Hazard analysis flash fire

The outputs of an event tree from a post-release frequency analysis are a number of outcomes ranging from more to less hazardous. An event tree highlights failure routes for which no protective system can intervene and where additional protective systems/mitigative action may be contemplated. The quantitative output is the frequency of each event outcome. These outcomes (which might specify BLEVE, flash fire, pool fire, jet fire) are used to determine individual and societal risk. 

As is seen from Fig. 11/4.3.1 -1, near the vicinity of the incident the severity will he more intense than further away. Also it gives an idea of the magnimde of the consequence of an event. To assure adequacy of the control measure it is necessary to realize the worst case scenario, which could be a cumulative or combination effect. Most likely the incident issue is important, hence the total range of hazards is important. Also the potential escalation zone at the interface area of the fatality zone and equipment zone is vital because severity in this zone may be wider. Qualitative estimation of consequences is done on the basis of previous experiences. In some cases, such as jet/flash fire gas dispersions, etc., detailed quantitative analysis based on computerized modeling may be called for. Various analysis types are discussed separately. 

---