The application of rock mechanics at nuclear waste repositories is a true multidisciplinary effort. A description and historical summary of the Waste Isolation Pilot Plant (WIPP) is presented. Rock mechanics programs at the WIPP are outlined, and the current rock mechanics modeling philosophy of the Westinghouse Waste Isolation Division is discussed.
The Waste Isolation Pilot Plant (WIPP) is located in Southeastern New Mexico about fifty kilometers east of Carlsbad. The WIPP was authorized by Congress in 1979 (Public Law 96-164) to provide a research and development facility to demonstrate the safe disposal of radioactive wastes resulting from the defense activities and programs of the United States exempted from regulation by the Nuclear Regulatory Commission. The WIPP is intended to receive, handle, and permanently dispose of transuranic (TRU) waste. To fulfill this mission, the U.S. Department of Energy (DOE) is constructing a full scale facility to demonstrate both technical and operational principles of the permanent isolation of transuranic waste. A variety of organizations are involved in the WIPP Project, including:
• The United States Department of Energy. The DOE is responsible for demonstrating whether defense-generated transuranic waste can be safely isolated in 225-million-year-old bedded salt formations located 655 meters below the earth's surface. The DOE's Carlsbad Area Office (CAO) manages the project.
• Sandia National Laboratories provides the research expertise to perform experiments and advise the DOE on scientific matters at the WIPP.
• Westinghouse Government and Environmental Services' Waste Isolation Division (WID) manages and operates the WIPP under contract with the DOE.
• The United States Environmental Protection Agency (EPA) is responsible for certifying whether radioactive and hazardous material disposal requirements are met.
• The state of New Mexico regulates the handling of hazardous materials and operations of the disposal facility.
• A variety of other agencies, committees, and panels at the federal, state, local, and private levels monitor progress at the WIPP and contribute to the project's development through regulation, review, and comment.
As is usual for undertakings of the magnitude of the WIPP, the project has passed through a long and somewhat complicated history. In 1955, the U. S. Atomic Energy Commission asked the National Academy of Sciences to study permanent disposal of radioactive wastes. After studying the issue, the Academy recommended disposal in salt deposits due to their low permeability and good containment properties. Initially a salt mine in Lyons, Kansas was selected as the potential site for a radioactive waste repository which was later abandoned. The salt formations of southeastern New Mexico were later identified as a potential site. These are certification of compliance with EPA regulations concerning underground nuclear waste disposal, issuance of a Resource Conservation and Recovery Act (RCRA) permit by the state of New Mexico, and a No Migration Variance Determination for the disposal phase from EPA. Current schedules call for completion of these steps in time to enable the DOE to declare the WIPP ready to receive waste by late 1997, with first waste receipt in April of 1998.
