1. Quantitative Risk Assessment

2. What is QRA
Systematic methodology to assess risks associated any installation
Taking into consideration all forms of hazards
Uses design information and historical data to estimate frequency of failure
Uses modelling software to assess consequence
Where/when is QRA needed
CIMAH 1989 – part of CIMAH safety report
EQA 1985 – a section under EIA

3. Risk = Severity x Likelihood
Definition
Risk = Severity x Likelihood
Extent of Damage
Fatality
Injuries
Losses
Analysis based on design and modeling equations
Likelihood of event
Based of failure frequency of process components
Analysis based on manufacturer’s and historical data

4. Hazard Identification Risk Estimation and Evaluation
Methodology
Hazard Identification
Frequency Analysis
Consequence Analysis
Risk Estimation and Evaluation
Risk Management

5. Hazard Identification
Purpose: to identify plausible hazard conditions
Methods
Check-list, Preliminary Hazard Review, HAZID, HAZOP etc.
Unstructured brainstorming?
Further Details

6. Frequency Analysis Sometimes referred to as Hazard Analysis
Purpose: To estimate the likelihood for a hazard scenario to occur
Methods
Event-Tree Analysis
Fault-Tree Analysis
Further Details

7. Consequence Analysis Further Details
Purpose: To assess the extent of damage
Typical Hazard
Toxic Release, Fire and Explosion
Modelling of hazard scenario
Toxic Release: Source (Release) Model, Dispersion
Fire and explosion: Source Model, Fire and Explosion, Heat Dispersion
Fatality Assessment: Probit Analysis
Nonfatal Consequence: Skin-burn, Property damage
Further Details

8. Risk Estimation and Evaluation
Purpose: To assess Risk and Make Safety Judgment
Methods
Individual Risk: IRPA, LSIR
Societal Risk
Tolerability Criteria
Further Details

9. Risk Management
Propose: to propose mitigating measure to reduce the potential impact of the hazard and possibly reduce the risk level
Method
Safe Work Procedure at every project stages
Emergency Response Management
Emergency Response Procedure