The Department of Energy (DOE) has prepared this report on the progress of site characterization activities at Yucca Mountain in southern Nevada. This report is the first of a series of reports that will hereafter be issued at intervals of approximately 6-months during site characterization. The DOE's plans for site characterization are described in the Site Characterization Plan (SCP) for the Yucca Mountain site. The SCP has been reviewed and commented on by the NRC, the State of Nevada, the affected units of local government, other interested parties, and the public. More detailed information on plans for site characterization is being presented in study plans for the various site characterization activities. This progress report presents short summaries of the status of site characterization activities and cites technical reports and research products that provide more detailed information on the activities. The report provides highlights of work started during the reporting period, work in progress, and work completed and documented during the reporting period. In addition, the report is the vehicle for discussing major changes, if any, to the DOE's site characterization program resulting from ongoing collection and evaluation of site information; the development of repository and waste-package designs; receipt of performance-assessment results; and changes, if any, that occur in response to external comments on the site characterization programs. 80 refs.

In accordance with the requirements of Section 113(b)(3) of the Nuclear Waste Policy Act of 1982 (Pub. L. No. 97-425), as amended, the US Department of Energy (DOE) has prepared this report on the progress of scientific investigation activities at Yucca Mountain in southern Nevada for October 1, 1989, through March 31, 1990. This report is the second of a series of reports that are issued at intervals of approximately six months during the period of scientific investigation. The progress report presents short summaries of the status of scientific investigation activities and cites technical reports and research products that provide more detailed information on the activities. The report provides highlights of work started during the reporting period, work in progress, and work completed and documented during the reporting period. In addition, the report is the vehicle for discussing major changes, if any, to the DOE's scientific investigation program. The progress report conveys information in a convenient summary form to be used for informational purposes only. It is not intended to be the mechanism for controlling and documenting technical or policy positions regarding changes in schedules or the technical program. Such changes are controlled through rigorous DOE change-control procedures. The progress report only describes such approval changes. 49 refs., 3 tabs.