Alloy 22 (UNS N06022) is the candidate material for the corrosion barrier of the double-wall waste package (WP) for the disposal of high-Gel nuclear waste at the proposed Yucca Mountain repository. A probabilistic temperature-dependent general corrosion model for the WP outer barrier (WPOB) was developed based on the 5-year weight-loss measurements of Alloy 22 crevice samples. The 5-year corrosion rate distribution is represented by a Weibull distribution, with scale factors = 8.88, shape factor b = 1.62, and location factor l = 0. The temperature-dependence of the general corrosion rate was modeled using an Arrhenius relation. An activation energy of 25.91 {+-} 2.46 kJ/mol was determined from the corrosion rates obtained from the short-term polarization resistance data for Alloy 22 specimens tested for a wide range of sample configurations, metallurgical conditions, and exposure conditions (temperature and water chemistry).

Citation: Lee, J.H., Elavat, H.A. United States. Yucca Mountain Project. A Probabilistic Performance Assessment Model for General Corrosion of Alloy 22 for High Level Nuclear Waste Disposal Container. Washington, D.C.: Department of Energy, 2003.

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