Direct Brine Release Calculations for the First Recertification of the

Waste Isolation Pilot Plant

2003 Radiochemistry Conference, Carlsbad, NM

Joshua S Stein, Sandia National Laboratories

The Waste Isolation Pilot Plant (WIPP), run by the US Department of Energy (DOE), is the only licensed, operational geologic repository in the world for transuranic nuclear waste generated by defense activities associated with nuclear weapons production. The first Compliance Recertification Application (CRA) is due to the EPA in 2004. An integral part of the CRA will be an updated Performance Assessment (PA). PA consists of a linked series of models and computer codes used to make a probabilistic assessment of the possible future states of the repository and the resulting radionuclide releases. Sandia National Laboratories, as the Scientific Advisor to the DOE, designs and runs the PA calculations. The PA for the CRA accounts for all changes in activities or assumptions since the original Compliance Certification Application (CCA). One of the release pathways considered by PA is the direct release of contaminated brine to the surface that might occur during a future drilling intrusion into the repository. A new set of direct brine release (DBR) calculations for the CRA incorporate changes to the "Repository Fluid Flow" conceptual model. These changes were presented to and accepted by the Salado Flow Peer Review panel in February 2003. The related "Direct Brine Releases" conceptual model was not modified. A description of the updated implementation of the DBR model will be discussed.