CIM Tailings Workshop Series comments
Jun 3rd, 2020
Within the frame of the CIM Tailings Workshop Series pre-workshop comments participants were asked three questions aiming at “feeding” the discussions.
Below are the three questions and our “short” replies.
What is a tailings system?
From a physical point of view, not in order of importance:
- start at the pumps in the mill,
- pipelines, spigots,
- all water management ancillary facilities (including diversions, decants, spillways),
- roadway at the crown,
- seepage collection facilities,
- decant raft and pipes,
- investigations and testing and finally
- design and construction.
From a management point of view:
- decision making processes,
- chain of command etc.
From a cyber point of view:
- remote monitoring,
- hacking, etc.
Hazards and Risks
Hazards are there since inception of design and include human factors such as:
- lack of effort and imagination,
- oversimplification of geological and hydro-geological (eg. too short boreholes),
- seismic conditions,
are obviously part of the hazards.
Then there are all the “classic hazards” to which we routinely add (since twenty years):
- epidemic (forbidding patrolling and monitoring, for example),
- (eco)terrorism and
- cyberthreats as needed.
We do not prepare a priori any list of risks because that is not possible if the consequences (metric) is not defined.
Indeed, risks do not exist per se, they only exist if there are hazards potentially coupled to consequences. It is very unfortunate that many people still confuse risks and hazards.
Failure modes and causes
Failure modes describe how a dam could fail, they neither describe why it fails nor how the intricacies of the system contribute to the failure.
Furthermore, looking at “credible” failure modes equates to censor in uncontrolled way the “reality” of things.
By “boxing” studies with failure modes, people miss important interdependencies that may exist within the system and outside the system (with another dam, for example).
It is time to change the approach to risk assessment. However, let’s not forget that Failure Modes may be useful to designers.
Tagged with: CIM, Failure Modes and Effects Analysis, Hazard identification, risks, Tailings Dams, workshop
Category: Consequences, Hazard, Probabilities, Risk analysis, Risk management