Hanford Waste Treatment Plant setting the tracks for large crane in Pretreatment Facility
Wed, October 13, 2010Suzanne Heaston, Bechtel National, Inc., (509) 371-2329, .(JavaScript must be enabled to view this email address)
Carrie Meyer, Department of Energy, (509) 372-0810, .(JavaScript must be enabled to view this email address)
Richland, Wash. — Crews at the Hanford Waste Treatment Plant, also known as the "Vit Plant," have begun installing two crane rails in the Pretreatment Facility, totaling more than 900 feet in length. Once installed, the rails will be used to hold and move a 30-ton capacity overhead crane the length of the facility's 400-foot hot cell, as well as in and out of a maintenance area. Complete with manipulator arm, hooks and hoists, the crane will be critical to maintaining the equipment housed in the hot cell.
When the Vit Plant is operational, the hot cell will be a highly radioactive area that will be accessed only by remote-handling equipment. It will be used to separate the high-level radioactive solid waste from the low-activity liquid waste.
"Setting the crane rails is part of our continued shift from civil construction activities—concrete and structural steel—to mechanical installations," Ty Troutman, area project manager for the facility said. "This shift is essential to completing facility construction in 2015 and reaching operations in 2019."
To install the steel rails, crews are lifting 40-foot sections and mounting them to steel beams protruding from the wall of the hot cell, more than 30 feet off the ground. The sections, which each weigh approximately 2,600 pounds, are then being welded together at the ends to create two smooth, continuous rails that run in parallel, the length of the hot cell.
The sections are being welded using a specialized process referred to as "thermite welding," one of two available techniques for welding rails. Thermite welding, which is widely used in the railroad industry, is the more mobile of the two techniques because it requires less and lighter-weight equipment.
The welding begins with creating a mold of the weld. The mold is then placed over the area to be welded and filled with an iron oxide and aluminum mixture. The mixture is then ignited, melted and cooled. Once cool, the mold is removed, and the weld is ground down between the rail sections to make it smooth and to ensure it meets quality inspection requirements.
"After the crane rails are installed, we will be able to lift the crane itself into place," Troutman said. "This is one of the final steps that must be completed before we can close the hot cell and progress construction above it." The crane will be lifted through the roof of the hot cell.
The rails will be completely installed later this fall. The crane is expected to arrive at the Vit Plant construction site this month, and it will be installed before the end of the year.
Currently, construction of the PT Facility is more than 30 percent complete. When complete, it will contain more than 113,000 cubic yards of concrete, nearly 17,000 tons of structural steel and 102 miles of piping.
Bechtel National, Inc. is designing and building the world’s largest radioactive waste treatment plant for the U.S. Department of Energy at the Hanford Site in southeastern Washington state. The $12.2 billion Waste Treatment and Immobilization Plant (WTP), also known as the "Vit Plant," will immobilize the radioactive liquid waste currently stored in 177 underground tanks using a process called "vitrification."
Vitrification involves blending the waste with molten glass and heating it to high temperatures. The mixture is then poured into stainless steel canisters. In this glass form, the waste is stable and impervious to the environment, and its radioactivity will dissipate over hundreds to thousands of years.
The WTP will cover 65 acres with four nuclear facilities — Pretreatment, Low-Activity Waste Vitrification, High-Level Waste Vitrification and Analytical Laboratory — as well as operations and maintenance buildings, utilities and office space.
Construction of the WTP began in 2001 and is now 56 percent complete. The plant will be operational in 2019.