Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8208780 | Applied Radiation and Isotopes | 2018 | 6 Pages |
Abstract
The abundance of 57Fe isotope in nuclear reactor core materials can be considerably enriched by neutron-capture 56Fe(n,γ) reactions. This is demonstrated using the sections of Zr-2.5 wt.%Nb pressure tubes removed from two CANDU* reactors. The tubes contained 0.11 and 0.04 wt% Fe and were irradiated for about 10 effective full power years (EFPY) up to ~1026 n/m2 fast neutron (E > 1 MeV) fluencies. The Mössbauer spectra of 57Fe in irradiated samples indicated up to 10 times larger areas than unirradiated off-cuts from the same pressure tubes. The observed effect is in accord with the values calculated for known thermal neutron-capture cross-sections and resonance capture integrals, neutron flux profiles and spectra, and times of irradiation. The build-up of 57Fe facilitated recording Mössbauer absorption spectra of alloys with minor amount of Fe down to ~ 400 ppm, despite intense background radiation emitted by samples. These findings can open new possibilities in post-irradiation studies of alloys used in nuclear reactors and in other objects subjected to large neutron fluencies.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Radiation
Authors
Jerzy A. Sawicki,