With radioactive contamination saturating the 209-East Critical Mass Laboratory at the U.S. Dept. of Energy’s Hanford Nuclear Waste Site in southeast Washington, contractor CH2M Hill Plateau Remediation Co. needed new techniques to demolish the nearly 9,000-sq-ft concrete research facility built in 1960.
After completing nearly two years of planning, Mike Swartz, deputy project manager for decommissioning and demolition at the firm, a unit of CH2M Hill Cos., Englewood, Colo., says the task's biggest challenge was removing its 11 slab tanks, each 4 ft tall by 20 ft long with 3-in.-thick concrete walls. Due to high levels of contamination in the tanks that once contained radioactive liquids, crews developed a first-ever “cutting shroud” while they were cut into five segments before being packaged for disposal at the Waste Isolation Pilot Plant in New Mexico.