societal, rather than a technical, decision for each country and that this decision need not be rushed. Geological disposition followed by closing the repository (geological disposal) is nevertheless the only permanent and final solution to the waste problem. The committee recommends that all countries maintain this option in their national planning.
This chapter begins with a discussion of surface storage, then compares its advantages and disadvantages with those of geological disposition, and finally summarizes the committee's views on these two options. This chapter also gives a brief overview of partitioning and transmutation, which could reduce but not eliminate the need for geological disposition, and the other alternatives.
Currently, most if not all, SNF and HLW are in surface (or near-surface) storage. Storage technologies have been used safely for half a century. 1 SNF storage, primarily at reactors, has not been seriously questioned on safety grounds. For example, the U.S. Nuclear Regulatory Commission has concluded that such storage is safe for at least the life of the reactor's operations, that is, for at least 40–60 years (USNRC, 1999). Assessment of the Swedish centralized storage facility, CLAB, showed that it could safely store SNF for 100 years or more (Söderman, 1997).
Safe storage in surface or near-surface facilities can be achieved by packaging SNF and HLW in suitably engineered structures or robust containers to assure that radioactive materials will not be released. The security of surface or near-surface storage can be achieved by restricting access of individuals and groups that might divert fissionable material for weapons use or use radioactive material for acts of terrorism. The technical community agrees that excellent safety and security have been achieved in most existing HLW and SNF storage facilities.
From a technical point of view, there has been no urgent need for final disposal facilities because of the recognized high level of safety of interim storage facilities, the relatively small volumes of long-lived radioactive waste from civilian programs, and the storage time needed to allow adequate cooling of the more radioactive waste before geological disposal can take place. (NEA, 1999b, p. 9)
As noted in the above quote, storage can be technologically advantageous by providing time for the wastes to cool thermally through radioactive decay, and societally advantageous, by allowing more time for delib-
1 The committee notes instances, especially regarding defense wastes in the United States and Russia, where storage conditions are not satisfactory. These have arisen primarily because the storage facilities, such as tanks, are well past their design lifetimes. Such examples illustrate the fact that storage facilities require continuing surveillance and maintenance.