[en] This report gives the results of a preliminary stability analysis for the proposed Exploratory Shaft at Yucca Mountain, Nevada. This work was accomplished between April 1982 and October 1982 and incorporates the data, program goals, and design concepts of that period. These guiding factors may be different than those of the publishing date and may therefore produce different results than would be produced now. The analysis includes investigation of geotechnical features, in-situ stress states, and presence of faults in order to make a preliminary determination of shaft lining requirements. It was found that only portions of the shaft wall that have joints would require bolting and mesh reinforcement before lining, but the level of expected activity at the shaft bottom may necessitate more extensive reinforcement. A shaft lining thickness of 12 in. of 5000-psi concrete should be very adequate for the proposed shaft. 7 references, 18 figures, 5 tables