Building Confidence in Deep Geological Disposal of Nuclear Fuel Waste: Canada's Approach

Abstract

At present used fuel from Canadian nuclear generating stations is safely stored at the station sites. Many years of experience have been accumulated with both pool storage and dry storage systems and supporting R and D indicates that these practices can be safely continued for many decades to come [l,2]. However, because the used fuel remains hazardous for thousands of years, it has long been recognized that such storage systems are not a permanent solution and that a passively-safe method of management that does not rely on institutional controls needs to be developed.

Like other countries, Canada is basing its plans for disposal of nuclear fuel waste on deep geological disposal, in the Canadian case in stable plutonic rock of the Canadian Shield. The most convincing way to demonstrate the long-term behaviour of such a disposal system would be to build one and monitor its performance in the long-term. Since such a procedure is not practical, society is faced with making decisions regarding the acceptability and the safety of deep geological disposal in the presence of unavoidable uncertainty. Thus the challenge that faces society and those charged with responsibility for nuclear fuel waste management is how to develop sufficient confidence to permit decisions to be made.

Is there a basis for such decision-making in Canada? The answer, in the view of the author, is yes. This confidence is based on:

• the technical approach, the use of multiple barriers for redundancy and defence in depth;


• the adoption of an observational approach to site characterization and to disposal vault design, construction, operation and eventually closure;


• an approach to the project, which is based on ongoing review and incremental decision-making and which recognizes that, throughout, the process must be flexible and responsive and that decisions are not irrevocable; and


• active and effective involvement of the public in the process.