ABSTRACT

Abstract Large industrial catastrophes and still growing problems with pollution of the environment constitute the reason for reconsideration of currently applied safety concepts. At the moment these concepts focus on the limitation of risks, the latter being defined as the product of probability of failure and consequences. Particularly when dealing with so called Low Probability/High Consequence Risks, the risk concept has revealed its limitations. Aspects of the process of reconsideration of current safety concepts are dealt with in this paper. It is concluded, that judgement of risk bearing activities should not be restricted to a judgement of risks, but shall also comprise a separate judgement of the consequences, irrespective of the risk. Control of consequences can be realized effectively by using robust passive safety measures in the form of structural protective systems. These systems, for example storage systems for bulk storage of hazardous substances, shall prevent uncontrolled release of the stored product under both normal operation conditions and in a calamity stage. It is emphasized that tightness criteria have to be defined in such a way, that consistency is established with the relevant hazard scenarios. An example from the waste business illustrates the way of reasoning presented in this paper. Keywords: Hazards, safety concepts, risks, consequence control, storage systems, tightness criteria.