RICHLAND, Wash. — Recently, the Hanford Waste Treatment Plant, also known as the “Vit Plant,” received a specially designed trolley that will be used to safely and efficiently change out the High-Level Waste Facility melters. The 100-ton melters are central to the vitrification process and are designed for a five-year lifespan, after which they must be removed and replaced.
The carbon steel trolley, also known as a “bogie,” weighs 26 tons and measures 17 feet long by 17 feet wide. It stands only 2 feet tall and has a capacity of 360 tons, which exceeds the weight of a 110-ton spent melter. The additional weight capacity accommodates residual glass and a 250-ton protective steel container that houses the spent melter and is used for radiation shielding.
The trolley runs on six low-profile track rollers that are similar to those used for launching ships or relocating large structures. However, the rollers used for melters are even lower profile than those typically used to move extremely heavy objects in the construction industry.
“Designing a way to safely and efficiently replace the high-level waste melters was challenging due to their weight, as well as the tight overhead clearances in the melter areas,” said Joe St. Julian, area project manager for the facility. “For example, a standard wheel, or even a standard roller, could not fit into the less than three feet of space available and still carry the weight of the spent melter and steel container.”
To further ensure safety, the trolley moves no more than 2 feet per minute and can stop within a distance of 1/32 of an inch. It operates using 12 electric motors and can be controlled either manually or remotely.
“We are committed to ensuring every aspect of the Vit Plant will operate safely and as designed during operations,” said Gary Olsen, federal area project manager for the facility. “This includes the equipment and materials dedicated to the vitrification process and everything that supports it.”
The trolley was manufactured by S.A. Technology in Loveland, Colo.
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 Waste Treatment and Immobilization Plant, 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 Vit Plant 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.