[en] Stress changes will be monitored in salt as part of facility-wide mechanical response monitoring and as part of several large-scale geochemical and thermomechanical tests. Of particular interest are the magnitudes of stresses resulting from repository activities such as excavation and thermal loading from emplaced waste, as well as time-dependent stress change associated with salt creep. This information affects various aspects of repository design and performance assessment, including: accuracy of predictive models and constitutive laws for salt used to evaluate long-term repository performance; external loads on the waste package; consolidation times for crushed salt backfill, both around the waste package and in the underground rooms, which in turn affect retrievability and long-term isolation capability; external loads on decommissioning seals, particularly those in the repository horizon; interpretation of results from other types of instruments, such as borehole extensometers; and maintenance requirements for underground openings during the operational phase of the repository. 4 refs., 8 figs., 1 tab