ML19212A729
| ML19212A729 | |
| Person / Time | |
|---|---|
| Issue date: | 07/31/2019 |
| From: | Office of Nuclear Regulatory Research |
| To: | |
| D. Stroup 415-1649 | |
| Shared Package | |
| ML19212A718 | List: |
| References | |
| Download: ML19212A729 (29) | |
Text
NRC-RES Fire PRA WorkshopModule IVAugust 5-9, 2019Rockville, MD NRC-RES/EPRI FIRE PRA METHODOLOGYTask 12 -Fire HRA Screening Examples Slide 2Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDOutline of the Presentation 1.Introduction to HRA 2.Overview of the EPRI/NRC Fire HRA Guidelines 3.Identification and definition of fire human failure events 4.Qualitative analysis 5.Fire HRA Application Experience 6.Quantitative analysis a)Screening b)Scoping c)Detailed EPRI approach & ATHEANA (detailed) 7.Recovery analysis 8.Dependency analysis 9.Uncertainty analysis Slide 3Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDScreening examples Slide 4Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDQuantitative Screening Approach SummaryScreening CriteriaShort Term Human ActionsLong Term Human ActionsDefinitionValueDefinitionValueSet 1 -like Internal Events HFE, but withsome fire effectsRequired within first hour of trip/fire 10x Internal Events HEPPerformed ~one hour after fire/trip (fire effects no longer dynamic, equipment damage understood, fire does not significantly affect ability of operators to perform action)same as Internal Events HEPSet 2 -like Set 1, but with spurious equipment or instrumentation effects in 1 safety-related train/division0.1, or 10x Internal Events HEP, whichever is greater0.1, or 10x Internal Events HEP, whichever is smallerSet 3 -new fire HFEs or prior IE HFEs needing to be significantly modified due to fire conditions 10.1, or 10x Internal Events HEP, whichever is smallerSet 4 -Alternate Shutdown (including MCR abandonment)1 for HFE, or 0.1 for single overall probability representing failure to reach safe shutdown Slide 5Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDGeneral Assumptions for Screening ExamplesActions have applicable plant emergency procedures and fire proceduresLimited information is available on fire locations and equipment impacts since fire modeling and circuit analysis are usually still in early stagesFire PRA model needs preliminary fire HEPs to test model logic and ensure that HFEs are not lost in the noiseFire effects minimized after one hourNote: Similar examples are being used to illustrate screening, scoping & detailed approaches, but scenario specifics may not be identical Slide 6Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDExample 1:Operator fails to switch turbine building SW headerFire cause a valve in the Service Water (SW) header line to spurious close and a low SW pressure condition develops.At the same time fire causes a reactor trip (RT).Annunciators activate and Service Water pressure indicates less than 72 psig Operator fails to respond per appropriate Alarm Response Procedure (ARP) and swap the turbine building SW header selector switch to the opposite header Slide 7Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDExample 1:Operator fails to switch turbine building SW headerSummary of internal events analysis
-MCR action
-Timing information: T SW= 14 minutesTcog= 4 minutesTexe= 1 minuteTdelay= 4 minutes
-Internal events HEP using HCR/ORE/THERP in EPRI HRA Calculator = 7.7 E-02Summary of fire context
-The fire does not impact the instrumentation required for diagnosis. (I.E No spurious)
-The MCR response to the fire does not impact the MCR response to this action.
Slide 8Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDExample 1:Screening Selection Criteria 1.Operator Action timeframe
-Short (<1 hour)
-Long (> 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />) 2.Spurious Instrumentation/Equipment effects in one safety
-related train
-Yes-No 3.New Fire HFE or Existing HFE needs to be significantly altered to reflect fire effects
-Yes-No Slide 9Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDScreening CriteriaShort Term Human ActionsLong Term Human ActionsDefinitionValueDefinitionValueSet 1 -like Internal Events HFE, but withsome fire effectsRequired within first hour of trip/fire 10x Internal Events HEPPerformed ~one hour after fire/trip (fire effects no longer dynamic, equipment damage understood, fire does not significantly affect ability of operators to perform action)same as Internal Events HEPSet 2 -like Set 1, but with spurious equipment or instrumentation effects in 1 safety
-related train/division0.1, or 10x Internal Events HEP, whichever is greater0.1, or 10x Internal Events HEP, whichever is smallerSet 3 -new fire HFEs or prior IE HFEs needing to be significantly modified due to fire conditions 10.1, or 10x Internal Events HEP, whichever is smallerSet 4 -Alternate Shutdown (including MCR abandonment)1 for HFE, or 0.1 for single overall probability representing failure to reach safe shutdownExample 1: Quantitative Screening Summary7.7E-2
- 10 = 7.7E-1 Slide 10Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDExample 2:Operator fails to align FPS water to AFW pumpsThe auxiliary feedwater(AFW) pumps take water from the condensate store tank (CST).With low lowlevel in the tank, the operator would align the Fire Protection System (FPS ) to the pumps.Consider the tank low lowlevel (10%) would be reached in 10 hrsafter the start of the fire. This is a local action and the operator must manually open two valves. Internal events HEP = 5E
-3 Slide 11Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDExample 2:Operator fails to align FPS water to AFW pumpsCable tracing for CST level transmitters hasbeen performed and the cues are not impacted by fireTiming information
-T sw= 11 hours1.273148e-4 days <br />0.00306 hours <br />1.818783e-5 weeks <br />4.1855e-6 months <br />
-10 hrsto low lowlevel then 1 additional hruntil tank is empty and pumps cavitate-T delay= 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br />
-Time to reach low lowlevel-Tcog= 2 minutes
-Texe= 10 minutes Slide 12Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDExample 2:Screening Selection Criteria 1.Operator Action timeframe
-Short (<1 hour)
-Long (> 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />) 2.Spurious Instrumentation/Equipment effects in one safety
-related train
-Yes-No 3.New Fire HFE or Existing HFE needs to be significantly altered to reflect fire effects
-Yes-No Slide 13Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDScreening CriteriaShort Term Human ActionsLong Term Human ActionsDefinitionValueDefinitionValueSet 1 -like Internal Events HFE, but withsome fire effectsRequired within first hour of trip/fire 10x Internal Events HEPPerformed ~one hour after fire/trip (fire effects no longer dynamic, equipment damage understood, fire does not significantly affect ability of operators to perform action)same as Internal Events HEPSet 2 -like Set 1, but with spurious equipment or instrumentation effects in 1 safety
-related train/division0.1, or 10x Internal Events HEP, whichever is greater0.1, or 10x Internal Events HEP, whichever is smallerSet 3 -new fire HFEs or prior IE HFEs needing to be significantly modified due to fire conditions 10.1, or 10x Internal Events HEP, whichever is smallerSet 4 -Alternate Shutdown (including MCR abandonment)1 for HFE, or 0.1 for single overall probability representing failure to reach safe shutdownExample 2: Quantitative Screening Summary Slide 14Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDExample 3:Operator fails to align FPS water to AFW pumps with failed alarmSame basic scenario as Example 2
-The auxiliary feedwater(AFW) pumps take water from the condensate store tank (CST).
-When low lowlevel in the tank is reached, the operator needs to align the FPS (fire protection system) to the pumps.Cable tracing has notbeen done therefore assume that fire fails the CST alarm at the 10% level
-The cue is no longer an alarm in MCR
-The fire procedure does direct the crew to locally check tank level to make sure there is enough inventory.
Slide 15Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDExample 3:Operator fails to align FPS water to AFW pumps with failed alarmLocal actionTiming information
-T sw= 11 hrs-10 hrsto low lowlevel then 1 additional hruntil tank is empty and pumps cavitate. -T delay= 2 hrs-Estimated time before the crew sends local operator to verify CST level. This action is low priority.
-Tcog= 15 minutes
-Time to determine CST level
-Texe= 10 minutes Slide 16Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDExample 3:Screening Selection Criteria 1.Operator Action timeframe
-Short (<1 hour)
-Long (> 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />) 2.Spurious Instrumentation/Equipment effects in one safety
-related train
-Yes-No 3.New Fire HFE or Existing HFE needs to be significantly altered to reflect fire effects
-Yes-No Slide 17Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDScreening CriteriaShort Term Human ActionsLong Term Human ActionsDefinitionValueDefinitionValueSet 1 -like Internal Events HFE, but withsome fire effectsRequired within first hour of trip/fire 10x Internal Events HEPPerformed ~one hour after fire/trip (fire effects no longer dynamic, equipment damage understood, fire does not significantly affect ability of operators to perform action)same as Internal Events HEPSet 2 -like Set 1, but with spurious equipment or instrumentation effects in 1 safety
-related train/division0.1, or 10x Internal Events HEP, whichever is greater0.1, or 10x Internal Events HEP, whichever is smallerSet 3 -new fire HFEs or prior IE HFEs needing to be significantly modified due to fire conditions 10.1, or 10x Internal Events HEP, whichever is smallerSet 4 -Alternate Shutdown (including MCR abandonment)1 for HFE, or 0.1 for single overall probability representing failure to reach safe shutdownExample 3: Quantitative Screening Summary Slide 18Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDExample 4:Operator fails to initiate bleed & feed and use of fire proceduresThe action to initiate bleed and feed will be done when the Steam Generators (SGs) are almost in dry outCue to initiate bleed and feed is when 2 SGs are at less than 15% WR levelIn this case half of the indicators of SG level are failed and fire procedures must be used to identify which indicators are accurateWith the main feedwater(MFW) and AFW unavailable at the beginning of the initiating event, theSG goes to dry out in 45 minutes Slide 19Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDExample 4:Operator fails to initiate bleed & feed and use of fire procedures MCR actionTiming information
-T SW= 45 minutes
-T delay= 20 minutes
-Tcog= 8 minutes
-additional time than standard bleed & feed due to using multiple procedures.
-Texe= 8 minutes Slide 20Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDExample 4:Screening Selection Criteria 1.Operator Action timeframe
-Short (<1 hour)
-Long (> 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />) 2.Spurious Instrumentation/Equipment effects in one safety
-related train
-Yes 1/2 the level indications are given an incorrect reading
-No 3.New Fire HFE or Existing HFE needs to be significantly altered to reflect fire effects
-Yes-NoSimultaneous use of multiple procedures Slide 21Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDScreening CriteriaShort Term Human ActionsLong Term Human ActionsDefinitionValueDefinitionValueSet 1 -like Internal Events HFE, but withsome fire effectsRequired within first hour of trip/fire 10x Internal Events HEPPerformed ~one hour after fire/trip (fire effects no longer dynamic, equipment damage understood, fire does not significantly affect ability of operators to perform action)same as Internal Events HEPSet 2 -like Set 1, but with spurious equipment or instrumentation effects in 1 safety
-related train/division0.1, or 10x Internal Events HEP, whichever is greater0.1, or 10x Internal Events HEP, whichever is smallerSet 3 -new fire HFEs or prior IE HFEs needing to be significantly modified due to fire conditions 10.1, or 10x Internal Events HEP, whichever is smallerSet 4 -Alternate Shutdown (including MCR abandonment)1 for HFE, or 0.1 for single overall probability representing failure to reach safe shutdownExample 4: Quantitative Screening Summary Slide 22Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDExample 5:Operator fails to maintain control from alternate shutdown locationMultiple MCR and local actionsProcedures exist but actions require significant coordination and communication among operatorsIn such cases, presume detailed analysis will be required if risk
-significant in fire PRA model Slide 23Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDScreening CriteriaShort Term Human ActionsLong Term Human ActionsDefinitionValueDefinitionValueSet 1 -like Internal Events HFE, but withsome fire effectsRequired within first hour of trip/fire 10x Internal Events HEPPerformed ~one hour after fire/trip (fire effects no longer dynamic, equipment damage understood, fire does not significantly affect ability of operators to perform action)same as Internal Events HEPSet 2 -like Set 1, but with spurious equipment or instrumentation effects in 1 safety
-related train/division0.1, or 10x Internal Events HEP, whichever is greater0.1, or 10x Internal Events HEP, whichever is smallerSet 3 -new fire HFEs or prior IE HFEs needing to be significantly modified due to fire conditions 10.1, or 10x Internal Events HEP, whichever is smallerSet 4 -Alternate Shutdown (including MCR abandonment)1 for HFE, or 0.1 for single overall probability representing failure to reach safe shutdownExample 5: Quantitative Screening Summary Slide 24Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MD Questions Slide 25Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDAdditional Examples Backup Slides Slide 26Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDExample 5:Operator fails to establish containment spray sump recirculation when RWST depletedOperator action to align containment spray (CS) to sump recircwhen the RWST is depletedThe operators cue on RWST level <37%, per the foldout page in Procedure E
-1 Transition to ES
-1.3, Transfer to Containment Sump Recirculation.The following assumptions are made:
-All equipment operates as designed
-Conditions requiring CS exist Slide 27Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDExample 5:Operator fails to establish containment spray sump recirculation when RWST depletedMCR actionSince CS is needed, fire is presumed to be severe in its consequencesRWST level indicators have cable tracing and the cues are not impacted by fireTotal system time window = for the 37% RWST level to have been reached, more than 60 min are assumed to have passed since the reactor tripInternal Events HEP using CBDTM/THERP in EPRI HRA Calculator = 3.6E
-03 Slide 28Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDExample 5:Screening Selection Criteria 1.Operator Action timeframe
-Short (<1 hour)
-Long (> 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />) 2.Spurious Instrumentation/Equipment effects in one safety
-related train
-Yes-No 3.New Fire HFE or Existing HFE needs to be significantly altered to reflect fire effects
-Yes-NoUncertain what multiple effects might occur Slide 29Fire HRA -Screening Analysis ExamplesFire PRA Workshop 2019, Rockville, MDScreening CriteriaShort Term Human ActionsLong Term Human ActionsDefinitionValueDefinitionValueSet 1 -like Internal Events HFE, but withsome fire effectsRequired within first hour of trip/fire 10x Internal Events HEPPerformed ~one hour after fire/trip (fire effects no longer dynamic, equipment damage understood, fire does not significantly affect ability of operators to perform action)same as Internal Events HEPSet 2 -like Set 1, but with spurious equipment or instrumentation effects in 1 safety
-related train/division0.1, or 10x Internal Events HEP, whichever is greater0.1, or 10x Internal Events HEP, whichever is smallerSet 3 -new fire HFEs or prior IE HFEs needing to be significantly modified due to fire conditions 10.1, or 10x Internal Events HEP, whichever is smallerSet 4 -Alternate Shutdown (including MCR abandonment)1 for HFE, or 0.1 for single overall probability representing failure to reach safe shutdownExample 5: Quantitative Screening Summary3.6E-03
- 10 = 3.6E-2