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Business Sensitive Risk-Informed Decision-Making: Basic Concepts Presentation to the State Energy Risk Assessment Workshop April 28-29, 2015 Presented by Steve Unwin, Ph.D. Pacific Northwest National Laboratory 1 PNNL-SA-108973
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Business Sensitive
Risk-Informed Decision-Making: Basic ConceptsPresentation to theState Energy Risk Assessment WorkshopApril 28-29, 2015
Presented by Steve Unwin, Ph.D.Pacific Northwest National Laboratory
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PNNL-SA-108973
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Outline
Risk DecisionsRisk ModelsRisk ManagementRisk PerceptionRisk GuidanceFirst Steps
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Risk-Informed Decision-Making
Decisions that take into account:Uncertain future eventsThe impacts of those eventsThe likelihoods of those events
Structuring data, judgment, and system logic in a coherent framework for decision-making
Risk-Informed versus Risk-Based decisionsThe reality of accounting for risk
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Modeling Risk
Hazardcondition that poses threat: presence of flammables or toxics, natural phenomena, potential for market upsets, threat of malevolent acts, presence of physical energies, ...
Scenariospecific hypothetical sequence of events that would result in adverse consequences
Riska combination of the adverse consequences and likelihoods of a scenario set
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Risk Models – What varies between them?
Scopenatural phenomena? terrorism? human factors? system boundaries? impact region of concern? ...
Depthmodel resolution: e.g., industries vs. facilities vs. systems vs. components (how far into the weeds?)
Precisionfull quantitative vs. order of magnitude vs. qualitative
Risk typessafety, environmental, production/outage, business, schedule, budget, public perception
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5/1/2015
Risk Type: Business – Risk (probability-weighted production loss) associated with forced outage of refinery units
0 200,000 400,000 600,000 800,000 1,000,000 1,200,000 1,400,000
CRUDE BLENDING
CRUDE UNIT
VACUUM DISTILLATION
DELAYED COKING
NAPHTHA HYDROTREATING
DISTILLATE HYDROTREATING
GAS OIL HYDROTREATING
REFORMING
FLUIDIC CAT CRACKING
OLEFIN TREATING
ALKYLATION
VAPOR RECOVERY/GAS TREAT
SOUR WATER STRIPPING
SULFUR RECOVERY
HYDROGEN PLANT
Downtime $ risk per quarter
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5/1/2015
Risk Type: Safety & Health – Frequency vs. number of individuals exceeding ERPG2 exposure due to presence of a selective catalytic reduction unit at a fossil plant
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Broadly Risk-Oriented: Representation of bulk power system interruption
NERC, 2010
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Structure of a Risk ModelModels
Mechanistic modelsnatural phenomenaengineered system behavior
Logic models (event trees, fault trees, networks)logical relationships between events
Evidence/likelihood modelsprobabilisticother
Consequence modelshealth, exposure, financial, reputation, ...
InputHard data/statistical modelsInformed judgment
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Example: Event tree that models fire risk in a research facility – Systematically defines scenarios
Ignition Failure to immediately extinguish
Ignition was in a Cluster area
Failure to prevent propagation beyond room/cluster
END STATE
Ignition occurs Personnel unable to extinguish immediately or no extinguishers present
No fire suppression system (sprinkler) in place, failure to actuate locally, or system ineffective
High combustibles / flammables load in adjacent rooms
No fire suppression (sprinkler) system in place, or failure to actuate globally, or system ineffective
Failure of other fire isolation system (fire wall)
Failure of emergency response organization to respond effectively
P1: Annual Frequency P2: Probability (Yes) P3: Probability (Yes) P4: Indicator P5: Probability (Yes) P6: Probability (Yes) P7: Probability (Yes) P8: Probability (Yes)
Yes Yes Yes Yes Yes Yes Yes 1. Building Cluster Damage
No 2. Local Cluster Damage
No 3. Local Cluster Damage
No 4. Local Cluster Damage
No 5. Local Cluster Damage
No Yes Yes Yes Yes 6. Building Cluster Damage
No OK
No OK
No OK
No OK
No Yes 7. Local Water Damage
No OK
No OK
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Risk Management
Doing what needs to be done tocontinually and economically reduce risks.
Once we know where the greatest risks lie,effectively manage them.
Where can resources be most effectively spent to reduce risk?Where might expenditures be reduced without significantly affecting risk?
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The Elements of Risk Management
Analysis
Evaluation
Control
Communication
Research
Monitoring
Determining risks and uncertainties
Identifying risk and uncertainty drivers. Assessing risk and uncertainty-reduction options
Reducing the uncertainties Reducing and controlling the risks
Communicating risks and their management to stakeholders
Ongoing confirmation/revision of assumptions about risk
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Risk-Informed Decision Portfolio
Risk tolerance criteria/goals, limits/objectivesnumerical risk acceptance levels
Risk-based prioritization/allocationrisk importance metrics
Cost/benefit analysisALARP
as low as reasonably practicablerisk-based cost-benefit analysis
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Risk objectives and limits. Risk acceptance criteria for public radiation exposure
1.0E-06
1.0E-05
1.0E-04
1.0E-03
1.0E-02
1.0E-01
1.0E+00
1.0E+01
1.0E-01 1.0E+00 1.0E+01 1.0E+02 1.0E+03 1.0E+04
Ann
ual E
xcee
denc
e Fr
eque
ncy
Maximum Individual Public Dose (mSv)
UK Health and Safety Executive Dose Tolerance
Basic safety limit
Basic safety objective
Targeted risk level
Greatest tolerable risk level
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Risk-ranking for explosion damage in chemical process facility
STRUCTURE RANK6 Fermentation Building 2.83 Process 95 Building 2.92 Control Room A 2.95 Extraction Building 3.04 Laboratory Area 3.17 Maintenance Building 3.3
10 Guard Shack 3.49 Stores 6.28 Warehouse 6.91 Administration Offices X
SOURCE RANKFermentation Area VCE 2.3Process 95 PVE 2.9Extraction Area PVE 3.3Process 95 VCE 3.8Extraction Area VCE 6.2Main Storage PVE 6.2Tank Farm B BLEVE 6.4Main Storage BLEVE 7.1Tank Farm B PVE 8.0
Vulnerable Structures
Explosion Sources
High rank = high protection priority
High rank = high prevention priority
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Cost-Benefit Criteria: Risk reduction / cost tradeoff
USNRC: US$ 2,000/person-rem (radiological dose) averted
UK HSE:UK£ 0.75 M per fatality averted
Range inferred from a variety of organizations (1990s):$20K - $100M per fatality averted
Cost
Risk-Reduction Unwarranted
expenditure
Cost-beneficialexpenditure
Cost-benefit acceptance thresholdAssessing
a risk-reduction option:
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ALARP:As Low (A Risk) As Reasonably Practicable
Reduce Risk Regardless of Cost
Follow Good Practice
Consider Cost of Risk-
Reduction
De
Minimis
Risk
Risk Intolerable
Tolerable if ALARP
Risk Tolerable
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Risk Perception
Perceived versus calculated
Factors driving risk perceptionPersonal controllability of exposureDreadedness of potential consequences“Visibility” of exposureFairness of risk and benefit distribution
Peter Sandman’s EquationRisk = Hazard + Outrage
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Risk Perception Factors
DNA Technology
SSTElectric FieldsDES
Nitrogen Fertilizers
Radioactive WasteCadmium Usage Mirex
Trichloroethylene2,4,5-T
Nuclear ReactorAccidentsUranium MiningPesticidesNuclear WeaponsFallout
PCBsAsbestosInsulation
Satellite CrashesMercury DDT
Fossil FuelsCoal Burning (Pollution)
Nerve Gas AccidentsD-CON
LNG Storage &Transport
Auto Exhaust (CO)
Coal Mining (Disease)Large Dams
SkyScraper FiresNuclear Weapons (War)
Coal Mining Accidents
General AviationSport Parachutes
UnderwaterConstruction
High ConstructionRailroad Collisions
Commercial AviationAlcoholAccidents
Auto RacingAuto Accidents
HandgunsDynamite
FireworksBridges
MotorcyclesBicycles
Electric Wir & Appl (Shock)SmokingRecreational Boating
Downhill Skiing Electric Wir & Appl (Fires)Home Swimming Pools Elevators
ChainsawsAlcohol
TractorsTrampolinesSnowmobilesPower Mowers
Skateboards
Smoking (Disease)
CaffeineAspirin
VaccinesLead Paint
RubberMfg.
Auto Lead
AntibioticsDarvonIUDValium
DiagnosticX-Rays
Oral ContraceptivesPolyvinylChlorideCoal Tar Hairdyes
HexachloropheneWater ChlorinationSaccharin
Water FluoridationNitrates
Microwave OvensLaetrile
Factor 2Unknown risk
Factor 1Dread risk
UncontrollableDreadGlobal CatastrophicConsequences FatalNot EquitableCatastrophicHigh Risk to Future
GenerationsNot Easily ReducedRisk IncreasingInvoluntary
Not ObservableUnknown to Those ExposedEffect DelayedNew RiskRisk Unknown to Science
From:
Slovic, P. (1987). Perception of risk. Science, 236, 280-285.
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Risk Standards / Methodology Guides / Risk Acceptance Criteria / Review Guides
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Risk reading: A few starting points -
Quantifying and Controlling Catastrophic Risks, by B. John Garrick (Academic Press, 2008)U.S. Nuclear Regulatory Commission, A Proposed Risk Management Regulatory Framework, NUREG-2150, 2012 Guidelines for Chemical Process Quantitative Risk Analysis (American Institute of Chemical Engineers, 2nd
Ed., 1999)NASA, Risk-Informed Decision Making Handbook, NASA/SP-2010-576, 2010
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First StepsObjectives/Drivers?
strategy selection, design support, optimizing operations, public communications, ...
Hazard space?incidents/accidentsnatural phenomenamalevolent actsmarket eventsetc.
Risk space?financialenvironmentalproductionsafetysecuritypublic perception
