A decisionmaking process used by the U. S. Department of Energy (DOE) to assess the prospects for safe and secure permanent disposal of high-level radioactive waste in an excavated, underground facility, known as a geologic repository. This decisionmaking process is based on (1) specific design work on the critical elements of the repository and waste package, (2) a total system performance assessment that will describe the probable behaviour of the repository, (3) a plan and cost estimate for the work required to complete the licence application, and (4) an estimate of the costs to construct and operate the repository.