Year: 2021
Type: article
Abstract: Zirconium alloys are used in safety–critical roles in the nuclear industry and their degradation due to ingress of hydrogen in service is a concern. In this work experimental evidence, supported by density functional theory modelling, shows that the α-Zr matrix surrounding second phase particles acts as a trapping site for hydrogen, which has not been previously reported in zirconium. This is unaccounted for in current models of hydrogen behaviour in Zr alloys and as such could impact development of these models. Zircaloy-2 and Zircaloy-4 samples were corroded at 350 °C in simulated pressurised water reactor coolant before being isotopically spiked with 2H2O in a second autoclave step. The distribution of 2H, Fe and Cr was characterised using nanoscale secondary ion mass spectrometry (NanoSIMS) and high-resolution energy dispersive X-ray spectroscopy. 2H− was found to be concentrated around second phase particles in the α-Zr lattice with peak hydrogen isotope ratios of 2H/1H = 0.018–0.082. DFT modelling confirms that the hydrogen thermodynamically favours sitting in the surrounding zirconium matrix rather than within the second phase particles. Knowledge of this trapping mechanism will inform the development of current understanding of zirconium alloy degradation through-life.
Source: Scientific Reports
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,990
Awards: G1015058392, Enhancing nuclear fuel efficiency through improved understanding of irradiation damage in zirconium cladding, G2158237762, G2647752202, G2703599441, G2996304452, G3146101534, G3305536412, G4320452524, Sir Henry Royce Institute - Manchester and NNL Equipment, Effect of Zr on the microstructure of corrosion resistant ODS steels, G4630886971, G4811893853, G504327055, G5424142534, G5432890613, EPSRC Centre for Doctoral Training in Materials for Demanding Environments, Sir Henry Royce Institute - Manchester Build, G6078643358, The Royce: Capitalising on the investment, G708391930, G7204459864, G7445816383, G7514479249, Sir Henry Royce InsStitute - recurrent grant, G87373762, MIDAS - Mechanistic understanding of Irradiation Damage in fuel Assemblies
OpenAlex ID: W3130083518