Abstract
The Hanford Nuclear Site near Richland, WA, has approximately 56 million gallons of high-level radioactive waste stored in carbon steel underground tanks awaiting treatment. Central to the future cleanup of this site is the transportation of this waste through carbon steel and stainless steel pipes to a vitrification plant, enabling long term disposal. Failures due to corrosion put the environment and workers at risk; therefore, measures to protect the metal from corrosion and to monitor corrosion are a high priority. We present corrosion forensic analyses on pipeline sections, both carbon steel and stainless steel, that were in service for several years transporting millions of gallons of radioactive nuclear waste. The unique challenges that limit or modify the use of routine corrosion analysis techniques are discussed with approaches and solutions dealing with performing the work in abnormal and dangerous environments. By using a combination of ultrasonic transducer measurements for non-destructive pipe wall thickness measurements and scanning electron microscopy analysis of coupons cut from selected areas on the pipes, corrosion and erosion corrosion was characterized to determine lifetimes for the pipe sections, guiding engineering and maintenance activities on the Hanford Nuclear Site.