(7b) Development of Quantitative Hazard Analysis Method for Inherently Safer Chemical Processes

Chemical plants have many kinds of chemical materials and operating conditions are also various. If the accident occurred, it has a possibility to give severe consequence.  Therefore it is important to analyze the hazard potentials in chemical plants. Worst case scenario is often used as quantitative hazard analysis in chemical plant, but assumptions of scenario are various by organizations or companies, and there are not detail description in the guideline or regulation which equipment we should select and the scenario what will occur. In this work, for the quantitative identification of hazard potentials, we reconsider the assumptions of the worst case scenario everyone obtains the same and accurate results.

In addition to worst case scenario, we defined the abnormal scenario, because there are some cases it is not possible to identify hazard potentials by only worst case scenario. Analysis of both scenarios makes it possible that we can comprehend the hazard potentials more accurately. And this report shows that these analyses based on “worst case scenario” and “abnormal scenario” becomes more effective by implementing on each life cycle stage, because there are different perspectives for safety measure on each stage.

The results of hazard potentials are plotted on the graph and ranked by their severity, and also to express how large accidents would occur by comparing to the past accident examples. If the equipment has high hazard potential, it is necessary to consider applying inherently safety measures. The inherently safety measures are one of the thinking for safety options, and when the implementation of safety measures is considered, it is also necessary to consider whether safety measures are effective and whether they generate new hazards. By using this analysis method, it is able to confirm them, and it would give effective safety measure options.