Explosion Risk Assessment (ERA) involves quantification of the probability of explosion accidental events, and their consequences.
Objectives
The main objectives of the explosion Risk Assessment study are to:
- Identify explosion hazards on the facility that may affect the facility equipment and targets/receptors and escalate to other parts of the facility,
- Quantify explosion risks arising from loss of containment,
- Determine the acceptability of the calculated explosion risks at the facilities and identification of the key explosion risk contributors. Risk contributors need to be identified by source and location,
- Assess the benefit of existing and possible, inherently safe, prevention, detection, control, and mitigation measures for identified explosion scenarios,
- Compare explosion risks of the design options being considered. This helps identifying design options with low risk, and selecting the option which is best from a risk and other techno commercial point of view,
- Provide recommendations for risk reduction where necessary, to ensure that the facilities explosion hazards are controlled within acceptable limits,
- Review the explosion prevention, detection, protection, and suppression measures in place in the current design and identify additional measures required to operate the facilities safely.
Methodology
The ERA methodology followed for Projects is detailed below:
- Identification of explosion hazards.
- Estimate hazard inventories, failure probabilities
- Identify Potential Explosion Sites (PES) based on review of the plot plans, 3D models, etc.
- Identify receptors to be evaluated as part of the study.
- Undertake explosion modelling for all identified potential explosion sites
- Determine event probabilities for each of these failure cases considering all probabilities such as direction probabilities, wind profile, failure probabilities, ignition probabilities, etc.
- For each of the failure case, review the impact of explosion events on the facility, and in particular:
- Assess the impact on the adjacent equipment, SCE, key structures, EER measures and supporting structure / elements / system, etc.
- Assess the impact on occupied process buildings.
- For each of the identified receptors, based on the event probabilities, fire and explosion assessment,
- determine the exceedance curve and calculate the impairment frequency using the vulnerability criteria.
- Review the existing protection measures in place based on the above review and identify
recommendations/design measures to limit the impact from explosion.
