AIRBORNE RELEASE FROM VITRIFIED HIGH LEVEL WASTE DUE TO SABOTAGE

A sabotage attack with a shaped charge to a transport and storage cask containing vitrified highlevel waste (HLW) could result in the generation of particulate radioactive matter from fractured glass in the cask interior and subsequently to an airborne release to the environment. This potential airborne source term has to be known for the assessment of radiological consequences. A series of small and real scale experiments on the effect of a conical shaped charge (CSC) attack onto non radioactive but chemically equivalent vitrified HLW mockups was performed under the project leadership of GRS in order to quantify the airborne release. The distribution of total mass released, as well as relevant chemical elements were measured as a function of the aerodynamic particle diameter. Glass aerosol particle and fragment size distributions from CSC impact onto the chemically doped glass targets show patterns generally obtained from brittle fracture upon transient energy input into brittle matter. They follow scaling laws allowing for the prediction of the release of waste material in various particle size ranges based on the measurement of the emitted total mass. The concentration of volatile elements such as for example cesium is found to be enriched in the respirable size range.