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| 4.4.6 ALARP Assessment As part of the overall hazard management process, SCEs must be identified and performance criteria defined for them such that the Residual Risk is reduced to a level that is ALARP. However, even if each chosen SCE is designed and operated such that the Residual Risk from failure of the SCE is ALARP, it may not mean that the overall risk associated with a designated petroleum activity is ALARP. As a consequence, as well as each SCE, each hazard and the achievement of inherent safety also needs to be considered and the demonstration requirements for this are given in section 4.4.6.2. 4.4.6.1 Safety Critical Elements Each SCE reduces a particular part of the risk from a Major Accident Hazard, but not necessarily to zero depending on the availability, reliability, survivability and the actual functionality chosen for the SCE. Therefore, for each SCE, it should be demonstrated that the process by which its performance was chosen ensures that the risk is ALARP. This does not mean that the whole analysis needs to be described, but the process must be given insufficient detail that it can demonstrate that it leads to a risk that is ALARP. Reference to more detailed studies or assessment should be provided. The ALARP Guidance document describes a number of ways in which it can be shown that a particular risk reduction measure reduces the risk to a level that is ALARP and the methods that are used to demonstrate this should be described here. Inmost cases, semi-quantitative or quantitative risk assessment techniques should be used to determine the appropriate SCE performance as engineering judgement and qualitative risk assessment are unlikely to be accurate enough assessment tools to do this. Download 0.73 Mb. Share with your friends:
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