[en] In 1979, six years after selecting the Delaware Basin as a potential disposal area, Congress authorized the U.S. Department of Energy to build the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico, as a Research and development facility for the safe management storage, and disposal of waste contaminated with transuranic radioisotopes. In 1998, 19 years after authorization and after site selection, the U.S. Environmental Protection Agency (EPA) certified that the WIPP disposal system complied with its regulations. The EPA's decision was primarily based on the results from a performance. assessment conducted in 1996, which is summarized in this special issue of Reliability Engineering and System Safety. This performance assessment was the culmination of four preliminary performance assessments conducted between 1989 and 1992. This paper provides a historical setting and context for how the performance of the deep geologic repository at the WIPP was analyzed. Also included is background on political forces acting on the project