engineering risk assessments and risk communication sarah arulanandam, hazard and risk group rwdi...
TRANSCRIPT
Engineering Risk Assessments and Risk Engineering Risk Assessments and Risk CommunicationCommunication
Sarah Arulanandam, Hazard and Risk Group RWDI West Inc.
DISCLOSURE OF MATERIAL ENVIRONMENTAL EXPOSURES: What should investors expect?January 20, 2005
Definitions of RiskDefinitions of Risk
Risk = frequency x consequence Frequency: accidental releases, upset conditions Consequences: short-term, acute
Risk = exposure x effect Exposure: low-level, continuous emissions Effect: long-term chronic
Risk = frequency x consequence x outrage Outrage: stakeholders, media, public, government
Risk = attractiveness of target x consequence Attractiveness: likelihood of attack
Risk = ???
TECHNOLOGY SELECTION
• Design & Construction Standards
• Control Options• Accident, Mitigation &
Recovery Options
RISK BASED DECISIONS
RISK ASSESSMENT• Public Involvement• Guidelines & Standards• Risk Utility• Risk Acceptability• Risk Communication
RISK ANALYSIS• Employee and Worker
Safety • Public Safety • Environmental• Financial
HAZARD ANALYSIS• Hazard Identification• Source Term Modelling• Dispersion Modelling &
Forecasting• Receptor Response
Modelling
FREQUENCY ANALYSIS• Historical Accident
Incident Data• Predictive Failure Models• Event Tree Analysis• Fault Tree Analysis
RISK RISK MANAGEMENTMANAGEMENT
Steps Involved in Steps Involved in Hazard and Risk ManagementHazard and Risk Management
Identify the hazards Define the system and characterize the
source Conduct dispersion modelling Estimate the consequences
Compare hazard results to accepted public health and safety criteria
Review the options for managing the hazards Examine failure frequencies and event
probabilities Estimate the risk
Compare risk results to accepted risk criteria Review the options for managing and
reducing the hazards and risks (i.e., alternate design and operating parameters, and accident control, reduction and mitigation strategies)
Hazard Analysis
RiskAnalysis
RiskManagement
Hazard Assessment
Risk Assessment
Hazard Management
Threat SpectrumThreat Spectrum(Courtesy of DND)(Courtesy of DND)
Least
Greatest
• Most Likely: High Yield Explosive (HYE)Most Likely: High Yield Explosive (HYE)
• Most Dangerous: Nuclear WeaponsMost Dangerous: Nuclear Weapons ----------------------------------------------------------------------------------• Greatest Threat: Contagious Biological PathogenGreatest Threat: Contagious Biological Pathogen
HYE
BiologicalToxins
Industrial Chemicals
Biological Pathogens
Radio-Isotopes
Chemical Weapons
NuclearWeapons
Example: Hazard IdentificationExample: Hazard Identification
Jet Fire:• Exposure to flame• Exposure to heat • Exposure to products
Flash Fire: • Initial exposure
(toxicity)• Exposure to flame• Exposure to heat• Exposure to products
Dispersing plume:• Exposure (toxicity)
Uncontrolled release
Immediate ignition
No immediate ignition
Delayedignition
No ignition
Safety Design and OptimizationSafety Design and Optimization
Compare alternative designs
Assess control systems and operational parameters
Compare risks to accepted standards
Generate alternatives and implementation strategies
Emergency PlanningEmergency Planning Recommendations
for emergency planning zones and land-use
Understand the nature and extent of the hazard
Select the level of protection required
Define an emergency planning zone (EPZ)
Communicate findings
Example: Example: Health and Safety Planning Health and Safety Planning
PrioritiesPriorities
Advance warning of an accident?
Accident occurs
Plume disperses
Exposure to dispersing plumeArea where acute effects may be experienced: • Emergency Response Plan
(responsibility of company)• Selection of EPZ criteria
Area where chronic effects may be experienced:• Public health response area
(shared responsibilities)• Selection of health criteria
Area where other impacts may be experienced
Potential release source
Public Involvement and Public Involvement and CommunicationsCommunications
Present an understanding of the hazards and risks at public meetings
Preparation of materials for presentation to stakeholders
Regulatory applications and expert testimony
Corporate due-diligence and policy development
Forensic Incident AnalysisForensic Incident Analysis
Accident investigation and reporting Describe the system Evaluate the
meteorology during the event
Recreate the incident What happened? Who was affected?
Applications: Hazard and Risk Applications: Hazard and Risk AssessmentsAssessments
Safety design and optimization Recommendations for emergency
planning zones and land-use Public involvement and communications Regulatory applications and expert
testimony Corporate due-diligence policy Accident investigation and reporting
Incidents
Accidents
The Heinrich PyramidThe Heinrich Pyramid
Unreported Occurrences