The Hanford Site near Richland, Washington has 177 underground waste tanks that store
approximately 253 million liters of radioactive waste from 50 years of plutonium production. To improve
the site’s ability to monitor for localized forms of corrosion that could occur in the waste tanks, a
program was started in 1995 to develop a new electrochemical noise based corrosion monitoring
system. Six systems have been installed and operated in double-shell tanks at Hanford over the last
ten years. Based on the performance of these systems, a new two-probe system was developed,
fabricated, and installed in late 2006. This paper summarizes the design of this system and presents
preliminary data following installation.