DTP2 on the move

4 Dec 2009 - Jim Palmer, ITER Remote Handling Section
Caption: Jim Palmer and David Hamilton (Remote Handling Section) together with Alex Martin (Internal Components Division) in the divertor region of the DTP2 facility.

With memories of the champagne inauguration in the distant past, and after several hard months of integration and system commissioning, the DTP2 team in Tampere, Finland is now firmly focused on operations.

DTP2 (Divertor Test Platform 2) is located on the premises of the VTT (the Technical Research Centre of Finland) and operated on behalf of the European Domestic Agency. Since delivery of the last DTP2 sub-systems in October 2008, the integration, commissioning and creation of all the control software has been carried out as a joint effort between VTT and the Technical University of Tampere's Institute of Hydraulics and Automation (IHA).

Within the last month, an important milestone was achieved through the demonstration that the prototype cassette multifunctional mover (CMM) can transport the second cassette radially through the vacuum vessel duct and move it toroidally to its final position, despite the very tight clearances of only a few centimeters between cassette and vacuum vessel structures (see this week's featured video).

Preliminary measurements indicate that the path repetition accuracy of the cassette during toroidal and radial motion are within 2 mm, which is impressive considering that the 9-tonne cassette is carried in a fully cantilevered fashion.

Because of the enormous loads involved, the need for a high degree of positional accuracy and the minimal operating space within the ITER Tokamak, the CMM demonstrator takes advantage of water hydraulics technology which has been an important R&D topic in IHA for many years. This, together with a good knowledge of virtual reality techniques, has allowed the DTP2 team to quickly pull together the wide array of engineering skills typical in the area of remote handling in response to the R&D needs of ITER.

The next phase of operations will involve the complex process of cassette grappling from its in-vessel position, mounting of a dexterous manipulator and tooling on the CMM, and gradual progression to fully remote operations from the DTP2 control room (with no direct operator views) to more closely replicate remote handling working conditions to be faced in ITER.