Yucca Mountain Licensing Standard Options for Very Long Time Frames: Technical Bases for the Standard and Compliance Assessments

In the existing U.S. Environmental Protection Agency (EPA) and Nuclear Regulatory Commission (NRC) regulations governing the spent nuclear fuel and high-level radioactive waste site at Yucca Mountain, Nevada, the time period of compliance was set at 10,000 years. Recently, a Court ordered that EPA and NRC either revise the regulation on this topic to be "based upon and consistent with" recommendations made by a panel of the National Academy of Sciences, who recommended a time period of compliance out to as long as one million years, or seek congressional relief. This report summarizes the technical issues related to establishing a meaningful, reasonable, and implementable standard for such a long time period of compliance assuming no congressional action is taken. The report also makes a set of recommendations.