High-level nuclear wastes at the Henford Site are stored underground in cmbon steel double-shell end single-shell tanks. The installation of a three-channel prototype corrosion monitoring system into double-shell tank 241-AZ-101 was completed in August 1996. A fidly operational eight-channel system based on the design and operation of the prototype was installed into doubleshell tank 241-AN-107 in September 1997. The 241-AN-107 system monitors fluctuations in corrosion current and potential (electrcchernical noise) occurring on eight electrode arrays immersed in the waste liquid and in the vapor space above the waste. The electrodes are designed to detect the onset of pitting and stress corrosion cracking should tank conditions change to allow these
phenomena to occur. This paper focuses on the design of the
241-AN-107 corrosion probe. Keywords: electrochemical noise, pitting, stress corrosion cracking, localized corrosiou nuclear waste tank corrosion, mild steel, nitrates, corrosion surveillance, and corrosion-monitoring.