F Reactor during operations in 1956.
F Reactor Area in July 2012.
A worker cuts and drains pipe at a waste site in F Area. The pipe contained sodium dichromate, which was used as an anti-corrosion agent.
An excavator scoops out a section of river outfall pipeline at an F Area waste site. The pipeline was used to discharge effluent into the Columbia River.
RICHLAND, Wash. – DOE contractors have completed cleanup of F Area, the first reactor area at the 586-square-mile Hanford site to be fully remediated.
F Reactor was the third of Hanford’s nine plutonium production reactors built along the Columbia River to produce plutonium for the nation’s defense program during World War II and the Cold War. The reactor operated from 1945 to 1965.
In 2003, F Reactor was placed in interim safe storage, a process known as “cocooning.” The reactor was torn down to little more than its radioactive core, sealed and reroofed to let radiation decay to more manageable levels over 75 years.
While six of Hanford’s reactors have been cocooned, F Area is the first to have all of its associated buildings and waste sites cleaned up. To complete the mission, contractors combined to demolish 112 facilities and remediate 88 waste sites, removing about 1.5 million tons of contaminated material from the two-square-mile site. The majority of the waste was packaged and transported to central Hanford’s Environmental Restoration Disposal Facility for permanent disposal.
“The cleanup of the F Reactor Area shows the tremendous progress workers are making along Hanford’s River Corridor,” said David Huizenga, Senior Advisor for Environmental Management. “The River Corridor is the complex’s largest environmental cleanup closure project. The F Area cleanup has substantially reduced risk to the Columbia River.”
Washington Closure Hanford, which manages the River Corridor Closure Project for Richland Operations Office, completed the final two phases of cleanup of F Area by remediating 55 waste sites and removing 646,000 tons of contaminated material. The River Corridor is a 220- square-mile area along the Columbia River.
“Many of the facilities, burial grounds, and waste sites associated with F Reactor were highly contaminated and required a safety conscious, highly skilled and dedicated workforce to complete the work,” Washington Closure President Carol Johnson said. “I am very proud of our
team. Congratulations to everyone involved who made the cleanup of the F Reactor Area a success.”
Some of the waste sites were large burial grounds containing contaminated soil and debris. Workers also found anomalies, including bottles, drums, high-pressure cylinders, spent nuclear fuel and high-dose irradiated items. Some of the anomalies required special methods to sample
and characterize the material, which called for additional hazard controls to ensure worker safety.
One waste site required workers to dig to groundwater, about 47 feet deep, to remove soil contaminated with chromium. Sodium dichromate, a chemical used as a corrosion inhibitor, was added to the river water to cool the reactor.
While cleanup of F Area is complete, workers will return to the site this fall to revegetate areas that were disturbed during cleanup. They will plant vegetation that is native to the Hanford site and has the best chance for survival.
What will remain at the site, aside from the cocooned reactor, is a concrete clearwell about the size of a football field that was used to hold filtered water for cooling the reactor. While preparing to demolish the below-ground structure in 2006, workers discovered the clearwell had been invaded by tiny bats. Today, the structure is home to about 6,000 Yuma bats that roost from March through October. It is the largest known maternity colony in eastern Washington.