ITER STR Feeder performance analysis under working and accidental scenarios

The ITER Structure Cooling Feeder system takes the responsibility of cooling the coil case, it distributes around the coils and has complicated geometry; the piping delivers supercritical helium and shrinks a lot compared to the room temperature status, which will bring high thermal stress; when the coils quench, high pressure of warm helium will flood from the case to the cryo-distribution at the other end of the Feeder, and the vibration may harm the piping; another threat is the earthquake, the long and fragile structure of the Feeder will suffer the acceleration in all directions. A number of analyses are performed to check and optimize the Feeder design, which are described in this paper.