Over the past three decades, Sandia National Laboratories has developed and applied a performance assessment (PA) methodology that has informed key decisions concerning radioactive waste management. This experience includes not only the WIPP and Yucca Mountain projects, but also the initial development and demonstration of the U.S. Nuclear Regulatory Commission’s initial PA capabilities for both high-level and low-level wastes, the subseabed disposal program, PAs for wastes stored at the Idaho National Engineering Laboratory, and PAs for greater confinement disposal (GCD) boreholes at the Nevada Test Site, as well as multiple international collaborations. These efforts have produced a generic PA methodology for the evaluation of total waste management systems that has gained wide acceptance within the international community. More importantly, this methodology has been used as an effective management tool to evaluate different disposal designs and sites; inform development of regulatory requirements; identify, prioritize and guide research aimed at reducing uncertainties for objective estimations of risk; and support safety assessments. This PA methodology could be adapted to evaluate analyses of different strategies and options that might be proposed to manage the back-end of the nuclear fuel cycle. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000.