Safety cases ALARP demonstration

It provides a framework so that individual application safety cases can demonstrate that the type of axle counter system that is being commissioned on a particular project reduces the risks to ALARP (relative... 

The regulatory environment is changing in Victoria with introduction from March 2000 of the Major Hazard Facilities Regulations, based on the Seveso II Directives. These are expected to flow on to the other states considered in this chapter. The key requirement of these regulations is the preparation of a Safety Case, which must demonstrate, among other requirements, that the risk from the new plant has been reduced to as low as is reasonably practicable - ALARP . The plants will incorporate a number of design features intended to reduce the risk from the facilities and demonstrate compliance with this criterion. 

The safety case concept requires that operators demonstrate that the systems and processes they have adopted ensure that their facility is sufficiently safe for all those people who are possibly impacted by their activities (workers and contractors at their facility, passengers and customers, people who live and work in surrounding areas). Most safety case regulations require the demonstration to take the general form of showing that risk is as low as reasonably practicable, or ALARP (or that risk has been reduced so far as practicable - SFAP). Clearly, safety cases are an example of the broad trend towards risk-based regulation (Hood et al. 2004). 

A Safety Case does not have to be quantified. Indeed, only half the European countries stipulate the use of Quantified Risk Analysis (QRA) in their Safety Case legislation (Rasche 2001). Nevertheless, it is difficult to demonstrate that risks have been reduced to the target ALARP threshold without some type of quantification. 

Some Safety Case reports contain an as low as reasonably practicable (ALARP) demonstration section that shows how the identified major hazards have been managed such that the associated level of risk is acceptable. The vexed topics of ALARP and acceptable risk are discussed in Chapter 1. 

A documented safety case needs to be produced to present the claims, arguments, and evidence that the plant or facility is safe to undertake its scope of operation throughout its required life. A safety case is the totality of documented information and arguments that substantiates the safety of the plant, activity, operation, or modification in question. It provides a written demonstration that relevant standards have been met and that risks have been reduced ALARP. The safety case for the plant should be a living document, which is subject to review, change, and amendment as time proceeds. 

Current practice in the UK demands demonstration of corrqiliance with the As Low As Reasonably Practicable (ALARP) principle for arty imdertaking. This demonstration is typically stmctnred in the form of a Safety Case. 

Application specific issues cannot be addressed at the concept level. To demonstrate ALARP, it is necessary to consider the specific application in conjunction with the Concept Safety Case, as the latter caimot deal with reasonable practicality in all situations and combinations of applications. 

Development of the methodology supporting the generic activities of safety risk analysis and management process for any system would bring benefits to the industry. Moreover, since the current practice in the UK is that demonstration of conpliance with the ALARP principle is structured in the form of a Safety Case, the process also needs to support the development of the Safety Case. 

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