Smoke and Toxic Gas Dispersion Analysis
The objective of the smoke and toxic gas analysis is to analyse the hazardous events which have been identified in the HAZID and which will lead to the impairment of escape and evacuation routes or Temporary Refuge (TR) (if applicable).
Escape routes can be impaired by either smoke or toxic gas engulfment, or catastrophic events to the installation that could lead to the loss of the facility. The effects of these hazards are assessed to determine what will impair the escape routes and TR. The integrity of the escape routes will be evaluated based on relevant impairment criteria.
The following events will be covered:
- Toxic release
- Flash fire
- Vapour cloud explosion
- Jet fire
- Pool fire
- Boiling liquid expanding vapour explosion (BLEVE)
- Toxic combustion products
Effects shall be modelled in terms of:
- Potential for flame engulfment or impingement
- Heat radiation levels
- Explosion overpressures
- Toxic concentration
Approach
The overall approach to this analysis is summarised as follows:
- Summarise the hazards capable of causing smoke or a flammable gas cloud or causing significant damage to the installation, as identified in the HAZID
- Investigate the dispersion of smoke and/ or gas from its various potential sources towards the escape route or TR
- Assess the effectiveness of the accommodation boundaries at preventing smoke and gas ingress
- Identify the consequences of smoke and/ or gas ingress into the escape route or TR, where they have been shown to be able to occur
- Assess other catastrophic incidents from other safety studies which could lead to impairment
- Assess the time to impairment of all the events which lead to impairment, as appropriate
- Review the prevention and mitigation systems that could reduce the potential for ingress
- Assess time required for pick up from sea, with or without flotation device
- Weather conditions that could hamper the above
This analysis is an essential step in identifying whether the EER goals have been achieved, and to assess the safety systems in place to reduce the potential for facility impairment to As Low As Reasonably Practicable (ALARP). The results for quantification of these hazards on the overall risks to the installations will be carried forward to the QRA.
Smoke and Toxic Gas Dispersion Analysis
The objective of the smoke and toxic gas analysis is to analyse the hazardous events which have been identified in the HAZID and which will lead to the impairment of escape and evacuation routes or Temporary Refuge (TR) (if applicable).
Escape routes can be impaired by either smoke or toxic gas engulfment, or catastrophic events to the installation that could lead to the loss of the facility. The effects of these hazards are assessed to determine what will impair the escape routes and TR. The integrity of the escape routes will be evaluated based on relevant impairment criteria.
The following events will be covered:
- Toxic release
- Flash fire
- Vapour cloud explosion
- Jet fire
- Pool fire
- Boiling liquid expanding vapour explosion (BLEVE)
- Toxic combustion products
Effects shall be modelled in terms of:
- Potential for flame engulfment or impingement
- Heat radiation levels
- Explosion overpressures
- Toxic concentration
Approach
The overall approach to this analysis is summarised as follows:
- Summarise the hazards capable of causing smoke or a flammable gas cloud or causing significant damage to the installation, as identified in the HAZID
- Investigate the dispersion of smoke and/ or gas from its various potential sources towards the escape route or TR
- Assess the effectiveness of the accommodation boundaries at preventing smoke and gas ingress
- Identify the consequences of smoke and/ or gas ingress into the escape route or TR, where they have been shown to be able to occur
- Assess other catastrophic incidents from other safety studies which could lead to impairment
- Assess the time to impairment of all the events which lead to impairment, as appropriate
- Review the prevention and mitigation systems that could reduce the potential for ingress
- Assess time required for pick up from sea, with or without flotation device
- Weather conditions that could hamper the above
This analysis is an essential step in identifying whether the EER goals have been achieved, and to assess the safety systems in place to reduce the potential for facility impairment to As Low As Reasonably Practicable (ALARP). The results for quantification of these hazards on the overall risks to the installations will be carried forward to the QRA.