Risk-based safety criteria

Regarding risk-based safety criteria, the philosophical basis of safety and risk in hazardous civilian industries is well understood and numerically defined. Perhaps, for combat aircraft, there should also be a flrst-principles-based set of risk criteria, particular to combat aircraft and equipment, using a cost-risk-benefit approach, which addresses both initial design and subsequent modification work in the context of combat risk. Existing defence safety standards, such as the UK s Def Stan 00-56, rely heavily on civilian safety standards. This seems unrealistic. (At time of writing, Def Stan 00-56 is under review.)... 

In this study assessments of individual road bridges exposed to accidental situations are discussed from a general point of view. Stewart (2010) recommended cost-benefit and other risk-based approaches particularly for low probability-high consequence events where public safety is a key criterion for decision making. That is why methodology of the risk optimisation based on Bayesian networks is developed here. It is noted that the terminology accepted in Eurocodes (EN 1990 2002 for the basis of structural design and EN 1991-1-7 2006 for accidental actions) and other European documents DIRECTIVE 2008 114 EC and Communication COM(2006) 786) is adopted. 

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. 

Determine the consequence and likelihood of the hazard scenario. This evaluation should include an examination of safety, environmental, and economic losses (including the requirements associated with safety and environmental regulations). Based on an assessment of the overall risk associated with the identified hazard, decide if additional safeguards or Layers of Protection/lndependent Protection Layers (IPL) are required. The criterion for acceptable risk could be single numerical value, or it could be determined through use of a risk matrix. 

Optimum design solutions in the creation of multi-barrier systems for longterm storage and final disposal of radioactive materials should be chosen based on probabilistic safety analysis for each viable option, supplementing the latter with the cost estimates for the implementation of the option, i.e., using the complex criterion risk-benefit. ... 

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