The U.S. Department of Energy and contractor CH2M HILL Plateau Remediation Company are developing tools and techniques to remove highly radioactive material from underwater storage at the Hanford Site in southeast Washington state.
Approximately 35 cubic yards (27 cubic meters) of highly radioactive material, called sludge, is currently stored under 17 feet (5 meters) of water in a concrete basin adjacent to Hanford’s K West Reactor, one of nine former plutonium production reactors at the Hanford Site. Thirty-five cubic yards is approximately equal to the volume of a 20-foot (6-meter) long cargo shipping container. Sludge is a gray, silty substance created when irradiated reactor fuel rods stored in the basin began to deteriorate years ago after production activities stopped in the 1980s.
The sludge must be removed before the basin, now past its design life,can be demolished to both protect the Columbia River and enable decommissioning and interim safe storage of the K West Reactor.
CH2M HILL Plateau Remediation Company (CHPRC) is responsible for transferring the hazardous material to safe storage at the center of the Hanford Site.
Workers (Above) use long-reach tools to access engineered containers that contain sludge in the basin (Right).
Sludge is highly radioactive, dense and difficult to handle. Its unique consistency (silt-like, but with some constituents almost twice as dense as lead), along with high levels of radioactivity (approximately 30,000 curies of radioactivity), makes it a challenge to remove. Disturbing the sludge increases clouds in the basin water, which affects workers and their ability to perform underwater operations.
CHPRC engineers have utilized modern technology to invent tools and modify equipment to retrieve the sludge safely and efficiently. Workers train for sludge retrieval at the Hanford Site’s Maintenance and Storage Facility (MASF). In MASF, CHPRC constructed a full-size mockup of the reactor basin. The replica allows workers to test engineered processes and become experts in using the retrieval tools.
In 2016, CHPRC will continue training workers and testing sludge retrieval systems and equipment at the mockup facility before moving that equipment to the 100 K Reactor Area for installation and further testing.
Construction for the K West Annex building that will house sludge retrieval equipment.