Fracture toughness of zirconium hydride and its influence on the crack resistance of zirconium alloys

Spontaneous fracture of growing precipitates with large misfit strain

“…A somewhat more detailed model of zirconium and zirconium-hydride system, by Matvienko (2004), utilized a cohesive zone crack tip model where a fracture stress of the precipitates where incorporated as a reduction of the cohesive stress. The analysis predicts the fracture toughness and measured results, (Simpson and Cann 1979). Both the theoretical work and experiments show that the zirconium hydride is very brittle as fracture occurs at only a few MPa √ m. Well known classical work give exact solutions for swelling spherical, elliptic and cylindrical inclusions.…”

“…The assumption is not irrelevant considering that many precipitates are fragile and occasionally breaking at very low load, cf. Simpson and Cann (1979). Thus, a limit solution giving the largest possible self-grown crack is obtained under vanishing remote load.…”

Fracture Strength of Embedded Hydride Precipitates in Zirconium and its Alloys

“…These types of tests were subsequently continued by Puls and co-workers [14,36,37,44]. In a parallel approach, fracture tests on macroscopic samples of bulk solid hydride material consisting of a range of hydrogen compositions were carried out by Simpson and Cann [46] and Puls et al [38], repeating some of the initial studies carried out by Barraclough and Beevers [7]. Results of these studies are summarized in Chap.…”

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

“…3OO0C, but only 1 ppm at 20°C (Sawatzky and Wilkins, 1967;Simpson and Cann, 1979;Cann and Atrens, 1980). When the solubility is exceeded at any particular temperature, brittle hydrides precipitate.…”

“…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.…”