Elimination of Crevice Corrosion of Pressure Tubes in CANDU Reactors: Effect of Bearing Pad Geometry

Abstract

Shallow corrosion marks have been observed in CANDU pressure tubes in locations of contact with fuel bearing pads. Such localized corrosion is avoided, if we reduce the heat flux towards the bearing surface of the pad to less than approximately 10% of the current value. Changes in bearing pad geometry can achieve such a reduction. The paper identifies geometries which eliminate crevice corrosion and describes the experimental and analytical method of defining them.