Design completed for cryostat auxiliary components

Under the terms of a Procurement Arrangement signed with the ITER Organization in 2011, the Indian Domestic Agency is supplying the 54 main stainless steel segments of the ITER cryostat, the giant "thermos" that will completely surround the tokamak, provide structural support, and ensure the thermal insulation of the superconducting magnets. The first segments arrived on site in December.

 

The scope of the procurement also covers two sub-systems—the torus cryopump housing and rectangular bellows. The design and technical specifications for both sub-systems have now advanced to the point where the dedicated technical annex of the Cryostat Procurement Arrangement—Annex B—is approved for the torus cryopump housing and being agreed for the rectangular bellows between the ITER Organization and Indian Domestic Agency.

 

These accomplishments, which open the way to procurement activities, would not have been possible without close collaboration, transparent communication and a strong common technical understanding between the ITER Organization, the Indian Domestic Agency and industry.

 

The torus cryopump housing has a number of functions. It supports the torus cryopumps, connects the cryopumps to the torus vacuum, and provides the volume to dilute hydrogen during the cryopump regeneration, maintaining confinement.

 

The rectangular bellows will be distributed among all port extensions on the three levels of the cryostat rectangular openings. Weighing between 1.8 tonnes and 5.9 tonnes each, their role is to seal the cryostat and to ensure the confinement of the vacuum between the cryostat and the port cells and also to compensate for relative displacements between the vacuum vessel, the cryostat, and the building. The development of the rectangular bellows was led by the ITER Organization in conjunction with a specialized bellows manufacturer. Extensive analysis work was performed in order to justify the structural integrity and qualification tests were conducted on several full-size prototypes in order to experimentally verify the compliance with the expansion joint project requirements.