3-5 A Risk-Based Monitoring Framework for Used Fuel Management
Nava C. Garisto, SENES Consultants Limited
Overview of a risk-based monitoring framework for used fuel management approaches.
9.1 Assessing the Options: NWMO Assessment Team Report June 2004
In the initial phase of its work, the NWMO identified ten questions to be asked and answered in its study. These were featured in the first discussion document, Asking the Right Questions? Soon after publication of that document, the NWMO assembled a multi-disciplinary Assessment Team of 9 individuals.
This diverse group was asked to build on the values and concerns of Canadians contained in the ten questions and to 1) develop a rigorous methodology for the assessment of the management approaches, and 2) perform a preliminary assessment using the methodology on a number of specific options for managing nuclear fuel waste.
The work of the Assessment Team has contributed two important elements to the NWMO study:
- First, it has created a preliminary description of the strengths and limitations of the management approaches, for consideration and dialogue. In advancing our understanding of some of the distinguishing features of the options, it provides the context for a substantive discussion on how to consider the relative risks, costs and benefits of the alternative management approaches.
- Secondly, through the broad and integrative approach taken, the work has brought into focus some of the difficult choices and trade-offs which will need to be addressed as part of the assessment of the approaches.
Highlights of the Assessment Team’s work include:
- A framework for assessing options for used nuclear fuel management was created, based on the values and direction of Canadians identified through NWMO engagement activities.
- The framework features eight objectives: fairness, public health and safety, worker health and safety, community well-being, security, environmental integrity, economic viability, and adaptability.
- The framework also features, for each objective, an identification and mapping of the factors that may influence the capacity to perform well against the objective. The resulting “influence diagrams”, created for each of the eight objectives, acted as a road map for the assessment.
- Three management options for used nuclear fuel were assessed using the framework – extended storage at nuclear reactor sites, centralized storage, and deep geological disposal.
- The multi-disciplinary group of individuals, who comprised the Assessment Team, did not assess each of the management options on the objectives in precisely the same way. In fact, the ranges in the scores for the three options assigned by Team members was quite wide, in most cases. The broad range of scores on many objectives reflected differing views among members of the Assessment Team concerning future environmental and social conditions in Canada as well as questions regarding how well the approaches might actually perform.
- Overall, the assessment found that each of the management options has specific, and quite different, strengths and weaknesses. No method perfectly addresses all of the values and objectives important to Canadians.
- The assessment also found that the deep geological repository option is expected to perform significantly better, when evaluated against the eight objectives, than the other two options, especially in the light of the long term during which any management option must perform well. The centralized storage option was expected to perform significantly better than the option of extended nuclear reactor site storage.
- Since the process of implementation necessarily will stretch out over an extended period of time no matter the management option ultimately selected, the Assessment Team suggested it is both desirable and advantageous to consider the development of any selected approach in a staged, flexible manner, This will provide an opportunity for new learning and new experience to be brought to bear on the difficult issue of choosing an approach to the management of used nuclear fuel that will enjoy a high degree of public acceptability.
Commissioned Comment on this Report
The NWMO is interested in the perspective of Canadians on the work of the Assessment Team and encourages comment on their report. Upon release of the Assessment Team report, NWMO approached three individuals to learn their perspective. Their comments are reproduced below for the review and consideration of interested Canadians.
9.2 Assessment of Benefits, Risks and Costs for Long Term Management Approaches for Used Nuclear Fuel
The Nuclear Fuel Waste Act (NFWA) requires the NWMO to include a comparison of the benefits, risks and costs of each management approach as part of the study. The NWMO commissioned Golder Associates Ltd., and Gartner Lee Ltd to provide two reports as input to this comparative assessment.
The first report provides an assessment of the benefits, risks and costs, by illustrative economic regions, for the three management approaches mandated for study in the NFWA;
- deep geological disposal in the Canadian Shield, based on the concept described by AECL in the Environmental Impact Statement on the Concept for Disposal of Canada’s Nuclear Fuel Waste and taking into account the views of the environmental assessment panel set out in the Report of the Nuclear Fuel Waste Management and Disposal Concept Environmental Assessment Panel dated February, 1998;
- storage at nuclear sites; and
- centralized storage, either above or below ground.
The assessment builds off of the work of the NWMO Assessment Team and the NWMO's second discussion document, Understanding the Choices. This earlier work had identified eight guiding objectives and a number of key influencing factors as reflective of the key values and concerns of Canadians on this issue.