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Tailings dams quantitative risk prioritization

Tailings and Mine Waste Conference (2019 : Vancouver, B.C.); University of British Columbia. Norman B. Keevil Institute of Mining Engineering

This paper assesses the quantitative risks of a portfolio of four dams. It is based on case histories and shows a predictive risk prioritization approach. Dams interdependencies are explicitly considered as interdependent scenarios significantly alter the portfolio risk prioritization. Stability analyses in static and pseudo-static conditions performed by the engineers as well as observations/inspections reports are used as input data. It is shown that the Factor of Safety is not a good discriminant to evaluate safety and thus risks. A documented and published symptom-based simplified probability of failure estimate is used to evaluate the probability of failure of each dam. Dams are benchmarked in relation to the world-wide historical performance as well as using a theoretical dewatered and slurry state tailings dams’ probabilities of failure. Consequences of dams’ breach are quantitatively evaluated using a multidimensional function. Potential for loss of lives is of course included and discussed as well as reputational damages. Indeed, a comprehensive risk metric is the cornerstone in risk communication which is becoming a crucial part of any risk assessment. Enhanced transparency, sensible information, better risk communication will help foster robust Corporate Social Responsibility, Social License to Operate and NI43-101. The risk portfolio is prioritized using various approaches, including a portfolio owner’s risk tolerance threshold. A discussion of the impact on possible prioritizations and decision-making is introduced as well. The paper shows that gut-feeling risk prioritization may be misleading and careful consideration of multiple parameters must be introduced before a sensible and sustainable roadmap can be delivered and communicated to the stakeholders and the public. Finally, a roadmap to portfolio mitigation is defined.

Text

2024-02-15

Attribution-NonCommercialNoDerivatives 4.0 International

http://hdl.handle.net/2429/87447

Unreviewed

http://creativecommons.org/licenses/by-nc-nd/4.0/