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PIPELINE QRA SEMINAR
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PIPELINE RISK ASSESSMENTRISK ACCEPTANCE CRITERION
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“comparing the level of risk found during the analysis
process with risk criteria established”
INTRODUCTION TO RISK ACCEPTANCE CRITERION
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• Why do you have a risk acceptance criterion?
• End-point of the risk assessment
• To be able to say whether the risk is acceptable or not
• Established by companies (internal) and/or authorities
(external)
• Base for decision-making
INTRODUCTION TO RISK ACCEPTANCE CRITERION
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• Usually talking about:
- Tolerable (acceptable - green)
- Intolerable (unacceptable - red)
• And then…
- ALARP (control to ALARP/acceptable if ALARP - yellow)
• What is ALARP?
INTRODUCTION TO RISK ACCEPTANCE CRITERION
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• Two conflicting objectives need to be balanced
-We have a desire to do everything physically possible to
remove all risks
- We have limited resources and that it is nearly always not
practical (nor physically possible) to remove all risk
• ALARP principle include demonstrate that the cost
involved in reducing the risk further would be grossly
disproportionate to the benefit gained
INTRODUCTION TO RISK ACCEPTANCE CRITERION
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• When is a risk tolerable (acceptable)?
• What is a risk intolerable (unacceptable)?
INTRODUCTION TO RISK ACCEPTANCE CRITERION
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• Everyday life – risk perception deciding the risk acceptance
criterion
Definition (Wikipedia)
“the subjective judgment that people make about the
characteristics and severity of a risk”
• 19 per 100.000 deaths from driving
• < 0.5 per 100.000 deaths from flying
• 268 per 100.000 deaths from cardiovascular diseases
INTRODUCTION TO RISK ACCEPTANCE CRITERION
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• Risk perception could be depending on a number of factors:
- Social context (e.g. group pressure)
- Benefits versus losses (i.e. what could be gained versus lost)
- Risk aversion (i.e. better many small accidents than one
catastrophe)
- Control (e.g. driver versus passenger)
- Experience (i.e. unknown or know)
• Driving versus flying
INTRODUCTION TO RISK ACCEPTANCE CRITERION
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• Working life – different theoretical approaches on how to
decide the risk acceptance criterion
- Comparison (e.g. statistics on accidents/fatalities and
other industries/activities)
- State-of-the-art (i.e. as safe as possible)
- Economics (i.e. price per human life)
• Different for organizations (e.g. the well being for many)
versus companies (e.g. economical aspects) versus
authorities (e.g. combinations)
INTRODUCTION TO RISK ACCEPTANCE CRITERION
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• Traffic authorithy in Sweden state that 22.3 million SEK
(5.5 million GEL) is the acceptable cost for saving a life
• Safety systems (e.g. traffic barrier) is analyzed with this
approach
• How many lives could we save with this implementation
of safety system – comparison with total cost and the
acceptable cost for saving a lie (or several lives)
EXAMPLE OF RISK ACCEPTANCE CRITERION – SWEDEN TRAFFIC AUTHORITY
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• Traffic authority in Norway state that 25.0 million NOK
(5.5 million GEL) is the acceptable cost for saving a life
• Offshore industry in Norway state that up to 100.0
million NOK (up to 27.3 million GEL) is the acceptable
cost for saving a life
EXAMPLE OF RISK ACCEPTANCE CRITERION – SWEDEN TRAFFIC AUTHORITY
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• What kind of risk acceptance criterions are there?
• Quantitative and qualitative (compare with quantitative risk assessment and qualitative risk assessment)
• You can have risk acceptance criteria for everything!
-Environmental
-Human safety (e.g. discomfort, injuries and fatalities)
-Economical
-Project (e.g. delay)
-Reputation
INTRODUCTION TO RISK ACCEPTANCE CRITERION
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-Environmental (e.g. allowable size of release and impact on the
environment)
-Human safety – individual risk (i.e. allowable risk for a single person)
- Human safety – group risk/societal risk (i.e. allowable risk for a defined
population)
- Human safety – consequence distance (e.g. allowable for dispersion of
gas)
-Economical (e.g. allowable potential loss from investment and cost)
-Project (e.g. allowable delay)
-Reputation (e.g. allowable attention from news, NGO’s and authorities)
INTRODUCTION TO RISK ACCEPTANCE CRITERION
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• Current risk acceptance criteria - consequence distance of
200 meters (no activities or structures)
• Difference between consequence distance of 200 meters
(fixed) and consequence distance of X meters (based on
calculations of allowable concentrations)
• Paper product versus actually practical (e.g. pipelines in
urban areas and supply of gas to industries/residences)
EXAMPLE OF RISK ACCEPTANCE CRITERION – GEORGIA PIPELINES
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• Future risk acceptance criteria – human safety based (e.g.
individual risk/societal risk)
• What could be the benefits?
- Flexibility - allow activities and structures within 200 meters
(sometimes not!)
- Actual knowledge and understand of the risk from the pipeline
EXAMPLE OF RISK ACCEPTANCE CRITERION – GEORGIA PIPELINES
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• Qualitative risk acceptance criteria
- Risk matrix
- Descriptions
• Descriptions support to the risk matrix
• Descriptions
- Human safety (e.g. minor injury or health effect or multiple
fatalities)
- Environmental (e.g. major environmental damage over an
extensive area, but recovery is possible)
- Reputation (e.g. National public, government or NGO concern)
QUALITATIVE RISK ACCEPTANCE CRITERION
Probability/frequency
HighMedium
LowLow Medium High
Consequence
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QUALITATIVE RISK ACCEPTANCE CRITERION
Probability/frequency
HighLow
Low High
Consequence
Probability/frequency
SevereSignificantModerate
MinorNegligible
Very unlikely
Unlikely Possible LikelyVery likely
Consequence Probability/frequency
HighMedium
LowLow Medium High
Consequence
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QUALITATIVE RISK ACCEPTANCE CRITERIONProbability/frequency
HighMedium
LowFatalities Injuries Discomfort
ConsequenceProbability/frequency
HighMedium
Low
Massive environmental
impact (no recovery)
Massive environmental
impact (recovery)
Small environmental impact (recovery)
Consequence
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• Quantitative risk acceptance criteria
- Numerical values (more or less)
• Human safety - individual risk
- individual risk for 1st person (e.g. operator)
- individual risk for 3rd person (e.g. public)
QUANTITATIVE RISK ACCEPTANCE CRITERION
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• Human safety – group risk/societal risk
- group risk/societal risk for 1st person and 3rd person
(including the entire population)
• Presented as FN-curve
- Frequency plotted against the number of fatalities
- Cumulative frequency of N or more fatalities
- Criteria 1 – 1 fatality with frequency 1 x 10-3 per year
- Criteria 2 – 10 fatalities with frequency 1 x 10-5 per year
- Criteria 3 – 100 fatalities with frequency 1 x 10-7 per year
• Offshore also presented as FAR (Fatal Accident Rate)
- Fatalities per 0.1 billion (108) working hours (or exposure hours)
QUANTITATIVE RISK ACCEPTANCE CRITERION
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• FN-curve
- Frequency plotted against the number of fatalities
- Cumulative frequency of N or more fatalities
- Criteria 1 – 1 fatality with frequency 1 x 10-3 per year
- Criteria 2 – 10 fatalities with frequency 1 x 10-5 per year
- Criteria 3 – 100 fatalities with frequency 1 x 10-7 per year
- Accident 1 – 100 fatalities with frequency < 1 x 10-9 per year
- Accident 2 – 10 fatalities with frequency 4 x 10-7 per year
- Accident 3 – 1 fatality with frequency 1 x 10-5 per year
- Accident 4 - …
QUANTITATIVE RISK ACCEPTANCE CRITERION
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• Who is deciding the risk acceptance criterion?
• Established by organizations (guidelines), authorities
(legal requirements) and companies (internal
requirements)
• Different theoretical approaches for organizations (e.g.
the well being for many) versus companies (e.g.
economical aspects) versus authorities (e.g.
combinations)
QUANTITATIVE RISK ACCEPTANCE CRITERION
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• Comparison of different quantitative risk acceptance criterion for individual risk:
- U.K. – 3rd party – acceptable at < 1.0 x 10-6 per year
- Netherlands – 3rd party - acceptable at < 1.0 x 10-8 per year
- Netherlands – 3rd party - unacceptable at > 1.0 x 10-6 per year (for new facilities)
- Netherlands – 3rd party - unacceptable at > 1.0 x 10-5 per year (for existing facilities)
- Venezuela – 1st party – acceptable at < 1.0 x 10-6 per year
- Venezuela – 1st party – unacceptable at > 1.0 x 10-3 per year
QUANTITATIVE RISK ACCEPTANCE CRITERION
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• Comparison of different activities and quantitative risk acceptance criterion for individual risk
(usually < 1.0 x 10-6 per year):
- dying (non-specific cause) - 1.0 x 10-2 per year
- smoking (20 cigarettes per day) – 5 x 10-3 per year
- 1.0 x 10-6 per year
- killed by lightning - 1.0 x 10-7 per year
- killed by meteorite - 1.0 x 10-11 per year
QUANTITATIVE RISK ACCEPTANCE CRITERION
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• Comparison of different quantitative risk acceptance
criterion for group risk/societal risk
- Dark blue – Flanders (region in Netherlands)
- Blue – Netherlands
- Pink – Denmark (where grey indicate ALARP)
- Red – indicative value for U.K.
QUANTITATIVE RISK ACCEPTANCE CRITERION
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• Comparison of different activities and quantitative risk acceptance criterion for group risk/societal risk
(usually FAR = 15 – fatalities per 108 working/exposure hours):
- staying at home - 3
- agriculture – 3.7
- 15
- driving a car - 57
- driving a motorcycle - 660
QUANTITATIVE RISK ACCEPTANCE CRITERION
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QUESTIONS?