PERMANENT DISPOSAL OF NUCLEAR WASTE IN A DEEP GEOLOGIC REPOSITORY NEAR CARLSBAD, NM

Congress directed the US Department of Energy (DOE) to provide safe and permanent isolation of spent nuclear fuel and long-lived radioactive wastes. The DOE National Security and Military Applications of Nuclear Energy Authorization Act of 1980, authorized DOE to construct and operate WIPP as a geologic repository. The WIPP Land Withdrawal Act (LWA) of 1992 designated the Environmental Protection Agency (EPA) as the primary regulator, and established regulatory conditions and standards. The EPA established radiation protection standards and repository certification/recertification requirements that must be revisited every five years from the first receipt of waste. EPA certified that WIPP would meet these conditions and standards in May 1998 following review of the WIPP Compliance Certification Application. In March 1999, WIPP received the first shipment of TRU waste. In March of 2004 WIPP celebrated five years of safe and environmentally compliant operations and submitted documentation to re-certify WIPP.

The WIPP repository is located 48 kilometers east of Carlsbad, New Mexico, and consists of rooms and tunnels excavated in a bedded salt formation, 655 meters below the land surface. TRU waste contains alpha-emitting radionuclides with atomic numbers greater than that of uranium (92) and has a half-life greater than 20 years in concentrations greater than 100 nanocuries per gram of waste. Most TRU waste is contaminated sludge and refuse from production of nuclear weapons, research and development, decontamination and decommissioning, and environmental restoration programs.

The repository safety strategy relies on the physical properties of the salt beds to provide permanent isolation of the emplaced waste. For added containment assurance magnesium oxide (MgO) is emplaced with the waste to provide a chemical barrier and ensure minimal migration of radionuclides released.

Over the past five years of WIPP operations several technical and programmatic changes have taken place. The compliance recertification application incorporates information and analysis from the WIPP certification, reflects the last five years of operations and changes, and presents an updated performance assessment based on additional data gathered from continued scientific studies and performance confirmation monitoring.