Analysis of ITER Magnet in Safety-Related Fault Condition—Case Study for PF3

The ITER magnet system contains stored energy, 41 GJ in the toroidal field system and up to ~10 GJ in the poloidal field (PF)/central solenoid system during plasma operation. A quench in the ITER magnet is regarded as a normal event, and the ITER magnet system has a redundant quench detection system and a reliable fast discharge system in order to achieve low probability of unmitigated quench and its propagation in the ITER magnet system. An electrical circuit model is developed by using a circuit simulator in order to estimate the arc power during fault conditions. The ANSYS 3-D model of the magnet, including electrical, thermal, and arcing inside the coil, is being constructed to analyze the thermal and electrical behavior of the magnet in an unmitigated quench. In this paper, thermal analyses of the fault condition related to the PF coil and impacts to the vacuum vessel are reported.