A coupled mechanical–chemical stability analysis for a low activity waste disposal facility at the Hanford site

The steel container and vitrified waste materials that comprise waste packages planned for subsurface disposal of low-activity wastes at Hanford are subject to corrosion processes that generate a net volumetric expansion. Stress state and deformation in an idealized disposal system were modeled as a function of expansion pressure. Potential expansion pressures from glass and steel corrosion product formation were estimated and compared with the computed critical inner pressures (Pc) required to induce mechanical instability. Even a moderate degree of steel corrosion was found to generate internal pressures significantly above Pc. However, a kinetics analysis suggests that between 270 and 2500 years would be required before the Pc is exceeded.