Daya Bay Nuclear Plant

For a major scientific research project in particle physics related to the Daya Bay Nuclear plant in China, the US Department of Energy (DOE) and the Chinese Institute of High Energy Physics (IHEP) launched a joint project to study the characteristics of antineutrinos — the interaction of mysterious energy particles radiating from the sun that pass through solid matter without resistance. Brookhaven National Laboratories here in the US initiated an investigation that resulted in the choice of Doerfer's Wheelift® transporter to handle sub-terrain movement of large test vessels that needed to move down and through tunnels deep in the mountains adjacent to the Daya Bay reactors.

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CHALLENGE: Daya Bay θ13 Reactor Neutrino Project cost containment drivers required an extremely reliable piece of equipment to safely and consistently transport material underground throughout "minimum" tunnel sizes.

SOLUTION: A diesel powered low profile eight axle Wheelift® Omni-directional Transporter rated for 130 metric tons (286,000 lb) payload (affectionately called the "Ox" in honor of the Chinese "year of the Ox"). Besides its ability to travel in much smaller tunnels than would otherwise be possible ( saving millions of dollars in tunneling costs), the scientific packages were extremely delicate and could not be tilted or jiggled while descending down into the tunnels. The Wheelift transporter delivered full measure on those critical points.

BENEFITS:

• Provided significant civil construction cost reduction allowing smaller tunnels and right angle intersections
  
• Provided routing and usage flexibility
• Reduced the construction schedule dramatically
• Eliminated construction of tunnel rail system
  
  

Wheelift Transporters

One of the most perplexing scientific questions today has to do with the matter we're made of. The big bang should have created equal amounts of matter and antimatter, and they should have annihilated each other completely. Yet today, the universe still contains plenty of matter while the antimatter has dwindled. Scientists believe that this puzzling phenomenon is tied to the properties of neutrino oscillation. While emitted in mass from the sun and stars, nuclear plants create antineutrinos that this project is studying in more controllable conditions.

The Wheelift transporter will not answer the perplexing scientific questions involved; however it has significantly reduced the project costs for moving the eight underground detectors throughout two miles of tunnels running through the solid granite mountains adjacent to the Daya Bay Reactors in southern China.

Described as "liquid onions," each neutrino detectors contains three layers. In the center is 20 tons of organic liquid scintillator that contains gadolinium, a heavy metal. Next is a layer of liquid scintillator without gadolinium. The outer layer uses mineral oil to act as shielding. This 100 metric ton "liquid onion" must be kept level and at tightly controlled g-forces at all times during movement.

Antineutrino Detector

The process begins with the Wheelift transporter being positioned underneath an Antineutrino Detector. Once in place, the transporter raises to make full contact with the detector. Once contact is established, the Transporter continues to raise — lifting the Antineutrino Detector in a controlled manner, while keeping the detector level at all times. With its precision fluid equalizing suspension, the transporter actually emulates the travel of being on precision ground rails, like that of a machine bed. The load being carried is totally isolated from variations in the travel surface.

The operator moves and controls the load using a wireless joystick controller to initiate Normal, Lateral, Diagonal and Rotate modes, utilizing the ability of full omni directional travel. During movement through the tunnels, the custom automatic guidance system provides steering by monitoring the granite walls of the tunnel. Manual control is maintained for the Transporter's speed and travel direction. For the equalizing suspension, the on-center rotation axles have interconnecting fluid lines that divide them into load sharing groups to assure that every wheel carries only its specific share of the load, regardless of variations, slopes, and irregularities in the tunnel surfaces. The transporter's load deck has a precision leveling system that assures the antineutrino detectors are held perfectly level at all times as the packages descend down the long slopes to reach the various test gallery levels. Just getting the antineutrino detectors into position initially isn't all. There are eight detectors which are periodically moved between galleries, "musical chairs" fashion, to allow the scientists to check and verify their data findings.

Wheelift Transporters and AGVs are manufactured in 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, and/or umbilical cord. Computerized all electric omni-directional drives are standard with individual axle ratings of 15, 20, or 30-ton.

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 500+ employees, Doerfer offers an array of engineering and manufacturing resources and is NQA-1 certified.

SUMMATION: This Daya Bay Nuclear reactor physics project to study neutrino oscillation is likely to be the forerunner into larger and more sophisticated projects such as the planned Homestake gold mine project in South Dakota.

TRADEMARKS

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.