Tuesday, April 12, 2016: 8:30 AM
371 A, B, D & E (George R. Brown )
Layer of Protection Analysis has become a cornerstone risk evaluation tool in the chemical industry since the original CCPS text on the topic was published in 2001. Now, 15 years later, the method is used by many companies as the primary means of determining the adequacy of controls for hazard scenarios as well as the required safety integrity level for recommended safety instrumented systems. This presentation will present the basics of the LOPA methodology including the critical evaluation of the hazard scenario, establishing the initiating event and its frequency, investigation of safeguards and selection of independent protection layers, a brief overview of enabling conditions and conditional modifiers, and comparison of the resulting calculated risk to established targets. Practical examples of the application of LOPA to several scenarios will be used to illustrate the use of the technique.