Corrosion Control Measures for Liquid Radioactive Waste Storage Tanks at the Savannah River Site

The Savannah River Site has stored radioactive wastes in large,underground, carbon steel tanks for approximately sixty years. Anassessment of potential degradation mechanisms determined thatthe tanks may be vulnerable to nitrate-induced pitting corrosionand stress-corrosion cracking. Controls on the solution chemistryand temperature of the wastes are in place to mitigate thesemechanisms. These controls are based upon a series of experimentsperformed using simulated waste solutions on materials ofconstruction used for the tanks. The technical bases and evolutionof these controls is presented in this paper.