POTENTIAL ROLE OF ACOUSTIC-EMISSION MICROSEISMICITY INVESTIGATIONS INTHE SITE CHARACTERIZATION AND PERFORMANCE MONITORING OF NUCLEAR WASTEREPOSITORIES

An experimental tunnel was excavated at the 420-m depth at Atomic Ener gy of Canada Limited's (AECL) Underground Research Laboratory (URL) to investigate rock mass response to excavation-induced stress changes. The results show how the development of excavation-induced damage can be monitored and characterized remotely and non-destructively by exami ning acoustic emission/microseismicity (AE/MS). Geological mapping, co nventional instrumentation and video camera monitoring were used to va lidate the seismic interpretation. In addition, we describe an AE/MS l aboratory test designed to study thermally-induced damage from emplace ment of a simulated nuclear waste container within the rock.