Historical background on performance assessment for the Waste Isolation Pilot Plant

In 1979, six years after selecting the Delaware Basin as a potential dispos al area, Congress authorized the US 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 wast e contaminated with transuranic radioisotopes. In 1998, 19 years after auth orization and 25 years after site selection, the US Environmental protectio n Agency (EPA) certified that the WIPP disposal system complied with its re gulations. The EPA's decision was primarily based on the results from a per formance assessment conducted in 1996, which is summarized in this special issue of Reliability, Engineering and System Safety. This performance asses sment was the culmination of four preliminary performance assessments condu cted between 1989 and 1992. This paper provides a historical setting and co ntext for how the performance of the deep geologic repository at the WIPP w as analyzed. Also included is background on political forces acting on the project. Published by Elsevier Science Ltd.