One of the Most Hazardous Facilities at Hanford Comes Down Following Two Years of Safety Preparations

The demolition of a former nuclear laboratory marks significant progress in the U. S. Department of Energy (DOE)'s cleanup of highly contaminated buildings on the Hanford Site in Washington State. The laboratory was one of the most contaminated buildings at the site.

"The Department of Energy's goal is to remove any buildings that are no longer of service on the site,” said Al Farabee, DOE federal project director. "The safe demolition of the 209-East Critical Mass Laboratory is a key part of our strategy to significantly reduce long-term surveillance and maintenance costs and shrink the Hanford Site cleanup footprint to 75 square miles or less by 2015.”

Contractor CH2M HILL Plateau Remediation Company (CH2M HILL) safely demolished the 8,979-square-foot nuclear facility after nearly two years of preparations. CH2M HILL is responsible for demolition and remediation of facilities and waste sites across the Hanford Site. The laboratory is one of the most contaminated of the 118 buildings the contractor has removed since its contract began in 2008.

Preparations for demolishing the nuclear facility included developing and testing techniques for safely removing the facility's unique hazards and complex structures.

For example, to remove tanks once used for storing radioactive liquids at the laboratory, CH2M HILL employees developed a "cutting shroud” to protect workers and the environment from radioactive contamination while cutting up the tanks. Workers first practiced with the actual tools and techniques in a controlled "mock-up” environment before performing the task over the summer.

Built in 1960 during the height of the cold war, the 209-East Critical Mass Laboratory was one of three buildings of its type in the DOE Complex. The laboratory was run by Battelle for years to identify controls for criticalities, the term used for the dangerous condition when fissile material can sustain a reaction by itself. The facility housed experiments to test the criticality limits of uranium and plutonium solutions.

After operations at the facility ceased in the 1980s, the bulk of the radioactive material was removed, and tanks and pipelines were flushed. Before the building could be demolished, several hazards had to be removed, including:

• Large pieces of equipment used for handling materials, called glove boxes, contaminated with plutonium
• Highly radioactive tanks
• Two underground storage tanks beneath 2.5 feet of concrete
• A 3-foot thick vault door made of steel and reinforced concrete
• 5-foot-thick concrete walls
• Piping insulation containing asbestos

"Due to the history of the facility and the contamination of the remaining structure, additional controls were put in place to protect the environment and the workforce such as enhanced dust suppression, continuous perimeter air sampling and fixative applications,” said Kurt Kehler, CH2M HILL vice president of decommissioning and demolition. "Even with the recent inclement weather we faced during the demolition phase, the work force performed the work safely and efficiently.”

Due to the level of contamination, some of the waste removed from the facility was packaged for shipment to the Waste Isolation Pilot Plant in New Mexico. The building debris was disposed of at the Environmental Restoration Disposal Facility, Hanford's onsite, engineered landfill for low-level (radioactive) waste.