Prerelease Mitigation Techniques

This chapter introduces the various methods of postrelease mitigation. First, however, prerelease mitigation techniques, different types of releases, and the potential consequences of hazardous material releases are discussed. These discussions are intended to provide the reader with some background into postmitigation concepts covered in detail later. An experienced engineer can use this chapter as a quick reference to the release mitigation techniques available. For someone new to this subject, this chapter will help to focus on appropriate strategies which are explored more fully in later chapters. 

For a more detailed technical discussion of release mechanisms and their consequences, refer to other CCPS publications (CCPS, 1988a,b, 1989a, 1996). 

Before any mitigation measures can be designed, an effective hazard identification study must be conducted. The results of such a study (a set of release scenarios) can be used to develop a coherent set of mitigation strategies. In the process industries, these studies are most commonly conducted using hazard and operability (HAZOP) studies, what-if checklists, failure modes and effects analyses (FMEA), and several other comparable techniques (CCPS, 1992). 

Mitigation techniques are divided into two categories prerelease and postrelease mitigation measures. Prerelease mitigation measures take effect 

Flare stacks that safely bum organic material released into vent headers are an example of a prerelease mitigation measure. The flare destroys the hazardous organic material before it reaches the environment. A dike around a storage tank is an example of a postrelease mitigation measure. The dike contains the release in a small area, reducing the total evaporation rate from the spill and so reducing the impact of the release. 

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