lopa workbook [2005]
DESCRIPTION
LOPA WorkbookTRANSCRIPT
Entry InstructionsReturn to WorksheetThe Blank White Cells are to allow descriptions to be writtenThe green cells have drop down boxes for you to choose standardised inputsThe Grey Cells have automated inputs depending on the choices made in the green cellsIf you make an error when using the drop downs on cells, please use the delete key and NOT the space key The GAP column for each scenario should read zero or less to close the protection gapLOPA: A worksheet for Layer of Protection AnalysisALARP*: A way of calculating Cost Benefit Analysis to justify added layers of protection yes or noExamples: Some worked examples to help youALARP from ExamplesALARP = As Low As Reasonably Practical (Ref Reducing Risks Protecting People - U.K. Health and Safety Executive
LOPAEntry InstructionsScenario DefinitionConditional
ModifiersIndependent Protection LayersNotesProtect-ion GapScenario
DescriptionTarget Tolerated Event Frequency (User
determined)Initiating Event FrequencyIgnition (valid only for fire
or explosion scenarios)Probability of Exposure/Time at
riskIndependent instrument layers must have separate sensors, logic
solvers and final elements.Other safety related protection
systemsTarget is0 or lessRef NoGive a complete Description of the
undesired outcome and the initiating eventDescribe Consequence of
the scenario, then use the drop downs in the blue rowDescribe the
initiatiating eventRecord the Probability of Ignition. (POI) in the
white row if relevantJustify the probability of exposure or time at
risk in the white row
David C. Veazey: This factor must be defined by Tech Center and
Reviewed by Process SafetyBPCS Control Action - describe in white
rowOperator response to alarms and written procedures - describe in
white rowSafety Instrumented System 1Safety Instrumented System
2Pressure Relief System - overpressure scenariosSRPS 1SRPS 2SRPS 3
Inititiating eventsConditional ModifiersIPLs1.0Interceptor
overflows - leads to fire possible single fatalityLevel control
failsOperation is 500kg released M.I.E. 24 hours for operator to
respond to alarms and procedures, low stress, recognized
event0.0123rd Party InterventionNone>24 hours for operator to
respond to alarms and procedures, low stress, recognized
event055101003Significant disabling Injury on site1.0E-044Fatality
on site1.00E-055BPCS Sensor failure0.11Atmospheric Tank
Failure1.E-033POI < 50kg released0.012POI < 5000kg released
M.I.E. >0.3 mJ0.111 - Other Safety related protection systems
(PFD=.1)0.11Atmospheric Tank FailurePOI 5000kg released10POI >
500kg released M.I.E. 10,000# releasedContainment building capable
of withstanding any credible releaseSafety StudyFrequency 1 in 1000
yrs
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick listPiping Leak < 100m
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick list0.1 Probability of
Exposure
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choiceLow stress operator response recognized event >
10 minutes to respond
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick list
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use the drop down list to make
selection1 - Other safety related protection systems (PFD=0.1)More
than 1 fatality offsite1.0E-077Frequency 1 in 10000000
yrs1.00E-077Double Mechanical Seal Pump Failure0.012Double
Mechanical Pump Seal Failure with announcement1.E-022POI due to
static in closed ungrounded vessel ordinary hydrocarbon0.11POI due
to static in closed ungrounded vessel ordinary hydrocarbon0.11No
BPCS Trip to safe shutdown10Credit for process designed/equivalent
to Dow Standards, practices and LPPs0.012Control valve failurePOI
due to static in closed ungrounded vessel ordinary hydrocarbon
Frequency 1 in 1000 yrs1.0E-033Frequency 1 in 100000000
yrs1.00E-088Canned/Magnetic Drive Pump Failure0.012Expansion Joint
Fails1.E-022Probability of ExposureConditional ModifierAlarm is
from BPCS - not independent10Dikes capable of mitigating initiating
event (Environmental event only)0.012Cooling Water FailureDikes
capable of mitigating initiating event (Environmental event
only)-2532111Frequency 1 in 10000 yrs1.0E-044Minor Injury off
site1.00E-044Cooling Water Failure0.11General Utility
Failure1.E-011Always exposed100.01 Probability of Exposure0.012High
stress operator response average training0.50Enclosure with
attached mitigation device such as scrubber or THROX0.012Double
Mechanical Pump Seal Failure with announcementProbability of
ExposureEnclosure with attached mitigation device such as scrubber
or THROXFrequency 1 in 100000 yrs1.0E-055Loss of electrical
power0.110.1 Probability of Exposure0.11Safety Study
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choice
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick list
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionFrequency 1 in 1000000 yrs1.0E-066Minor Injury on
site1.00E-033General Utility Failure0.11Heat Exch. tube leak 10
minutes to respond0.11Enclosure with elevated stack0.11Expansion
Joint Fails0.01 Probability of ExposureEnclosure with elevated
stackFrequency 1 in 10000000 yrs1.0E-077More than 1 fatality
offsite1.00E-0773rd Party Intervention0.012Heat Exch. tube leak
>100 tubes1.E-0110.01 Probability of Exposure0.01210Low stress
operator response recognized event > 24 hr to respond0.012High
stress operator response average training0.50General Utility
Failure0.1 Probability of ExposureHigh stress operator response
average trainingERROR:#VALUE!0Frequency 1 in 100000000
yrs1.0E-088More than 1 fatality on site1.00E-066Lightning Strike as
an Initiating Event0.0013Heat Exch. tube rupture 1/4 hr to
respond0.11Heat Exch. tube leak >100 tubes0Low stress operator
response recognized event > 1/4 hr to respondSafety Study
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choice
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick list
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionSignificant disabling Injury on site1.00E-044Piping Leak
< 100m0.0013Enclosure with Containment or
treatment0.012Management systems (Describe in Notes)0.11Heat Exch.
tube rupture 100m0.012Containment Building capable of withstanding
all releases0.0013Alarm is from BPCS - not independent10Heat Exch.
tube rupture >100 tubes0 ERROR:#VALUE!0Pipe Rupture-20% Cross
Section)0.00014Dikes/Bunds capable of mitigating incident to low
risk0.012None00NonePipe Rupture->100 m (>20% Cross
Section)0.0013Lightning Strike as an Initiating
Event1.E-033Management System (Describe in notes)0.11PRD (No
evidence of fouling)0.0120 Safety Study
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choice
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick list
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionAtmospheric Tank Failure0.0013Loss of electrical
power1.E-0111 - Other safety related protection systems
(PFD=0.1)0.11No PRD relevant to scenario100PFD=.01 Internal
mechanical trip independent of SIS or BPCSPressure Vessel Failure
Significant Release0.000015Operator Failure Action more than once
per quarter1.E-0112 - Other safety related protection systems
(PFD=0.01)0.012SIS - SIL 10.11Lightning Strike as an Initiating
Event0PFD=.1 Internal mechanical trip independent of SIS or
BPCSERROR:#VALUE!0Expansion Joint Fails0.012Operator Failure Action
once per quarter or less1.E-0223 - Other safety related protection
systems (PFD=0.001)0.0013SIS - SIL 20.012Loss of electrical
power0PRD (No evidence of buildup)Heat Exch. tube leak 100
tubes0.11Pipe Rupture->100 m (>20% Cross
Section)1.E-033None10Operator Failure Action once per quarter or
less0SIS - SIL 2Heat Exch. tube rupture 100 m1.E-022High stress
operator response average training10Alarm is from BPCS - not
independent10Pipe Rupture->100 m (>20% Cross Section)Pressure
Vessel Failure Significant Release1.E-055Low stress operator
response recognized event > 10 minutes to respond0.11High stress
operator response average training10Piping Leak - 24 hr to
respond0.012Low stress operator response recognized event > 10
minutes to respond0.11Piping Leak - >100 mRegulator
failure1.E-011No Alarm Available10Low stress operator response
recognized event > 24 hr to respond0.012Pressure Vessel Failure
Significant ReleeaseERROR:#VALUE!0Single Mechanical Pump Seal
Failure1.E-011No Alarm available10Pump Failure Loss of
FlowUnauthorized changes to logic solver program 5.E+01-2Regulator
failureSafety Study
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choice
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick list
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionUnloading/Loading Hose Failure1.E-011Single Mechanical
Pump Seal FailureUnauthorized changes to logic solver
programERROR:#VALUE!0Unloading/Loading Hose Failure
Safety Study
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choice
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick list
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionERROR:#VALUE!0
Safety Study
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choice
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick list
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionERROR:#VALUE!0
Safety Study
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choice
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick list
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionERROR:#VALUE!0
Safety Study
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choice
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick list
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionERROR:#VALUE!0
Safety Study
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choice
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick list
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionERROR:#VALUE!0
Safety Study
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choice
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick list
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionERROR:#VALUE!0
Safety Study
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choice
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick list
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionERROR:#VALUE!0
ALARP - CostBenefit
Scenario NoProtection GapStage 1 Achieved Event frequencyProtection GapDescription of possible additional IPLCapital cost of Add. IPLOperational Cost of added IPL/yearRisk Reduction achievedAnticipated future life of plant (years)Value of risk reduction (e.g. fatalities or cost avoided)Ratio of Cost to Benefit11.E-05028001501025100000029.11109.000E-069.000E+0022501.E-024ERROR:#DIV/0!100ERROR:#DIV/0!ERROR:#DIV/0!ERROR:#DIV/0!01.E-05-2ERROR:#DIV/0!1000ERROR:#DIV/0!ERROR:#DIV/0!ERROR:#DIV/0!0ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!300030010501000000ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!300010010501000000ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!
ExamplesEntry InstructionsScenario DefinitionConditional
ModifiersIndependent Protection LayersNotesProtect-ion GapScenario
DescriptionTarget Tolerated Event Frequency Initiating Event
FrequencyIgnition (valid only for fire or explosion
scenarios)Probability of Exposure/Time at riskIndependent
instrument layers must have separate sensors, logic solvers and
final elements.Other safety related protection systemsTarget is0 or
lessRef NoGive a complete Description of the undesired outcome and
the initiating eventDescribe Consequence of the scenario, then use
the drop downs in the blue rowDescribe the initiatiating
eventRecord the Probability of Ignition. (POI) in the white row if
relevantJustify the probability of exposure or time at risk in the
white row
David C. Veazey: This factor must be defined by Tech Center and
Reviewed by Process SafetyBPCS Control Action - describe in white
rowOperator response to alarms and written procedures - describe in
white rowSafety Instrumented System 1Safety Instrumented System
2Pressure Relief System - overpressure scenariosSRPS 1SRPS 2SRPS 3
Inititiating eventsConditional ModifiersIPLs1.0R 201 Temperature
control fails (Temperature Transmitter) and initiates runaway
reaction at 185deg CPossible rupture of R201 causes 1 fatality on
site, possible injury off siteTE 201 loop failure, heating demand
stays on beyond normal closure set pointThis is an overpressure
scenarioReaction step is 7 x per day and 1 hour - this is a
regularly occupied areaBPCS trip relies on failed temperature
transmitter loop - so no creditHard wired loop from separate
temperature transmitter to alarm, operator has choice of trips inl.
Manual isolationAdded Pressure transmitter linked to steam block
valvePressure safety Valve PSV 201 designed for this scenario -
dumps to containment vesselSIS A added to close gap. Need o make
sure that both steam control valve and block valve are fail
closed.Target FactorsConditional Modifiers for Layer of Protection
AnalysisIndependent Protection Layer tableSafety StudyFatality on
site
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick listBPCS Instrument Loop
Failure
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list100% probable
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick listAlways
exposed
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick listNo BPCS Trip to safe
shutdown
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choiceLow stress operator response recognized event >
10 minutes to respond
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick listSIS - SIL 1
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirementsPRD (No evidence of fouling)
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionTarget Event DescriptionTargetTarget Event FactorTarget
Event DescriptionTargetTarget Tolerated Event Frequency Initiating
Event Initiating EventInitiating Event FactorInitiating
EventInitiating Event Frequency (per year)Initiating Event
FactorConditional ModifierConditional ModifierIndependent
Protection LayerPFDsCredit FactorMinor Injury on
site1.0E-033Fatality off site1.00E-066BPCS Instrument Loop
Failure0.113rd Party Intervention1.E-022100% probable/no ignition
needed10100% probable10>24 hours for operator to respond to
alarms and procedures, low stress, recognized event0.0123rd Party
InterventionNone>24 hours for operator to respond to alarms and
procedures, low stress, recognized event0551000112Significant
disabling Injury on site1.0E-044Fatality on site1.00E-055BPCS
Sensor failure0.11Atmospheric Tank Failure1.E-033POI < 50kg
released0.012POI < 5000kg released M.I.E. >0.3 mJ0.111 -
Other Safety related protection systems (PFD=.1)0.11Atmospheric
Tank FailurePOI 1,000# released Fast Burning MaterialBPCS
Independent of Initiating Event3.0BPCS Failure leads to runaway
reaction - possible rupturePossible rupture of R201 causes 1
fatality on site, possible injury off siteBPCS failure - unusual
Initiator , but study anywayThis is an overpressure
scenarioReaction step is 7 x per day and 1 hour - this is a
regularly occupied areaBPCS has failed - no indicationHard wired
loop from separate temperature transmitter to alarm, operator has
choice of trips inl. Manual isolationAdded Pressure transmitter
linked to steam block valvePressure safety Valve PSV 201 designed
for this scenario - dumps to containment vesselScenario 1 required
SIS A, so do scenario 2 and 3Fatality off site1.0E-066Frequency 1
in 1000000 yrs1.00E-066Single Mechanical Seal Pump
Failure0.11Cooling Water Failure1.E-011POI > 5000kg
released10POI > 500kg released M.I.E. 10,000#
releasedContainment building capable of withstanding any credible
releaseSafety StudyFatality on site
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick listBPCS Instrument Loop
Failure
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list100% probable/no ignition
needed
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick listAlways
exposed
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choiceLow stress operator response recognized event >
10 minutes to respond
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick listSIS - SIL 1
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirementsPRD (No evidence of fouling)
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionMore than 1 fatality offsite1.0E-077Frequency 1 in
10000000 yrs1.00E-077Double Mechanical Seal Pump Failure0.012Double
Mechanical Pump Seal Failure with announcement1.E-022POI due to
static in closed ungrounded vessel ordinary hydrocarbon0.11POI due
to static in closed ungrounded vessel ordinary hydrocarbon0.11No
BPCS Trip to safe shutdown10Credit for process designed/equivalent
to Dow Standards, practices and LPPs0.012Control valve failurePOI
due to static in closed ungrounded vessel ordinary hydrocarbon
Frequency 1 in 1000 yrs1.0E-033Frequency 1 in 100000000
yrs1.00E-088Canned/Magnetic Drive Pump Failure0.012Expansion Joint
Fails1.E-022Probability of ExposureConditional ModifierAlarm is
from BPCS - not independent10Dikes capable of mitigating initiating
event (Environmental event only)0.012Cooling Water FailureDikes
capable of mitigating initiating event (Environmental event
only)055100112Frequency 1 in 10000 yrs1.0E-044Minor Injury off
site1.00E-044Cooling Water Failure0.11General Utility
Failure1.E-011Always exposed100.01 Probability of Exposure0.012High
stress operator response average training0.50Enclosure with
attached mitigation device such as scrubber or THROX0.012Double
Mechanical Pump Seal Failure with announcementProbability of
ExposureEnclosure with attached mitigation device such as scrubber
or THROX4.0LPG Sphere overfills leading to overpressure , possible
rupture - fire/explosionMajor event caused by faiure of level trip
on high pressure input pumpLevel transmitter/trip failslarge
release will certainly find ignition sourcePeople cannot avoid
exposure but tank is being filled less than 10% of timeTrip
operates on pump starter control circuit, but does not receive
signal because loop has failedOperator is trained to respond to
thisIndependent level trip loop to pump power supplyPressure trip
closes inlet valveRelief system operates - is sized for full pump
flowNeed to assure that a) there is a detection network which
alarms if relief valves operate, b) if filling is more than 10% of
time due to business , further protection is needed . Note: it
might be possible to eliminate the scenario if the pump dead head
pressure is less than the SWP of the sphere. Also it may be
allowable to account for a second relief system if it is
independent of the first. This relief scenario needs a dispersion
analysis.Frequency 1 in 100000 yrs1.0E-055Loss of electrical
power0.110.1 Probability of Exposure0.11Safety StudyFrequency 1 in
10000000 yrs
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick listBPCS Instrument Loop
Failure
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick listPOI > 5000kg
released
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick listAlways
exposed
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick listNo BPCS Trip to safe
shutdown
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choiceLow stress operator response recognized event >
10 minutes to respond
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick listSIS - SIL 2
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirementsNone
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirementsPRD (No evidence of fouling)
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionFrequency 1 in 1000000 yrs1.0E-066Minor Injury on
site1.00E-033General Utility Failure0.11Heat Exch. tube leak 10
minutes to respond0.11Enclosure with elevated stack0.11Expansion
Joint Fails0.01 Probability of ExposureEnclosure with elevated
stackFrequency 1 in 10000000 yrs1.0E-077More than 1 fatality
offsite1.00E-0773rd Party Intervention0.012Heat Exch. tube leak
>100 tubes1.E-0110.01 Probability of Exposure0.01210Low stress
operator response recognized event > 24 hr to respond0.012High
stress operator response average training0.50General Utility
Failure0.1 Probability of ExposureHigh stress operator response
average training16710001202Frequency 1 in 100000000 yrs1.0E-088More
than 1 fatality on site1.00E-066Lightning Strike as an Initiating
Event0.0013Heat Exch. tube rupture 1/4 hr to respond0.11Heat Exch.
tube leak >100 tubes0Low stress operator response recognized
event > 1/4 hr to respondSafety Study
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choice
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick list
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionSignificant disabling Injury on site1.00E-044Piping Leak
< 100m0.0013Enclosure with Containment or
treatment0.012Management systems (Describe in Notes)0.11Heat Exch.
tube rupture 100m0.012Containment Building capable of withstanding
all releases0.0013Alarm is from BPCS - not independent10Heat Exch.
tube rupture >100 tubes0 ERROR:#VALUE!0Pipe Rupture-20% Cross
Section)0.00014Dikes/Bunds capable of mitigating incident to low
risk0.012None00NonePipe Rupture->100 m (>20% Cross
Section)0.0013Lightning Strike as an Initiating
Event1.E-033Management System (Describe in notes)0.11PRD (No
evidence of fouling)0.0120 Safety Study
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choice
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick list
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionAtmospheric Tank Failure0.0013Loss of electrical
power1.E-0111 - Other safety related protection systems
(PFD=0.1)0.11No PRD relevant to scenario100PFD=.01 Internal
mechanical trip independent of SIS or BPCSPressure Vessel Failure
Significant Release0.000015Operator Failure Action more than once
per quarter1.E-0112 - Other safety related protection systems
(PFD=0.01)0.012SIS - SIL 10.11Lightning Strike as an Initiating
Event0PFD=.1 Internal mechanical trip independent of SIS or
BPCSERROR:#VALUE!0Expansion Joint Fails0.012Operator Failure Action
once per quarter or less1.E-0223 - Other safety related protection
systems (PFD=0.001)0.0013SIS - SIL 20.012Loss of electrical
power0PRD (No evidence of buildup)Heat Exch. tube leak 100
tubes0.11Pipe Rupture->100 m (>20% Cross
Section)1.E-033None10Operator Failure Action once per quarter or
less0SIS - SIL 2Heat Exch. tube rupture 100 m1.E-022High stress
operator response average training10Alarm is from BPCS - not
independent10Pipe Rupture->100 m (>20% Cross Section)Pressure
Vessel Failure Significant Release1.E-055Low stress operator
response recognized event > 10 minutes to respond0.11High stress
operator response average training10Piping Leak - 24 hr to
respond0.012Low stress operator response recognized event > 10
minutes to respond0.11Piping Leak - >100 mRegulator
failure1.E-011No Alarm Available10Low stress operator response
recognized event > 24 hr to respond0.012Pressure Vessel Failure
Significant ReleeaseERROR:#VALUE!0Single Mechanical Pump Seal
Failure1.E-011No Alarm available10Pump Failure Loss of
FlowUnauthorized changes to logic solver program 5.E+01-2Regulator
failureSafety Study
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choice
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick list
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionUnloading/Loading Hose Failure1.E-011Single Mechanical
Pump Seal FailureUnauthorized changes to logic solver
programERROR:#VALUE!0Unloading/Loading Hose Failure
Safety Study
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choice
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick list
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionERROR:#VALUE!0
Safety Study
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choice
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick list
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionERROR:#VALUE!0
Safety Study
Richard Gowland: Richard Gowland:Use the drop down to select a
consequence and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select an
Initiating Event and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down to select the
probability of ignition and enter from pick list
Richard Gowland: Richard Gowland:Use the drop down list and enter
the choice you make from the pick list
Richard Gowland: Richard Gowland:Use the drop down list to select
and enter choice
Richard Gowland: Richard Gowland:Use the drop down list to selct
input and enter from pick list
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use drop down list for SIS SIL
requirements
Richard Gowland: Richard Gowland:Use the drop down list to make
selectionERROR:#VALUE!0
ALARP - from Examples
Scenario NoProtection GapStage 1 Achieved Event frequencyProtection GapDescription of possible additional IPLCapital cost of Add. IPLOperational Cost of added IPL/yearRisk Reduction achievedAnticipated future life of plant (years)Value of risk reduction (e.g. fatalities or cost avoided)Ratio of Cost to Benefit11.E-050Emergency dumping to containment100001001025100000055.56109.000E-069.000E+0022521.E-050Emergency dumping to containment100001001025100000055.561009.000E-069.000E+0022531.E-050Emergency dumping to containment100001001025100000055.5610009.000E-069.000E+0022541.E-061add second trip SIS or change SIS A to SIL 3300010010501000000177.789.000E-079.000E-01455ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!0ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!ERROR:#VALUE!