Resolution of the long-term performance issues at the Waste Isolation Pilot Plant

The Waste Isolation Pilot Plant (WIPP) is a geological repository for dispo sal of U.S. defense transuranic radioactive waste. Built and operated by th e U.S. Department of Energy (DOE), it is located in the Permian age salt be ds in southeastern New Mexico at a depth of 655 m. Performance assessment f or the repository's compliance with the 10,000-year containment standards w as completed in 1996 and the U.S. Environmental Protection Agency (EPA) cer tified in 1998 that the repository meets compliance with the EPA standards 40 CFR 191 and 40 CFR 194. The Environmental Evaluation Group (EEG) review of the DOE's application for certification identified a number of issues. T hese related to the scenarios, conceptual models, and values of the input p arameters used in the calculations. It is expected that these issues will b e addressed and resolved during the first 5-year recertification process th at began with the first receipt of waste at WIPP on March 26, 1999, and sch eduled to be completed in March 2004.