ML18115A228
| ML18115A228 | |
| Person / Time | |
|---|---|
| Issue date: | 04/25/2018 |
| From: | Wong A NRC/NRR/DMLR/MRPB |
| To: | |
| Wong A, NRR-DMLR 415-3081 | |
| References | |
| Download: ML18115A228 (5) | |
Text
DRAFT - UNCERTIFIED INFORMATIONDRAFT UNCERTIFIED INFORMATION 1 of 5QuestionRAI B.1.43-2 (Closed Treated Water Systems)BackgroundFor the "detection of aging effects" program element, Section 4.13 of RBS-EP-15-00007 states that the WaterChemistry - Closed Treated Water Systems program manages the effects of aging in an environment oftreated water. For the vacuum release accumulators in LRA Table 3.3.2-3 (TK1A and TK1B on drawing PID-09-10F), the internal environment is listed as treated water with the aging management program listed asWater Chemistry Control - Closed Treated Water Systems.IssueBased on the information shown on drawing PID-09-10F, "System 118 Service Water Normal," theaccumulators and portions of the associated piping do not appear to have an internal environment of treatedwater because these components are supplied by the compressed air system. It is not clear to the staffwhether these components have a treated water internal environment and whether the aging affects for thesecomponents will be managed by the Water Chemistry Control - Closed Treated Water Systems program aslisted in LRA Table 3.3.2-3.In addition, based on information in Standby Service Water Quarterly Valve Operability Test procedures (STP-256-6305 and STP-256-6306 for valves SOV-522A, B, C, D and SOV-523A, B, C, D), air is periodicallyintroduced into portions of the piping as part of the vacuum release solenoid valve function verification. Basedon the piping configurations in various isometric drawings, it appears that air cannot be vented in someportions of the associated piping, between the check valves and the treated water source. Consequently,there will be an air water interface in a portion of the pipe, with the air being periodically replenished, similar tothe situation in NRC Information Notice 2013 06, "Corrosion in Fire Protection Piping Due to Air and WaterInteraction." It is not clear to the staff that the Water Chemistry Control - Closed Treated Water Systemsprogram activities account for this situation.Request 1.Clarify the information provided in LRA Table 3.3.2-3 (TK1A and TK1B on drawing PID-09-10F), withregard to the internal environment of the vacuum release accumulators and portions of the associatedpiping, and whether aging effects of these components will be managed by the Water ChemistryControl - Closed Treated Water Systems program.
2.Provide additional information to show that the activities in the Water Chemistry Control - ClosedTreated Water Systems adequately account for the potential air-water interface in the portions of thepiping that cannot be vented between the check valves and the treated water source (associated withSOV-522A, B, C, D, and SOV 523A, B, C, D).ResponseA previous response to RAI B.1.43-2 was submitted in letter RBG-47834, dated March 8, 2018.The following response is the same as the response in letter RBG-47834 except additionalinformation has been provided regarding the internal environments associated with the auxiliarybuilding vacuum release piping and valves. In addition, a change is made to LRA Table 3.3.2-18-11. The following response supersedes the previous response submitted in letter RBG-DRAFT - UNCERTIFIED INFORMATIONDRAFT UNCERTIFIED INFORMATION 2 of 547834.1.LRA Table 3.3.2-3 vacuum release accumulators (TK1A and TK1B on drawing PID-09-10F) containinstrument air. The LRA is revised to identify that the Compressed Air Monitoring Program managesthe aging effects for the internal surfaces of the vacuum release accumulators and associated piping.
2.Normally closed SOV-522A, B, C, and D are located downstream of the two instrument airaccumulators. If necessary, the service water system in the containment relies on this instrument air torelease a vacuum in the system piping.Normally closed SOV-523A, B, C, and D are not associated with accumulators containing instrumentair. If necessary to release system vacuum, the valves open to admit air from the auxiliary building intothe service water system.The RAI Issue discussion refers to NRC Information Notice 2013-06, "Corrosion in Fire ProtectionPiping Due to Air and Water Interaction". This information notice discusses fire water systems whichmay contain highly oxygenated, raw, untreated water. The RBS service water system containsdemineralized water treated with sodium nitrite and molybdate as corrosion inhibitors. Because of thispiping internal environment, significant corrosion is not expected.To confirm the insignificance of corrosion in the subject piping, inspections will verify that unacceptabledegradation is not occurring. For the portions of the containment piping that cannot be vented betweenthe check valves and the treated water source, the One-Time Inspection Program will perform avolumetric inspection of a piping segment associated with SOV-522A, B, C, or D.The auxiliary building piping between the solenoid valves (SOV-523A, B, C, and D) and the rest of theservice water system is exposed to treated water internally. A vacuum would only be created in theservice water piping under emergency conditions and air would not be drawn into the auxiliary buildingpiping during valve stroke testing. Unlike with the similar containment building piping, there are no airaccumulators supplying the auxiliary building piping. Thus, there is no motive force for air to enter theauxiliary building service water piping during valve stroke testing. Nevertheless, for conservatism, theauxiliary building piping is included in the Table 3.3.2-3 line item, below, for carbon steel pipingexposed to treated water and the One-Time Inspection Program will perform a volumetric inspection ofa piping segment associated with SOV-523A, B, C, or D.Normally closed SOV-523A, B, C, and D have stainless steel valve bodies. Since portions of thestainless steel valve bodies exposed to an air-indoor internal environment are not susceptible to agingeffects, the LRA Table 3.3.2-3 line item for stainless steel valve body exposed to a treated waterinternal environment is sufficient to address aging effects for the valves.The carbon steel piping out-board of valves SOV-523A, B, C, and D is highlighted in yellow on LRAdrawing PID-09-10F, which indicates it is evaluated in LRA Section 2.3.3.18, "Auxiliary Systems in DRAFT - UNCERTIFIED INFORMATIONDRAFT UNCERTIFIED INFORMATION 3 of 5Scope for 10 CFR 54.4(a)(2)." A line item is added to Table 3.3.2-18-11, "Service Water - StandbySystem, Nonsafety-Related Components Affecting Safety-Related Systems," to provide agingmanagement review results for this piping.The changes to LRA Table 3.3.2-3 and the associated notes, Table 3.3.2-18-11, Table 3.3.1, Section A.1.32,and B.1.32 follow with additions underlined.
Table 3.3.2
-3: ServiceWater SystemComponentTypeIntendedFunction MaterialEnviron-mentAgingEffectRequiringManagementAgingManagementPrograms NUREG-1801ItemTable1 ItemNot esAccumulatorPressure boundary CarbonsteelCondensation (int)Loss of materialCompressedAir MonitoringVII.D.A-263.3.1-55 BPipingPressure boundary CarbonsteelCondens-ation (int)Loss of materialCompressedAir MonitoringVII.D.A-263.3.1-55 BPipingPressure boundary CarbonsteelTreatedwater (int)Loss of materialOne-TimeInspectionVII.C2.AP-2023.3.1-45 A, 309Notes for Tables 3.3.2-1 through 3.3.2-18-26Plant-Specific Notes309. The One-Time Inspection Program will confirm the insignificance of corrosion for service water systemcontainment and auxiliary building vacuum release piping that may have an air/water interface. The One-TimeInspection Program will use NDE techniques to inspect this piping for loss of material.Table 3.3.2-18-11: Service Water - Standby System, Nonsafety-Related Components Affecting Safety-RelatedSystemsComponentTypeIntendedFunction MaterialEnvironmentAging EffectRequiringManagementAgingManagementProgramNUREG-1801 ItemTable 1ItemNotesPipingPressure boundary CarbonsteelAir -indoor (int)Loss of materialExternalSurfacesMonitoring V.D2.E-293.2.1-44 E DRAFT - UNCERTIFIED INFORMATIONDRAFT UNCERTIFIED INFORMATION 4 of 5Table 3.3.1: Auxiliary SystemsItemNumberComponentAging Effect/MechanismAgingManagementProgramsFurtherEvaluationRecommendedDiscussion3.3.1-45Steel piping,pipingcomponents,and pipingelements;tanksexposed toclosed-cyclecooling waterLoss of materialdue to general,pitting, and crevicecorrosionChapter XI.M21A,"Closed TreatedWater Systems" NoConsistent with NUREG-1801. Loss of materialfor steel componentsexposed to closed-cyclecooling water ismanaged by the WaterChemistry Control -Closed Treated WaterSystems Program.The One-TimeInspection Program willconfirm theinsignificance ofcorrosion for servicewater systemcontainment andauxiliary buildingvacuum release pipingthat may have anair/water interface. TheOne-Time InspectionProgram will use NDEtechniques to inspectthis piping for loss ofmaterial.
DRAFT - UNCERTIFIED INFORMATIONDRAFT UNCERTIFIED INFORMATION 5 of 5A.1.32 One-Time InspectionThe program will include activities to verify effectiveness of aging management programs and activities toconfirm the insignificance of aging effects as described below.A representative sample of service watersystem containment and auxiliary buildingvacuum release piping that cannot bevented between the check valves and thetreated water source.One-time inspection will confirm that loss ofmaterial is not occurring or is occurring so slowlythat the aging effect will not affect the componentintended function during the period of extendedoperation.Inspections will be performed within the 10 years prior to the period of extended operation.B.1.32 ONE-TIME INSPECTIONThe program will include activities to verify effectiveness of aging management programs and activities toconfirm the insignificance of aging effects as described below.A representative sample of service watersystem containment and auxiliary buildingvacuum release piping that cannot bevented between the check valves and thetreated water source.One-time inspection will confirm that loss ofmaterial is not occurring or is occurring so slowlythat the aging effect will not affect the componentintended function during the period of extendedoperation.Inspections will be performed within the 10 years prior to the period of extended operation.