Simulation and experimental validation of first wall ⁄ blanket assembly and maintenance for the next step fusion reactor

This paper is a review of the studies carried out at JRC Ispra on assembly and maintenance by remote handling of first wall and blanket, following the approach of coupling computer and experimental simulation. For this purpose, a CAD ⁄ CAE laboratory for computer simulation of teleoperation, TELEMAC, and an experimental heavy robotics facility, ROBERTINO, have been set up. This paper explains the reasons for using simulation equipment, subsidiary to the use of large prototype transporters, to contribute to the next step reactors design with reduced time and cost. Maintenance procedures can be simulated in a virtual environment, prior to their implementation on ROBERTINO, which allows experimental simulation on reduced or full scale simplified mock-ups. ROBERTINO can also be used for experimental validation of operations of general interest, performed by means of prototype tools. The paper reports the results of test campcugns carried out so far, in collaboration with ENEA, one concerning the simulation studies of whole blanket segments maintenance on reduced scale mockups and another concerning the experimental validation of pipes cutting⁄welding using bore tools (i.e. acting from inside the pipes). These results confirm the validity of the proposed approach. The paper shows how the JRC simulation equipment could be used to assess, on full size mock-ups, the feasibility of the blanket modules attachment to the back-plate, for any design concept following the evolution of the ITER project.