Considerations of transient electromagnetic forces in structural behaviors for ITER shield blanket components

The structural designs of the ITER FW/shield blanket components take into account proper dissipation of the transient electromagnetic (EM) forces, and thus reduce the impact of those forces. In this paper we analyze how the blanket/electrical strap components react to EM forces and evaluate whether the design complies with the SDC-IC criteria under the envisioned fault conditions. Specifically, analyses were performed to evaluate the fatigue lifetime of the US proposed solid electric strap designs under a combined mechanical displacement and EM transient load. The stress analysis was performed using dynamic and time-independent static analysis. These results show that the EM forces tend to bend the strap away from its attachment points and lead to a large plastic strain, which results in a relatively short lifetime, and fails to meet ITER requirements. The study also shows that it is necessary for the analysis to take into account the time evolution of the EM force to correctly estimate the anticipated strain range. The views and opinions expressed herein do not necessarily reflect those of the ITER Organization.