To be effective, Adaptive Staging should involve the implementer, the regulator, stakeholders, and the general public. It must be accepted and understood throughout the management system and by all stakeholders in terms that include consideration of technical, societal, political, institutional, as well as regulatory systems. Adoption of Adaptive Staging requires, on the part of all involved parties, a readiness to accept and address uncertainties and to acknowledge that unexpected outcomes and occurrences, which are inevitable, are also learning opportunities to improve the system.
Adaptive Staging can bring significant benefits, in the committee’s view, to the extent that it can be implemented credibly by the organizations charged with waste management. A fundamental frailty of waste management programs is the ambivalence of societies to undertake the irreversible steps required for final disposal of wastes, even though safe management is seen as essential everywhere. Adaptive Staging can be a way to build the trust needed to take these irreversible steps, but Adaptive Staging itself requires some trust as a precondition, if the long, slow process of learning is to be permitted to unfold in the face of surprises and changes in the guiding hypotheses (i.e., the safety case).
If Adaptive Staging is effective, program changes are likely to decrease with time, as ways are found by the learning-driven process to make the design more robust within a given budget, or more cost-effective for a given level of technology. That is, Adaptive Staging would be expected to converge to Linear Staging from a technological and natural scientific perspective, assuming a stable social environment. This trajectory will not be followed, of course, if unexpected events continue happening. It may be possible to develop and maintain a technical consensus on the likely performance of the repository system, so that the Adaptive process would, over time, build increasing public confidence in the behavior of the repository geology and engineered barriers.
It seems less likely that the social environment of the program can be similarly well defined. The repository is planned to be open for a time period several times as long as the time that has elapsed since the rise of the environmental movement. The social setting of nuclear energy changed with remarkable speed from postwar optimism to one in which dread became the dominant political and economic factor by the late 1970s. These changes occurred in less time than the economic lifetime of the power plants built for civilian purposes, being among the factors leading in some cases to large-scale stranding of expensive capital assets. The social context is historical; it has been and will continue to be path-dependent, so that both extrapolation from the past and causal predication will be unreliable for some time to come. Adaptive Staging not only affects the geologic repository but also has impacts on the entire radioactive waste management system, as described in the next chapter.