was used in this work to study the metal close to the metal/oxide interface in the zirconium alloy Zircaloy-2 exposed to three and nine annual cycles of operation in a commercial boiling water reactor. The two exposure times correspond to before and after the onset of acceleration in corrosion, hydrogen pickup, and growth. The alloying elements Sn, Fe, Cr, and Ni were observed to be redistributed after exposure. After both three and nine cycles, clusters containing Fe and Cr and typically of a spheroidal shape with an approximate diameter of 5 nm were observed to be located in layers presumed to be layers of -loops. On average, the cluster number density was slightly higher after nine cycles, with larger and more Cr-rich clusters. However, there were large grain-to-grain variations, which were larger than the differences between the two exposure times. Ni was only occasionally observed in the clusters. Sn was observed to be slightly enriched in the Fe–Cr clusters, but the Sn concentration was higher between than inside the layers of clusters. After nine cycles, clusters of Sn were detected in regions that were depleted of Fe and Cr. Enrichment of Sn, Fe, and Ni at features that appeared to be -component loops was observed after nine cycles, whereas no such features were observed after three cycles. Enrichment of Sn and Fe, and small amounts of Cr and Ni, was observed at grain boundaries after both exposure times. After three cycles, a partially dissolved second phase particle of Zr(Fe,Cr)2 type that contained about ten times more Cr than Fe was observed.

Irradiation

Boiling water reactor

Zirconium alloys

Dislocation loops

Atom probe tomography

Clustering

Author

Johan Eriksson

Chalmers, Physics, Microstructure Physics

Gustav Sundell

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Pia Tejland

Studsvik

Hans-Olof Andrén

Chalmers, Physics, Microstructure Physics

Mattias Thuvander

Chalmers, Physics, Microstructure Physics

Journal of Nuclear Materials

0022-3115 (ISSN)

Vol. 561 153537

Areas of Advance

Energy

Materials Science

Subject Categories

Materials Chemistry

Infrastructure

Chalmers Materials Analysis Laboratory

DOI

10.1016/j.jnucmat.2022.153537

More information

Latest update

3/28/2022