[en] The report is the sixteenth in a series issued approximately every six months to report progress and results of site characterization activities being conducted to evaluate Yucca Mountain as a possible geologic repository for the disposal of spent nuclear fuel and high-level radioactive waste. This report highlights work started, in progress, and completed during the reporting period. In addition, this report documents and discusses changes to the Office of Civilian Radioactive Waste Management (OCRWM) Site Characterization Program (Program) resulting from the ongoing collection and evaluation of site information, systems analyses, development of repository and waste package designs, and results of performance assessment activities. Details on the activities summarized can be found in the numerous technical reports cited throughout the progress report. Yucca Mountain Site Characterization Project (Project) activities this period focused on implementing the near-term objectives of the revised Program Plan issued last period. Near-term objectives of the revised Program Plan include updating the US Department of Energy's (DOE) repository siting guidelines to be consistent with a more focused performance-driven program; supporting an assessment in 1998 of the viability of continuing with actions leading to the licensing of a repository; and if the site is suitable, submittal of a Secretarial site recommendation to the President in 2001 and license application the US Nuclear Regulatory Commission (NRC) in 2002. During this reporting period, the Project developed and baselined its long-range plan in December 1996. That revision reflected the detailed fiscal year (FY) 1997 work scope and funding plan previously baselined at the end of FY 1996. Site characterization activities have been focused to answer the major open technical issues and to support the viability assessment