Integration of regulations and science for HLW disposal

It is difficult to integrate the uncertain, experimental, and evolving nature of science with the specificity that characterizes regulations. The scientific community has criticized the EPA standard and the NRC implementing regulation for being overly prescriptive and inflexible. On the other hand, some interest groups see flexibility as permission to subjugate safety to schedule and cost considerations. A proposed integration is based on three ideas that arc specific to Yucca Mountain: (1) total containment of waste over long time-periods is a simple concept that is amenable to regulation, (2) partial mitigation of releases over long time-periods is a complex concept that is not readily amenable to regulation, and (3) retrievably placing waste in the unsaturated zone presents an opportunity for building assurance about containment with long-term confirmatory measurements. A complete safety argument can be presented to obtain a construction authorization, with uncertainty to be reduced and resolved prior to closure of repository. The focus of regulatory concern in the construction authorization phase of licensing would be on measurements that demonstrate the conceptual repository will prevent water from reaching the waste for a very long time. In this demonstration, large-scale long-term effects of waste heat on water would be treated theoretically. In the confirmatory period leading to closure, the regulatory focus would be on measurements that provide assurance that the repository as designed and built will indefinitely limit the contact of water with waste to negligible amounts. In this demonstration, large-scale long-term effects of waste heat on water would be driven by emplaced waste