The newly refurbished articulated boom of JET’s remote handling system will save considerable time for the installation of the ITER-like wall during this summers’ shut down.

The forthcoming shutdown of the JET facility will see the implementation of a number of enhancements designed to improve its scientific and technical capabilities. These activities are cast within the “JET programme in support of ITER” aimed at providing ITER with answers needed to consolidate its design choices and to allow and plan its efficient exploitation. The installation of an ITER-like wall with beryllium and tungsten tiles in JET will be one of the central objectives of this shutdown. This will mean having to replace around 4,500 carbon tiles actually present in the machine. To perform the shutdown as efficient as possible, all the work will be done by Remote Handling. The final step in upgrading an articulated boom to further improve the efficiency was marked by an impressive presentation given by the Remote Handling Group.

On 23 February Bernhard Haist and colleagues from the JET Remote Handling Group proudly demonstrated picking up and moving of a component with the newly upgraded articulated boom. This proof of principle was the final step in the several year-long process of extending an already existing boom and bringing it to readiness for the challenging tasks ahead. The rationale for opting for the extension of this boom has been the dramatic time saving (up to 30 percent) resulting from using two booms with nigh equal space coverage capability. To gain access to the inside of the JET torus, two of the eight main horizontal ports are reserved for Remote Handling. Both booms are hyperredundant multi-joint devices to allow them to “snake” their way through the narrow ports and around the torus. The upgraded boom will work in parallel with the other one to transfer components and tools between storage facilities outside the torus and the workplace within the torus.

Shutdown means a planned refurbishment or enhancement of the JET experimental reactor. In the recent years Remote Handling has come to play a central role in the planning and execution of the entire task. However, the work to prepare a Remote Handling shutdown starts several years before the actual shutdown. Already at the stage of conceptual design of the new components required to serve the purposes of the enhancement/refurbishment Remote Handling engineers are involved, to ensure that the design of all new components is compatible with Remote Handling tooling.

The JET Remote Handling system makes use of special manipulators to extend the operators own arms into the torus environment. These manipulators provide the operator with a sense of touch and feel and together with the associated Closed Circuit TV system create a sense of being inside the Torus. The net effect is to enable the human operator to do the task even though it is being done within a hostile environment.

One of the major activities during the coming shutdown will be the replacement of the entire first wall armour using Remote Handling. This project aims at installing an ITER-like wall and divertor in JET. ITER, the next generation fusion experiment, will use beryllium and tungsten as first wall materials within the torus. The combination of these metals has never been tested in a tokamak with a geometry and plasma parameters close to those of ITER. A key aim of the experiments with the ITER-like wall will be to develop regimes of operation for ITER compatible with beryllium and tungsten as first wall materials.

Final preparations are currently underway for the various tasks within the different projects to be completed during the shutdown. The projects also include, for instance, the upgrade of the neutral beam power and the installation of new diagnostics. With regard to Remote Handling, the preparations for the more challenging tasks have to be completed and verified in so-called mockup trials. The in-vessel tasks trials are performed using the real remote handling equipment commanded from the remote handling control room. The trials are conducted on a mock-up facility comprising three-quarters of the Torus in-vessel environment with both dummy components and also spare and prototype real components.

With the start of the shutdown the Remote Handling group at JET will be giving a final demonstration of their wide range of expertise which is unique within the fusion community and covers mechanical, electrical and electronic engineering, software, real time control, ergonomics, pneumatics, hydraulics, welding and cutting.

You will find more information, impressive pictures and stunning movies about Remote Handling on the EFDAJET web page.

Richard Kamendje & Petra Nieckchen