Land use planning (LUP) around Seveso sites.
The Cooperation Agreement of June 2016 translating the Seveso III Directive into Belgian law provides for appropriate distances to be maintained between Seveso sites and areas frequented by the public. In addition, the Code de Développement Territorial (CoDT) specifies that for permit applications concerning property in the vicinity of a major risk establishment, the opinion of the Service Public de Wallonie is sought. The same applies to applications for single permits or environmental permits submitted by manufacturers. The “Risques d’Accidents Majeurs” (RAM) unit is responsible for issuing the above-mentioned opinion.
ISSeP carries out risk mapping, based on isohazard curves, compiled in the form of vulnerable zones on the SPW Geoportail. These LUP studies are carried out on the basis of safety files submitted by operators when applying for permits.
To achieve this, a rigorous scientific risk quantification methodology has been developed. This methodology, whether for conventional chemical sites or sites storing explosives, although some notable differences are to be noted, is a probabilistic approach, with a combination between the consequences calculated for each credible accident scenario that could occur in the company and the frequencies of occurrence of these scenarios, with the aim of obtaining an individual risk. The effects considered are thresholds linked to the irreversibility of the effects, i.e.: toxic effect (mainly AEGL3), radiative effect (6.4 kW/m²) and overpressure effect (50 mbar). Isorisk curves are calculated using two simulation software packages: Safeti from DNV GL for liquid and gaseous substances, and IMESAFR from A-P-T Research.
On the basis of the risk curves obtained, the RAM unit issues a favorable, unfavorable or conditionally favorable opinion, depending on the compatibility of the curves with areas frequented by the public.
The RAM unit also provides technical advice on the analysis of Safety Reports, Hazard Identification Notices and Safety Studies, the calculation of consequences using Phast & IMESAFR software, and assistance with non-Seveso permit applications.
A number of specific studies have been commissioned by the RAM unit, such as a study of fire protection barrier requirements for small fireworks depots, or an assessment of methods for calculating the volume of existing firewater retention basins for Seveso-type logistics companies.
A study is underway to understand the fire risks associated with new-generation Lithium-Ion batteries, including an experimental study to assess the characteristics of these fires, in order to gain a better understanding of the risks of thermal runaway, the modes of propagation from one cell to another, and to quantify the risk of fire and its effects.
The Hazardous Installations unit also carries out studies to characterize the flammability and explosivity of nanometric and micrometric combustible dusts from various national and international industrial sectors.