The cryogenic requirements of ITER include a network of 4 km cryolines and 7 km warm lines together with 9 cryodistribution boxes. This network transfers cryogens from cryoplants of capacities 75 kW @ 4.5 K and 1 MW @ 80 K. To ensure development and testing as per the desired ITER standards, a dedicated Prototype Cryoline (PTCL) test facility exists at India laboratory and has been used to to test and qualify a scaled section of 29 m of prototype cryoline, consisting of six process pipes with an Outer Vacuum Jacket (OVJ) of 600 mm diameter and carrying helium at 4.5 K and at 80 K in the ITER-India laboratory at IPR. The layout included 90 degree and 160 degree bends, Tee elements, out of plane section and straight elements. It is 1:1 scale in diameter and 1:5 in length, as compared to the torus and cryostat cryolines for ITER.
The principal challenge in cryodistribution is the development of cold circulators having mass flow rate of the order 3 kg/s at 4.3 K and 0.15 MPa pressure head. The same has been developed and tested at a dedicated test facility at JAEA Japan. The tests have established all modes of operation and performance of the cold circulators at nominal and maximum operational conditions.