Dust control at Yucca Mountain project.
Kissel-F; Jurani-R; Dresel-R; Reaux-C
Proceedings of the Eighth US Mine Ventilation Symposium, Rolla, Missouri, June 11-17, 1999. Rolla, Missouri: University of Missouri-Rolla Press, 1999 Jun; :203-208
This report describes actions taken to control silica dust at the Yucca Mountain Exploratory Studies Facility, a tunnel located in Southern Nevada that is part of a scientific program to determine site suitability for a potential nuclear waste repository. The rock is a volcanic tuff containing significant percentages of both quartz and cristobalite. Water use for dust control was limited because of scientific test requirements, and this limitation made dust control a difficult task. Results are reported for two drifts, called the Main Loop Drift and the Cross Drift. In the Main Loop Drift, dust surveys and tracer gas tests indicated that air leakage from the TBM head, the primary ventilation duct, and movement of the conveyor belt were all significant sources of dust. Conventional dust control approaches yielded no significant reductions in dust levels. A novel alternative was to install an air cleaning station on a rear deck of the TBM trailing gear. It filtered dust from the contaminated intake air and discharged clean air towards the front of the TBM. The practical effect was to produce dust levels below the exposure limit for all TBM locations except close to the head. In the Cross Drift, better ventilation and an extra set of dust seals on the TBM served to cut down the leakage of dust from the TBM cutter head. However, the conveyor belt was much dustier than the belt in the main loop drift. The problem originated with dirt on the bottom of the belt return side and muck spillage from the belt top side. Achieving lower dust levels in hard rock tunneling operations will require new approaches as well as a more meticulous application of existing technology. Planning for dust control will require specific means to deal with dust that leaks from the TBM head, dust that originates with leaky ventilation systems, and dust that comes from conveyor belts. Also, the application of water could be more efficient if automatic controls were used to adjust the water flow rate to the mining rate.
Tunneling; Tunnel-workers; Dust-control; Dust-control-equipment; Dust-analysis; Dust-exposure; Dust-inhalation; Dust-measurement; Dust-particles; Dust-sampling; Silica-dusts; Respirable-dust; Airborne-dusts; Airborne-particles; Quartz-dust; Statistical-analysis
Proceedings of the Eighth US Mine Ventilation Symposium, Rolla, Missouri, June 11-17, 1999