First analysis of remote handling maintenance procedure in the hot cell for the ITER ICH&CD antenna – RVTL replacement

Abstract This paper deals with a first analysis of the Remote Handling (RH) maintenance procedure for the replacement of Removable Vacuum Transmission Lines (RVTL) of the ICRH antenna Port Plug (PP). In the framework of the grant F4E-2009-GRT-026, CEA IRFM studied the maintenance in parallel with the design of the antenna provided by CCFE. The RVTL are 8 components of the ICRH antenna which form the interface between the matching system and the four port junction integrating the straps. A folded stub is attached to the principal line to ensure water cooling of the interspace. At the front and the rear of the RVTL are installed double RF windows that provide the first tritium barrier. In case of failure of the first window, all the RVTL have to be replaced. Due to the contamination and activation, the replacement must take place in the hot cell. The complete maintenance sequence is studied. It starts when the PP is in place in the Tokamak equatorial port, it continues with: the preparation in the port cell, transfer to the HC, cleaning, RVTL replacement, returns to the port cell. It finishes with reconnection to the port. The ITER requirements [1] and the hot cell constraints [2] are used to extract specifications for the RH tooling (for handling, cutting, welding, etc.). Each step is studied and suitable tools identified. For specific steps, mechanical concepts for dedicated tools are proposed. Furthermore, the critical steps identified are simulated to check the feasibility.