To enable mitigation of deleterious effects from hydride on the mechan
ical behaviour of Excel alloy, Zr-3.5 wt.% Sn-0.8 wt.% Mo-0.8 wt.% Nb,
the behaviours of hydrogen and hydride in the alloy have been studied
. Properties of interest are the terminal solid solubility, diffusivit
y, heat of transport, stress reorientation, and the initiation and cra
ck growth of delayed hydride cracking. The results obtained are compar
ed with those of other zirconium-rich alloys, notably Zr-2.5 wt.% Nb.