Basic Level 1. PSA course for analysts · 2010-09-13 · Initiating Event Analysis Slide 3....

Basic Level 1. PSA course for analystsBasic Level 1. PSA course for analysts

Initiating Event AnalysisInitiating Event Analysis

IAEA Training in level 1 PSA and PSA applications

Initiating Event Analysis

Slide 2.

ContentContent

Initiating event selection and groupingNumerical screening of initiating eventsTransients and LOCAsSupport system initiating events

Initiating event selection and groupingInitiating event selection and groupingNumerical screening of initiating eventsNumerical screening of initiating eventsTransients and Transients and LOCAsLOCAsSupport system initiating eventsSupport system initiating events


Slide 3.

DEFINITION OF INITIATING EVENTSDEFINITION OF INITIATING EVENTS

Definition:“An initiating event is an event that creates a disturbance in the plant and has a potential to lead to core damage, depending on the successful operation of the various mitigating systems of the plant.” (IAEA Safety Series No. 50-P-4)

Definition:Definition:““An initiating event is an event that creates a disturbance An initiating event is an event that creates a disturbance in the plant and has a potential to lead to core damage, in the plant and has a potential to lead to core damage, depending on the successful operation of the various depending on the successful operation of the various mitigating systems of the plant.mitigating systems of the plant.”” (IAEA Safety Series No. (IAEA Safety Series No. 5050--PP--4)4)


Slide 4.

GROUPING OF INITIATING EVENTSGROUPING OF INITIATING EVENTS

Selection of initiating events based on:Scope of the PSA

Operating mode to be modelledFull powerShutdown and low power

Initiating event categoryInternal initiating eventsinternal and external hazards

Selection of initiating events based on:Selection of initiating events based on:Scope of the PSAScope of the PSA

Operating mode to be modelledOperating mode to be modelledFull powerFull powerShutdown and low powerShutdown and low power

Initiating event categoryInitiating event categoryInternal initiating eventsInternal initiating eventsinternal and external hazardsinternal and external hazards


Slide 5.


Selection methodsEngineering evaluationReference to previous listsDeductive analysisOperational experience

Selection methodsSelection methodsEngineering evaluationEngineering evaluationReference to previous listsReference to previous listsDeductive analysisDeductive analysisOperational experienceOperational experience


Slide 6.


PLANT RESPONSESUCCESS CRITERIASUPPORT SYSTEMSOPERATOR ACTIONSLEVEL 2 IMPACTS

PLANT RESPONSEPLANT RESPONSESUCCESS CRITERIASUCCESS CRITERIASUPPORT SYSTEMSSUPPORT SYSTEMSOPERATOR ACTIONSOPERATOR ACTIONSLEVEL 2 IMPACTSLEVEL 2 IMPACTS


Slide 7.

NUMERICAL SCREENINGNUMERICAL SCREENING

MOST PSAs INCLUDE FAIRLY “STANDARD” SET OF INITIATING EVENTS FROM FRONTLINE SYSTEM FAILURES (TRANSIENTS, LOCAs, ETC.)

NUMERICAL ARGUMENTS TYPICALLY USED TO LIMIT SCOPE OF SUPPORT SYSTEM INITIATING EVENTS AND EXTERNAL INITIATING EVENTS

NUMERICAL CRITERIA ARE OFTEN NOT JUSTIFIED OR ARE NOT CONSISTENT WITH QUANTIFICATION OF OTHER PSA INITIATING EVENTS

MAJOR PROBLEM IN SOME REVIEWS

MOST MOST PSAsPSAs INCLUDE FAIRLY INCLUDE FAIRLY ““STANDARDSTANDARD”” SET OF SET OF INITIATING EVENTS FROM FRONTLINE SYSTEM INITIATING EVENTS FROM FRONTLINE SYSTEM FAILURES (TRANSIENTS, FAILURES (TRANSIENTS, LOCAsLOCAs, ETC.), ETC.)

NUMERICAL ARGUMENTS TYPICALLY USED TO LIMIT NUMERICAL ARGUMENTS TYPICALLY USED TO LIMIT SCOPE OF SUPPORT SYSTEM INITIATING EVENTS AND SCOPE OF SUPPORT SYSTEM INITIATING EVENTS AND EXTERNAL INITIATING EVENTSEXTERNAL INITIATING EVENTS

NUMERICAL CRITERIA ARE OFTEN NOT JUSTIFIED OR NUMERICAL CRITERIA ARE OFTEN NOT JUSTIFIED OR ARE NOT CONSISTENT WITH QUANTIFICATION OF ARE NOT CONSISTENT WITH QUANTIFICATION OF OTHER PSA INITIATING EVENTSOTHER PSA INITIATING EVENTS

MAJOR PROBLEM IN SOME REVIEWSMAJOR PROBLEM IN SOME REVIEWS


Slide 8.


CANNOT BE JUSTIFIED ONLY BY ESTIMATED INITIATING EVENT FREQUENCY

MUST CONSIDER RISK CONSEQUENCESLEVEL 1 MODELS / SUCCESS CRITERIAOPERATOR ACTIONSLEVEL 2 CONSEQUENCES

RISK CONTRIBUTORSHIGH FREQUENCY / LOW CONSEQUENCESMEDIUM FREQUENCY / MEDIUM CONSEQUENCESLOW FREQUENCY / HIGH CONSEQUENCES

CANNOT BE JUSTIFIED ONLY BY ESTIMATED INITIATING CANNOT BE JUSTIFIED ONLY BY ESTIMATED INITIATING EVENT FREQUENCYEVENT FREQUENCY

MUST CONSIDER RISK CONSEQUENCESMUST CONSIDER RISK CONSEQUENCESLEVEL 1 MODELS / SUCCESS CRITERIALEVEL 1 MODELS / SUCCESS CRITERIAOPERATOR ACTIONSOPERATOR ACTIONSLEVEL 2 CONSEQUENCESLEVEL 2 CONSEQUENCES

RISK CONTRIBUTORSRISK CONTRIBUTORSHIGH FREQUENCY / LOW CONSEQUENCESHIGH FREQUENCY / LOW CONSEQUENCESMEDIUM FREQUENCY / MEDIUM CONSEQUENCESMEDIUM FREQUENCY / MEDIUM CONSEQUENCESLOW FREQUENCY / HIGH CONSEQUENCESLOW FREQUENCY / HIGH CONSEQUENCES


Slide 9.

NUMERICAL SCREENING NUMERICAL SCREENING LIVING PSALIVING PSA

IMPROVED MODELS AND RESULTSREFINED THERMAL / HYDRAULIC ANALYSESREFINED SUCCESS CRITERIAOPERATOR RECOVERY ACTIONSIMPROVED DATA

SCREENING BASED ON PRELIMINARY MODELS / RESULTS OFTEN NOT VALID FOR FINAL MODELS / RESULTS

MUST CONSISTENTLY REEVALUATE SCREENING CRITERIA AFTER EVERY PSA UPDATE

IMPROVED MODELS AND RESULTSIMPROVED MODELS AND RESULTSREFINED THERMAL / HYDRAULIC ANALYSESREFINED THERMAL / HYDRAULIC ANALYSESREFINED SUCCESS CRITERIAREFINED SUCCESS CRITERIAOPERATOR RECOVERY ACTIONSOPERATOR RECOVERY ACTIONSIMPROVED DATAIMPROVED DATA

SCREENING BASED ON PRELIMINARY MODELS / SCREENING BASED ON PRELIMINARY MODELS / RESULTS OFTEN NOT VALID FOR FINAL MODELS / RESULTS OFTEN NOT VALID FOR FINAL MODELS / RESULTSRESULTS

MUST CONSISTENTLY REEVALUATE SCREENING MUST CONSISTENTLY REEVALUATE SCREENING CRITERIA AFTER EVERY PSA UPDATECRITERIA AFTER EVERY PSA UPDATE


Slide 10.


** GENERAL RULE **

QUANTIFY THE INITIATING EVENT

LET THE PSA MODELS CONFIRM ITS ACTUAL SIGNIFICANCE

** GENERAL RULE **** GENERAL RULE **

QUANTIFY THE INITIATING EVENTQUANTIFY THE INITIATING EVENT

LET THE PSA MODELS CONFIRM ITS ACTUAL LET THE PSA MODELS CONFIRM ITS ACTUAL SIGNIFICANCESIGNIFICANCE


Slide 11.

CONSEQUENTIAL IMPACTSCONSEQUENTIAL IMPACTS

INITIATING EVENT STARTS SERIES OF POSSIBLE RESPONSES

EQUIPMENT SUCCESSES / FAILURESOPERATOR ACTIONS

DO NOT COMBINE INITIATOR AND CONSEQUENCES

THE FOLLOWING CONSEQUENTIAL CONDITIONS ARE NOT INITIATING EVENTS

STATION BLACKOUTATWSOVERCOOLING

INITIATING EVENT STARTS SERIES OF POSSIBLE INITIATING EVENT STARTS SERIES OF POSSIBLE RESPONSESRESPONSES

EQUIPMENT SUCCESSES / FAILURESEQUIPMENT SUCCESSES / FAILURESOPERATOR ACTIONSOPERATOR ACTIONS

DO NOT COMBINE INITIATOR AND CONSEQUENCESDO NOT COMBINE INITIATOR AND CONSEQUENCES

THE FOLLOWING CONSEQUENTIAL CONDITIONS ARE THE FOLLOWING CONSEQUENTIAL CONDITIONS ARE NOT INITIATING EVENTSNOT INITIATING EVENTS

STATION BLACKOUTSTATION BLACKOUTATWSATWSOVERCOOLINGOVERCOOLING


Slide 12.

TRANSIENTS AND LOCASTRANSIENTS AND LOCAS

TOO MUCH EMPHASIS ON LOCASSIZE, LOCATION, FREQUENCYCOMPLEX SUCCESS CRITERIA

TOO LITTLE EMPHASIS ON TRANSIENTSBROAD INITIATING EVENT GROUPSTREATMENT OF TRANSIENT-INDUCED IMPACTSSCOPE OF SUPPORT SYSTEM INITIATING EVENTS

FULL-SCOPE LEVEL 1 PSA RESULTS TYPICALLY DOMINATED BY TRANSIENTS AND SUPPORT SYSTEM FAILURES

TOO MUCH EMPHASIS ON LOCASTOO MUCH EMPHASIS ON LOCASSIZE, LOCATION, FREQUENCYSIZE, LOCATION, FREQUENCYCOMPLEX SUCCESS CRITERIACOMPLEX SUCCESS CRITERIA

TOO LITTLE EMPHASIS ON TRANSIENTSTOO LITTLE EMPHASIS ON TRANSIENTSBROAD INITIATING EVENT GROUPSBROAD INITIATING EVENT GROUPSTREATMENT OF TRANSIENTTREATMENT OF TRANSIENT--INDUCED IMPACTSINDUCED IMPACTSSCOPE OF SUPPORT SYSTEM INITIATING EVENTSSCOPE OF SUPPORT SYSTEM INITIATING EVENTS

FULLFULL--SCOPE LEVEL 1 PSA RESULTS TYPICALLY SCOPE LEVEL 1 PSA RESULTS TYPICALLY DOMINATED BY TRANSIENTS AND SUPPORT SYSTEM DOMINATED BY TRANSIENTS AND SUPPORT SYSTEM FAILURESFAILURES


Slide 13.

TRANSIENTTRANSIENT--INDUCED IMPACTSINDUCED IMPACTS

PRIMARY OVERPRESSURESECONDARY OVERPRESSUREOVERCOOLINGATWSMAKEUP / LETDOWNREACTOR COOLANT PUMP SEAL FAILUREENVIRONMENTAL / PHYSICAL DAMAGECONTAINMENT

PRIMARY OVERPRESSUREPRIMARY OVERPRESSURESECONDARY OVERPRESSURESECONDARY OVERPRESSUREOVERCOOLINGOVERCOOLINGATWSATWSMAKEUP / LETDOWNMAKEUP / LETDOWNREACTOR COOLANT PUMP SEAL FAILUREREACTOR COOLANT PUMP SEAL FAILUREENVIRONMENTAL / PHYSICAL DAMAGEENVIRONMENTAL / PHYSICAL DAMAGECONTAINMENTCONTAINMENT


Slide 14.

SUPPORT SYSTEM INITIATING EVENTSSUPPORT SYSTEM INITIATING EVENTS

“PARTIAL” SYSTEM FAILURES

OPERATOR ACTIONS / RECOVERY

OFFSITE POWER

VENTILATION / ROOM COOLING

““PARTIALPARTIAL”” SYSTEM FAILURESSYSTEM FAILURES

OPERATOR ACTIONS / RECOVERYOPERATOR ACTIONS / RECOVERY

OFFSITE POWEROFFSITE POWER

VENTILATION / ROOM COOLINGVENTILATION / ROOM COOLING


Slide 15.

SUPPORT SYSTEM INITIATING EVENTSSUPPORT SYSTEM INITIATING EVENTS

GENERIC DATA NOT DIRECTLY RELEVANT

GENERIC EXPERIENCE USEFUL FOR “SANITY CHECK”

DEVELOP PLANT-SPECIFIC MODELS

ACCOUNT FOR OPERATOR ACTIONS

GENERIC DATA NOT DIRECTLY RELEVANTGENERIC DATA NOT DIRECTLY RELEVANT

GENERIC EXPERIENCE USEFUL FOR GENERIC EXPERIENCE USEFUL FOR ““SANITY CHECKSANITY CHECK””

DEVELOP PLANTDEVELOP PLANT--SPECIFIC MODELSSPECIFIC MODELS

ACCOUNT FOR OPERATOR ACTIONSACCOUNT FOR OPERATOR ACTIONS


Slide 16.

OPERATOR ACTION DEPENDENCIESOPERATOR ACTION DEPENDENCIES

MUST ACCOUNT FOR DEPENDENCIES WITH OPERATOR ACTIONS IN INITIATING EVENT MODELS

QUANTIFY SEPARATE INITIATING EVENTS

INITIATING EVENT CAUSED BY ONLY HARDWARE FAILURES

NO PRECEDING ERROR DEPENDENCE

INITIATING EVENT CAUSED BY COMBINATION OF HARDWARE FAILURES AND OPERATOR ERRORS

DEPENDENCE ON PRECEDING ERRORSDIFFERENT POST-INITIATOR ERROR RATES

MUST ACCOUNT FOR DEPENDENCIES WITH MUST ACCOUNT FOR DEPENDENCIES WITH OPERATOR ACTIONS IN INITIATING EVENT MODELSOPERATOR ACTIONS IN INITIATING EVENT MODELS

QUANTIFY SEPARATE INITIATING EVENTSQUANTIFY SEPARATE INITIATING EVENTS

INITIATING EVENT CAUSED BY ONLY HARDWARE INITIATING EVENT CAUSED BY ONLY HARDWARE FAILURESFAILURES

NO PRECEDING ERROR DEPENDENCENO PRECEDING ERROR DEPENDENCE

INITIATING EVENT CAUSED BY COMBINATION OF INITIATING EVENT CAUSED BY COMBINATION OF HARDWARE FAILURES AND OPERATOR ERRORSHARDWARE FAILURES AND OPERATOR ERRORS

DEPENDENCE ON PRECEDING ERRORSDEPENDENCE ON PRECEDING ERRORSDIFFERENT POSTDIFFERENT POST--INITIATOR ERROR RATESINITIATOR ERROR RATES


Slide 17.


HIGHER FREQUENCY THAN TOTAL FAILURE

CONDITIONAL CORE DAMAGE FREQUENCY MAY BE HIGH

ACCOUNT FOR ASYMMETRIES IN PLANT DESIGN

HIGHER FREQUENCY THAN TOTAL FAILUREHIGHER FREQUENCY THAN TOTAL FAILURE

CONDITIONAL CORE DAMAGE FREQUENCY MAY BE CONDITIONAL CORE DAMAGE FREQUENCY MAY BE HIGHHIGH

ACCOUNT FOR ASYMMETRIES IN PLANT DESIGNACCOUNT FOR ASYMMETRIES IN PLANT DESIGN


Slide 18.


ONE AC BUS

ONE DC BUS

OFFSITE POWER TRANSFORMERS

ONE TRAIN OF COOLING WATER

ONE TRAIN OF VENTILATION

ONE AC BUSONE AC BUS

ONE DC BUSONE DC BUS

OFFSITE POWER TRANSFORMERSOFFSITE POWER TRANSFORMERS

ONE TRAIN OF COOLING WATERONE TRAIN OF COOLING WATER

ONE TRAIN OF VENTILATIONONE TRAIN OF VENTILATION


Slide 19.

ONSITE ELECTRIC POWER FAILURESONSITE ELECTRIC POWER FAILURES

IMPACTS ON PLANT RESPONSE“SAFETY-RELATED” BUSES“NON-SAFETY” BUSES

IMPACTS ON POWER RECOVERYPOWER SUPPLY TO BUSTRANSFORMER FAILUREBUSWORK FAILURE

IMPACTS ON PLANT RESPONSEIMPACTS ON PLANT RESPONSE““SAFETYSAFETY--RELATEDRELATED”” BUSESBUSES““NONNON--SAFETYSAFETY”” BUSESBUSES

IMPACTS ON POWER RECOVERYIMPACTS ON POWER RECOVERYPOWER SUPPLY TO BUSPOWER SUPPLY TO BUSTRANSFORMER FAILURETRANSFORMER FAILUREBUSWORK FAILUREBUSWORK FAILURE


Slide 20.

PRECURSOR EVENTSPRECURSOR EVENTS

CONDITIONS THAT REQUIRE RAPID AUTOMATIC OR MANUAL POWER REDUCTION (MORE THAN ~30 % POWER)

AUTOMATIC / MANUAL PLANT RUNBACK

PLANT-SPECIFIC MODEL FOR INITIATING EVENT FREQUENCY

CONDITIONS THAT REQUIRE RAPID AUTOMATIC OR CONDITIONS THAT REQUIRE RAPID AUTOMATIC OR MANUAL POWER REDUCTION (MORE THAN ~30 % MANUAL POWER REDUCTION (MORE THAN ~30 % POWER)POWER)

AUTOMATIC / MANUAL PLANT RUNBACKAUTOMATIC / MANUAL PLANT RUNBACK

PLANTPLANT--SPECIFIC MODEL FOR INITIATING EVENT SPECIFIC MODEL FOR INITIATING EVENT FREQUENCYFREQUENCY


Slide 21.

PLANT RUNBACK MODELSPLANT RUNBACK MODELS

SUCCESSFUL RUNBACKPLANT STABILIZED AT REDUCED POWERNO PSA INITIATING EVENT

RUNBACK FAILUREPLANT TRIPPSA INITIATING EVENTMAY BE GROUPED WITH OTHER SIMILAR INITIATORS

SUCCESSFUL RUNBACKSUCCESSFUL RUNBACKPLANT STABILIZED AT REDUCED POWERPLANT STABILIZED AT REDUCED POWERNO PSA INITIATING EVENTNO PSA INITIATING EVENT

RUNBACK FAILURERUNBACK FAILUREPLANT TRIPPLANT TRIPPSA INITIATING EVENTPSA INITIATING EVENTMAY BE GROUPED WITH OTHER SIMILAR INITIATORSMAY BE GROUPED WITH OTHER SIMILAR INITIATORS


Slide 22.

PLANT RUNBACK MODELS / DATAPLANT RUNBACK MODELS / DATA

AVOID DETAILED MODELS FOR RUNBACK LOGIC / SIGNALS / CIRCUITS

DERIVE FAILURE RATES FROM OBSERVED EXPERIENCE

RELIABILITY OF RUNBACK FUNCTIONACTUAL EXPERIENCE USUALLY WORSE THAN MODEL PREDICTIONSCATEGORIES OF RUNBACK CHALLENGES

AVOID DETAILED MODELS FOR RUNBACK LOGIC / AVOID DETAILED MODELS FOR RUNBACK LOGIC / SIGNALS / CIRCUITSSIGNALS / CIRCUITS

DERIVE FAILURE RATES FROM OBSERVED DERIVE FAILURE RATES FROM OBSERVED EXPERIENCEEXPERIENCE

RELIABILITY OF RUNBACK FUNCTIONRELIABILITY OF RUNBACK FUNCTIONACTUAL EXPERIENCE USUALLY WORSE THAN ACTUAL EXPERIENCE USUALLY WORSE THAN MODEL PREDICTIONSMODEL PREDICTIONSCATEGORIES OF RUNBACK CHALLENGESCATEGORIES OF RUNBACK CHALLENGES


Slide 23.

LOSS OF OFFSITE POWERLOSS OF OFFSITE POWER

OFFSITE POWER RECOVERY CURVE

ELECTRIC POWER RECOVERY TIME WINDOWS

INITIATING EVENT FREQUENCIES

PSA MODEL IMPACTS

OFFSITE POWER RECOVERY CURVEOFFSITE POWER RECOVERY CURVE

ELECTRIC POWER RECOVERY TIME WINDOWSELECTRIC POWER RECOVERY TIME WINDOWS

INITIATING EVENT FREQUENCIESINITIATING EVENT FREQUENCIES

PSA MODEL IMPACTSPSA MODEL IMPACTS


Slide 24.

OFFSITE POWER RECOVERY CURVESOFFSITE POWER RECOVERY CURVES

AVOID DETAILED LOGIC MODELS FOR TRANSMISSION LINES, GRID CONNECTIONS, SWITCHYARD

DETAILED MODELS TYPICALLY OPTIMISTIC, COMPARED WITH ACTUAL EXPERIENCE

PLANT-SPECIFIC EXPERIENCE TYPICALLY VERY LIMITED

DERIVE CURVES FROM REGIONAL TRANSMISSION LINE DATA

USE GENERIC EXPERIENCE FOR “SANITY CHECK”

AVOID DETAILED LOGIC MODELS FOR TRANSMISSION AVOID DETAILED LOGIC MODELS FOR TRANSMISSION LINES, GRID CONNECTIONS, SWITCHYARDLINES, GRID CONNECTIONS, SWITCHYARD

DETAILED MODELS TYPICALLY OPTIMISTIC, DETAILED MODELS TYPICALLY OPTIMISTIC, COMPARED WITH ACTUAL EXPERIENCECOMPARED WITH ACTUAL EXPERIENCE

PLANTPLANT--SPECIFIC EXPERIENCE TYPICALLY VERY SPECIFIC EXPERIENCE TYPICALLY VERY LIMITEDLIMITED

DERIVE CURVES FROM REGIONAL TRANSMISSION LINE DERIVE CURVES FROM REGIONAL TRANSMISSION LINE DATADATA

USE GENERIC EXPERIENCE FOR USE GENERIC EXPERIENCE FOR ““SANITY CHECKSANITY CHECK””


Slide 25.


SIMPLIFIED MODEL FROM REGIONAL TRANSMISSION LINE DATA

FORCED OUTAGES

OMIT DURATIONS LESS THAN ~1 MINUTE

TRANSMISSION LINE CORRIDORSVOLTAGES AND ROUTING NEAR PLANTCOMMON RIGHT-OF-WAYSIMILAR DIRECTIONAL ROUTING

SIMPLIFIED MODEL FROM REGIONAL TRANSMISSION SIMPLIFIED MODEL FROM REGIONAL TRANSMISSION LINE DATALINE DATA

FORCED OUTAGESFORCED OUTAGES

OMIT DURATIONS LESS THAN ~1 MINUTEOMIT DURATIONS LESS THAN ~1 MINUTE

TRANSMISSION LINE CORRIDORSTRANSMISSION LINE CORRIDORSVOLTAGES AND ROUTING NEAR PLANTVOLTAGES AND ROUTING NEAR PLANTCOMMON RIGHTCOMMON RIGHT--OFOF--WAYWAYSIMILAR DIRECTIONAL ROUTINGSIMILAR DIRECTIONAL ROUTING


Slide 26.


MODEL EACH CORRIDOR AS A SINGLE LINE

DERIVE UPPER BOUND CURVE FROM “N”INDEPENDENT CORRIDORS

95TH PERCENTILE RECOVERYCONSERVATIVE IF TRUE INDEPENDENCE APPLIES

DERIVE LOWER BOUND CURVE FROM FULL CORRELATION OF ALL CORRIDORS

5TH PERCENTILE RECOVERYACCOUNTS FOR REGIONAL / GRID IMPACTS

MODEL EACH CORRIDOR AS A SINGLE LINEMODEL EACH CORRIDOR AS A SINGLE LINE

DERIVE UPPER BOUND CURVE FROM DERIVE UPPER BOUND CURVE FROM ““NN””INDEPENDENT CORRIDORSINDEPENDENT CORRIDORS

95TH PERCENTILE RECOVERY95TH PERCENTILE RECOVERYCONSERVATIVE IF TRUE INDEPENDENCE APPLIESCONSERVATIVE IF TRUE INDEPENDENCE APPLIES

DERIVE LOWER BOUND CURVE FROM FULL DERIVE LOWER BOUND CURVE FROM FULL CORRELATION OF ALL CORRIDORSCORRELATION OF ALL CORRIDORS

5TH PERCENTILE RECOVERY5TH PERCENTILE RECOVERYACCOUNTS FOR REGIONAL / GRID IMPACTSACCOUNTS FOR REGIONAL / GRID IMPACTS


Slide 27.

OFFSITE POWER RECOVERY CURVESOFFSITE POWER RECOVERY CURVESRecoveryFraction 95th Percentile

Median

5th Percentile

Time


Slide 28.

ELECTRIC POWER RECOVERY TIME WINDOWSELECTRIC POWER RECOVERY TIME WINDOWS

DC BATTERY LIFE

PLANT THERMAL / HYDRAULIC RESPONSESTEAM GENERATOR DRYOUTCORE UNCOVERY

PSA SCENARIOS / SUCCESS CRITERIAREACTOR COOLANT PUMP SEAL FAILUREBLEED-AND-FEED COOLINGHIGH PRESSURE / LOW PRESSURE INJECTIONCONTAINMENT COOLING

DC BATTERY LIFEDC BATTERY LIFE

PLANT THERMAL / HYDRAULIC RESPONSEPLANT THERMAL / HYDRAULIC RESPONSESTEAM GENERATOR DRYOUTSTEAM GENERATOR DRYOUTCORE UNCOVERYCORE UNCOVERY

PSA SCENARIOS / SUCCESS CRITERIAPSA SCENARIOS / SUCCESS CRITERIAREACTOR COOLANT PUMP SEAL FAILUREREACTOR COOLANT PUMP SEAL FAILUREBLEEDBLEED--ANDAND--FEED COOLINGFEED COOLINGHIGH PRESSURE / LOW PRESSURE INJECTIONHIGH PRESSURE / LOW PRESSURE INJECTIONCONTAINMENT COOLINGCONTAINMENT COOLING


Slide 29.

LOSS OF OFFSITE POWER INITIATING EVENTSLOSS OF OFFSITE POWER INITIATING EVENTS

SUBDIVIDE TOTAL FREQUENCY BY EVENT DURATIONLESS THAN 30 MINUTES30 MINUTES - 1 HOUR1 HOUR - 2 HOURSMORE THAN 2 HOURS

PSA MODEL IMPACTSDIESEL GENERATOR OPERATING MISSION TIMESAVAILABLE SYSTEMSOPERATOR ACTIONS

HOUSE EVENTS IN FAULT TREES

SUBDIVIDE TOTAL FREQUENCY BY EVENT DURATIONSUBDIVIDE TOTAL FREQUENCY BY EVENT DURATIONLESS THAN 30 MINUTESLESS THAN 30 MINUTES30 MINUTES 30 MINUTES -- 1 HOUR1 HOUR1 HOUR 1 HOUR -- 2 HOURS2 HOURSMORE THAN 2 HOURSMORE THAN 2 HOURS

PSA MODEL IMPACTSPSA MODEL IMPACTSDIESEL GENERATOR OPERATING MISSION TIMESDIESEL GENERATOR OPERATING MISSION TIMESAVAILABLE SYSTEMSAVAILABLE SYSTEMSOPERATOR ACTIONSOPERATOR ACTIONS

HOUSE EVENTS IN FAULT TREESHOUSE EVENTS IN FAULT TREES


Slide 30.

LOSS OF VENTILATION / ROOM COOLINGLOSS OF VENTILATION / ROOM COOLING

USUALLY MOST IMPORTANT FOR ELECTRICAL / ELECTRONICS EQUIPMENT

SWITCHGEAR ROOMSCONTROL / LOGIC CABINET ROOMSMAIN CONTROL ROOM

MECHANICAL EQUIPMENT IN SMALL ENCLOSED ROOMS

VERY IMPORTANT FOR SOLID-STATE EQUIPMENTENCLOSED CABINETSENCLOSED ROOMS FOR FIRE / FLOODINGUPGRADE / BACKFIT DESIGNS

USUALLY MOST IMPORTANT FOR ELECTRICAL / USUALLY MOST IMPORTANT FOR ELECTRICAL / ELECTRONICS EQUIPMENTELECTRONICS EQUIPMENT

SWITCHGEAR ROOMSSWITCHGEAR ROOMSCONTROL / LOGIC CABINET ROOMSCONTROL / LOGIC CABINET ROOMSMAIN CONTROL ROOMMAIN CONTROL ROOM

MECHANICAL EQUIPMENT IN SMALL ENCLOSED MECHANICAL EQUIPMENT IN SMALL ENCLOSED ROOMSROOMS

VERY IMPORTANT FOR SOLIDVERY IMPORTANT FOR SOLID--STATE EQUIPMENTSTATE EQUIPMENTENCLOSED CABINETSENCLOSED CABINETSENCLOSED ROOMS FOR FIRE / FLOODINGENCLOSED ROOMS FOR FIRE / FLOODINGUPGRADE / BACKFIT DESIGNSUPGRADE / BACKFIT DESIGNS


Slide 31.

LOSS OF VENTILATION / ROOM COOLINGLOSS OF VENTILATION / ROOM COOLING

ROOM HEATUP ANALYSES

EQUIPMENT THERMAL FRAGILITY ANALYSES

RECOVERY TIME WINDOWS

RECOVERY SUCCESS CRITERIA

PSA MODEL IMPACTS

ROOM HEATUP ANALYSESROOM HEATUP ANALYSES

EQUIPMENT THERMAL FRAGILITY ANALYSESEQUIPMENT THERMAL FRAGILITY ANALYSES

RECOVERY TIME WINDOWSRECOVERY TIME WINDOWS

RECOVERY SUCCESS CRITERIARECOVERY SUCCESS CRITERIA

PSA MODEL IMPACTSPSA MODEL IMPACTS


Slide 32.

ROOM HEATUP ANALYSESROOM HEATUP ANALYSES

REALISTIC ANALYSES OFTEN NOT AVAILABLE

DESIGN-BASIS CALCULATIONSCONSERVATIVE HEAT LOADSASSUMPTIONS ABOUT RECOVERY

PSA MODELS REQUIRE TEMPERATURE VS. TIME AFTER LOSS OF VENTILATION

SIMPLIFIED CALCULATIONS PROVIDE REASONABLE ESTIMATES

ACTUAL TESTS

REALISTIC ANALYSES OFTEN NOT AVAILABLEREALISTIC ANALYSES OFTEN NOT AVAILABLE

DESIGNDESIGN--BASIS CALCULATIONSBASIS CALCULATIONSCONSERVATIVE HEAT LOADSCONSERVATIVE HEAT LOADSASSUMPTIONS ABOUT RECOVERYASSUMPTIONS ABOUT RECOVERY

PSA MODELS REQUIRE TEMPERATURE VS. TIME AFTER PSA MODELS REQUIRE TEMPERATURE VS. TIME AFTER LOSS OF VENTILATIONLOSS OF VENTILATION

SIMPLIFIED CALCULATIONS PROVIDE REASONABLE SIMPLIFIED CALCULATIONS PROVIDE REASONABLE ESTIMATESESTIMATES

ACTUAL TESTSACTUAL TESTS


Slide 33.

EQUIPMENT THERMAL FRAGILITY ANALYSESEQUIPMENT THERMAL FRAGILITY ANALYSES

FAILURE LIKELIHOOD AS A FUNCTION OF TEMPERATURE

TYPICALLY NOT AVAILABLE FROM MANUFACTURER

POSSIBLE INFORMATIONQUALIFICATION TEMPERATURERATED OPERATING TEMPERATUREMAXIMUM PERMISSIBLE OPERATING TEMPERATURE

CONSTRUCT FRAGILITY CURVES FROM AVAILABLE INFORMATION

FAILURE LIKELIHOOD AS A FUNCTION OF FAILURE LIKELIHOOD AS A FUNCTION OF TEMPERATURETEMPERATURE

TYPICALLY NOT AVAILABLE FROM MANUFACTURERTYPICALLY NOT AVAILABLE FROM MANUFACTURER

POSSIBLE INFORMATIONPOSSIBLE INFORMATIONQUALIFICATION TEMPERATUREQUALIFICATION TEMPERATURERATED OPERATING TEMPERATURERATED OPERATING TEMPERATUREMAXIMUM PERMISSIBLE OPERATING TEMPERATUREMAXIMUM PERMISSIBLE OPERATING TEMPERATURE

CONSTRUCT FRAGILITY CURVES FROM AVAILABLE CONSTRUCT FRAGILITY CURVES FROM AVAILABLE INFORMATIONINFORMATION


Slide 34.

VENTILATION RECOVERY SUCCESS CRITERIAVENTILATION RECOVERY SUCCESS CRITERIA

EXTENSION OF ROOM HEATUP ANALYSES

RECOVERY OPTIONSOPEN DOORSPORTABLE FANSALTERNATE CHILLED WATER / FORCED COOLING

SIMPLE LOCAL ACTIONS MAY NOT BE ADEQUATE IF ALL COOLING IS FAILED FOR THE WHOLE BUILDING

EXTENSION OF ROOM HEATUP ANALYSESEXTENSION OF ROOM HEATUP ANALYSES

RECOVERY OPTIONSRECOVERY OPTIONSOPEN DOORSOPEN DOORSPORTABLE FANSPORTABLE FANSALTERNATE CHILLED WATER / FORCED COOLINGALTERNATE CHILLED WATER / FORCED COOLING

SIMPLE LOCAL ACTIONS MAY NOT BE ADEQUATE IF SIMPLE LOCAL ACTIONS MAY NOT BE ADEQUATE IF ALL COOLING IS FAILED FOR THE WHOLE BUILDINGALL COOLING IS FAILED FOR THE WHOLE BUILDING


Slide 35.

VENTILATION RECOVERY TIME WINDOWSVENTILATION RECOVERY TIME WINDOWS

PROBABILITY DISTRIBUTION FOR TIME UNTIL EQUIPMENT FAILURE

ROOM HEATUP CURVESEQUIPMENT THERMAL FRAGILITY CURVES

TIME WINDOWS FOR OPERATOR ACTIONS

SEQUENTIAL IMPACTS AS ROOMS HEAT UPPSA EQUIPMENT0PERATOR ACTION DEPENDENCIES

PROBABILITY DISTRIBUTION FOR TIME UNTIL PROBABILITY DISTRIBUTION FOR TIME UNTIL EQUIPMENT FAILUREEQUIPMENT FAILURE

ROOM HEATUP CURVESROOM HEATUP CURVESEQUIPMENT THERMAL FRAGILITY CURVESEQUIPMENT THERMAL FRAGILITY CURVES

TIME WINDOWS FOR OPERATOR ACTIONSTIME WINDOWS FOR OPERATOR ACTIONS

SEQUENTIAL IMPACTS AS ROOMS HEAT UPSEQUENTIAL IMPACTS AS ROOMS HEAT UPPSA EQUIPMENTPSA EQUIPMENT0PERATOR ACTION DEPENDENCIES0PERATOR ACTION DEPENDENCIES


Slide 36.

ReferencesReferences

IAEA-Safety Series 50-P-4 Procedures for Conducting Probabilistic Safety Assessments of Nuclear Power Plants (Level 1)IAEA-TECDOC-719 Defining initiating events for the purposes of probabilistic safety assessmentIAEA-TECDOC-749 Generic initiating events for PSA for WWER reactorsIAEA-TECDOC-1144 Probabilistic safety assessments of nuclear power plants for low power and shutdown modes

IAEAIAEA--Safety Series 50Safety Series 50--PP--4 Procedures for Conducting Probabilistic Safety 4 Procedures for Conducting Probabilistic Safety Assessments of Nuclear Power Plants (Level 1)Assessments of Nuclear Power Plants (Level 1)IAEAIAEA--TECDOCTECDOC--719 Defining initiating events for the purposes of probabilisti719 Defining initiating events for the purposes of probabilistic c safety assessmentsafety assessmentIAEAIAEA--TECDOCTECDOC--749 Generic initiating events for PSA for WWER reactors749 Generic initiating events for PSA for WWER reactorsIAEAIAEA--TECDOCTECDOC--1144 Probabilistic safety assessments of nuclear power plants fo1144 Probabilistic safety assessments of nuclear power plants for r low power and shutdown modeslow power and shutdown modes

Basic Level 1. PSA course for analysts · 2010-09-13 · Initiating Event Analysis Slide 3....

Documents

Transcript of Basic Level 1. PSA course for analysts · 2010-09-13 · Initiating Event Analysis Slide 3....