Isostatic Hot-Pressing Mechanism Maps for Pure and Natural Sodium Chloride: Applications to Nuclear Waste Isolation in Bedded and Domal Salt Formations.

摘要

The mechanical behavior of crushed rock salt is of interest to the WIPP Project because the mined WIPP salt is a candidate material for use as backfill around the waste packages and in the underground openings during and after the operational phase. It is anticipated that in response to the convergence of the mine openings, the crushed salt will compact sufficiently to serve as an effective component in WIPP seal systems. In this report, the model for isostatic hot-pressing is applied to the problem of compaction of both pure sodium chloride and natural (WIPP) salt to develop a model capable of predicting densification rates as a function of temperature and applied pressure. Calculations for pure dry salt suggest that under conditions in situ, the contribution to densification by diffusional processes is negligible; all compaction will occur by dislocation creep. Assuming then that compaction will occur only by dislocation processes, the model is extended to nominally dry, WIPP salt. Model predictions are shown to agree favorably with limited test data, and the kinds of laboratory tests that may be done to validate the model are discussed. 78 refs., 13 figs., 2 tabs. (ERA citation 14:026374)