Prediction of Maximum Allowable Temperatures for Dry Storage of Zircaloy-Clad Spent Fuel in Inert Atmosphere

The internal pressurization creep of Zr alloys for spent-fuel dry storage feasibility

“…These maps are as accurate as the constants and parameters used in the various deformation models and indicate grain-boundary sliding (GBS) to be the rate-controlling mechanism at the inert dry storage (IDS) conditions. 4 However, the parameters used were apparently based on theoretical models. While GBS is a probable underlying deformation mechanism, no evidence exists for such a mechanism to be operative in Zircaloys, especially under internal pressurization (α = σ θ /σ z = 2, where σ θ and σ z are the hoop and axial stresses).…”

“…21 As pointed out by Chin, the LMP approach overpredicts the rupture life. 3,4,6,16 In addition, "extrapolation beyond the tested values of the parameters is . .…”

Waste Isolation Study

“…At most, up to about one percent of the SNF assemblies have stainless steel claddings and the defense HLW has no cladding but is contained in a glass log within a stainless steel canister. Work has been done to develop cladding degradation models as a result of creep rupture (Chin andGilbert 1989, Peehs andFleish 1986). A process model was developed and prelirmnary performance calculations were done in two recent studies (CRWMS M&O 1996b and1996d) that showed that cladding may provide a significant banier to radionuclide transport.…”

Total system performance assessment - 1995: An evaluation of the potential Yucca Mountain repository

“…Once spent fuel assemblies are placed inside the waste disposal container, the container is also filled with a similar inert environment before it is sealed off. Among various degradation modes of zircaloy cladding in an inert environment during storage and/or permanent disposal periods, creep rupture is the most dominant mechanism (Chin and Gilbert, 1989). Therefore, creep rupture of zircaloy cladding is considered the dominant degradation mode of intact fuel rods.…”