Keeping it Secure

Departments - Technical Tips

How to leverage uniquely engineered transporters for the safe transportation and storage of nuclear spent fuel.

July 10, 2012
Elizabeth Engler Modic
1. Constellation Energy was looking for a secure way to handle, transport, and load spent fuel casks. Wheelift provided the solution through weatherized, diesel powered, autonomously operating, and self-propelled heavy-load transporters. 2. Transporting spent nuclear fuel requires extreme care for safety. Wheelift offers motion control flexibility and precision alignment for positioning canisters in the fuel building. The transporter is relatively flat with the ability to raise and lower up to 10" and level in any quadrant. 3. Control of Wheelift’s transporters can be from a distance, minimizing radiation dose. The transporters are custom engineered to application specific requirements and manufactured in central Iowa.

“Magical is the term we frequently hear when people experience the maneuverability and precision offered through Wheelift’s heavy load transporters,” explains Mel Terry, Wheelift systems applications concepts designer and an advisor to Doerfer Companies' Wheelift group.

Innovation is often the brainchild of frustration. That certainly has been the case for industry veteran Terry who began applying air bearings to heavy crane and rigging activities in the late 1960s. By the 1980s, he had patented and manufactured solutions designed for heavy rigging that were duly recognized by large manufacturing companies facing the challenges and time-consuming process of moving extremely heavy loads over uneven industrial floor conditions.

Fast forward a couple decades. Terry’s extensive testing, experimentation, and creativity in air bearing based systems received recognition in Europe, Asia, and throughout North America, for his work on a variety of applications.

“I ultimately set about the task of designing a wheel based technology that could provide very similar equalized loading and self-loading as well as all-directional steering capabilities across a number of load sharing axle assemblies,” Terry explains.

This effort resulted in a patentable equalizing suspension axle system ideally suited to carrying loads from 50 tons to 400 tons. In 2004, Terry joined the Doerfer Companies and helped create the Wheelift Systems Group, a rising leader in ultra-heavy capacity transporter systems that is revolutionizing operations across industries.

Leveraging the uniquely engineered transporters was Wheelift’s key to securing work with Constellation Energy in 2008.

Constellation Energy has a diversified fleet of nuclear facilities. Engineers at the company sought a secure means of handling, transporting, and loading spent fuel casks into horizontal storage modules at their Ginna Nuclear Plant in upstate New York.

Transporting spent nuclear fuel requires extreme care for safety. Positioning in the fuel building and at the ISFSI site requires motion control flexibility and precision alignment capability. The final design consisted of a weatherized, diesel powered, autonomously operating self-propelled transporter with additional axles than would normally be required, to assure operation on asphalt haul paths.

The project manager at Ginna explains, “We incorporated, for the first time, a self-propelled modular transporter from the Doerfer Company. The transporter is capable of handling our entire canister load, which is approximately 125 tons when fully loaded. We saw it as a significant upgrade to the existing self-leveling trailer and cab normally used in this kind of situation.

“We saw this as an upgrade for several reasons. First, from a safety standpoint, the modular transporter involves the ability of controlling from a distance from the transporter, as it is moving (minimizing radiation) dose to the employees. Also, it doesn’t contain mechanical linkage to drive the tires together as several transporters have (which have been problematic),” he adds. “The SPMT is able to level and adjust to very tight tolerances so that a separate leveling system is not required to align to the horizontal storage module. This in and of itself is a significant benefit over the existing system.”

Wheelift transporters are capable of handling up to 400 tons with superb maneuverability.

He points to additional benefits: The transporter is relatively flat with the ability to raise and lower up to 10" and level in any quadrant. It can travel transversely, straight, back, forward, and in circles.

When the cask transporter approaches an alley that runs between storage modules, rather than turn into the alley the transporter stops, rotates its axles 90°, and drives sideways down the alley. With only a foot or so of clearance, the maneuverability is revolutionary.

Transporting of the nuclear spent fuel, from where it is loaded to long-term storage modules, is approximately one-quarter mile. Although the transporter can rate for a capacity of 215 tons, in order to accommodate travel on the asphalt roads leading to the storage areas at some sites it was de-rated to 135 tons. The transporters have infinitely variable travel speed 0 to 110fpm.

“The Ginna nuclear plant has found that their spent fuel transporter has year round usage for a variety of heavy haul applications that would have required outside rigging companies, which they are now able to handle themselves,” Terry shares. “For example, the change out of a cooling pump motor is typical of the tasks our transporters are called on to perform.”

Terry goes on to say, “This is typical of every industrial application we have done to date. Invariably, the customers wind up using the transporters for a wide variety of tasking other than what they originally planned.”

According to the lead engineer at Exelon Corp.’s Oyster Creek nuclear facility, the engineers saw similar results, explaining that they needed to put the horizontal storage modules closer together due to space constraints.

“We found that Doerfer was able to maintain a schedule and cost right on budget. They were not late at all. Easy to deal with, more bang for the buck, lower dose, people stay further away, things happen quicker. You can plan your schedule right on the mark,” shares the engineer in a post-project interview.

One thing he really likes about Wheelift’s solution is that it only requires one operator, who can work remotely, with the ability to maneuver it to within sixty-fourth of an inch.

In his words, “[It is] easy to place on the spot, takes less time and less dose.”

In addition, the Wheelift transporters at Ginna and Oyster Creek have both a diesel and landline power system, so there is always a backup as well as the capability to operate in enclose areas using shore power.

“Wheelift's heavy load capabilities are applicable to virtually any process that requires moving heavy loads in tightly congested areas, particularly spaces that have inadequate headroom or enough capacity for crane coverage,” Terry says.

In a general sense, Wheelift is a solutions-based heavy load transport firm for diverse industries – from aerospace to shipbuilding and heavy turbine assembly to mining. They specialize in heavy load product assembly operation, using in-plant self-propelled modular transporters, of both manually operated and automatic guided vehicle configurations, providing cost savings for very large assembly operations that often require very precise movements.

“Wheelift’s new multi-axle Uniload equalizing suspension technology dramatically changes how industries can build and assemble their heavy products,” Terry states. “We can also build wheel assemblies into the bases of heavy precision tooling fixtures and scaffolding structures. Fluid suspension completely isolates the moving tools from undulations and other irregularities in plant floor surfaces. This is a functionality that is just not possible with conventional rails, wheels, rollers, or castered assemblies. Guaranteed equalize loading is the key to an entirely new era in heavy manufacturing.”

To view more about Wheelift search heavyagv on and hear directly those experienced with Wheelift’s transporters.


Waverly, IA