The fracture and aerosol release of impacted HLW-glasses due to accidental canister drops in a disposal site

Abstract For the disposal of HLW-canisters in a salt dome, two different accident scenarios have to be considered, canister drops in the reloading hall or in a borehole with drop heights of 10 m and 600 m, and reference drop velocities of 14 m/s and 80 m/s. The experimental program had two parts: • - Laboratory scale drop tests with bare and canistered waste glass probes (scale: 1:10) to obtain basic data. • - Full scale drop tests with inactive HLW-canisters, specified as planned for the German salt repository ( H = 1.335 m , O = 0.43 m , weight: 550 kg, canister: SST 1.4833, wall: 5 mm). The size distributions of the broken fines were measured by sieving and those of the filtered airborne particles by particle size analysis. The dominating parameter is the impact velocity (i.e. impact energy), further test parameters show no measurable influence, especially the canister influence on the fracture or aerosol release is negligible. Source terms, evaluated for the respirable fraction (particles with d m are between 2 × 10 −4 % for a 10 m drop and 0.1% for a 600 m borehole drop.