Explosion and fire hazard assessment for explosives, ammunition and fertilizing agents facilities after EU directive 96/82/EC 'Seveso II': Contribution for guidelines proposal

摘要

The European Directive 96/82/EC, "Seveso II", requires the quantification of the impact induced in the event of a major accident. However, for explosive materials, no Eurocode, procedures, algorithms nor specific reference values for damage calculations were specified within the Directive. In order to confirm the validity of "Seveso II Risk Assessments" damage calculations, EU Member States can only refer back to their own previously existing legislation on explosives. But calculation methods, scaling laws, and reference values for safety distances vary from one Member State to the other one. Also the progress that has been made in improving the quality and safety of modem explosives has not necessarily been reflected in all state legislation, some of which is more than 50 years old. A strong need exists, within Europe, for the adoption of a harmonised approach for assessing the potential damage from major accidents involving explosives. This article illustrates a methodology suitable for use as the basis of achieving a consistent approach within Europe. The procedure presented here is a development of a method first used for undertaking the explosion and fire hazard assessments for mass detonating explosives, which was published in the March/April 2003 issue of the "Journal of Explosives Engineering". The original method has been further refined, by experience from the consideration of ammunition and oxidizing agents, and also extended to include not only the maximum possible impact of an accident but also the maximum probable impact. Formulae for the first approximation calculation of the effects induced in the surroundings by impacting factors due to the occurrence of the accident are proposed. Threshold values for each impacting factors are given with reference to damage severity levels. A graphical representation of the results from the hazard assessment is achieved by the use of iso-damage areas in which boundaries of the severity damage levels are fixed for each given probability of occurrence of the major accident.