The DTT device: Preliminary remote maintenance strategy

Highlights: • Preliminary remote maintenance strategy for the DTT device. • Requirements for the development of the DTT remote maintenance systems. • Multiple alternatives for the remote maintenance of DTT divertor cas- settes • Multiple alternatives for the remote maintenance of DTT rst wall modules (inboard and outboard modules) In this paper we show an overview of the preliminary strategy planned for remote maintenance of neutron–activated and contaminated components of DTT machine, in the 2019 reference configuration. The remote maintenance of such a complex machine has impact on different aspects of the DTT machine: layout of the tokamak hall, vacuum vessel and cryostat structures, in–vessel components. To date, the number and size of vacuum vessel ports as well as the segmentation and size of in–vessel mechanical components of DTT have been established by a compromise between operational and maintenance needs. An extensive multidisciplinary work has been done in deriving the requirements for the DTT remote maintenance strategy. Each vacuum vessel sector is divided into five ports: in the current configuration, the top and bottom divertor cassettes are expected to be removed, respectively, from four lower lateral ports and from four equatorial horizontal ports; the first wall modules at the inboard side are expected to be installed/removed from all the upper ports; the first wall modules at the outboard and upper sides are segmented such that they can be removed from four equatorial horizontal ports. The work describes the current strategies for divertor and first wall remote maintenance systems, as well as a first conceptual design of the remote maintenance equipment of DTT machine.