of Adaptive Staging on the security of any country. First, for countries whose national security depends on nuclear activities there must be a secured management process in place for handling waste. Thus, there are national security implications arising from the disposal of some defense-related high-level radioactive waste when such waste contains such materials as highly enriched uranium or plutonium. The Adaptive Staging approach offers additional flexibility before emplacement to choose or blend wastes according to their security requirements or their radioactivity content and thermal throughput.
Following the tragic events of September 11, 2001, attention must be given to the impacts on program goals and objectives that relate to security of radioactive wastes and the increased awareness of their vulnerability to terrorism. A number of organizations and individuals have raised issues with regard to security that may have a direct or indirect bearing on repository programs. Among these are potential vulnerabilities at generator sites, particularly spent fuel in pool storage at nuclear power plant sites, and vulnerabilities during transportation of spent fuel from plant sites either to a consolidated interim storage facility or a repository. These issues have been discussed in a recent National Research Council report on counter-terrorism (NRC, 2002b).
As noted previously, Adaptive Staging can slow the initial pace of underground waste emplacement. At the very least, it removes the certainty of placing the high-level waste underground by a given date. The inevitable pressures to accelerate the emplacement of waste, due to nuclear proliferation or terrorist concerns, counters the tendency of Adaptive Staging to proceed in a more deliberate and cautious manner. Adaptive Staging may lead to longer periods in which the waste is more accessible to humans. If the time scales become very long (decades to centuries), then institutional stability cannot be guaranteed. In this case, security could become a concern. However, even under the most optimistic waste emplacement schedules, significant amounts of wastes are likely to remain at reactor storage sites for decades.15 Furthermore, waste must be transported to the repository site regardless of how the repository program is organized. If rapid removal of high-level waste from surface storage at reactor sites is considered to be necessary to address terrorist threats, then other solutions beyond a geologic repository program will have to be considered. From this perspective there appears to be no significant difference in impact on security between Adaptive Staging and Linear Staging.
Adaptive Staging has the following impacts on the regulatory framework:
it increases regulatory review steps;
it requires flexibility from the regulator in formulating and applying regulation;
it requires flexibility in the license amendment process;
it provides the regulator with increased flexibility to amend regulations if experience warrants; and
In the United States anticipated quantities of spent nuclear fuel exceed the statutory limit of the proposed repository at Yucca Mountain (see Chapter 5).