Modeling of runaway electron induced damage on boron-nitride tiles in WEST

The runaway electron (RE) - induced damage on boron nitride (BN) tiles mounted on the inner bumpers of the WEST tokamak is modeled employing available empirical input and experimental constraints, concerning the post-mortem documentation of the damaged material topology and infra-red camera observations of the long-time decay of the surface temperature. A newly developed work-flow for the modeling of brittle failure due to RE impacts, recently validated against a controlled DIII-D experiment, is employed. Monte Carlo simulations of RE transport into BN provide volumetric heat source maps for finite-element simulations of the linear thermoelastic material response, while the brittle failure onset is predicted on the basis of the Rankine criterion. The physics of thermal stress driven failure and explosion are well captured by this model, which exhibits high sensitivity to RE impact parameters. Despite the accidental nature of the damage events, the workflow predicts failure in accordance with observations for realistic loading specifications expected in WEST disruptions. • Novel and successfully validated work-flow of RE-induced brittle failure is employed for modelling of WEST boron nitride tiles damage inflicted by REs in C9 campaign. • Despite the accidental nature of the damage events, main features of RE-PFC interaction are inferred from the empirical evidence. • The simulation results are consistent with the observations of cumulative material loss and the long-time decay of the tile surface temperature. • The physics of thermal stress driven failure and explosion are well captured by this model, which exhibits high sensitivity to RE impact parameters.