Yucca Mountain - Nye County, Nev.
The Exploratory Studies Facility (ESF) was a high-profile construction project for the U.S. Department of Energy. The primary purpose of this project was to determine the suitability of the site for high-level nuclear waste. Awarded in 1993 under a series of yearly contracts, the Kiewit team was responsible for constructing 40,000 ft. of tunnel including the main bores, geological drifts, and scientific alcoves and chambers.
The majority of the ESF tunnel was driven with a 25-ft.-dia. Tunnel Boring Machine (TBM). A second TBM was used to drive a 16-ft.-dia. cross tunnel section. Roadheaders or controlled drill-and-blast methods were used for excavation of the drifts, alcoves and chambers. The excavated material was removed by a continuous horizontal conveyor dumping onto a 700-ft. overland conveyor. Ground support was through patterned rock bolts and steel sets as required. Other work included surface-based drilling, building erection, utilities, and a precast concrete operation.
The contract also called for construction services, technical support, design review, quality control and specification development. The construction activities were conducted in accordance with the requirements of the scientific community, not mining productivity goals. To achieve this, the field organization team was set up to respond to the needs of the scientific community on an immediate basis. All construction was performed to stringent Nuclear Quality Assurance and Control Standards.