Why a deep geological repository?
Recommending an approach
In November 2005, we submitted our final report to the Minister of Natural Resources, recommending an approach known as Adaptive Phased Management (APM). The technical end point of APM is the containment and isolation of Canada's used fuel in a deep geological repository. The approach was adopted as Canada’s plan in June 2007.
Being responsible to the needs of future generations
The options study clearly identified the deep geological repository as the appropriate approach. A deep geological repository uses a combination of engineered and natural barriers to safely contain and isolate used fuel. It can be actively managed and monitored for as long as society wishes to do so. It can also be sealed at a future date, when the community, the NWMO and regulators agree that it is appropriate to do so. The repository would then be passively safe, meaning it would not rely upon human institutions and active management in order to contain and isolate used fuel over the long term. This responsive and prudent approach is consistent with what Canadians said is required to ensure safe management of the used fuel for tens of thousands of years.
International best practices
There is also consensus among major nuclear regulatory and monitoring organizations that deep geological repositories are the responsible way forward.
Additional background on the deep geological repository approach
- A geological repository uses multiple barriers that include the waste form, container, sealing materials and the host rock. The system is designed such that the failure of one component would not jeopardize the safety of the containment system as a whole.
- The host rock would be stable and predictable over long periods of time.
- The low permeable host rock would ensure that the waters in the deep rock are isolated and do not mix with surface waters.
- The deep geological repository system would maintain a chemical and hydrological environment that is favourable to the stability and performance of the repository.
- Natural analogues provide evidence that engineered-barrier system components are stable for very long periods under similar deep geologic conditions.
- The depth of the repository would be such that future inadvertent human intrusion into the closed repository would be very unlikely.
- International progress on repository implementation gives assurance that geological disposal is a sound technical solution and provides practical experience.
- Safety assessment case studies indicate that any impacts are likely to be well below recommended dose constraints and natural background dose rates.
- A geological repository can be built and operated safely using proven technologies.
- The radionuclides in the used fuel decay with time.
- The repository site can be monitored to confirm repository system performance.
