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 packa ges planned for subsurface disposal of low-activity wastes at Hanford are s ubject to corrosion processes that generate a net volumetric expansion. Str ess state and deformation in an idealized disposal system were modeled as a function of expansion pressure. Potential expansion pressures from glass a nd steel corrosion product formation were estimated and compared with the c omputed critical inner pressures (P-c) required to induce mechanical instab ility. Even a moderate degree of steel corrosion was found to generate inte rnal pressures significantly above Pc. However, a kinetics analysis suggest s that between 270 and 2500 years would be required before the P-c is excee ded. (C) 2001 Elsevier Science Ltd. All rights reserved.