The DTT device: Safety, fuelling and auxiliary system

•The assessment of the radiation fluxes, loads and radiation damage is crucial in the design of the DTT machine, as a significant neutron yield by D-D reactions is expected.•Concerning safety, an accurate shielding assessment is necessary to effectively the design DTT building.•Fuelling and pumping are crucial for plasma production but at the same time are relevant in the licensing assessment for a radiogenic device.•DTT is a superconductive long pulse devise that needs that most of the components inside the vacuum vessel are actively water cooled.•The cryostat plays an important role because it forms part of the secondary confinement barrier.