Quantitative Risk Assessment

QRAWhat is QRA?

Quantitative Risk Assessment (QRA) is a method for calculating individual, environmental, employee and public risk levels.

Why QRA is needed?

Satisfactory demonstration of acceptable risk levels is often a requirement in, for example, the approval of major hazard plant construction plans, or significant changes to operations which may include areas such as plant modification and changes in operational manning levels

Who need QRA?

Facilities requiring Quantitative Risk Assessment (QRA) studies may include production and processing facilities, high pressure pipelines or storage and importation sites including liquefied natural gas (LNG). QRA may be a requirement of applicable legislation and/or internal company governance to show that risks are identified and controlled to an acceptable level. The criteria for risk acceptability may be defined by local regulations or company / investor policy.

Our Methodology

We carry out Risk Assessment for existing as well as proposed units using most prevalent and relevant methodologies that involve the steps of identifying hazards associated with the operations and selecting worst case scenario for consequences estimation. Adopting reputed software models for consequences estimation. We suggest the measures to minimize or mitigate risks to meet appropriate acceptability criteria and/or demonstrating that the risks are as low as reasonably practicable (ALARP).

The method may include some or all of the following

  • Identification of Hazards
  • Selection of scenarios to be modeled
  • Estimation of Frequency of Failure(By Fault Tree Analysis OR Event Tree Analysis)
  • Consequence Analysis: An analysis of the severity / consequence of accident scenarios
  • Predicted number of fatalities / casualties for each scenario
  • Estimation of Individual risk
  • Group / Societal risk
  • Potential loss of life
  • Location specific risk
  • Preventive / mitigation measures

We have experience of modeling most major accident consequences including fires, explosions, toxic gas releases and hazardous spills. A wide range of software modeling tools is used to assess the effects of such hazards on people (on- and off-site), the asset and the environment.

Our Experience

We have performed numerous studies into the effects of fires at hazardous installations.

In QRA study, Jet fires, flash fires, pool fires and BLEVEs can be modeled to calculate flame temperature and heat flux in the vicinity of the flame. The consequences to persons, structures or equipment can be estimated using this information.

Pool fires can be modeled using a number of techniques and the heat fluxes around the fire calculated.

Gas Dispersion Studies: Concentration of toxic gas at specific location after specific time of leakage can be modeled.

Customer References