Performance of Ag-In-Cd in Pressurized Water Reactors

An alloy composed of 80% Ag, 15% In, and 5% Cd was selected for the first commercial pressurized water reactors on the basis of its attractive nuclear properties, ease of fabrication, and low relative cost. Representative samples of a nickel-plated Ag-In-Cd control rod from Yankee Core I showed that the plating had not protected the base metal from the reactor coolant. However, the alloy displayed good irradiation stability, as evidenced by only minor changes in dimensions, microstructure, and mechanical properties. Stainless steel clad Ag-In-Cd absorbers have performed well in several reactors, both as cruciform arrays of cylindrical rods and as clusters of rods arranged in concentric rings.