Exploratory Shaft Test Facility in basalt. Project B-314 preconceptual design report

The Basalt Waste Isolation Project (BWIP) has been chartered to assess the feasibility of disposing high-level nuclear waste in a repository within the Hanford Site and to identify and characterize a site for such a repository if feasibility is shown. The BWIP site-identification studies to date have shown that such storage appears to be feasible and have narrowed the site location to a current area of 70 mi2 within the Hanford Site. A site characterization plan is scheduled to be submitted to the US Nuclear Regulatory Commission (NRC) in May 1981 defining the plans to further reduce this potential area to that of a reference repository site. Subsequent to completion of the work outlined in that plan, a detailed site characterization plan will be submitted to the NRC in early 1982 defining the effort required to fully characterize the candidate site, so that it may be considered by DOE for banking and for comparison with sites in other geologic media. This banking decision requires characterization of the host rock. Thus, an Exploratory Shaft Test Facility (ESTF) is proposed to provide access to the candidate rock horizon as part of the characterization process. The proposed test facility to provide the in situ test space needed will consist of a drilled shaft and underground test chambers at an expected depth of 3700 ft. The finished shaft inside diameter will be 6 ft. Approximately 460 ft of chambers will be provided at the base of the shaft for testing space. The objectives of this preconceptual design effort were to: develop a feasible reference facility concept utilizing existing technology, provide the technical basis for functional design criteria (to be written later), assemble schedule and cost data for project planning, and recommend alternatives that should be considered in subsequent design