Positioning parts weighing hundreds of metric tons with an accuracy to within 1/10th of a millimeter

Key figures

0,1
mm

tolerance for the positioning of items weighing over 800 metric tons

1250
t

weight of the largest ITER part lifted by a CNIM tool

10 000
t

of component parts of the assembly lifted using CNIM tools

ITER Tokamak, currently under construction at the Cadarache site in France, is the world’s largest experimental reactor designed to produce fusion power.

In December 2016, ITER chose CNIM to engineer, manufacture and install special tools for the assembly of the Tokamak’s external components. This five-year framework contract for Purpose Built Tools (PBT) includes various steps.

For the first part of the contract, CNIM designed nine types of special tools, some of which were capable of handling items 17-meters tall weighing 700 metric tons with a precision of about a tenth of a millimeter.

TFC pairs IT

Manutention complexe

L’un des outillages majeurs développé par CNIM au cours du contrat « Purpose Build Tool » est le Toroidal Field Coils Pairs in-pit Installation Tool (TFC pairs IT). C’est un système de manutention complexe conçu pour installer les bobines de champs toroïdales pesant environ 700 tonnes dans le puits du Tokamak.

Ces aimants supraconducteurs, également appelé TF Coils, assurent une fonction critique au sein d’ITER : ils sont responsables du confinement du plasma, chaud à 150 millions de degrés C°, à l’intérieur de la chambre à vide.

The TFC pairs IT is the most complex and largest systems of all the deliverables covered by the PBT contract. Based on an extremely complex kinematic sequence featuring 18 simultaneously controlled 700-bar hydraulic ram, it will move the TFC superconductors a few millimeters in three axes and ensure their precise positioning to within 1/10th of a millimeter. It will also perform the final adjustment of the Tokamak’s nine sectors*.

*A Tokamak sector mainly consists of portions of vacuum chamber, heat shielding and two TF coils.

 

This will be the only tool in the industry providing this level of performance. We have finished the design studies. The tool’s manufacture will be launched in spring 2019 in the CNIM workshops at  Seyne-sur-Mer and will last five months,

says Guillaume Ribot, manager of the PBT project at CNIM.

 

Manutention de la base du Cryostat

Other exceptionally large tools designed for ITER include a lifting beam system. This system notably installed ITER’s heaviest part, the base of the cryostat, weighing 1,250 metric tons. This handling system comprises four beams, two of them fitted with hydraulic rams which will balance the load. It handles the cryostat base and positions it in the pit very precisely.

CNIM successfully met the many challenges raised by handling such a massive structure inside the assembly building notabily a load that must be lifted over the Sub-Sector-Assembly-Tools (SSAT) at 25 m-height. (see picture on the right © ITER ORG)

More info on handling the base of the ITER cryostat

Cryostat Feed Through

Au total, 20 CTF seront positionnés grâce à cet outillage, dont 17 seront placés en position finale. Les 3 autres seront insérés une fois que la construction du cryostat sera plus avancée. CNIM a développé pour cela un support de stockage, qui devra notamment résister aux séismes durant la phase de transition.