# Zirconium

## Understanding the role of Fe, Cr and Ni in Zircaloy-2 with special focus on the role of Ni on hydrogen pickup

Ni as an alloying addition in Zircaloy leads to an increase in hydrogen pick-up fraction. Atomic scale simulations of tetragonal ZrO2, based on density functional theory, are used to identify a possible mechanism for this observation. First, defect …

## The effect of pressure on hydrogen solubility in Zircaloy-4

The effect of pressure on the room temperature solubility of hydrogen in Zircaloy-4 was examined using synchrotron X-ray diffraction on small ground flake samples in a diamond anvil cell at pressures up to 20.9 GPa. Different combinations of hydrogen …

## Iodine defect energies and equilibria in ${\\text{ZrO}_2}$

Incorporation energies and defect equilibria in monoclinic, tetragonal and cubic phases of ${\\text{ZrO}_2}$ are predicted, using density functional theory calculations, for iodine dopant concentrations between ${10^{-5}}$ and ${10^{-3}}$ atoms per …

## The impact of azimuthally asymmetric carbon deposition upon pellet-clad mechanical interaction in advanced gas reactor fuel

Cracked nuclear fuel pellets were modelled in the r-θ plane with an azimuthally varying clad surface temperature boundary condition using the PELICAN set of fuel performance models for the commercial finite element software, Abaqus. The temperature …

## The effect of Sn–VO defect clustering on Zr alloy corrosion

Density functional theory simulations were used to study Sn defect clusters in the oxide layer of Zr-alloys. Clustering was shown to play a key role in the accommodation of Sn in ${\\text{ZrO}\\_2}$, with the …

## The effect of Nb on the corrosion and hydrogen pick-up of Zr alloys

Zr-Nb alloys are known to perform better in corrosion and hydrogen pick-up than other Zr alloys but the mechanism by which this happens is not well understood. Atomistic simulations using density functional theory of both tetragonal and monoclinic …

## Discrete dislocation plasticity modeling of hydrides in zirconium under thermal cycling

Understanding the ratcheting effect of hydrogen and hydride accumulation in response to thermal cycling is important in establishing a failure criterion for zirconium alloy nuclear fuel cladding. We propose a simple discrete dislocation plasticity …

## First-principles calculation of the elastic dipole tensor of a point defect: Application to hydrogen in α-zirconium

The elastic dipole tensor is a fundamental quantity relating the elastic field and atomic structure of a point defect. We review three methods in the literature to calculate the dipole tensor and apply them to hydrogen in α-zirconium using density …

## In-situ digital image correlation for fracture analysis of oxides formed on zirconium alloys

Repeated breakdown of the protective oxide layer can be a key factor in the oxidation of zirconium alloys. Hence, accurate measurement of the oxide fracture strength is crucial for simulating the oxidation of these alloys. High resolution digital …

## From solid solution to cluster formation of Fe and Cr in alpha-Zr

To understand the mechanisms by which the re-solution of Fe and Cr additions increase the corrosion rate of irradiated Zr alloys, the solubility and clustering of Fe and Cr in model binary Zr alloys was investigated using a combination of …