[en] This report presents the lessons learned from the preclosure performance assessment review (PAR) of the Draft Site Characterization Plan---Conceptual Design Report (SCP-CDR). The PAR analyzes the operations of the waste handling facilities as presented in the SCP-CDR against appropriate regulatory and design criteria. The PAR applies to the design presented in a working draft released in April, 1986. We will analyze the design presented in the SCP-CDR, the other is to test safety assessment methods and tools. This report addresses only the second of these objectives. The PAR analysis consists of assessments of offsite and occupational doses resulting from routine and accidental events during preclosure operations at the repository. The activities related to the PAR are divided into subject areas. These areas include (1) the description of repository facilities and operations, (2) the development of radioactive material inventories and radiation dose rates, (3) the development of radioactive material-release scenarios and source terms, (4) the assessment of offsite dose equivalents, and (5) the assessment of occupational radiation dose equivalents. This report contains a summary of the analyses in these fives areas and lists those preclosure analyses not performed as part of the PAR. Chapters detail the strengths and weaknesses of each analysis and include recommendations for improving the analyses. 15 refs., 1 fig., 1 tab