A quality assurance program is required by the Nuclear Regulatory Commission (NRC) to ensure that the Department of Energy (DOE) can safely construct and operate a high-level radioactive waste repository. DOE is currently preparing an application to NRC for authorization to construct the repository. The quality assurance program includes procedures to assure NRC that the information DOE provides is verifiable and well documented. DOE will use the results of a computer simulation to demonstrate that the repository can be safely operated over the 10,000-year period required by the Environmental Protection Agency's health and safety standards. This testimony is based on ongoing and published GAO work. The testimony provides the history of DOE's actions to correct quality assurance problems, the status of DOE's efforts to improve the quality assurance program, and preliminary observations on the effect of quality assurance problems on DOE's ability to successfully meet its 2004 milestone for submitting an application to NRC requesting authorization to construct the repository.