The Norwegian Guideline for Probabilistic Explosion Risk Simulations

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractMany approaches to the problem of selecting explosion loads based on advanced CFD simulation models on scenarios have been suggested during the past 3-5 years. In order to accelerate and harmonize the development of probabilistic explosion simulation methods, Norsk Hydro and Statoil took an initiative in 1998 to develop a guideline that recently was issued as a NORSOK standard.The guideline treats the complete calculation of explosion risk from the gas leak to the structural response. The result is a probability distribution of the explosion loads or the structural response. Based on company specific acceptance criteria the dimensioning explosion load can then be selected with a lot of input data and judgements that has to be made.A test study of the guideline with identical studies performed by five consultants has demonstrated the importance of focusing on input data and judgements that has to be made. There were some discrepancies between the results from the five consultants. Some of this discrepancy is judged to be due to different interpretation of input data and some due to the implementation of the procedure itself. For four of the five consultants the most interesting results are in the same range and would lead to the same conclusions. The main conclusion from the test study is that with right focus on input data it is possible to get consistent results by following the procedure.