Proceedings of the Eighth International Conference on Probabilistic Safety Assessment & Management (PSAM)
290 Probabilistic Safety Assessment of an Industrial Facility (PSAM-0231)
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- Ris (Zotero)
- Reference Manager
The European Seveso Directive applies to major accident risks due to the presence of dangerous substances in facilities. It covers both industrial activities and the storage of dangerous chemicals. The latest amendments to the Seveso II Directive include the application of probabilistic approaches for risk assessment of these corresponding facilities.
In July 2003, following this initiative, the French Ministère de l'Ecologie et du Développement Durable (MEDD) produced a new law advocating the use of probabilistic risk studies to demonstrate an acceptable level of safety of the above mentionned facilities. Probabilistic safety assessment (PSA) methods are already widely applied to installations in the nuclear industry. The question of correctly applying such methods to the industrial activities covered by the Seveso Directive has been raised. In this optic the Institute of Radioprotection and Nuclear Safety (IRSN) was called upon by the MEDD to carry out a PSA study of a selected Liquid Petroleum Gas (LPG) distribution site based on the experience gained through many years of application of the PSA methodology in the nuclear field.
One of the problems encountered when applying the PSA methodology to industrial facilities for risk assessment is related to the number of possible consequences and theirs effects. The IRSN study presents an overall analysis of the Boiling Liquid Expanding Vapour Explosion (BLEVE) consequence over the site. The analysis was aimed to quantify the effects produced over the different facility's zones (one for large storing capacities and two for products delivering or reception for trucks carriers and railway wagons) by each initiator postulated to occur (e.g. LPG leaks) leading to the BLEVE consequence. The study and modelling of the physical phenomenon produced a new methodology for assessing and quantifying the effects between zones. Also, it proposes a new approach for assessing and quantifying the BLEVE risk of facility's capacities as a function of the relative leakage point position and the reliability of the fire protection system. As a result, new concepts were introduced and quantify, such as direct and indirect effects probabilities.
One of the crucial points in PSA is the reliability data available and its correct adequacy. In order to overcome this difficulty, several data sources were consulted and analyzed with a focus into the operational feedback information.
Even with the highly conservative assumptions used for the pilot study, the results finally obtained show that, given some adaptations, the PSA methodology used in the nuclear field can be applied consistently to other industrial facilities and will enable the computation of the risk of undesirable consequences.