Europe delivers equipment for ITER’s cold vacuum circuit

When ITER starts to operate, cryogenic liquids will flow around it through a long network of pipes and valves. Like arteries pumping oxygen throughout a body, the cryodistribution system will deliver cold helium to some of the main ‘organs’ of the device. The cooldown is vital to activate the superconducting magnets and their thermal shields, as well as the cryopumps. Think of them as ‘vacuum cleaners’ surrounding the machine. Two of them will pump air out of the cryostat and six of them will pump fusion exhaust gases from the torus.

The cryopumps will work in turns to create the conditions needed for plasma, and to extract any waste during operations. Particles are sucked in the cryopumps by charcoal-coated panels, cooled with helium at 4K (-269 ºC). ITER’s high vacuum will rely on a well-synchronised supply of cryogenics for the torus and cryostat cryopumps.

To manage this complex cycle, Fusion for Energy (F4E) will provide a series of Instrumentation and Control (I&C) cabinets. Stacked in a booth the size of a telephone box, the equipment in the cabinets will allow to turn on and off the faucets along the cryodistribution lines, and monitor thousands of variables like pressure, temperature, valve position or mass flowrate.

After successful site acceptance tests, the first set was delivered to ITER towards at the end of last year. F4E worked together with GTD, who led the design of the cabinets and the software development. The manufacturing of the remaining cabinets is underway at the premises of Framatome and CEARA,  expected to be completed by the beginning of 2025.

The cabinets were the missing link to complete a first front-end cryopump distribution loop. With the first-of-a-kind models in Cadarache, ITER Organization can now run the integrated pre-commissioning tests to check the system’s performance. “Finally, the work of many teams and partners is coming together, under F4E’s coordination,” states Josep Benet, Project Manager for Cryodistribution in F4E. “The intricated lines and the strict parameters, running ITER’S vacuum cryodistribution is no easy task. We had the added difficulty of having to detach parts of the electronic systems, so that they are only exposed to compatible levels of radiation and electromagnetism”, he explains.

Europe has been a major contributor to this circuit, where cryogenics interact with ITER’s vacuum and fuel recycling systems. In recent years, F4E delivered the eight cold valve boxes connecting the cryopumps to the cold network and the warm regeneration box to extract the trapped particles from them. At present, the cryopumps, built by the RI – ALSYOM consortium, are near the end of manufacturing.