6
Failure modes analysis
This section provides a high level Failure Modes Analysis (FMA) outlining potential TSF failure pathways and the corresponding mitigation strategies, presented in Appendix B.
6.1 Failure definition Failure is defined for this FMA as a catastrophic loss of containment and release of tailings or water from the TSF embankment. Failure pathways resulting in seepage losses or release of tailings slurry from the pipeline without catastrophic loss of TSF containment have not been considered for this assessment.
6.2 TSF components and sub-components
A list of UMG TSF components and sub-components is presented in Table 6.1. The lining system includes the general fill as a composite component for this assessment.
Table 6.1
Upper Mundic Gully TSF components and sub-components
Component
Structure
Sub-components
Function
Description ID
Foundation F Foundation
Supports embankment
Liner + Embankment + Mine spoil dump
Upper Mundic Gully TSF
Embankment E
Mitigates water and tailings seepage
Pipeline
PL Pipeline
Conveys tailings slurry to the UMG TSF
6.3 Initiating events and failure modes Initiating events and failure modes considered for this FMA are summarised in Table 6.2. The initiating event descriptions provide broad groupings for simplicity. Examples of more specific events which may fall under these descriptions include poor pond management or unintentional valve operation for Operating Error, loading of weak foundations for Static Loading, and overpressure, corrosion, or equipment damage for Pipe Burst.
Table 6.2
Upper Mundic Gully TSF initiating events and failure modes
Initiating events
Failure modes
Description
ID
Description
ID
Flood Event
FE
Overtopping
OT
Seismic Event
SE
Embankment Instability
EI
Operating Error
OE
Foundation Instability
FI
Static Loading
SL
Piping
PI
Pipe Burst
PB
External Impact
EI
Project No PS213278 Upper Mundic Gully - Tailings Management Plan Mount Morgan Gold Mine Heritage Minerals
WSP March 2026 Page 10
Powered by FlippingBook