Progress on Divertor Remote Handling
At the beginning of August, the Divertor Remote Handling (RH) Program achieved a major milestone with the completion of the factory acceptance tests for the prototype Cassette Multi-functional Mover (CMM). The CMM prototype will be the centre piece of a full scale remote handling test facility, called the Divertor Test Platform 2 (or DTP2 for short), being developed by the European Domestic Agency in Finland for the demonstration of the RH cassette replacement processes planned for ITER.
In ITER, the Cassette Mover will be required to transport divertor cassettes weighing 9 to10 tonnes along a complex trajectory in order to negotiate the path along the divertor access duct from the transfer cask to the plasma chamber. This process must be executed with pinpoint accuracy since the access route is such that delicate plasma facing elements of the 3.5m long x 2.5m high cassette have to pass within a few centimetres of the vacuum vessel surfaces.
The detailed design and manufacture of the Cassette Mover prototype was carried out by the Spanish company Telstar Tecnologia Mecanica S.L. at its works in Terrassa, near Barcelona. At the same time, in the opposite corner of Europe, Finnish engineers from VTT and Tampere University of Technology (members of the Finnish Fusion association Tekes) have been constructing a massive mock-up facility to replicate a section of the ITER divertor region. This 20m long, 65 tonne structure comprises elements manufactured by companies in Finland (TP-Konepajat Oy) and Luxembourg (Gradel S.A.).
In addition, the Finnish Team has been preparing the control and operational infrastructure for the Divertor Test Platform 2 facility. By taking advantage of today's virtual prototyping techniques, software engineers from Tampere University of Technology have been developing and testing the software necessary to control the CMM while it was still being designed and constructed in Spain. This was achieved by linking the control hardware (supplied by Procon Systems S.A., Spain) to a virtual model of the CMM which not only replicates its kinematics, but also its dynamic characteristics (like servo valve response, hydraulic fluid properties etc).
The next milestone for this project will be the arrival of the Cassette Mover prototype in Tampere, which is planned for during the coming month. At that point all these various Teststand elements, sourced throughout Europe, will be brought together as a whole and the job of carefully scrutinising the ITER divertor replacement approach can begin.
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