ML18213A073
| ML18213A073 | |
| Person / Time | |
|---|---|
| Issue date: | 07/31/2018 |
| From: | Tammie Rivera NRC/RES/DRA/FRB, Electric Power Research Institute |
| To: | |
| Shared Package | |
| ML18213A072 | List: |
| References | |
| Download: ML18213A073 (14) | |
Text
Joint EPRI/NRC
-RES Fire PRA WorkshopAugust 6-10, 2018Module III
-Fire AnalysisTask 13: Seismic Fire InteractionsA Collaboration of the Electric Power Research Institute (EPRI) & U.S. NRC Office of Nuclear Regulatory Research (RES) 2 Task 13 -Seismic Fire InteractionsScope of this TaskTask 13 covers the Seismic Fire Interactions review
-Little has changed compared to the guidance available in the IPEEE days-The review remains a qualitative, walk
-down based approach to identify and address potential vulnerabilities or weaknesses
-The procedure does not recommend any quantitative work in this areaThe main goal of the outlined methodology is to verify that thethe risk associated with seismically induced fires is low.
3Corresponding PRA Standard ElementTask 13 maps to element SF
-Seismic Fire
-SF Objective (per the PRA Standard):To qualitatively assess the potential risk implications of seismic/fire interaction issues 4SF HLRs (per the PRA Standard)HLR-SF-A: The Fire PRA shall include a qualitative assessment of potential seismic/fire interaction issues in the Fire PRA (5 SRs)HLR-SF-B: The Fire PRA shall document the results of the seismic/fire interaction assessment in a manner that facilitates Fire PRA applications, upgrades, and peer review (1 SR) 5Task 13: Seismic Fire InteractionsSeismically Induced Fires A severe seismic event may cause fires inside or outside an NPP by damaging . . .
-Pipes and storage tanks containing flammable liquids or gases
-Electrical equipmentAn EPRI study and NPPs experiencing earthquakes havedemonstrated that these events are rare.
6Task 13: Seismic Fire InteractionsBackgroundSeismic Fire Interactions originated with the Fire Risk Scoping Study (NUREG/CR
-5088, 1989)The conclusion of that study was:"It would appear that this is an issue which is moreeasily corrected than quantified. A series of simplesteps was outlined which if implemented on a plantspecific basis would significantly reduce the potentialimpact of such considerations."This conclusion remains valid today.
7Task 13: Seismic Fire InteractionsKey CompartmentsThe review should focus on those compartments that house equipment and cables needed to support post
-seismic safe shutdown-Review your seismic
-related procedures and identify key equipment (components and cables) and any required manual actions
-To the extent possible, map equipment to compartments
-Identify the associated compartments and focus efforts on these compartmentsAreas/compartments housing the key equipment (components and cables)Areas where a manual action takes placeAccess paths for manual actions 8Task 13: Seismic Fire InteractionsSeismically
-Induced FiresPotential sources:
-Unanchored electrical equipment such as that where motion during seismic event might cause a fire
-Unanchored gas cylinders
-Flammable gas piping
-Flammable liquid piping or storage tanksIf any significantsources are identified, consider potential plant modifications to minimize potential hazard.Corresponding PRA Standard SR: SF
-A1 9Task 13: Seismic Fire InteractionsDegradation of FP Systems and FeaturesReview:-General plant practice related to seismic restraints for fire protection systems and features
-Installed systems and features; assess potential for seismic
-induced failureAssess potential significance of system or feature failure to post-seismic event operations.If any potential vulnerabilities are identified, consider fixes to reduce likelihood of failure.Corresponding PRA Standard SR: SF
-A2 10Task 13: Seismic Fire InteractionsSpurious Detection SignalsA seismic event will likely trigger activation of various fire detection systems
-especially smoke detectorsConsider how the operators will respond to multiple fire detection signals
-You can't ignore them even though many may be false
-Have you identified the issue in your response procedures?
-Have you (can you) prioritize your response based on the important compartments?Consider potential procedural enhancements to recognize and deal with this issueCorresponding PRA Standard SRs: SF
-A2 and SF-A3 11Task 13: Seismic Fire InteractionsSpurious Suppression Actuation/ReleaseReview the fixed fire protection systems in key areas for the potential that they might spuriously operate
-Got any of those mercury switches left?
-How about a non
-seismic deluge valve?
-What happens if a sprinkler head is damaged or a pipe breaks?
-Are storage tanks for gaseous suppressants seismically robust?If any potential vulnerabilities are identified, consider fixes to reduce likelihood of spurious suppressant release.Corresponding PRA Standard SR: SF
-A4 12Task 13: Seismic Fire InteractionsManual Fire FightingAccess pathways to key areas
-could something block the path and are there alternative paths?Required fire fighting assets
-will assets remain available after an earthquake?
-Especially fire water system and fire hosesDo post-seismic response procedures allow for manual fire fighting needs and responsibilities?If any potential vulnerabilities are identified, consider fixesCorresponding PRA Standard SR: SF
-A5 13Task 13: Seismic Fire InteractionsSummarySeismic fire interaction is considered a low risk phenomenonNPP and other industry experiences partly verify this premiseA qualitative approach is suggested for verifying that plant specific conditions confirm low risk notionSystemic or procedural upgrades are recommended for identified potential vulnerabilities 14Mapping HLRs & SRs for the PP Technical Element to NUREG/CR-6850, EPRI 1011989Technical Elem e n t HLR SR 6850 Sections Comments SF A The Fire PRA shall include a qualitative assessment of potential seismic/fire interaction issues in the Fire PRA 1 13.3.1 and 13.6.2 2 13.3.2 , 13.3.3, 13.6.3, 13.6.4, and 13.6.5 3 13.3.2, 4 13.3.1, 13.3.2 , 13.3.3, 13.6.3, 13.6.4, and 13.6.5 Although 6850/1011989 does not explicitly reference seismic response procedures, the suggested guidance implies review of such procedures.
5 13.3.4 and 13.6.6 B The Fire PRA shall document the results of the seismic/fire interaction assessment in a manner that facilitates Fire PRA applications, upgrades, and peer review 1 13.6.7 6850/1011989 provides minimal discussions on documenting SF