Risk and its consequence

Introduction

The work environment is a high-risk one. There are H&S risks for the workforce and process risk to the plant itself. The plant is noisy and hot, adding to the existing Karratha high air temperatures. This can make for a difficult, stressful working environment taking a mental and physical toll on the workforce.

The SC states that H&S is a key consideration and takes precedence over all aspects of the refurbishment work. The company lists the hierarchy of factors in undertaking the refurbishment work.

The first requirement is that work is carried out safely, the next that it is carried out to the necessary quality standards and the last that it is completed to schedule and cost. There are several reasons described below for the high priority given to H&S.

Health and safety risks

There are two distinct types of risks present during the execution of the refurbishment work. These are H&S and process risk. H&S risk (figure 4:10) includes immediate risks from working at heights, from slips, trips and falls, line of fire and so on. There are also risks due to hazardous materials and dangerous environments of the plant. These includes cyclical heating and freezing of pipe work, where pipes are energised at intervals during the day, the presence of high-pressure air-lines and risk to personnel presented by possible loss of containment (LOC).

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Figure 4:9- Process trip points

Figure 4:10 Health & Safety Risk

Process failure outcomes are potentially costlier and more catastrophic than health and safety ones.

Examples of process failure are the Piper Alpha disaster in the North Sea in 1988 and the BP Deep-Water Horizon oil spill in the Gulf of Mexico, which lasted from the 20th April 2010 to final sealing on the 15th July 2010. To mitigate against process risk, trains or other process will shut down

automatically if anomalies are detected. There are numerous points (figure 4:9) on the plant that can Process trip points

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cause the plant to trip. These are identified where possible with red ribbon. These small-bore pipework, instrument airlines, switches, gauges and levers can cause a train trip if interfered with.

The operator’s role, demands experience and knowledge. Each trip may have a unique cause and finding a solution to restart demands a comprehensive understanding of how the whole system works and operates. There is a high monetary cost, as a result lost revenue/train/day. It is highly stressful for the operators and there is the potential of harm to personnel. All personnel must vacate the site to safe muster points following a plant trip.

Consequently, there is a constant awareness among personnel of the ever presence spectre of a trip, the possible trip points and the consequence of each trip. SC as an owner operator, aware of the risks and potentials for harm have put in place the following procedures over many years, described below.

4.1.3.1 Mitigation of existing risk

There are several methods used to reduce the risks encountered daily from potential hazards during the operation and reconstruction of the plant. The risks are reduced to a point which is as low as reasonably practicable (ALARP) using some of the following systems.

Integrated Safe System of Work (ISSOW)

To mitigate the risks described above SC have a system of checks and controls called the integrated safe system of work (ISSOW). The ISSOW is a complex system using a permit to work (PTW) and a colour coded lock process to ensure that process plant is safely isolated before any work is carried out. Figure 4:11 details a small section of an ISSOW flowcharting developed for a relatively simple scope of work. The development of this requires a great deal of input from the operating staff, management and supervision to build up a robust schematic detailing a particular isolation, control and deisolation process for a particular activity, that is safe, workable and practicable. Still, it has now been recognised that in trying to cover all eventualities, the system has become overly complex and burdensome, impeding workflow unnecessarily. Currently the process is undergoing some simplification and rationalisation.

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Figure 4:11- ISSOW flowchart section

The ISSOW process (figure 4:11) is used in the work planning and execution. The design phase of any work scope involves input from the plant operators, to determine potential repercussions of particular actions and process. The operators know the plant intimately and can determine where and in what sequence the isolations need to be in place before a system can be quarantined, how the isolations are to be maintained during the refurbishment works and how and in what sequence the isolations are removed as work is completed. This is extremely complex work, where mistakes can lead to potentially catastrophic outcomes. There is an onus not just on the operators to get their planning and control systems right, but on everyone involved, including designers, managers, supervision and the workforce to have an appropriate understanding of the systems, the processes and the potential hazard and risks. This necessitates that personnel working at the plant have good cognitive processing abilities, superior data retention ability and communication skills. The management, supervision and the workforce work with an awareness of the potential for harm from

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two risk types as discussed, putting added pressure on people who are already undertaking demanding and complicated work tasks.

The Critical Path Method (CPM) project planning provide milestones for the LPS production planning, with issues soon uncovered with its use particularly as it interacted with the use of the LPS.

Therefore, investigation of its use was undertaken with the following section describes the investigation and analysis.