ORE2 Tailings deployment steps: 5.1 Failure definition We designed ORE2_Tailings™ to support RIDM for tailings dams portfolios reliability enhancements. One achieves reliability by reducing failure likelihood to a certain level, and risks are tolerable. Thus it is necessary to clearly state what one considers the success of a structure within the portfolio. Indeed, unless we clearly define success, failure remains an ambiguous term. ORE2_Tailings™ considers a dam successful if it: stands as built and does not break allowing for…
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A comment to a blogpost on tailings failures inspired this comment on the eternal confusion between tailings hazard and risks. Some voices are rising to state that the real number of tailings dams on the planet is around 35,000. Based on that number they then engage in a biased risk discourse. Indeed, we think those arguments are misleading and not helping the cause of tailings risk reduction. Let’s discuss why. The true number of tailings dams on the planet The number…
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Tailings dams knowledge base creation is about how to acquire the information needed to perform well documented risk assessments. Of course, there are many possible ways to create the necessary knowledge-base for a risk assessment that is compliant with the new Global standard. Today we will discuss a few possible ways to do so at a high-level.At Riskope we passionately believe that only a blending of these approaches is capable of bringing the answers needed for high quality risk assessments…
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Dam risks informational gap impacts to a certain extent all dams: hydro, tailings and finally, toxic dumps. There are thousands of active dams around the world significantly different because of: age, function, materials, construction style and care, maintenance care and finally “behavior” or performance. Oroville dam was one of those, like other recent mining catastrophes and the Michigan failures. What do all dams have in common? Dams are all exposed to hazards, e.g. natural, man-made such as excess of confidence,…
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The comparison of ORE2_Tailings estimated dam failure probabilities is an important element of Riskope continued commitment to test the validity of the approach. Quantitative risk assessment in tailings One can perform a Quantitative Risk Assessments (QRA) using various methods. Indeed, for tailings dam risks, they all consist in evaluating the: probability of failure of the dam generated by various pertinent hazards, potential consequences of a dam system collapse (failure) and finally the risk. The technical and mathematical tools for performing…
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Dam monitoring effect is a case history. A client acquired a mining properties portfolio. It included inactive dams at closed mines. Some of these structures were relatively well documented, while others were not. As a result, the client was facing important decisions, one of them being the effort to enhance the knowledge on the structures. The question the client asked was: “What happens to a particular dam if the level of knowledge we have on an inactive dam goes from…
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Lately several tailings dam failures rocked the mining world. Despite the relative high frequency of these events we have heard engineers qualify the failures as “one in a million”, “extremely rare” or even “black swans”. Today we want to discuss a few concepts on tailings dams design and experience. In particular, we will focus on some disconcerting qualifiers like the ones we just cited above. For example, given the experience of tailings dams catastrophic failures resulting from combinations of various…
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The Church of England Pensions Board and the Council of Ethics of the Swedish National Pension Funds published some recently collected numbers shedding some light on Tailings dams failures. How many active dams in the world did we assume earlier? In the literature we oftentimes see the number 3500 to characterize the total tailings dam inventory in the world. We used that number in both the following papers: Oboni, C., Oboni F., Factual and Foreseeable Reliability of Tailings Dams and…
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