Simulation of particle impact on protective coating of high-level waste storage packages

Integrity and survivability of high-level waste packages are critical for their storage and during their transport. Multi-layer, multi-component coatings composed of TiCN/ZrO₂-TiO₂-Al₂O₃/MoS₂ on the outer shield material can provide engineered barriers resistant to corrosion; radiation, diffusion, and thermal cycling effect that are also wear tolerant and mechanically robust. While waste packages are designed to survive some structural damage, potential coatings applied to future packages may be affected by the development of micro-cracks. In such a case neutrons and gamma rays might interact with the external coatings. In this research, particle impact with multi-layered, multi-component coatings is studied to assess the damage expected in the coatings if micro cracking would happen and heavy particles (neutrons) leak into the coatings. As a first step to investigate this scenario, the open source code SRIM has been used to perform the study using protons as a simulation of the heavy particle interaction. The simulation provides a tool to determine the optimal coating thickness to be manufactured in order to limit the coating surface damage to within minimum values.