The effects of stress, temperature and hydrogen content on hydride-induced crack growth in Zr-2.5 Pct Nb

Effect of processing on properties of thin walled calandria tubes for pressurised heavy water reactor

“…The reduction in the relative basal pole intensity in the HAZ of the weld in Route-1 could be due to effect of high temperature exposure during welding in this region. During welding the material in FZ and HAZ are The strain energy minimization in hydrided Zircaloy-4 materials orients the hydride plates normal nearly parallel to h0 0 0 1i direction [13]. Thus the orientation of hydrides strictly depends on the basal pole texture developed in the two routes.…”

Hydride-Related Degradation of SNF Cladding Under Repository Conditions

“…The potential for collecting hydrogen, concentrated hydride precipitation, and hydride blistering in the ID region is insignificant or negligible, because the temperature is higher than the OD region and, hence, the thermal driving force for hydrogen collection is either absent or negligible. Therefore, the conditions are similar to those of the isothermal simulation tests conducted in laboratory (Simpson and Puls 1979;Puls et al 1982;Shi and Puls 1996), and the conservative value of critical stress-intensity factor of e5.5 MPa-m'" (see Section 5.1) can be used to predict potential propagation of the incipient cracks.…”

“…Furthermore, test I conditions of most of these simplified accelerated studies of DHC are characterized by several other aspects, i.e., unirradiated hydrided specimens, Mode I compact-tension specimens, little or no residual stress in the specimens, negligible driving force for hydrogen diffusion due to temperature gradient, and short test duration (i.e., typically less than several days versus 10-20 years for DHC in CANDU pressure tubes, and long-term for SNF cladding in a waste repository). Based on laboratory studies of this type, a threshold stress-intensity factor KIH of 5.5-8.0 MPamln was reported for CANDU pressure tube materials (Simpson and Puls 1979;Puls et al 1982;Shi and Puls 1996).…”

Potential corrosion and degradation mechanisms of Zircaloy cladding on spent nuclear fuel in a tuff repository

“…Delayed failure due to hydriding has been However, a Zircaloy-2 pressure tube did fail recently (August Although reported in local newspapers in A series of papers deals with delayed hydride cracking (Puls et al, 1982;Hillner, 1982;Dutton, 1978;Dutton et al, 1977;Simpson and Puls, 1979;Simpson and Cann, 1979). which in turn requires hiqh stress intensity factors.…”