Underground » Health and Safety
This report is the compilation of a two stage project:
- Stage 1: Coal Mine Safety Regime (CMSR): A New “Safety Case” Process and its Implications to Australian Coal Mining (completed in September 2007);
- Stage 2: Acceptable Risk: A Matter of Establishing Adequate Control (completed in April 2009).
The work undertaken in this project follows on directly from project C14019 Risk and Coal Mining Governance, this report is available to purchase/download.
Safety Case, as practiced in the oil and gas industry, is a single, comprehensive, detailed, risk assessment based argument that all hazards, risks and controls have been established and incorporated into an effective Safety Management System.
This ACARP project addresses the history, nature and current status of Safety Case Regimes (SCR) as they have been applied in industries other than mining across the globe. It also suggests that the principles of SCR, based on those defined by the National Offshore Petroleum Authority (NOPSA) are generally acceptable to the involved coal mining industry representatives.
This report goes on to suggest that the principles can be fully addressed through a model that considers the specific needs of the coal mining industry. Industry specific factors were considered such as:
- Significant potential uncertainty related to the nature and magnitude of some major hazards;
- The people intensity of the mining process and the potential impact of human behaviour;
- The inability of the industry to currently separate the person from the hazard (as is often possible in other industries); and
- The need to include dynamic approaches to addressing constant change.
It was also seen to be critical to recognise that the coal mining industry has progressed considerably in their journey to effectively integrate risk management into their businesses and sites.
As a result, the industry representatives from five mining companies or organisations that were involved in this study considered leading practice risk management practices across the Australian mining industry and, based on that image, developed the Coal Mine Safety Regime (CMSR) model.
CMSR is a model of risk management processes that covers the major key OH&S decision locations from overall site management to face personnel. It is possible to use CMSR as the basis for an argument that the site is safe because the risk management processes are in place, designed to be effective and operated with appropriate quality.
The CMSR model was examined versus current practice in six coal mines in NSW and Queensland. Although some differences were found, most issues were not about the absence of related risk management practices but rather their design and quality control. Therefore this paper concludes that CMSR may be a viable approach to demonstrating that a mine is “safe” while making an appropriate desirable step change in the design and quality of current risk management approaches, rather than replacing current approaches with a SCR that is not only new but also inadequately designed to address all mining OH&S risk issues. It also provides an opportunity for the coal mining regulators to evolve their regulatory approach.
It appears that Western Australia will launch some form of Safety Case Regime for mining in the near future. Experts agree that it is the next logical step (Gunningham, 2007). The coal mining companies have an opportunity to influence this evolution by establishing a mechanism to discuss CMSR further.
“For designers and operators, having a well-defined acceptable level of risk would provide a clear target for managing their technology… Perhaps the most widely sought quantity in the management of hazardous technologies is the acceptable level of risk.” (Fischhoff 1994)
This report overviews both the relevant literature and the current context of acceptable risk in the Australian coal mining industry. There are many and varied stakeholders concerned with the establishment of acceptable risk, with differing needs for consideration in any analytical process.
Note that 'acceptable risk' is defined in the relevant new ISO 31000 Standard as “The level of risk reduction which is as low as reasonably practicable (ALARP)”.
The difficulty in objectively establishing acceptable risk is critically examined in this report, including the current potentially dangerous practice of re-ranking risk with a '5 by 5' Risk Matrix to suggest a risk is acceptable.
The report goes on to suggest that the way to consider whether a risk is ALARP should be based, not on risk calculations, but rather on an analysis of the effectiveness of relevant controls. Techniques designed for this purpose are briefly overviewed. The sources include the following:
- NASA / US Military Control Rating Method
- Layer of Protection Analysis (LOPA)
- Newmont Gold's' Major Incident Control Analysis (MACA)
- GHD SQRA Control Effectiveness Estimation Methods
- BHP Billiton's' Risk Control Analysis Method
All of the above techniques have limitations in site risk management some applications where the process should examine all controls for an unwanted event and the analysis could be lead by a moderately skilled facilitator. It is suggested that techniques that can be used by a moderately skilled internal facilitator can be used for the vast majority of site risk assessments.
Bow Tie Analysis (BTA) was identified as a common part of at least 2 of the above listed technique. BTA is a practical site method for identifying controls currently used at some mine sites.
The need to consider the site context can be seen more clearly when a model for site risk management is used to discuss the various objectives for establishing ALARP. The four layer model suggests that there are four primary objectives for applying risk assessment on a good practice site:
- Overall site major, principal or catastrophic risk management;
- Project, change or serious incident risk management;
- Routine and unique job / task risk management done by a team; and
- Every-day, informal, face level risk management done by the individual.
This report included site case studies using Bow Tie Analysis (BTA) plus two additional methods of trying to establish control adequacy. The first method involves the use of leading practice compendiums of controls for selected unwanted events. These compendiums were developed using the BTA method and the intent was to compare the identified control sets to site practice in order to establish acceptability.
The site work found that it would be very difficult if not impossible to develop effective leading practice control compendiums because, though unwanted events are often generic, the causes of the events vary greatly between mines due to conditions and other factors.
The second method for examining control effectiveness, also using BTA, was developed in conjunction with the sites. This method was similar, though more basic, then the methods developed by Newmont and BHP Billiton mentioned in the report.
The second visit to each site included the use of BTA to identify existing controls for a selected unwanted event, as well as the use of a “Control Effectiveness Estimation Method (CEEM)”. CEEM was developed during this project with the assistance of site and corporate personnel. It is a matrix that considers both the Type of Control, using the Hierarchy of Control, and the Quality of the Control, considering the likelihood that a control will work when required.