Year
2010
Abstract
The potential for internal corrosion of hermetically sealed stain- less steel containers of plutonium oxide is assumed to increase dramatically when an aqueous electrolyte phase of high chloride ion concentration forms in contact with an internal container surface. This potential for liquid formation will not be uniformly distributed over the inner surface, but rather will be influenced by contact with solid phase contained material, by total moisture content, by temperature, and by the hydration and solution ther- mochemical properties of the various phases in the heterogeneous material. With knowledge of the amount of contained moisture, the contained quantities of certain material phases with highest affinity for moisture, and the thermal profile of the container and contents, it is possible in principle to determine whether a liquid phase can form and if so, where in the container it will occur. This paper discusses the likely moisture distribution and liquid phase formation in existing packages based on temperature mea- surements, thermal models, thermodynamics of known phases, and measured water partial pressures.