DOE recognized early that there are advantages in staging a repository development program; hence its request to National Research Council to perform the present study. Some of the attributes stressed by the committee as essential for Adaptive Staging are incorporated into the U.S. program; for example, stakeholders have access to a great amount of documentation and information.5 DOE has also been introducing other characteristics of Adaptive Staging into its program, the obvious examples being the increased emphasis on a potential pilot stage (see Appendix F, Section F.1.4), development of a safety case approach (see Section 5.1.1), and demonstration of the feasibility of waste retrieval (see Section 5.1.3).
DOE has not incorporated all attributes simultaneously, and therefore its approach remains essentially Linear (see Figure 5.1 and Section F.2 in Appendix F). This linearity is illustrated by the recurring tendency to propose unrealistically tight program schedules and by the lack of transparency in some decision processes. The major milestones in Figure 5.1 are, of course, important decisions, but these are not Decision Points because these milestones correspond mainly to regulatory licensing decisions. Adaptive Staging envisions many more Decision Points than decisions to apply for licenses. For example, there may be a long period of operations between receipt of the license to receive and emplace waste and pre-closure activities. This time period would be divided into several work stages of appropriate duration—a small number of years for each—separated by Decision Points, at which DOE would then evaluate new knowledge gained from operational experience, monitoring and research, and other information. With all of this information, DOE would update the safety case, as needed, and decide how to proceed.
As mentioned in Section 2.4, Adaptive Staging does not require program “stops” at each Decision Point. A Decision Point can be conducted in parallel with program operations. Decision Points can be folded into the schedule so that, if a problem arises, it can be addressed without disrupting the entire program.
An example of Linear approach in DOE’s current program is its view that reversibility is guaranteed because Congress can direct the abandonment of the Yucca Mountain site (Williams, 2002). The committee concludes that reversibility is not an inherent attribute of the DOE program; rather, DOE considers reversibility as something externally imposed. DOE has not, to date, demonstrated a commitment to transparency in its decision-making. For example, the decisions to adopt the titanium drip shield and to select C-22 alloy for the container occurred suddenly and with little external discussion. Further examples of Linearity in DOE’s approach are in given in Appendix F.
Like all national repository programs, the U.S. repository program must be implemented in a country-specific legal, institutional, and societal context. This context is shaped by several factors, including the following: