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H Reactor Cocooning Complete

10.20.2005

Cocooning has been completed at Hanford’s H Reactor, well ahead of the December 2005 Tri-Party Agreement milestone.

“Cocooning H Reactor marks another visible milestone in our efforts to clean up the Columbia River Corridor,” said Keith A. Klein, manager of the U.S. Department of Energy’s Richland Operations Office. “As work progresses, we are not only changing the skyline of the Hanford Site, but also continuing to drive down the risks to our workers, the community and the environment."

Called cocooning for short, the Reactor Interim Safe Storage Closure project involves demolishing each facility’s reactor building down to the four-foot-thick concrete shield walls surrounding the reactor core. All openings in the remaining structure are sealed and a new roof is installed.

Temperature and moisture sensors are used to remotely monitor conditions inside the sealed reactor building. Once every five years, workers will enter the structure to conduct inspections and make and needed repairs.

With the exception of installing a new roof, most of the cocooning work involves demolition. The reactor building footprint is reduced 80 percent during cocooning.

Construction on H Reactor began in 1948 and the reactor began operating in 1949. In 1964, President Johnson announced that H, DR and F reactors would be shut down. H Reactor ceased operation in 1965. Engineering work for cocooning began in 1999 and demolition began in December 2001.

H Reactor was the first of Hanford’s reactors where explosives were used to fracture the four-foot-thick concrete support structures. The process saved considerable time and reduces the risk to workers compared to traditional demolition techniques.

“This makes the fifth of nine reactors cocooned, which means beyond the half-way point with the job of placing Hanford’s surplus reactors in interim safe storage,” said Pat Pettiette, president of Washington Closure Hanford. Washington Closure manages the $1.9 billion, seven-year River Corridor Closure Project for DOE. The project includes cocooning the surplus plutonium production reactors located along the banks of the Columbia River.

C Reactor was the first facility to be cocooned, in 1998. DR Reactor was completed in 2002, F Reactor in 2003 and D Reactor in 2004. K East and K West reactors are scheduled to be done in 2011 and N Reactor in 2012. B Reactor is not scheduled pending a decision whether to cocoon or preserve it as an interpretive center.

• Completed in late-October 2005, H Reactor is the fifth of nine surplus plutonium production reactors to be cocooned at Hanford. C Reactor was completed in 1998, DR in 2002, F Reactor in 2003, and D Reactor in 2004. | High Resolution Photo (PDF)
• The H Reactor complex contained nearly 100 structures during its operating years (1949-1965). All of the ancillary facilities have been removed. The footprint of the H Reactor building, located in the bottom of the photograph, has been reduced 80 percent. The reactor will remain in interim safe storage for up to 75 years. | High Resolution Photo
• The front face of the H Reactor core looks much the same as one at its sister facility at Hanford, B Reactor (pictured), the world’s first full-scale nuclear reactor. | High Resolution Photo