Case Studies



Case Study # 13



Aircraft Assembly F35 (# 2)

Aircraft Flex Mfg. (# 1)

Alumnia Processing (# 4)

Copper Refining (# 7)

Copper Rolling Mill (# 14)

Heat Exchangers # (9)

Heavy Equipment (# 6)

Injection Molding (# 8)

Mining Truck Assembly (# 10)

Naval Shipyard (# 22)

Nuclear Nutrino (# 12)

Nuclear Spent Fuel (# 11)

Nuclear Yucca Mountain (# 13)

Precast Structures (# 5)

Robot-Flashjet (# 3)

Shipbuilding (# 15)

Transformer Assembly (# 16)


Nuclear Yucca Mountain

The Office of Civilian Radioactive Waste Management (OCRWM), with Bechtel SAIC Co. for the Yucca Mountain project identifies Wheelift as a viable transportation solution for sub-terrain disposal of spent nuclear fuel & radioactive waste.


Click on images for larger view and captions


Sub-terrain repository at Yucca Mountain


 Spent Fuel Package Placement


An electric Wheelift Transporter can move each loaded Waste Package down through the Bechtel designed Yucca Mountain repository's main access tunnel to branch emplacement tunnels. Once the Transporter arrives at the pre-assigned emplacement tunnel and the tunnel's isolation doors are opened, the transporter can negotiate sharp right angle turns into side drift emplacement tunnels. The transporter's shielded doors will next be opened and a retractable deck will move the waste package from the transporter. The ideal means of offload is for the transporter to be utilized in carrying not only spent fuel package, but the support structure it will set on in the drift. The transporter would simply lower the package onto a flat floor or elevation-prepared foot pads and then drive away. Or, A gantry could lift the waste package off the deck and deposit it in its designated position inside the tunnel. Before the repository is permanently closed, the overlapping and interlocking drip shields will be placed over the waste packages.

 Secure view

Self-loading Transporters

Underground, the Yucca Mountain project will have approximately 100 miles of tunnels and will hold 70,000 metric tons of waste. The gross vehicle weight for each transporter would be 300 ton, with 120 ton allocated to the waste package shielding. The self-loading transporters are typically designed for grades of 4% or more, therefore being fully capable of the maximum grade seen throughout the system of 2.6%. Hundreds of miles of tunneling costs can be dramatically reduced by eliminating the need for long radius turns into side emplacement tunnels, along with considerably smaller diameter tunnels in many cases, eliminating the need for the elaborate tunnel floors required for a rail system would save additional money. Wheelift transporter's fluid equalizing suspension tolerates considerable unevenness in the travel surface to the tune of plus or minus 4" over the length of the transporter's wheelbase.


 Yucca Mountain Repository Tunnels

Yucca Mountain project

In the Yucca Mountain project, underground power and communications would be provided by an overhead buss trolley at a nominal 480 volts (In addition to an onboard auxiliary power source). Outside the tunnel system, at the waste processing buildings, the transporter would be self-propelled with an onboard diesel generator. The transporter's "drive-anywhere" capability without being confined to regimented rail systems offers a degree of flexibility that can be found by no other means.


CHALLENGE: Provide an underground radiation shielded transporter system requiring no rails, steel guides, etc. that have to be left in place, which will be subject to 10,000+ years of various unknown disintegration processes.

SOLUTION: A fleet of fully shielded, radioactive hardened, 100% backup, electrically powered heavy capacity Wheelift® transporters.


  • Eliminates risk - no remaining infrastructure left in place
  • Allows multiple put-aways to happen simultaneously shortening the fill process
  • Accommodates right angle tunnel designs providing built in protection from gamma radiation "shine" from entombed packages.
  • Wireless remote operating capability
  • Significant reduction in capital outlay over a fixed rail design
  • Hundreds of millions of dollars in savings in tunneling costs

 Emplacement transporter on-board control system

The on-center rotation axle assemblies with their zone controlled fluid equalizing suspension have interconnecting fluid lines within the zones that let all the axles in the zone share fluid and fully maintain equalized loading as the transporters travel over undulating terrain. The computerized control assures that each zone is seeing only its share of the total load. In this system, every wheel carries only its designated portion of the load, regardless of variations, slopes, and irregularities in the tunnel surfaces.

 Uniload® wheel modules


The Wheelift Module provides high carrying capacity along with a degree of flexibility not attainable through other technologies. Wheelift Transporters and AGVs enable manufacturing flexibility with configurable work processes facilitating new design freedoms benefiting worldwide niche markets.

Wheelift Transporters and AGVs are manufactured in central Iowa and are custom engineered to application specific requirements. Chassis and fixtures are available with load capacities to 500+ tons and deck heights as low as 18.5". Power options include diesel, LP gas, battery, or umbilical cord. Computerized all electric omni-directional drives are standard with individual axle ratings of 15, 20, or 25-ton and expandable to much large capacity axles if warranted.

Wheelift® is a Doerfer Companies technology. Doerfer engineers and builds application specific manufacturing machinery and systems. Operating from four North American locations with over 700,000 sq. ft. and 700+ employees (250 of which are engineers), Doerfer offers expanded technical and manufacturing resources, is NQA-1 certified, and follows ISO 9001 standards.

SUMMATION: At this Bechtel project, adopting the concept of Wheelift Transporters for sub-terrain tunneling for storage of high radiation spent fuel can, among many other benefits, offer hundreds of millions of dollars savings in tunneling costs.



The following terms that are used through this website: Wheelift®, Uniload®, SynchroSteer®, StackAxle®, TrackAxle™ and OmniAxle are all trademarks that are exclusively licensed to Doerfer Companies.