Used fuel management is a long-term issue and any solution should not only be acceptable to our generation but should also be so for future generations.
Reviewing the approaches taken by several countries, it appears to me that an important consideration for Canada may be that we should take care not to foreclose options for the future generations and take precaution at the same time not to saddle them with undue burden in the management of used fuel.
On these two considerations alone, one could see that :
(i) reactor site storage, although easily retrievable may not be a good long term option since it leaves many sites to be managed adding to the future burden and is not configurable for disposal, and
(ii) disposal may not be a good option since it makes used fuel resource inaccessible (or extremely difficult to access).
The only suitable option for the long term appears to be one that is essentially designed in a way that (i) used fuel can be easily managed and retrieved if and when required, and (ii) the facility can easily transition to disposal if and when the future generations so decide. This provides future generations the ability to exercise whatever options they may have at their disposal (including technologies that we might not have seriously considered so far).
Throw into this mix other considerations such as terrorism, security, economics and the all the rest, a long-term storage option that is centralized, located deep underground (thereby less prone to surface hazards and terrorism), manageable with a minimum of effort (i.e. passive) and easily configurable for disposal may be the optimum solution for the long-term management of used fuel.
Such a system can succeed current storage at an appropriate time perhaps following plant closuresat the earliest or at the end of the service life of reactor site storage at the latest. Given that there is no urgency to implement a solution, the program can benefit from considerable leadtime avaliable for selecting a site for centralized storage/disposal and developing a suitable long-term technology.
Mohan Rao, PhD., PEng. Vice-President Hardy Stevenson and Associates