[en] The leachability of borosilicate glass, is being studied. An important part of the program is the assessment of waste glass durability as a function of separate and synergistic effects of elements of the multibarrier isolation system. To accomplish this task, static and dynamic repository system tests are being conducted. In the static-repository tests, the effects of five potential repository rock types, including salt, basalt, shale, granite, and tuff, on the leachability of simulated waste glasses were evaluated as a function of the ratio of sample surface area to volume of leachant (SA/V). Next, the effects of simulated, rock-equilibrated water, and one actual groundwater composition on glass leaching were studied, and the results were compared to leaching by deionized water. Finally, the effects on glass leaching of the complete engineered system consisting of rock, canister materials, and backfill were assessed. Some of the conclusions are presented