Custom valves pave way for nuclear waste cleanup

By Control Engineering Staff September 2, 2005

A set of custom valve and valve automation products from Flowserve is playing a significant role in a major nuclear waste cleanup effort. The devices are being used for the control, isolation, and treatment of radioactive waste slurries at the Hanford Waste Treatment Project (WTP) in Washington State.

The site has one the of the largest concentrations of radioactive waste in the world, the result of 45 years of plutonium production for nuclear weapons from the Manhattan project through the Cold War. Some 53 million gal. of waste is stored there in 177 underground tanks. In December 2000, the U.S. Department of Energy’s Office of River Protection awarded Bechtel National Inc. a contract to design, construct, and commission the WTP to remediate the hazard. The $5.7 billion build-out is expected to take up to 10 years to complete.

Among the many needs of the waste treatment process were specialized valves for installation in containment vessels called “bulges.” Each bulge is roughly the size of a small swimming pool and designed to contain the pumps, valves, and piping required to transfer radioactive liquid waste slurry from existing storage tanks to a waste pretreatment building for processing.

Flowserve recommended high-performance plug valves for the slurries. Although it did not yet have a valve in its product line that would meet the contractor’s remote repair requirements, its Durco Mach 1 high-performance plug valve, which had not yet been released, could be modified for the needed remote operation and repair and met other requirements. Changes were made to design and build adjustable stainless steel extensions with double universal joints to enable remote operation and repair of the valves from outside the bulge containment vessels.

In addition, Flowserve modified another plug valve design to meet the need for jumper valves within the pretreatment building. Here, the challenge was to develop a “jack nut” feature that would enable remote release and replacement of the plug and sleeve cartridge assembly by a robot. Successfully meeting these requirements led to a multi-million order for the automated jumper valves.

Click here to download a pdf that describes all the details of this project.

—Jeanine Katzel, senior editor, Control Engineering,