  Runaway electron loads onto material structures are a major concern for
future large tokamaks due to the efficient avalanching at high plasma currents.
Here, we perform predictive studies using the JOREK code for a plausible plasma
configuration in the European DEMO fusion power plant with focus on a
pessimistic scenario in which a multi mega-ampere runaway electron beam is
formed. The work first comprises axisymmetric predictions of runaway electron
beam formation in a mitigated scenario and of the simultaneous vertical motion
of the beam due to loss of position control. The subsequent runaway electron
beam termination triggered by a burst of MHD activity during the course of the
vertical motion is then simulated in 3D with the runaway electron fluid
self-consistently coupled to the MHD modes. Finally, the resulting deposition
pattern of the runaway electrons onto wall structures is calculated with a
relativistic test particle approach. This way, the suitability of a possible
sacrificial limiter concept for the protection of first wall components is
assessed.
