[en] This preliminary safety analysis addresses potential threats to the health and safety of workers and the general public due to both radiological and conventional hazards during the preclosure period, for a nuclear waste repository in basalt (NWRB). Activities evaluated as part of this study include construction of shafts and underground facilities; receiving, handling, emplacement, and retrieval of high level radioactive waste; and permanent closure of the underground openings. Analysis techniques used in this study were primarily qualitative, and consisted of identification of safety hazards, and analysis of consequences of potential accidents. This study was based on a conceptual system design description (CSDD) for the repository developed in 1983, and as such is not definitive, but rather provides a basis for a systematic approach to a more detailed safety analysis