The JET experimental reactor undergoes a planned refurbishment period (called a shutdown) typically every 1 to 3 years. During this time plasma experiments are suspended, the torus is vented (i.e. the vacuum is ended) and brought to normal atmospheric pressure just above room temperature. This is the time when the Remote Handling equipment enters the torus to do planned refurbishment work.
However, the work to prepare a Remote Handling shutdown starts several years before then. First the plasma physicists think up a new series of fusion experiments and begin to design the new components required. Already at this stage the Remote Handling engineers are involved, to ensure that the design of all new components is compatible with Remote Handling tooling.
Then the Remote Handling design engineers at JET start to design tools and (if needed) robotic equipment such as dedicated end-effectors, to assist in the installation of the new torus components.
At the same time Remote Handling operation engineers work out strategies of how to best achieve certain installation tasks and develop the task logistics, procedures and computerised manoeuvres. The new work procedures are derived in a Virtual Reality simulation, and later tested and fine-tuned in a physical full-scale mockup facility, using the real robotic equipment and the real Remote Handling tools, but mostly using dummy components.