Stress state dependence of in-reactor creep and swelling. Part 2: Experimental results

Irradiation creep relaxation of void swelling-driven stresses

“…Results obtained on all but the swelling-driven-creep specimens were reported in a previous paper [1], which provides experimental details of materials, the irradiation vehicle design, creep and swelling measurement methods and temperature and flux distributions within the irradiation vehicle. Briefly, non-irradiated and previously irradiated stainless steel tubing sections, having the chemical composition shown in Table 2, were used to manufacture the swelling driven creep assemblies shown in Fig.…”

“…The radial positions (in inches) are measured relative to the test vehicle centerline. Also shown in Table 3 are pre-and re-irradiation conditions for seven specimens that were stressed uniaxially under axial load as previously reported in [1]. Results obtained on these specimens are included here in Tables 3 and 4 for comparison to results obtained on the swelling-driven creep specimens.…”

“…In a recent paper, Hall and Flinn [1] reported results of an in-reactor multiaxial-creep and swelling experiment that was conducted ca. 1977-1979 to obtain data for development of the needed equations.…”

“…Using a continuum plasticity model that was developed and recently reported by Hall [2,3], Hall and Flinn [1] analyzed results of this experiment, and concluded that in the presence of significant swelling, stress-affected swelling and swelling-dependent creep each are functions of both deviatoric and hydrostatic invariants of stress. This means that isotropic swelling may be affected in a purely deviatoric stress state, such as that of a torsion spring, and that deviatoric creep may be enhanced in a multiaxial stress state having a large tensile isotropic (hydrostatic) stress component.…”

Modifications and applications of the mechanistic gaseous swelling model for UMo fuel

“…The only different treatment in this work is the omission of a volumetric factor in the expression of intergranular gas density for the recrystallized grain area. As for mechanical influence, evidence indicated that the hydrostatic pressure could affect the gas bubble swelling [11][12][13][14][15]. Ideally, UMo fuel meat is considered sealed by Al alloy cladding, allowing no fission gas release to free volume under normal operation.…”