In response to a request from the U.S. Environmental Protection Agency (EPA), the National Research Council, through a Panel of the Committee on Radioactive Waste Management, studied the problems of verifying the satisfactory implementation of (i.e., compliance with) environmental radiation standards for deep geologic repositories for high-level radioactive wastes. This report contains the major conclusions and recommendations of the study. The report begins with a summary of the Panel's major conclusions and recommendations. Important background information on radioactive wastes--their origin, the amounts presently in existence, and possible permanent disposal of the wastes in deep geologic formations--is discussed in Chapter 1. The potential risks posed by these wastes is described in Chapter 2. The long-term environmental radiation standards that EPA is required to establish, and the feasibility and means of assuring compliance with such standards are examined in Chapter 3. The information that is required for purposes of assuring long-term compliance is described in Chapter 4, and the status and limitations of current knowledge are examined in Chapter 5.