ML110970066

License Amendment Request to Revise Operability Requirements and Actions for RCS Leakage Instrumentation

ML110970066
Person / Time
Site:	Limerick
Issue date:	04/06/2011
From:	David Helker Exelon Generation Co, Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML110970066 (28)

Text

{{#Wiki_filter:10 CFR 50.90 April 6, 2011 U.S.Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Limerick Generating Station, Units 1 and 2 Facility Operating License Nos.NPF-39 and NPF-85 USNRC Docket Nos.50-352 and 50-353

Subject:

License Amendment Request to Revise Operability Requirements and Actions for RCS Leakage Instrumentation

References:

1.TSTF-514-A, Revision 3,"Revised BWR Operability Requirements and Actions for RCS Leakage Instrumentation", dated November 24,2010.2.Notice of Availability of the Models for Plant-Specific Adoption of Technical Specifications Task Force Traveler TSTF-514, Revision 3,"Revise BWR Operability Requirements and Actions for RCS Leakage Instrumentation," dated December 17, 2010.In accordance with 10 CFR 50.90,"Application for amendment of license, construction permit, or early site permit," Exelon Generation Company, LLC (EGC)requests an amendment to the Technical Specifications (TS)for Limerick Generating Station (LGS), Units 1 and 2.The proposed amendment modifies the Actions to be taken when the containment atmosphere gaseous radioactivity monitoring system and the primary containment pressure and temperature monitoring system are the only operable reactor coolant leakage detection monitoring systems.The modified Actions require additional, more frequent monitoring of other indications of Reactor Coolant System (RCS)leakage and provide appropriate time to restore another monitoring system to Operable status.This change is consistent with the U.S.Nuclear Regulatory Commission (USNRC)approved Safety Evaluation on Technical Specification Task Force (TSTF)Traveler, TSTF-514-A, Revision 3,"Revised BWR Operability Requirements and Actions for RCS Leakage Instrumentation" dated November 24, 2010 (Reference 1), as made available in the Federal Register on December 17, 2010 (Reference 2).Attachment 1 of this submittal provides a description of the proposed changes, the requested confirmation of applicability, plant specific verifications, and variations in the proposed LGS TS changes from the approved TSTF-514-A (Reference 1).Attachment 2 provides the existing TS page markups showing the proposed changes.Attachment 3 provides the associated TS Bases markups for information only.The proposed changes have been reviewed by the LGS Plant Operations Review Committee and approved by the Nuclear Safety Review Board in accordance with the requirements of the EGC Quality Assurance Program. U.S.Nuclear Regulatory Commission April 6, 2011 Page 2 EGC requests approval of the proposed amendment by April 6, 2012.Once approved, the amendment shall be.implemented within 60 days.There are no regulatory commitments contained in this letter.In accordance with 10 CFR 50.91,"Notice for public comment;State consultation," paragraph (b), EGC is notifying the Commonwealth of Pennsylvania of this application for license amendment by transmitting a copy of this letter and its attachments to the designated State Official.Should you have any questions concerning this letter, please contact Ms.Wendy E.Croft at (610)765-5726.I declare under penalty of perjury that the foregoing is true and correct.Executed on the 6th day of April 2011.Respectfully, David P.Helker Manager, Licensing and Regulatory Affairs Exelon Generation Company, LLC Attachments:1.2.3.Evaluation of Proposed Changes Markup of Technical Specifications Pages Markup of Technical Specifications Bases Pages (For Information Only)cc: USNRC Region I, Regional Administrator USNRC Senior Resident Inspector, LGS USNRC Project Manager, LGSR.R.Janati, Bureau of Radiation Protection ATTACHMENT 1 Evaluation of Proposed Changes Limerick Generating Station, Units 1 and 2 Facility Operating License Nos.NPF-39 and NPF-85

Subject:

Revise Operability Requirements and Actions for RCS Leakage Instrumentation 1.0

SUMMARY

DESCRIPTION 2.0 DETAILED DESCRIPTION

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria 4.2 Precedent 4.3 No Significant Hazards Consideration 4.4 Conclusions 5.0 ENVIRONMENTAL CONSIDERATION

6.0 REFERENCES

Revise Operability Requirements and Actions for RCS Leakage Instrumentation Attachment 1: Evaluation of Proposed Changes Page 1 of 5 1.0

SUMMARY

DESCRIPTION This evaluation supports a to amend Operating Licenses NPF-39 and NPF-85 forLimerickGenerating Station (LGS)Units 1 and 2, respectively. The proposed changes would the Operating Licenses to modify the Actions to be taken when the containment atmosphere gaseous radioactivity monitoring system and the primary containment pressure and temperature monitoring system are the only operable reactor coolant leakage detection monitoring systems.The modified Actions require additional, more frequent monitoring of other Reactor Coolant System (RCS)leakage indications and provide appropriate time to restore another monitoring system to Operable status.This change is consistent with the U.S.Nuclear Regulatory Commission (USNRC)approved Safety Evaluation on Technical Specification Task Force (TSTF)Traveler, TSTF-514-A, Revision 3,"Revised BWR Operability Requirements and Actions for RCS Leakage Instrumentation" dated November 24, 2010 (Reference 6.1), as referenced in the Federal Register Notice of Availability on December 17, 2010 (Reference 6.2).Variations from the USNRC-approved TSTF-514-A, Revision 3 are detailed in Section 3.0 of this submittal. 2.0 DETAILED DESCRIPTION The background for this application is stated in the referenced model safety evaluation in the USNRC's Federal Register Notice of Availability published on December 17, 2010 and514-A, Revision 3.Consistent with NRC-approved TSTF-514-A, Revision 3 the proposed changes are as follows:*Technical Specification (TS)Limiting Condition for Operability (LCO)3.4.3.1,"Leakage Detection Systems" is revised to add a new Action.The new Action, TS 3.4.3.1 Action F, is applicable when the containment atmosphere gaseous radioactivity monitoring system and the primary containment pressure and temperature monitoring system are the only operable reactor coolant leakage detection monitoring systems (Le., all other monitoring systems are inoperable). The new Action requires analyzing grab samples of the primary containment atmosphere and monitoring RCS leakage using administrative means every 12 hours in addition to restoring another monitoring system to Operable status within 7 days.*The TS Bases are revised to clearly definetheRCS leakage detection instrumentation Operability requirements in the LCO Bases and to eliminate discussion from the TS Bases that could be erroneously construed as Operability requirements. The TS Bases are also revised to reflect the changes to the Technical Specifications and to more accurately reflect the existing TS.NOTE: Proposed revisions to the TS Bases are also included in this application for information only.The changes to the affected TS Bases pages will be incorporated in accordance with the TS Bases Control Program. Revise Operability Requirements and Actions for RCS Leakage Instrumentation Attachment 1: Evaluation of Proposed Changes Page 2 of 5

3.0 TECHNICAL EVALUATION

Exelon Generation Company, LLC, (EGC)has reviewed the Federal Register Notice of Availability dated December 17, 2010.This review also included the referenced information provided in TSTF-514-A, Revision 3.EGC has concluded that the justifications presented in the TSTF proposal and the Federal Register Notice of Availability prepared by the USNRC staff are applicable to LGS, Units 1 and 2 with the variations noted below, and justify this amendment for the incorporation of the changes to the corresponding TS.Additional reviews have determined that the proposed changes do not require any exemption or relief from regulatory requirements other than the TS, and do not affect conformance to any General Design Criteria differently than described in the Updated Final Safety Analysis Report (UFSAR).LGS Units 1 and 2 are Standard TS plants and differ from the BWR/4 Improved Standard Technical Specifications (ISTS)used as the TS reference/markup in TSTF-514-A, Revision 3.A list is provided below of the variations in the proposed LGS TS changes from the approved TSTF-514-A, Revision 3:*Based on the addition of the proposed LGS TS 3.4.3.1 Action F the current TS 3.4.3.1 Action F has been renumbered to TS 3.4.3.1 Action G.The change is consistent with the approved TSTF-514-A, Revision 3 intent and aligns with the current LGS TS.*In order to remain consistent with the current LGS TS 3.4.3.1 Action the proposed LGS TS 3.4.3.1 Action F was modified for LGS to require two operable TS LCO monitoring systems (the containment atmosphere gaseous radioactivity monitoring system and the primary containment pressure and temperature monitoring system), as opposed to the single operable TS LCO monitoring system proposed by TSTF-514-A, Revision 3 Condition[0].This change is more conservative than the TSTF-514-A, Revision 3 proposal and aligns with the current LGS TS.*The current LGS TS 3.4.3.1 Action F (proposed TS 3.4.3.1 Action G)requires HOT SHUTDOWN within 12 hours if two or more leakage detection instruments are inoperable with the exception of TS 3.4.3.1 Action E.TS 3.4.3.1 Action E allows two inoperable monitoring systems (the primary containment atmosphere gaseous radioactivity monitoring system and the drywell unit coolers condensate flow rate monitoring system)for 30 days with 12 hour compensatory grab samples.The proposed LGS TS 3.4.3.1 Action F allows two inoperable monitoring systems (the drywell floor drain sump flow monitoring system and the drywell unit coolers condensate flow rate monitoring system)for 7 days with 12 hour compensatory grab samples of the primary containment atmosphere and 12 hour administrative monitoring of RCS leakage.A review of past operating experience from 1/1/2006 to 2/9/2011 at LGS Units 1 and 2 identified that the proposed Action F would have been entered three times for a total of 6 hours and 34 minutes.Although the proposed change to the LGS TS is an increase in the amount of time the plant is allowed to operate with the drywell floor drain sump flow monitoring system and the drywell unit coolers condensate flow rate monitoring system inoperable, the proposed Action F is more conservative than TS 3.4.3.1 Action E, is consistent with the approved TSTF-514-A, Revision3intent, and has operating experience to suggest it will be an infrequently entered Action statement. Revise Operability Requirements and Actions for RCS Leakage Instrumentation Attachment 1: Evaluation of Proposed Changes Page 3 of 5*The current LGS TS 3.4.3.1 Action F (proposed 3.4.3.1 Action G)requires HOT SHUTDOWN within 12 hours if two or more leakage detection instruments are inoperable with the exception of TS 3.4.3.1 Action current 3.4.3.1 Action F (proposed TS 3.4.3.1 Action G)is being modified to include the exception of the proposed LGS TS 3.4.3.1 Action F.The change is consistent with the approved TSTF-514-A, Revision 3 intent and aligns with the current*The current LGS TS 3.4.3.1 Action F (proposed 3.4.3.1 Action G)requires HOT SHUTDOWN within 12 hours if the associated Completion Time of Actions A, B, C, D or E are not met.The current LGS TS 3.4.3.1 Action F (proposed TS 3.4.3.1 Action G)is being modified to include proposed LGS TS 3.4.3.1 Action F.The change is consistent with the approved TSTF-514-A, Revision 3 intent and aligns with the current LGS TS.*The proposed LGS TS Bases have been edited from the TSTF-514-A, Revision 3 Bases changes to reflect the specific LGS configuration and any variations from TSTF-514-A, Revision 3 described above and to correct previously existing typographical errors.These changes to the TSTF-514-A, Revision 3 for the LGS submittal have been evaluated in the LGS-specific No Significant Hazards Consideration Determination in Section 4.3.The only variations or deviations in EGC's proposal have been delineated above.The remainder of the EGC proposed changes are consistent with the TS changes described in the Federal Register Notice of Availability dated December 17, 2010 or the referenced information provided in TSTF-514-A, Revision 3.

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements /Criteria A description of the proposed changes and their relationship to applicable regulatory requirements and guidance was provided in the December 17, 2010, Federal Register Notice of Availability referenced information in TSTF-514-A, Revision 3.4.2 Precedent This change is consistent with the U.S.Nuclear Regulatory Commission (USNRC)approved Safety Evaluation on Technical Specification Task Force (TSTF)Traveler, TSTF-514-A, Revision 3,"Revised BWR Operability Requirements and Actions for RCS Leakage Instrumentation" dated November 24, 2010 , as referenced in the Federal Register Notice of Availability on December 17, 2010.4.3 No Significant Hazards Consideration Determination In accordance with 10 CFR 50.90,"Applicationforamendment of license, construction permit, or early site permit," Exelon Generation Company, LLC (EGC)requests an amendment to the Technical Specifications (TS)for Limerick Generating Station, Units 1 and 2.The proposed amendment modifies the Actions to be taken when the containment atmosphere gaseous radioactivity monitoring system and the primary containment pressure and temperature monitoring system are the only operable reactor coolant leakage detection monitoring systems.The modified Actions require additional, more frequent monitoring of other Reactor Coolant Revise Operability Requirements and Actions for RCS Leakage Instrumentation Attachment 1: Evaluation of Proposed Changes Page 4 of 5 System (RCS)leakage indications and provide appropriate time to restore another monitoring system to Operable status.evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92,"Issuance of amendment," as discussed below: 1.the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated? Response: No.The proposed changes clarify the Operability requirements for the RCS leakagedetectioninstrumentation and modify the time allowed for the plant to operate when the only operable RCS leakage detection instrumentation monitors are the containment atmosphere gaseous radioactivity monitoring system and the primary containment pressure and temperature monitoring system.The monitoring of RCS leakage is not a precursor to any accident previously evaluated. The monitoring of RCS leakage is not a direct method used to mitigate the consequences of any accident previously evaluated. Therefore, the proposed amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated. The proposed changes also renumber the current TS Actions to accommodate the new TS Action.This change is administrative in nature and does not involve a significant increase in the probability or consequences of an accident previously evaluated. 2.Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated? Response: No.The proposed changes clarify the Operability requirements for the RCS leakage detection instrumentation and modify the time allowed for the plant to operate when the only operable RCS leakage detection instrumentation monitor monitors are the containment atmosphere gaseous radioactivity monitoring system and the primary containment pressure and temperature monitoring system.The proposed changes do not involve a physical alteration of the plant (no new or different type of equipment will be installed) or a change in the methods governing normal plant operation. Therefore, the proposed amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated. The proposed changes also renumber the current TS Actions to accommodate the new TS Action.This change is administrative in nature and does not create the possibility of a new or different kind of accident from any accident previously evaluated. 3.Does the proposed amendment involve a significant reduction in a margin of safety?Response: No.The proposed changes clarify the Operability requirements for the RCS leakage detection instrumentation and increase the time allowed for the drywell floor drain sump Revise Operability Requirements and Actions for RCS Leakage Instrumentation Attachment 1: Evaluation of Proposed Changes Page 5 of 5 flow monitoring system and the drywell unit coolers condensate flow rate monitoring system to be inoperable concurrently from 12 hours to 7 days.Increasing the amount of time the plant is allowed to operate with these two leakage detection monitors inoperable does not significantly the margin of safety due to the addition of compensatory actions to analyze grab samples of the primary containment atmosphere once per 12 hours and monitor RCS leakage by administrative means once per 12 hours.The overall likelihood that an increase in RCS leakage will be detected before it potentially results in gross failure is maintained with the addition of the actions.Therefore, the proposed amendment does not involve a significant reduction in a margin of safety.The proposed changes also renumber the current TS Actions to accommodate the new TS Action.This change is administrative in nature and does not involve a significant reduction in a margin of safety.Based on the above, EGC concludes that the proposed amendment does not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and accordingly, a finding of no significant hazards consideration is justified. 4.4 Conclusions In conclusion, based on the considerations discussed above, (1)there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2)such activities will be conducted in compliance with the Commission's regulations, and (3)the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.5.0 ENVIRONMENTAL CONSIDERATION EGC has reviewed the environmental evaluation included in the model safety evaluation provided in the December 17, 2010 Federal Register Notice of Availability referenced information in TSTF-514-A, Revision 3.ECG has concluded that the staffs findings presented in that evaluation are applicable to LGS, Units 1 and 2, and the evaluation is hereby incorporated by reference for this application.

6.0 REFERENCES

6.1 TSTF-514-A, Revision 3,"Revised BWR Operability Requirements and Actions for RCS Leakage Instrumentation" dated November 24, 2010.6.2 Notice of Availability of the Models for Plant-Specific Adoption of Technical Specifications Task Force Traveler TSTF-514, Revision 3,"Revise BWR Operability Requirements and Actions for RCS Leakage Instrumentation," dated December 17, 2010. ATTACHMENT 2 Markup of Technical Specifications Pages Limerick Generating Station, Units 1 and 2 Facility Operating License Nos.NPF-39 and NPF-85 REVISED TECHNICAL SPECIFICATIONS PAGES 3/4 4-8 3/44-8a 110wi tor lant I ion 11 ri rna ry tainrnent tmos raeji oa i vi rnoni ri n r drain ump low monitoring tern, cJryvvell unit I r coneien f1 ow ra monitoring nd d.primary containmen pres ure and ture monitoring sy tern.OPERATIONAL CONDITIONS 1, , nd mary containment ga radioactivi until tional Condition 2.monitor not required to be A.With the primary containment gaseous radioactivity monitoring system1, analyze grab primary containment a at least once r 12 hours AND restore primary containment a gaseous radioactivi monitoring tem to OPERABLE tus within 30 B.With the 1 floor drain ump flow monitoring system inoperable, restore the 11 r drain sump low monitoring stem to OPERABLE tatus within 30 s AND inc monitor ng of I unit cooler con den flow rate (SR 4.4...1.)to once every 8 Y1OUrs.With the drywell unit cool condensate flow rate monitoring inoperable, AND the mary containment atmosphere gaseous radioactivity monitoring system a channel check of the mary containment a re gaseous monitoring (SR 4.4..1.a)once per 8 hours.D.With the mary containment pressure and rature monitoring system inoperable, restore the primary containment pressure and ture monitoring to OPERABLE status within 30 days.With the primary containment atmosphere gaseous radioactivity monitoring system inoperabl AND the 11 unit coolers condensate flow rate monitoring i rabIe, restore the primary containment a gaseous radioactivity taring to OPERABLE status within 30 days OR restore the drywell unit coolers condensate flow rate monitoring to OPERABLE status within 30 days.With the primary containment atmosphere gaseous radioactivi monitoring system inoperable, analyze grab samples of primary containment atmosphere at least once per 12 hours.LIMERICK-UNIT 1 3/448 Amendment+-l-,-+/-4Q.,-l&9-, r I n 11 p r i rna ry trno i vi mon i ri nq tern, l).dryweII loor cl in sump low moni II d.Iht?pr mdry inment ratu moni rinq sy tern.OPERArrONAL ainment rational Condition monitor not ired to be 1\.With primary containment atmos inoperabr , analyze rab sampl 0 per 12 hou AND restore primary monitoring to OPERABLE monitoring re at least once radioactivi B. trle drywell loor low moni rinq drywell floor clrain ump fl ow mon tori nq tern f\ND inc moni tori nq drywe 11 uni 4.4.3..1.)to once tern inoperabl , restore the OPERABLE tatus within 30 cool r concJc2nsd fl ow ra te (SR drywe 11 un!t I rs concJen a flow mon i tori ng sy tem ii, rimary containment gaseous radioactivity monitoring system rform a channel chec of the primary containment a re qaseous monitoring stern (SR 4.4..l.a)once per 8 hour., radioactiv Wi th J\ND the C.D.With the primary containment pres u and rature monitoring system inoperabl, tore the primary containment pressure and ture monitoring system to OPERABLE status within 30 With the primary containment re qaseous radioactivi monitoring system inoperable AND thed1 uni cool rs condensate flow rate monitoring system inoperabl , restore the primary containment gaseous radioactivity monitoring system to OPERABLE status within 30 OR restore the drywell unit coolers condensate flow rate monitoring to OPERABLE status within 30 With the primary containment re gaseous radioactivity monitoring system inoperable, analyze grab samples of primary containment atmosphere at least once per 12 hours.LIMERICK-UNIT 2 3/4 4-8 Amendment No..;4,-l-GJ,-1-*, Insert 1 With the drywell floor drain sump monitoring system inoperable AND the drywell unit 1"'1"\'....IO'1"C'1"""'t'\rlot'\C'-:::.1'o flow rate monitoring system inoperable analyze grab samples of the primary containment atmosphere once per 12 hours, AND monitor Reactor Coolant System leaKaCle by administrative means once per 12 hours AND restore either the drywell floor drain sump monitoring system to OPERABLE status within 7 days OR restore the drywell unit condensate flow rate monitoring system to OPERABLE status within 7 days. 1k Action ncl in fl0T r trla n ONS , COLD SHUTDOltJN Vi.4..1rabl ka on 11 demon tra conta nment n rda with b.Perform a CHANNEL FUNCTIONAL rumentation in accordance with not apply to containment p detect on requency Control Program.ratu monitoring sy tem.form a CHANNEL CALIBRATION of required lea detection instrumentation in rdance with the Surveillance Control Program.fhi does not pply to containment pressure and ture monitoring d.Monitor primary containment pressu s primary containment ccordance with the Surveillance Frequency Control ture in LIMERICK-UNIT 1 3/4 4-8a Amendment No.+4G, ra n prj in ion inment vii th LJ.of required I with t Surveillance to containment p sure detection Control ture I;v i th the containment detection in rumentation Control ram.rhi does ture monitoring system.tvJonitor primary wi h primary containment Control Progr'am.rature in LIMERICK-UNIT 2 3/4 4-8a Amendment No.-+/--W,+4+, ATTACHMENT 3 Markup of Technical Specifications Bases Pages (For Information Only)Limerick Generating Station, Units 1 and 2 Facility Operating License Nos.NPF-39 and NPF-85 REVISED TECHNICAL SPECIFICATIONS BASES PAGES B 3/4 4-3 B 3/44-3a B 3/4 4-3c B 3/4 4-3d u re tr1e drywell ttie (jrywell equi IDENTIF ED 1 ka i equi drain tank identifi source from an unidentified source tative information to the operators from the RCPB in ide the tly monitored vari bl which include yi lding drain flow , and drywell 1 unit cooler conden te flow rate drywell fhe primary mean of i ing lea in the drywell drain ump low monitoring for UNIDENTI lED LEAKAGE and drain tank flow monitoring for IDENTIFIED LEAKAGE.not germane to this Tech and the associated drywell flow monitoring system is not included.drywell floor drain ump flow monitoring sy tem monitors UNIDENTIFIED LEAKAGE colI in the loor drain ump.UNIDENTIFIED LEAKAGE con i ts of leakage from RCPB componen in ide the drywell which are not normally ect to lea and otherwise routed to the drywel I equi drain sump.Ihe mary containment floor drain sump ha transmitters that upply level indication to main control room via the plant monitoring system.rhe floor drain ump level transmitters re a sociated with Hi Low1I switches that open/close the sump tank drain valves automatically. fhe level instrument processing unit calculates an average leak rate (gpm)for a given measurement ad which resets whenever the sump drain valve loses.The level processing unit provides n alarm to the main control room each time the average leak rate changes a ned value ince the last time the alarm was reset.For the 11 loor dra n sump flow monitoring system, the int basis is a 1 gpm change in UNIDENTIFIED LEAKAGE.In addition to the drywell floor drain sump flow monitoring described above, the discharge of each sump is monitored by an independent flow element.The measured flow rate from the flow lement is i and recorded.A main control room alarm is also provided to indicate an excessive sump discharge rate measured via the flow e-Iement.fhis system, referred to as the"drywell floor drain flow totalizer", is not credited for d 1 floor drain sump flow monitoring system operabil ity.LIMERICK-UNIT 1 B 3/4 4-3 Amendment 4G, boundary (RCPS)required a the in ri of the RCPS i impaired (Ref.re provided to alert the operators when and also to supply source from an unidentified source information to the operators to permit from the RCPS inside the drywell is Iy monitored variables which include yi lding drain flow rates, and drywell 11 unit cool conden ate flow rate and drywell fhe imary means of quanti ing leakage in the drywell in ump low monitoring sy em for UNIDENTIFIED LEAKAGE and drain tank flow monitoring system for IDENTIFIED LEAKAGE.not germane to thi fech and the associ ted drywell low monitoring sy tern i not included.fhe drywellIrd in ump low monitoring monitors UNIDENTIFIED LEAKAGE coil ted in Ule floor drain ump.UNIDENTIFIED LEAKAGE consi ts of leakage from RCPS n the drywel I which not normally ect to lea nd otherwise routed to the drywell equi drain sump.The primary containment floor drain sump ha ransmit tha upp y level indication to the main control room via the plant monitoring fhe floor drain sump level transmitters are associated with Hi/Low 1 that lose the sump tank drain valves automatically. The level in rument proces 1ng un t calculates an average leak rate (gpm)for a given measurement period which resets whenever the sump drain valve closes.fhe level processing unit provides an alarm to the main control room each time the average leak rate by rmined value ince the last time the alarm was reset.For the drywell floor drain flow monitoring system, the jnt basis is a 1 gpm change in UNlDENTI lED In addi ion to the drywell floor drain sump flow monitoring system described above, the discharge of ch sump is monitored by anit flow element.The measured flow rate from the flow element is j rated and recorded.A main control room alarm is also provided to indicate an excessive sump discharge rate measured via the flow lement.This , referred to as the"drywell floor drain flow totalizer", is not credited for drywell floor drain sump flow monitoring system operabil ity.LIMERICK-UNIf 2 S 3/4 4-3 Amendment Insert 2 In addition to meeting the OPERABILITY requirements, the monitors are typically set to provide themostsensitive response without causing an excessive number of spurious alarms. in sump rms in by flow to provi i r not 11 i r low n t from the flow continuous con den d r a in fl ow r a 11 tor, but pre sure monitoring sy tem provide an indirect method for re and/or pressure ri in the drywell above normal a reactor coo 1 ant or team 1 (Ref.@fies (Criterion 1 of the NRC Policy A control room I and, if rrective action.fhe all riti 1 cra k izes (Ref.(before a ignificant break ln RCS lea detection If S ta temen t.to evaluate the significance down the ctor for further investi I rates a re well below the rates Therefore, these actions de the RCPB occur.of the indicated on and icted for responses rhe jr)'ldcll floor drain SUFflP flo'ii Fflonitoring S)'stCFfl is rcquired:o quaAtif)' UNIOErnIFIED LEAI<AGE flom the ReS.fMC otAcr Awnitoring systems pro',idc early alarmsf7 to thQ of]Qr61tor gO (loser exam;nat;on of other detect;on S)stCfflS wi 11 be lila deR d!tellfli nc the cxh:nt of any correct;'rfe acti Of!that Ffly be requi red.II';th M1)I eEikEigeP' IftDniteeing fee leakage in tl.e REPS i2 degloded.*' LIMERICK UNIT 1 B 3/4 4-3a Amendment rywell floor (jrain sump i ndi ion nd 1 arms n are added her by low ra fhe high flow of 1 gpm over the cool r condensate flow rate quantifi r, of RCS UNIDENTIFIED to the ttld t prov i rom the flow transmitter total continuous con den ate drain conden a dra n low ra in I k ra The drywell ai r an added indicator, but not nd pres ure monitoring systems provide an indirect method for A rature nd/or pres ure ri in the drywell above normal of ctor coo I ant or team lea kage (Ref.f.@to the RCPS exists if the barrier contains a crack that i I to propaga rapidly.Lea rate 1 imits are set low enough to (j e tee t the1eak age em itted fro masin 91 e era c kin the R CPS (Ref s.jl and.foe I iF t IH: Jl;:!T: r.;H t';1.;i-;'::;1;

t==: rs to evaluate the significance of the indicated 1 and, i ry, hut down the reactor for further investigation and corrective ction.fhe al lowed lea rates are well below the rates predicted for ritical crack i Therefore, these actions provide adequate response beforeai go if i nt breathe RePB can occur.RCS lea detection sati fies Criterion 1 of the NRC Policy Statement.

rho drY1dclj floor dra i n,::uffip f13\tf[flOAi tori ng 5ysteffl is required to quaflti f, tid: JZ froffi the ReS.The other ffionitoring systeffis provide early a1arffis L to the operators 50 C 1 oscr p)(Jffli flati Ofl of other detecti Ofl SystCfflS 11 be A'lade te.Q..Jf!!lt*H'ftlinQ thQ ext8nt of dny corrective action that ffiay be required.IJith an) illepel mtM1toi 111t:'1 fel 11iRePB 13LIMERICK-UNIT 2 B 3/4 4-3a Amendment Insert 3 This LCO requires instruments of diverse monitoring principles to be OPERABLE to provide confidence that small amounts of UNIDENTIFIED LEAKAGE are detected in time to allow actions to place the plant in a safe condition, when RCS leakage indicates possible RCPB degradation. The LCO requires four instruments to be OPERABLE.The drywell floor drain sump monitoring system is required to quantify the UNIDENTIFIED LEAKAGE rate from the RCS.The identification of an increase in UNIDENTIFIED LEAKAGE will be delayed by the time required for the UNIDENTIFIED LEAKAGE to travel to the drywell floor drain sump and itmaytake longer than one hour to detecta1 gpm increase in UNIDENTIFIED LEAKAGE, depending on the origin and magnitude of the leakage.This sensitivity is acceptable for containment sump monitor OPERABILITY. The reactor coolant contains radioactivity that, when released to the primary containment, can be detected by the gaseous primary containment atmospheric radioactivity monitor.A radioactivity detection system is included for monitoring gaseous activities because of its sensitivity and rapid response to RCS leakage, but it has recognized limitations. Reactor coolant radioactivity levelswillbe low during initial reactor startup and for a few weeks thereafter, until activated corrosion products have been formed and fission products appear from fuel element cladding contamination or cladding defects.If there are few fuel element cladding defects and low levels of activation prOducts, it may not be possible for the gaseous primary containment atmospheric radioactivity monitor to detecta1 gpm increase within 1 hour during normal operation. However, the gaseous primary containment atmospheric radioactivity monitor is OPERABLE when it is capable of detectinga1 gpm increase in UNIDENTIFIED LEAKAGE within 1 hour given an RCS activity equivalent to that assumed in the design calculations for the monitors (Reference 9).The LCO is satisfied when monitors of diverse measurement means are available. Thus, the drywell floor drain sump monitoring system in combination with a gaseous primary containment atmospheric radioactivity monitor, a primary containment air cooler condensate flow rate monitoring system, and a primary containment pressure and temperature monitoring system provides an acceptable minimum. r IONS rature monitoring inoperable, the tem'indirect ility to mit ng rech requirements a sociated rature monitoring system will ill r'mary con may cantin I primary con D.radi ctivity monitor nd the monitor inoperable, the only loor drain ump monitor and the drywell ACTION i to restore ither of the to regain the intended leakage ures that the plant will not be time period.W ile primary i INOPERABLE, rimary containment every 12 hours since ACTION , f?tn" F'ACTION of Condition A, S, C, D.annot be met within the etion Time, the plant must be to an OPERATIONAL CONDITION in not apply.fo achieve this tatus, the plant must be brought to SHUTDOWN within 12 hours and COLD SHUTDOWN within the next 24 hours.letion limes are reasonable, based on operating experience, to in an orderly manner and without challenging plant systems.f for the performance of a CHANNEL CHECK of the required primary containment a ri monitoring rhe check gives reasonable confidence that the channel is operating p y.LH1ERICK-B 3/4 4-3c Amendment-+/-4G, r'formed D.ItJi th vvi ttl Ule pply.inment pressure and rabIe, inue for up to 30 given the sy tern'capabi i to However, other more limiting Tech rements ssociated containment pn:ssure/rature monitoring system will ti 11 primary containment tmo gaseous radioactivity monitor nd the ir cool condensate low rate monitor inoperable, the only kage i the drywell loor drain ump monitor and the drywell in trumentation. fhi condition does not provide the required of I ion.file i ACTION i to restore ither of the monitors to OPERABLE status wi n 30 to regain the intended leakage diversity. fhe 30 day letion fime en ures that the plant wi1I not be nco n f i!]lH'a ti 0nra1 tim e ri 0d.hi let he p ri mar inment radioactivity monitor i , rimary...... containment grab samples will be taken and anal every 12 hours Slnce AC'r;lnt A.rementsaI so apply.lNSE'((.TrIn lred ACTION of Conditions A,B,C, be met within theia letion fime, the plant must be brought to an OPERATIONAL CONDITION in which LCO not Iy.fo achieve this tus, the plant must be to t1t HOT SHUTDOWN wi in 12 hours and COLD SHUTDOWN within the next 24 hours.fhe I lowed letion rimes are reasonable, based on operating experience, to perform the IONS in an orderly manner and without challenging plant rformance of a CHANNEL CHECK of the required primary containment c monitor ng The check gives reasonable confidence that the channel operating properly.LIMERICK UNlf 2 B 3/4 4 3c Amendment+GJ, Insert 4 F.With the drywell floor drain sump monitoring system inoperable and the drywell unit coolers condensate flow rate monitoring system inoperable, one of the two remaining means of detecting leakage is the primary containment atmospheric gaseous radiation monitor.The primary containment atmospheric gaseous radiation monitor typically cannot detecta1 gpm leak within one hour when RCS activity is low.Indirect methods of monitoring RCS leakage must be implemented. Grab samples of the primary containment atmosphere must be taken and analyzed and monitoring of RCS leakage by administrative means must be performed every 12 hours to provide alternate periodic information. Administrative means of monitoring RCS leakage include monitoring and trending parameters that may indicate an increase in RCS leakage.There are diverse alternative mechanisms from which appropriate indicators may be selected based onplantconditions. It is not necessary to utilize all of these methods, but a method or methods should be selected considering the current plant conditions and historical or expected sources of UNIDENTIFIED LEAKAGE.The administrative methods are the drywell cooling fan inlet/outlet temperatures, drywell equipment drain sump temperature indicator, drywell equipment drain tank hi temperature indicator, and drywell equipment drain tank flow indicator. These indications, coupled with the atmospheric grab samples, are sufficient to alert the operating staff to an unexpected increase in UNIDENTIFIED LEAKAGE.In addition to the primary containment atmospheric gaseous radiation monitor and indirect methods of monitoring RCS leakage, the primary containment pressure and temperature monitoring system is also available to alert the operating staff to an unexpected increase in UNIDENTIFIED LEAKAGE.The 12 hour interval is sufficient to detect increasing RCS leakage.The Required Action provides 7 daystorestore another RCS leakage monitor to OPERABLE status to regain the intended leakage detection diversity. The 7-day Completion Time ensures that the plant will not be operated in a degraded configuration for a lengthy time period. CHANNEL FUNCTIONAL of monitor can ri i thea1 rm j red RCS I ka rm their i nt and I a ti ve a CHANN L CALIBRATION of required lea detection 1 bration the accuracy of the instrument ruments I ted inii nment.primary containment pres ure and temperature for fhe allowable lea rates from the reactor coolant system have been based on the nd experimentally observed behavior of cracks in pipes.fhe normally round leakage due to equipment design and the detection capability of the instrumentation for determining system lea was also considered. The evidence obtained from experiments s that for leakage somewhat greater than that specified for UNlDENTI lED LEAKAGE the probability is small that the imperfection or rack associated with such lea would grow rapidly.However, in all cases, if the leakage rates exceed the values specified or the leakage is located and known to be PRESSURE BOUNDARY LEAKAGE, the reactor will be shutdown to al low further investigation and corrective action.The limit of 2 gpm increase in UNIDENTIFIED LEAKAGE over a 24 hour riod and the monitoring of drywell floor drain sump and drywel1 equipment drain tank ow rate at least once every eight (8)hours conforms with NRC staff positions specified in NRC Generic Letter 88-01,"NRC Position on IGSCC in BWR Austenitic Stainless Steel Piping," as revised by NRC Sa Evaluation dated March 6, 1990.The ACTION requirementforthe 2 gpm increase in UNIDENTIFIED LEAKAGE limit ensures that such leakage is identified or a plant shutdown is initiated to allow further investigation and corrective action.Once identified, reactor operation may continue dependent upon the impact on tota 1 lea ka ge.LIMERICK-UNIT 1 B 3/4 4-3d Amendment No.-+/-4-{}, FUNCTIONAL I f trlat the moni tor j i t I ka t j r rforma of a CHANNEL CAL BRATION of requiredI.libra ion v rifi Ule (curacy of the in trument loca in containment. mary containment pressure and ra tu for.. Hay iCYLGS UFSAR, 5.2.5.2.1.4 LGS U ion....1.1(GE/\P ,riI 968.NUREG-75/067, October 1975.Lion.2..6.fhe Ilowabl from the reactor coolant have been based on the predicted and experimentally observed behavior of cracks in pes.The normally ba round I due to design and the ion capabili of the instrumentation for determining system ea was also considered. The evidence obtained from rimen that for lea somewhat greater than that ified for UNIDENTIFIED LEAKAGE the probability i small that the i ion or rack a sociated with uchlea would grow rapidly.However, in all cases, if the I rates exceed the values specified or the lea is located and known to be PRESSURE BOUNDARY LEAKAGE, the reactor will be shutdown to al low further investigation and corrective tion.The limit of 2 gpm increa in UNIDENTI lED LEAKAGE over ahour period and the monitoring of drywell floor drain sump and drywell equi drain tank flow rate at least once every eight (8)hours conforms with NRC staff positions peci ied in NRC Generic Letter 88 01,"NRC Position on IGSCC in BWR Austenitic StainlsI Piping," as revised by NRC Sa Evaluation dated March 6, 1990.The ACTION requirement for the 2 gpm increase in UNIDENTIFIED LEAKAGE limit ensures that such 1 kage is identified or a plant shutdown is initiated to allow further investigation and corrective action.Once identified, reactor operation may continue upon the impact on total leakage.LIMERICK UNIT 2 B 3/4 4-3d Amendment+GJ, Insert 5 Revision 0,"Reactor Coolant Pressure Boundary Leakage Detection Systems," May 1973.Insert 6 9.LGS UFSAR, Section 5.2.5.2.1.5}}