Consequence Risk Assessment

Risk can be defined as a combination of the likelihood of an event and its consequence.

The Process Risk Assessment aims to quantify both consequence and likelihood of the Major Accident Events (MAEs) identified in the facility.

Consequence assessment will estimate the severity of the damage to people safety, environment and assets and the frequency assessment will provide the associated frequency of occurrence.

Quantitative Risk Assessment will provide details inputs for Risk based decision making during the Risk Management phase.

Results of the Risk Assessment will be also used to optimise the Design Accidental Loads of critical elements, to assess the survivability of the emergency systems, to optimise the Escape, Evacuation and Rescue means and to ensure adequacy of the Temporary Refuge.

  • Fire and Explosion Risk Analysis (FERA):
    FERA is a detailed approach to quantify the risk related to hydrocarbon release leading to fire and explosion. The aim is to evaluate the potential damages to the targets (i.e. critical equipment and/or structures) and identify the possible requirement for additional risk reduction measures to help prevent and/or mitigate the effects of the identified fire and explosion scenarios. The FERA can be carried out using different tools from simple models and guidelines to sophisticated modelling software (e.g. 2D software PHAST or Computational Fluid Dynamics (CFD) software FLACS).

  • Smoke and Gas Dispersion Analysis (SGDA):
    SGDA is a detailed approach to quantify the risk related to smoke and gas release (toxic or flammable). The aim is to evaluate the potential impact to the targets (air intakes of equipment, living areas or enclosed spaces, sources of ignition such as flare) and identify the possible requirement for additional risk reduction measures to help prevent and/or mitigate the effects of the identified scenarios. Specific modelling tools (e.g. 2D software PHAST or 3D Computational Fluid Dynamics (CFD) software FLACS) are used to support this study.

  • Flare Dispersion Analysis:
    Companies wishing to achieve a controlled level of safety and to comply with local Authorities’ safety requirements need to demonstrate that flares are properly designed and that risks related to flare radiations are managed and reduced to an acceptable level. Consequence assessment to evaluate the radiation generated by the flare can be carried out with FLARESIM software. When a highly detailed assessment is needed to take into account the facility geometry, the radiation levels can be evaluated using Computational Fluid Dynamics (CFD) software.

  • Vent Dispersion Analysis:
    In order to achieve a controlled level of safety and to comply with local Authorities’ safety requirements, vents are to be properly designed and risks related to vent dispersion are to be managed and reduced to an acceptable level. Consequence assessment to evaluate the flammable and toxic gas dispersion during venting can be carried out with PHAST software. When a highly detailed assessment is needed to take into account the facility geometry, the dispersion modelling can be performed using Computational Fluid Dynamics (CFD) software such as FLACS.