Cleanup work progresses with pump removal at Hanford Tank Farms

The Department of Energy's Office of Environmental Management reports that workers at the Hanford Site, near Richland, Wash., have performed a technically complex operation to remove a large legacy mixer pump from Tank SY-101 in the 200 West Area. The removal allows for the future installation of tank waste retrieval equipment as part of the next phase of waste cleanup at the site.

A short video on the Hanford Site's YouTube channel shows aspects of the operation, including the pump being lifted out of the tank with a specially designed hydraulic lift system named Hercules.

Hanford Site Tank Farms: The 10-ton, 50-foot-long pump was installed in Tank SY-101 in 1993 to mix waste and reduce the buildup of hydrogen in the tank. The tank is one of just three double-shelled tanks in Hanford's 200 West Area-part of the Hanford Site Tank Farms, which contain approximately 56 million gallons of legacy nuclear waste from the site's plutonium production past.

There are 177 underground waste tanks at Hanford. Cleanup crews are required to remove at least 99 percent of the waste in every storage tank-or, as explained on the Hanford Site website, "at least as much waste as can be removed based on available technology." The waste removed from the tanks ultimately will be treated and stabilized at the Waste Treatment and Immobilization Plant, which is being constructed by Bechtel National. This facility, also known as the Vit Plant, will use a vitrification process in which waste is mixed and heated with glass-forming chemicals to immobilize it.

H2C systems: The challenging removal of the massive mixer pump required a great deal of planning and training. Workers with contractor Hanford Tank Waste Operations & Closure (H2C) first had to rehearse the removal and test equipment at an off-site mock-up in Richland. Then, once on-site, they used the H2C-designed Hercules system to free the pump in a controlled manner. Additional systems, such as high-pressure water jets, were used to clean, handle, and package the pump for disposal.

H2C field work supervisor Lisa Meredith commented on the pump removal, saying she felt "pretty ecstatic and . . . a lot of relief actually" that it went off so well. "A lot of work went into this, and we've been waiting for this day for a very long time."

H2C acting president and program manager Jeff Stevens observed that the pump-removal project "probably touched every department and every organization in the company. This truly was a group effort, and everybody should be very proud."

Andy Wiborg, director of the Hanford Field Office Tank Farm Programs Division, noted that the pump-removal operation "was important because it safely removed a large, specialized piece of equipment that had served its purpose and was standing in the way of future work in SY Farm. The team carried out this high-hazard work with strong radiological controls, careful planning, and disciplined execution."