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Areas to Account for Mitigation Systems Evaluating Post-Leak asme download Mitigation of Consequence Evaluating post-leak response is an important step ieee download in the consequence analysis. In this step, the various mitigation systems in place are evaluated for their effectiveness in limiting the consequence areas. Toxic releases are typically characterized as a prolonged buildup, then reduction, in cloud concentration, with accumulated exposure throughout. Flammable events more often are releases that are either ignited quickly, or the material is quickly dispersed below its lower flammability limit. For these reasons, different approaches are necessary for evaluating the post-leak response for the types of consequences accounted for in API RBI. Mitigations systems and their effect on flammable release consequences are presented here. 5.8.4.2 Effects of Mitigation Measures on Flammable Consequence Magnitudes

The adjustments to the magnitude of the consequence for flammable releases based on unit mitigation systems are provided in Table 5.10. These values are based on engineering judgment, utilizing experience in evaluating mitigation measures in quantitative risk analyses. The consequence area reduction factor, factmit , to account for the presence of mitigation systems is provided in Table 5.10. 5.8.5 Adjustment of Consequence Areas for Energy Efficiencies Comparison of calculated consequences with those of actual historical releases indicates that there is a need to correct large instantaneous releases for energy efficiency. In API RBI, this correction is made for instantaneous events exceeding a release mass of 4536 kgs [10,000 lbs] by dividing the calculated consequence areas by the adjustment factor, eneff n , given by Equation.(3.18).  15 Note that the adjustment defined by Equation (3.18) is not applied to continuous releases. (3.18) 5.8.6 Blending of Results Based on Release Type The Level 1 consequence area calculations yield significantly different results depending on whether the continuous area equations are used or the instantaneous area equations are used