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{{Adams
#REDIRECT [[RA-17-0051, Supplement to License Amendment Request Proposing Changes to Catawba and McGuire Technical Specification 3.8.1, AC Sources - Operating]]
| number = ML17325A588
| issue date = 11/21/2017
| title = Supplement to License Amendment Request Proposing Changes to Catawba and McGuire Technical Specification 3.8.1, AC Sources - Operating
| author name = Henderson K
| author affiliation = Duke Energy Carolinas, LLC
| addressee name =
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000369, 05000370, 05000413, 05000414
| license number = NPF-009, NPF-017, NPF-035, NPF-052
| contact person =
| case reference number = RA-17-0051
| document type = Letter, Technical Specifications
| page count = 151
}}
 
=Text=
{{#Wiki_filter:Kelvin Henderson526 S. Church StreetCharlotte, NC  28202Mailing Address:EC07H/ P.O. Box1006Charlotte, NC  28202980.373.1295Kelvin.Henderson@duke-energy.comSerial: RA-17-005110 CFR 50.90November21, 2017U.S. Nuclear Regulatory CommissionATTN: Document Control DeskWashington, DC  20555-0001CATAWBA NUCLEAR STATION, UNIT NOS. 1 AND 2DOCKET NOS. 50-413AND 50-414RENEWED LICENSE NOS. NPF-35 AND NPF-52MCGUIRE NUCLEAR STATION, UNIT NOS. 1 AND 2DOCKET NOS. 50-369 AND 50-370RENEWED LICENSE NOS. NPF-9 AND NPF-17
 
==SUBJECT:==
SUPPLEMENT TO LICENSE AMENDMENT REQUEST PROPOSING CHANGES TO CATAWBA AND MCGUIRE TECHNICAL SPECIFICATION 3.8.1,"AC SOURCES -OPERATING"
 
==REFERENCES:==
1.Duke Energy letter, License Amendment Request Proposing Changes to Catawba and McGuire Technical Specification 3.8.1, "AC Sources -Operating", dated May 2, 2017 (ADAMS Accession No. ML17122A116).2.Nuclear Regulatory Commission letter,McGuire Nuclear Station, Units 1 and 2 and Catawba Nuclear Station, Units 1 and 2 -Supplemental Information Needed for Acceptance of Requested Licensing Action RE: License Amendment Request Proposing Changes to Technical Specification 3.8.1, "AC Sources -Operating" (CAC Nos. MF9667 through MF9674, dated June 30, 2017 (ADAMS Accession No. ML17167A317).3.Duke Energy letter, Supplement to License Amendment Request Proposing Changes to Catawba and McGuire Technical Specification 3.8.1, "AC Sources -Operating", dated July 20, 2017 (ADAMS Accession No. ML17201Q132).4.Nuclear Regulatory Commission letter, Catawba/McGuire -Acceptance of Requested Licensing Action Re: EDG AOT Extension/Shared Systems LAR (CACs MF9667 through MF9974), dated August 10, 2017 (ADAMS Accession No. ML17226A002).Ladies and Gentlemen:
By letter dated May 2, 2017 (Reference 1), Duke Energy Carolinas, LLC (Duke Energy) submitted a License Amendment Request (LAR)for Catawba Nuclear Station (CNS), Units 1 U.S.Nuclear Regulatory CommissionRA-17-0051Page 2and 2and McGuire Nuclear Station (MNS), Units 1 and 2.The proposed changewould extend the Completion Time for an inoperable diesel generator in Technical Specification(TS)3.8.1, "AC Sources-Operating"at both stations. The proposed change would also alter the AC power source operability requirements for the Nuclear Service Water System (NSWS), Control Room Area Ventilation System (CRAVS), Control Room Area Chilled Water System (CRACWS) and Auxiliary Building Filtered Ventilation Exhaust System (ABFVES)(i.e., shared systems).By letter dated June 30, 2017 (Reference 2),the Nuclear Regulatory Commission (NRC) requested supplemental information from Duke Energy.By letter dated July 20, 2017 (Reference 3), Duke Energy provided responses to the supplemental information request.The NRC concluded that Duke Energy did provide technical information in sufficient detail to enable the NRC staff to complete its detailed technical review and make an independent assessment regarding the acceptability of the proposed amendment in terms of regulatory requirements and the protection of public health and safety and the environmentby letter dated August 10, 2017 (Reference4).A public meeting was held on September20, 2017 between Duke Energy and the NRC staff todiscuss the proposed change.Based on the meeting Duke Energy has decided to provide another supplement to the LAR in the Enclosure to this letterwhich revises the portion of the proposed change associated with AC power source operability requirements for shared systems.Thisrevision to the proposed change is applicable to both CNS and MNS. Specifically, two new Limiting Conditions for Operation (LCO) are proposed to beadded to CNS and MNS TS 3.8.1. One new LCO reflectsa qualified circuit between the offsite transmission network and the opposite unit's Onsite Essential Auxiliary Power Systemnecessary to supply power to the NSWS, CRAVS, CRACWS and ABFVES (i.e., shared systems). The other new LCO reflectsa DG from the opposite unit necessary to supply power to the NSWS, CRAVS, CRACWS and ABFVES.The Enclosure to this letter also provides additional technical information to support the proposed change specifically for CNS.Attachments1and 2 providerevised TS markups for CNS and MNS to reflect the proposedchange. Attachments 3 and 4 providethe CNSand MNSTS Bases pages marked up to reflect the proposed change (for information only). The TS Bases changes will be processed after LAR approval under the TS Bases Control Program for CNSand MNS.The conclusions of the original Significant Hazards Consideration Determination and Environmental Considerations contained in the May 2, 2017 LAR (Reference 1) are unaffected as a result of this LAR supplement.This document contains no new regulatory commitments.
U.S. Nuclear Regulatory Commission RA-17-0051 Page 3 Should you have any questions concerning this letter, or require additional information, please contact Art Zaremba at 980-373-2062. I declare under penalty of perjury that the foregoing is true and correct. Executed on November 21, 2017. Kelvin Henderson Senior Vice President, Nuclear Corporate
 
==Enclosure:==
License Amendment Request Supplemental Information Attachments: 1. Revised Catawba Technical Specification Marked Up Pages 2. Revised McGuire Technical Specification Marked Up Pages 3. Revised Catawba Technical Specification Bases Marked Up Pages (For Information Only) 4. Revised McGuire Technical Specification Bases Marked Up Pages (For Information Only)
U.S.Nuclear Regulatory CommissionRA-17-0051Page 4cc:C. Haney, Region II AdministratorU.S. Nuclear Regulatory CommissionMarquis One Tower245 Peachtree Center Avenue NE, Suite 1200Atlanta, GA 30303-1257M. Mahoney, Project Manager (CNS and MNS)U.S. Nuclear Regulatory Commission11555RockvillePikeMail Stop 8 G9A Rockville, MD 20852-2738J.D. AustinNRC Senior Resident InspectorCatawba Nuclear StationG.A. HuttoNRC Senior Resident InspectorMcGuire Nuclear StationS.E. Jenkins, ManagerRadioactive & Infectious Waste ManagementDivision of Waste ManagementSC Dept. of Health and Env. Control2600 Bull St.
Columbia, SC29201W.L. Cox, III, Section ChiefDiv. of Environmental Health, RP SectionNC Dept. of Env. & Natural Resources1645 Mail Service CenterRaleigh, NC 27699-1645 U.S.Nuclear Regulatory CommissionRA-17-0051Page 5bcc:M.C. NolanA.H. ZarembaJ.L. VaughanR.I. RishelELLFile: (Corporate)T.SimrilC.E.CurryL.A. Keller C. Bigham C.A. Fletcher A. Michalski NCMPA-1 PMPA NCEMC T.Lowery(For CNS Licensing/Nuclear Records)CNS Master File 801.01 -CN04DMS.D. CappsN.E. Kunkel S. Snider J. Glenn J. Thomas J.F. Hussey L. Hentz P. Howell (For MNS Licensing/Nuclear Records)
MNS Master File 801.01 -MG02DM U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 1EnclosureLicense Amendment Request Supplemental Information U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 21.DESCRIPTION OF THE PROPOSED CHANGE (REVISED)The proposed change submitted May 2, 2017 (ADAMS Accession No. ML17122A116) to modify Catawba (CNS)and McGuire Nuclear Station (MNS)Technical Specification (TS) 3.8.1, "AC Sources -Operating,"is being revised in the following sections to reflect two new Limiting Conditions for Operation (LCO). The first new LCO reflects a qualified circuit between the offsite transmission network and the opposite unit's Onsite Essential Auxiliary Power System necessary to supply power to the Nuclear Service Water System (NSWS), Control Room Area Ventilation System (CRAVS), Control Room Area Chilled Water System (CRACWS) and Auxiliary Building Filtered Ventilation Exhaust System (ABFVES) (i.e., shared systems). The other new LCO reflects a diesel generator (DG) from the opposite unit necessary to supply power to the NSWS, CRAVS, CRACWS and ABFVES. Corresponding Conditions, Required Actions(RA)and Completion Times are also being proposedfor both CNS and MNS.The changes that are presented in this Enclosureand that are also reflected in Attachments 1 and2, supersede the requested TS 3.8.1changes from the original May 2, 2017amendment requestsubmittal entirely.The TS revisions presented below for CNS and MNS are similar in content and structure to TS 3.8.1, "AC Sources -Operating" for Calvert Cliffs Nuclear Power Plant.Note: The requirement for shared systemsto have both an operable normal and emergency power supply in order to be considered operable is still proposed to be deleted from the CNS and MNS TS Bases.1.1Catawba Technical Specification 3.8.1 Change RequestCNS TS 3.8.1 will be revised as followsandthe TS markups that reflect the proposed change are contained in Attachment 1.A new LCO 3.8.1.c is addedthat states: "One qualified circuit between the offsite transmission network and the opposite unit's Onsite Essential Auxiliary Power System necessaryto supply power to the Nuclear Service Water System (NSWS), Control Room Area Ventilation System (CRAVS), Control Room Area Chilled Water System (CRACWS) and Auxiliary Building Filtered Ventilation Exhaust System (ABFVES); and"A new LCO 3.8.1.d is added that states: "One DG from the opposite unit necessaryto supply power to the NSWS, CRAVS, CRACWS and ABFVES;"A Note is added to the APPLICABILITY that states: "The opposite unit electrical power sources in LCO 3.8.1.c and LCO 3.8.1.d are not required to be OPERABLE when the associated shared systems areinoperable."Condition A is revised to state: "One LCO 3.8.1.a offsite circuit inoperable."
Required Action A.1 is revised to state: "Perform SR 3.8.1.1 for required OPERABLE offsite circuit(s)."
U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 3The Completion Time (CT) for existing RA A.3 is revised to state:"72 hoursAND17 days from discovery of failure to meet LCO 3.8.1.a or LCO 3.8.1.b"Condition B is revised to state: "One LCO 3.8.1.b DG inoperable."A new RA B.1 with an "AND" connector andthe associated CT are inserted as follows:B.1Verify both DGs on the opposite unit OPERABLE.AND1 hourANDOnce per 12 hours thereafterThe existing RA B.1 is renamed "B.2" and is revised to state: "Perform SR 3.8.1.1 for the required offsite circuit(s)."The existing RA B.2 is renamed "B.3."
The existing RA B.3.1 is renamed "B.4.1" and is revised to state: "Determine OPERABLE DG(s) is not inoperable due to common cause failure."The existing RA B.3.2 is renamed "B.4.2" and is revised to state: "Perform SR 3.8.1.2 for OPERABLE DG(s)."A new RA B.5 with an "AND" connector and associated CT are inserted as follows:B.5Ensure availability of Emergency Supplemental Power Source (ESPS).ANDPrior to entering the extended Completion Time of ACTION B.6ANDOnce per 12 hours thereafter U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 4The existing RA B.4 is renamed "B.6."  The associated CT is revised to state: "72 hours from discovery of unavailable ESPSAND24 hours from discovery of unavailable ESPS when in extended Completion TimeAND14 days AND17 days from discovery of failure to meet LCO 3.8.1.a or LCO 3.8.1.b" New Condition C and associated RAs and CT is added as follows:C.Required Action and associated Completion Time of Required Action B.1 not met.C.1.1Restore both DGs on the opposite unit to OPERABLE status.ORC.1.2Restore LCO 3.8.1.b DG to OPERABLE status.72 hours U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 5New Condition D and associated RAs and CTs is added as follows:D.LCO 3.8.1.c offsite circuit inoperable.-------------------NOTE------------------Enter applicable Conditions and Required Actions of LCO3.8.9, "Distribution Systems-Operating," when ConditionD is entered with no AC power source to atrain.---------------------------------------------D.1Perform SR3.8.1.1 for the required offsite circuit(s).ANDD.2Declare NSWS, CRAVS, CRACWS or ABFVES with no offsite power available inoperable when the redundant NSWS, CRAVS, CRACWS or ABFVES is inoperable.ANDD.3Declare NSWS, CRAVS, CRACWS and ABFVES supported by the inoperable offsite circuit inoperable.1hourANDOnce per 8hours thereafter24 hours from discovery of no offsite power to one train concurrent with inoperability of redundant required feature(s)72 hours U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 6New Condition E and associated RAs and CTs is added as follows:E.LCO 3.8.1.d DG inoperable.-------------------NOTE------------------Enter applicable Conditions and Required Actions of LCO3.8.9, "Distribution Systems-Operating," when ConditionE is entered with no AC power source to atrain.---------------------------------------------E.1Verify both LCO 3.8.1.b DGs OPERABLE, the opposite unit's DG OPERABLE and ESPS available.ANDE.2Perform SR3.8.1.1 for the required offsite circuit(s).ANDE.3Declare NSWS, CRAVS, CRACWS or ABFVES supported by the inoperable DG inoperable when the redundant NSWS, CRAVS, CRACWS or ABFVES is inoperable.AND1 hourANDOnce per 12 hours thereafter1 hourANDOnce per 8 hours thereafter4 hours from discovery of Condition E concurrent with inoperability of redundant required feature(s)
U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 7E.(continued)E.4.1Determine OPERABLE DG(s) is not inoperable due to common cause failures.ORE.4.2Perform SR 3.8.1.2 for OPERABLE DG(s).ANDE.5Declare NSWS, CRAVS, CRACWS or ABFVES supported by the inoperable DG inoperable.24 hours24 hours14 daysNew Condition F and associated RAs and CT is added as follows:F.Required Action and associated Completion Time of Required Action E.1 not met.F.1.1Restore both LCO 3.8.1.b DGs and opposite unit's DG to OPERABLE status and ESPS to available status.ORF.1.2Restore LCO 3.8.1.d DG to OPERABLE status.ORF.1.3Declare NSWS, CRAVS, CRACWS and ABFVES supported by the inoperable DG inoperable.72 hoursExisting Condition C is renamed "G" and is revised to state: "Two LCO 3.8.1.aoffsite circuits inoperable.OROne LCO 3.8.1.a offsite circuit that provides power to the NSWS, CRAVS, CRACWS and ABFVES inoperable and the required LCO 3.8.1.c offsite circuit inoperable."
U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 8Existing RA C.1 is renamed "G.1" and the associated CT is revised to state: "12 hours from discovery of Condition G concurrent with inoperability of redundant required features"Existing RA C.2 is renamed "G.2."
Existing Condition D is renamed "H" and is revised to state:"One LCO 3.8.1.a offsite circuit inoperable.ANDOne LCO 3.8.1.b DG inoperable."The Note above existing RA D.1 is revised to state: "Enter applicable Conditions and Required Actions of LCO 3.8.9, "Distribution Systems -Operating," when Condition H is entered with no AC power source to anytrain."Existing RA D.1 is renamed "H.1" and existing RA D.2 is renamed "H.2."
Existing Condition E is renamed "I" and is revised to state:"Two LCO 3.8.1.b DGs inoperable.ORLCO 3.8.1.b DG that provides power to the NSWS, CRAVS, CRACWS and ABFVES inoperable and LCO 3.8.1.d DG inoperable."Existing RA E.1 is renamed "I.1."Existing Condition F is renamed "J."  Existing RA F.1 is renamed "J.1."
Existing Condition G is renamed "K" and is revised to state:"Required Action and associated CompletionTime of Condition A, C, F, G, H, I, or J not met.ORRequired Action and associated Completion Time of Required Action B.2, B.3, B.4.1, B.4.2, or B.6 not met.ORRequired Action and associated Completion Time of Required Action E.2, E.3, E.4.1, E.4.2,or E.5 not met."Existing RA G.1 is renamed "K.1."  Existing RA G.2 is renamed "K.2."
Existing Condition H is renamed "L" and is revised to state: "Three or more LCO 3.8.1.a and LCO 3.8.1.b AC sources inoperable."
U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 9Existing RA H.1 is renamed "L.1."A new NOTE is added at the beginning of the SURVEILLANCE REQUIREMENTS section of TS 3.8.1 which states: "SR 3.8.1.1 through SR 3.8.1.20 are only applicable to LCO 3.8.1.a and LCO 3.8.1.b AC sources. SR 3.8.1.21 is only applicable to LCO 3.8.1.c and LCO 3.8.1.dAC sources."New Surveillance Requirement (SR) 3.8.1.21 and associatedFrequency is added as follows:SR  3.8.1.21 For the LCO 3.8.1.c and LCO 3.8.1.d AC electrical sources, SR 3.8.1.1, SR 3.8.1.2, SR 3.8.1.4, SR 3.8.1.5, and SR 3.8.1.6 are required to be met.In accordance with the Surveillance Frequency Control Program1.2McGuireTechnical Specification 3.8.1 Change RequestMNS TS 3.8.1 will be revised as followsandthe TS markups that reflect the proposed change are contained in Attachment 2.A new LCO 3.8.1.c is added that states: "One qualified circuit between the offsite transmission network and the opposite unit's Onsite Essential Auxiliary Power System necessary to supply power to the Nuclear Service Water System (NSWS), Control Room Area Ventilation System (CRAVS), Control Room Area Chilled Water System (CRACWS) and Auxiliary Building Filtered Ventilation Exhaust System (ABFVES); and"A new LCO 3.8.1.d is added that states: "One DG from the opposite unit necessary to supply power to the NSWS, CRAVS, CRACWS and ABFVES;"A Note is added to the APPLICABILITY that states: "The opposite unit electrical power sources in LCO 3.8.1.c and LCO 3.8.1.d are not required to be OPERABLE when the associated shared systems are inoperable."Condition A is revised to state: "One LCO 3.8.1.a offsite circuit inoperable."
Required Action A.1 is revised to state: "Perform SR 3.8.1.1 for required OPERABLE offsite circuit(s)."The Completion Time (CT) for existing RA A.3 is revised to state:"72 hoursAND17 days from discovery of failure to meet LCO 3.8.1.a or LCO 3.8.1.b"Condition B is revised to state: "One LCO 3.8.1.b DG inoperable."
U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 10A new RA B.1 with an "AND" connector and associated CT are inserted as follows:B.1Verify LCO 3.8.1.d DG OPERABLE.AND1 hourANDOnce per 12 hours thereafterThe existing RA B.1 is renamed "B.2" and is revised to state: "Perform SR 3.8.1.1 for the required offsite circuit(s)."The existing RA B.2 is renamed "B.3."The existingRA B.3.1 is renamed "B.4.1" and is revised to state: "Determine OPERABLE DG(s) is not inoperable due to common cause failure."The existing RA B.3.2 is renamed "B.4.2" and is revised to state: "Perform SR 3.8.1.2 for OPERABLE DG(s)."A new RA B.5 with an "AND" connector and associated CT are inserted as follows:B.5Ensure availability of Emergency Supplemental Power Source (ESPS).ANDPrior to entering the extended Completion Time of ACTION B.6ANDOnce per 12 hours thereafter U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 11The existing RA B.4 is renamed "B.6."  The associated CT is revised to state: "72 hours from discovery of unavailable ESPS**AND24 hours from discovery of unavailable ESPS when in extended Completion TimeAND14 days AND17 days from discovery of failure to meet LCO 3.8.1.a or LCO 3.8.1.b"New Condition C and associated RAs and CT is added as follows:C.Required Action and associated Completion Time of Required Action B.1 not met.C.1.1Restore LCO 3.8.1.d DG to OPERABLE status.ORC.1.2Restore LCO 3.8.1.b DG to OPERABLE status.72 hours U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 12New Condition D and associated RAs and CTs is added as follows:D.LCO 3.8.1.c offsite circuit inoperable.-------------------NOTE------------------Enter applicable Conditions andRequired Actions of LCO3.8.9, "Distribution Systems-Operating," when ConditionD is entered with no AC power source to a train.
---------------------------------------------D.1Perform SR3.8.1.1 for the required offsite circuit(s).ANDD.2Declare NSWS, CRAVS, CRACWS or ABFVES with no offsite power available inoperable when the redundant NSWS, CRAVS, CRACWS or ABFVES is inoperable.ANDD.3Declare NSWS, CRAVS, CRACWS and ABFVES supported by the inoperable offsite circuit inoperable.1hourANDOnce per 8hours thereafter24 hours from discovery of no offsite power to one train concurrent with inoperability of redundant required feature(s)72 hours U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 13New Condition E and associated RAs and CTs is added as follows:E.LCO 3.8.1.d DG inoperable.-------------------NOTE------------------Enter applicable Conditions and Required Actions of LCO3.8.9, "Distribution Systems-Operating," when ConditionE is entered with no AC power source to a train.
---------------------------------------------E.1Verify both LCO 3.8.1.b DGs OPERABLEandESPS available.ANDE.2Perform SR3.8.1.1 for the required offsite circuit(s).ANDE.3Declare NSWS, CRAVS, CRACWS or ABFVES supported by the inoperable DG inoperable when the redundant NSWS, CRAVS, CRACWS or ABFVES is inoperable.AND1 hourANDOnce per 12 hours thereafter1 hourANDOnce per 8 hours thereafter4 hours from discovery of Condition E concurrent with inoperability of redundant required feature(s)
U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 14E.(continued)E.4.1Determine OPERABLE DG(s) is not inoperable due to common cause failures.ORE.4.2Perform SR 3.8.1.2 for OPERABLE DG(s).ANDE.5Declare NSWS, CRAVS, CRACWS andABFVES supported by the inoperable DG inoperable.24 hours24 hours14 daysNew Condition F and associated RAs and CT is added as follows:F.Required Action and associated Completion Time of Required Action E.1 not met.F.1.1Restore both LCO 3.8.1.b DGs to OPERABLE status and ESPS to available status.ORF.1.2Restore LCO 3.8.1.d DG to OPERABLE status.ORF.1.3Declare NSWS, CRAVS, CRACWS and ABFVES supported by the inoperable DG inoperable.72 hoursExisting Condition C is renamed "G" and is revised to state: "Two LCO 3.8.1.a offsite circuits inoperable.OROne LCO 3.8.1.a offsite circuit that provides power to the NSWS, CRAVS, CRACWS and ABFVES inoperable and the required LCO 3.8.1.c offsite circuit inoperable."
U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 15Existing RA C.1 is renamed "G.1" and the associated CT is revised to state: "12 hours from discovery of Condition G concurrent with inoperability of redundant required features"Existing RA C.2 is renamed "G.2."
Existing Condition D is renamed "H" and is revised to state:"One LCO 3.8.1.a offsite circuit inoperable.ANDOne LCO 3.8.1.b DG inoperable."The Note above existing RA D.1 is revised to state: "Enter applicable Conditions and Required Actions of LCO 3.8.9, "Distribution Systems -Operating," when Condition H is entered with no AC power source to any train."Existing RA D.1 is renamed "H.1" and existing RA D.2 is renamed "H.2."
Existing Condition E is renamed "I" and is revised to state:"Two LCO 3.8.1.b DGs inoperable.ORLCO 3.8.1.b DG that provides power to the NSWS, CRAVS, CRACWS and ABFVES inoperable and LCO 3.8.1.d DG inoperable."Existing RA E.1 is renamed "I.1."Existing Condition F is renamed "J."  Existing RA F.1 is renamed "J.1."
Existing Condition G is renamed "K" and is revised to state:"Required Action and associated Completion Time of Condition A, C, F, G, H, I, or J not met.ORRequired Action and associated Completion Time of Required Action B.2, B.3, B.4.1, B.4.2, or B.6 not met.ORRequired Action and associated Completion Time of Required Action E.2, E.3, E.4.1, E.4.2, or E.5 not met."Existing RA G.1 is renamed "K.1."  Existing RA G.2 is renamed "K.2."
Existing Condition H is renamed "L" and is revised to state: "Three or more LCO 3.8.1.a andLCO 3.8.1.b AC sources inoperable."
U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 16Existing RA H.1 is renamed "L.1."A new NOTE is added at the beginning of the SURVEILLANCE REQUIREMENTS section of TS 3.8.1 which states: "SR 3.8.1.1 through SR 3.8.1.20 are only applicable to LCO 3.8.1.a and LCO 3.8.1.b AC sources. SR 3.8.1.21 is only applicable to LCO 3.8.1.c and LCO 3.8.1.d AC sources."New Surveillance Requirement (SR) 3.8.1.21 and associated Frequency is added as follows:SR  3.8.1.21 For the LCO 3.8.1.c and LCO 3.8.1.d AC electrical sources, SR 3.8.1.1, SR 3.8.1.2, SR 3.8.1.4, SR 3.8.1.5, and SR 3.8.1.6 are required to be met.In accordance with the Surveillance Frequency Control Program2.TECHNICAL EVALUATION The NSWS, CRAVS, CRACWS and ABFVES (LCOs 3.7.8, 3.7.10, 3.7.11 and 3.7.12 respectivelyfor CNS and LCOs 3.7.7, 3.7.9, 3.7.10 and 3.7.11 respectively for MNS) require certain componentson both CNSand MNSunits to be OPERABLE in Modes 1, 2, 3 and 4.ACRAVS fanthat is powered from Unit 2, for example, could be required for Unit 1.Therefore, these systemsare classified as "shared systems" for the AC electrical power requirements. The term "shared systems" for CNS and MNS isdefined as the shared components of Train A or Train B of the NSWS, CRAVS, CRACWS and ABFVES.The CNS and MNS "shared systems"were describedin Duke Energy's supplemental response letter dated July 20, 2017 (ADAMS Accession No. ML17201Q132).Since the qualified offsite circuits and dedicated DGs not only provide support to their specified unit, but also can support shared systems, the two new LCOs proposed in Section 1 above for power sources that are aligned to the opposite unit Onsite Essential Auxiliary Power System that is supplying power to a train of shared systemsare providedto reflect this dependency in the Technical Specifications in order to fully satisfy the intent of 10 CFR 50.36.These new LCO requirements(designated LCO3.8.1.c and LCO 3.8.1.d), in conjunction with the requirements for the applicable unit(or unit-specific)AC electrical power sources in LCO 3.8.1.a and LCO 3.8.1.b, ensure that power is available to two trains of the NSWS, CRAVS, CRACWS and ABFVES.The new LCOs also support removal of the requirement in the CNS and MNS TS Bases for shared systems(NSWS, CRAVS, CRACWS and ABFVES)to have both anormal and emergency power supply in order to be considered operable.Specific technical justification for each aspect of the proposed change is provided below for Catawba (Section 2.1) and McGuire (Section 2.2) and will be presented in the same order that was used in Sections 1.1 and 1.2to describe the TS 3.8.1 change requests.2.1Catawba Evaluationof the TS 3.8.1 Change RequestIn order to continue to meet Criterion 3 of 10 CFR 50.36with the removal of the requirement from the CNS TS Bases to maintain both normal and emergency power for operability of the shared systems(NSWS, CRAVS, CRACWS and ABFVES),the oppositeunit's AC power sources that are necessaryto support the NSWS, CRAVS, CRACWS and ABFVES are incorporated into TS 3.8.1withinnew LCOs3.8.1.c and 3.8.1.d.Eachtrain of NSWS, CRAVS, U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 17CRACWS and ABFVESis connected to an onsite Class 1E electrical power distribution subsystem from either unit.The word "necessary" used in LCO 3.8.1.c and LCO 3.8.1.d clarifies that the respective AC power source is aligned to the opposite unit Onsite Essential Auxiliary Power System that is supplying power to a train of shared systems.For example, in a normal alignment at CNS, Unit 1 Essential Bus 1ETA supplies Train A of shared systemsandUnit 2 Essential Bus 2ETB supplies Train B of shared systems.Thus for this normal plant configuration, the 2B offsite circuit and 2B DG, both of which supply power to 2ETB, would be LCO 3.8.1.c and LCO 3.8.1.d AC sources for Unit 1 TS 3.8.1.Similarly, the 1A offsite circuit and 1A DG, both of which supply power to 1ETA, would be LCO 3.8.1.c and LCO 3.8.1.d AC sources for Unit 2 TS 3.8.1.However, since the 2A offsite circuit and 2A DG are not necessary to supply power to a train of shared systems in the normal plant configuration,they would not be LCO 3.8.1.c and LCO 3.8.1.d AC sources.And since the 1B offsite circuit and 1B DG are not necessary to supply power to a train of shared systems in the normal plant configuration,they would not be LCO 3.8.1.c and LCO 3.8.1.d AC sources.It is important to note that if desired or required to maintain operability, Train A shared equipment can be swapped to receive power from Unit 2 Essential Bus 2ETA. Similarly, Train B shared equipment can be swapped to receive power from Unit 1 Essential Bus1ETB.The Note that is added to the Applicability section takes exception to the requirements for the required AC sources in LCO 3.8.1.c and LCO 3.8.1.d provided the associated shared systems are inoperable. This exception is intended to allow declaring the shared systems supported by the opposite unit inoperable either in lieuof declaring the LCO 3.8.1.c andLCO 3.8.1.d AC sourcesinoperable, or at any time subsequent to entering ACTIONS for an inoperable LCO 3.8.1.c or LCO 3.8.1.d AC source.This exception is acceptable since, with the shared systems supported by the opposite unit inoperable and the associated ACTIONS entered, the LCO 3.8.1.c and LCO 3.8.1.d AC sourcesprovide no additional assurance that acceptable fuel design limits and reactor coolant pressure boundary limits are not exceededas a result of abnormal transients and also provide no additional assurance that adequate core cooling is provided and containment operability and other vital functions are maintained in the event of a postulated design basis accident (DBA).Adding "LCO 3.8.1.a" to Condition A clarifies that the Condition pertains to a qualified circuit between the offsite transmission network and the Onsite Essential Auxiliary Power System rather than a qualified circuit between the offsite transmission network and the opposite unit's Onsite Essential Auxiliary Power System.Changing "OPERABLE offsite circuit" to "required OPERABLE offsite circuit(s)" in RA A.1 reflects that it could be necessary to verify the operability of more than one offsite circuit when a LCO 3.8.1.a offsite circuit is inoperable, since an offsite circuit may be alignedto theopposite unit Onsite Essential Auxiliary Power System that is supplying power to a train of theNSWS, CRAVS, CRACWS and ABFVES(i.e., a LCO 3.8.1.c offsite circuit).The proposed maximum CTof 17 days for RA A.3 limits the total time that LCO 3.8.1.a or LCO 3.8.1.b is not met while concurrently or simultaneously in Conditions A and B.The existing CT is the sum of the CT for RA A.3 (i.e., 72 hours) and existing RA B.4 (i.e., 72 hours).CNS is proposing to increase the CT for existing RA B.4 to 14 days; thus the maximum CT for RA A.3 will be increased from 6 days to 17 days.Adding "LCO 3.8.1.b" to Condition B clarifies that the Condition pertains to unit-specific DGrather than a DG from the opposite unit necessary to supply power to the NSWS, CRAVS, CRACWS and ABFVES.
U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 18New RA B.1 provides assurance that both opposite unit DGs are operablewhen a LCO 3.8.1.b DG is inoperable.Renaming RAs B.1, B.2, B.3.1, B.3.2 and B.4 are administrative changes."OPERABLE DG" is changed to "OPERABLE DG(s)" in new RAs B.4.1 and B.4.2 to reflect that the RAs are to be performed for a LCO 3.8.1.d DG in addition to theOPERABLE LCO 3.8.1.b DG.New RA B.5 is added as a prerequisite for entering the extended CT of new RA B.6 (i.e., 14 days).As specified in the TS Bases markups (Attachment 3), Emergency Supplemental Power Source (ESPS) availability requires that:1.The load test has been performed within 30 days of entry into the extended CT.2.The ESPS fuel tank is verified locally to be greater than or equal to a 24 hour supply.3.The ESPS supporting system parameters for starting and operating are verified to be within limits for functional availability (e.g., battery state of charge).The CT of 72 hours from discovery of unavailable ESPS ofnew RA B.6 (formerly RA B.4)is based on the existing CT for an inoperable DG.The 24 hour CT of new RA B.6 is based on Branch Technical Position 8-8 and indicates that if the ESPS unavailability occurs sometime after 72 hours of continuous DG inoperability (i.e., after entering the extended CT for an inoperable DG), then the remaining time to restore the ESPS to available status or restore the DG to operable status is limited to 24 hours.The 14 day CT of new RA B.6 is in accordance with Branch Technical Position 8-8, which indicates that operation may continue when a DG is inoperable for a period that should not exceed 14 days, provided a supplemental AC power source is available.The ESPS is the supplemental AC power source for CNS.The 17 day CT of new RA B.6 limits the total time that LCO 3.8.1.a or LCO 3.8.1.b is not met while concurrently or simultaneously in Conditions A and B.The existing CT is the sum of the CT forRA A.3 (i.e., 72 hours) and existing RA B.4 (i.e., 72 hours).CNS is proposing to increase the CT for existing RA B.4 to 14 days; thus the maximum CT for new RA B.6 will be increased from 6 days to 17 days.New Condition C reflects that with an opposite unit DG inoperable, the remaining operable unit-specific DG and the required offsite circuits are adequate to supply power to the onsite Class 1E Distribution System.The CT of new RAs C.1.1 and C.1.2 are in accordance with Regulatory Guide 1.93, which indicates operation may continue in this condition for a period that should not exceed 72 hours. The 72 hour CT takes into account the capacity and capability of the remaining AC power sources, a reasonable time for repairs and the low probability of a DBA occurring during theperiod.New Condition D is added for an inoperable qualified circuit between the offsite transmission network and the opposite unit's Onsite Essential Auxiliary Power System necessary to supply power to the NSWS, CRAVS,CRACWS and ABFVES.The Note above new RA D.1indicates that when Condition D is entered with no AC source to atrain, the Conditions and RAs for LCO 3.8.9, "Distribution Systems -Operating," must be immediately entered.This allows new Condition D to provide requirements for the loss of a LCO 3.8.1.c offsite circuit and LCO 3.8.1.d DG without regard to whether a train is de-energized.LCO 3.8.9 provides the appropriate restrictions for a de-energized train.
U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 19New RA D.1 ensures a highly reliable power source remains with the one necessaryLCO 3.8.1.c offsite circuit("necessary" only when the offsite circuit isaligned to the opposite unit Onsite Essential Auxiliary Power System that is supplying power to a train of the NSWS, CRAVS, CRACWS and ABFVES)inoperable by verifying the operability of the remaining required offsite circuits.The CT for new RA D.1 is consistent with NUREG-1431andthe CT for existing RA A.1.New RA D.2 only applies if the train cannot be powered from an offsite source and is intended to provide assurance that an event coincident with a single failure of the associated DG will not result in a complete loss of safety function for the NSWS, CRAVS, CRACWS or the ABFVES. The 24 hour CT for new RA D.2 is considered acceptable because it minimizes risk while allowing time for restoration before subjecting the unit to transients associated with shutdown. The remaining operable offsite circuits and DGs are adequate in this condition to supply power to the Class 1E Distribution System. The 24 hour CT also takes into account the component operability of the redundant counterpart to the inoperable NSWS, CRAVS, CRACWS or ABFVES, the capacity and capability of the remaining AC sources, a reasonable time for repairs and the low probability of a DBA occurring during this period.New RA D.3 reflects that if the inoperable qualified circuit between the offsite transmission network and the opposite unit's Onsite Essential Auxiliary Power System necessary to supply power to the NSWS, CRAVS, CRACWS and ABFVES cannot be restored to operable status within 72 hours, then the NSWS, CRAVS, CRACWS and ABFVES components associated with the inoperable offsite circuitmust be declared inoperable. The ACTIONS associated with the LCOs for those shared systems will ensure that appropriate action is taken.The 72 hour CT for new RA D.3 takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs and the low probability of a DBA occurring during this period.New Condition E is added for an opposite unit DG necessaryto supply power to the NSWS, CRAVS, CRACWS and ABFVES inoperable.The Note above new RA E.1 indicates that when Condition E is entered with no AC source to atrain, the Conditions and RAs for LCO 3.8.9, "Distribution Systems -Operating," must be immediately entered. This allows new Condition E to provide requirements for the loss of a LCO 3.8.1.c offsite circuit and LCO 3.8.1.d DG without regard to whether a train is de-energized.LCO 3.8.9 provides the appropriate restrictions for a de-energized train.The new RA E.1 to verify both unit-specific DGs are operable, the other opposite unit's DG is operable and the ESPS is available forms the basis for the 14 day CT of new RA E.5.The verification in this RA provides assurance that the other three safety-related DGs and the ESPS are capable of supplying the Class 1E AC Electrical Power Distribution System.New RA E.2 ensures a highly reliable power source remains with the one necessary LCO 3.8.1.dDG("necessary" only when the DG is aligned to the opposite unit Onsite Essential Auxiliary Power System that is supplying power to a train of the NSWS, CRAVS, CRACWS and ABFVES)inoperable by verifying the operability of the remaining required offsite circuits.The CT for new RA E.2 is consistent withNUREG-1431andthe CT for existing RA A.1.New RA E.3 is intended to provide assurance that a loss of offsite power, during the period a LCO 3.8.1.d DG is inoperable, does not result in a complete loss of safety function for the NSWS, CRAVS, CRACWSor the ABFVES. Four hours (i.e., the CT for new RA E.3) from discovering the LCO 3.8.1.d DG inoperable coincident with one train of NSWS, CRAVS, CRACWS or ABFVESinoperablethat is associated with the other train that has emergency U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 20power is acceptable because it minimizes risk while allowing time for restoration before subjecting the unit to transients associated with shutdown.The four hour CT also takes into account the capacity and capability of the remaining NSWS, CRAVS, CRACWS and ABFVES train, a realistic time for repairs and the low probability of a DBA occurring during this period. The remaining operable DGs and offsite circuits are adequate in this condition to supply electrical power to the onsite Class 1E Distribution System. Thus, on a component basis, single failure protection for the NSWS, CRAVS, CRACWS or ABFVES may have been lost; however, function has not been lost.New RA E.4.1 provides an allowance to avoid unnecessary testing of operable DGs. If it can be determined that the cause of the inoperable LCO 3.8.1.d DG (opposite unit DG necessaryto supply power to the NSWS, CRAVS, CRACWS and ABFVES) does not exist on the operable DGs, then SR 3.8.1.2 does not have to be performed. In accordance with new RA E.4.2, if the cause of the initial inoperable LCO 3.8.1.d DG cannot be confirmed not to exist on the remaining DGs, then performance of SR 3.8.1.2 suffices to provide assurance of continued operability of the DGs.According to Generic Letter 84-15,"Proposed Staff Actions to Improve and Maintain Diesel Generator Reliability,"the 24 hour CT is reasonable to confirm that the operable DGs are not affected by the same problem as the inoperable LCO 3.8.1.d DG.New RA E.5 reflects that if the opposite unit DG that is needed to supply power to the NSWS, CRAVS, CRACWS and ABFVES cannot be restoredto operable status within 14 days, then the NSWS, CRAVS, CRACWS and ABFVEScomponents associated with the inoperable DG must be declared inoperable.The Actions associated with the NSWS, CRAVS, CRACWS and ABFVES will ensure the appropriate actions are taken.The CT of 14 days is justified by new RA E.1 (verify both unit-specific DGs are operable, the other opposite unit DG is operable and the ESPS is available).The 14 day CT is also consistent with the proposed CT in ACTION B when ESPS is available.New Condition F is added to indicate that with an additional safety-related DG inoperable or the ESPS unavailable, the remaining operable DG and qualified circuits are adequate to supply electrical power to the onsite Class 1E Distribution System.New RA F.1.1 is provided to restore both of the unit-specific DGs to operable, the other opposite unit DG to operable and the ESPS to available. New RA F.1.2is provided to restore the LCO 3.8.1.d DG to operable.Either of the new RAs F.1.1 and F.1.2 must be completed within 72 hours.The 72 hour CT for RAs F.1.1 and F.1.2 is consistent with Regulatory Guide 1.93,"Availability of Electric Power Sources."The 72 hour CT also takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs and the low probability of a DBA occurring during the period.New RA F.1.3 reflects that if the opposite unit DG that is necessaryto supply power to the NSWS, CRAVS, CRACWS and ABFVES cannot be restoredto operable status within 72 hours, then the NSWS, CRAVS, CRACWS and ABFVES components associated with the inoperable DGmust be declared inoperable.The ACTIONS associated with the LCOs for those shared systems will ensure that appropriate action is taken.The 72 hour CT for new RA F.1.3 takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs and the low probability of a DBA occurring during this period.Renaming Condition C to Condition G is an administrative change.Adding "LCO 3.8.1.a" to new Condition G  clarifies that the portion of the Condition pertains to the qualified circuits between the offsite transmission network and the Onsite Essential Auxiliary Power System U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 21rather than a qualified circuit between the offsite transmission network and the opposite unit's Onsite Essential Auxiliary Power System.The second part of Condition G after the "OR" connector is added to reflect when the offsite circuit required by LCO 3.8.1.c and one offsite circuit required by LCO 3.8.1.a are concurrently inoperable, if the LCO 3.8.1.a offsite circuit is credited with providing power to the NSWS, CRAVS, CRACWS and ABFVES.Renaming RAs C.1 and C.2 to G.1 and G.2 is an administrative change. Changing "Condition C" to "Condition G" in the CT for new RA G.1 is an administrative change.Renaming Condition D to Condition H is an administrative change.Adding "LCO 3.8.1.a" and "LCO 3.8.1.b" to new Condition H clarifies that the Condition pertainsto a qualified circuit between the offsite transmission network and the Onsite Essential Auxiliary Power System (rather than a qualified circuit between the offsite transmission network and the opposite unit's Onsite Essential Auxiliary Power System) andto a DG capable of supplying the Onsite Essential Auxiliary Power Systems (rather than a DG from the opposite unit necessary to supply power to the NSWS, CRAVS, CRACWS and ABFVES).Changing "Condition D" to "Condition H" in the NOTE above new RA H.1 is an administrative change. Renaming RAs D.1 andD.2 to H.1. and H.2 is an administrative change.Renaming Condition E to Condition I is administrative change.Adding "LCO 3.8.1.b" to new Condition I clarifies that thisportion of the Condition pertains to the unit-specific DGs rather than aDG from the opposite unit necessary to supply power to the NSWS, CRAVS, CRACWS and ABFVES.The second part of Condition I after the "OR" connector is added to reflect that with one LCO 3.8.1.d DG inoperable and the LCO 3.8.1.b DG that provides power tothe NSWS, CRAVS, CRACWS and ABFVES inoperable, there are no remaining standby AC sources to theshared portions of theNSWS, CRAVS, CRACWS and ABFVES.Renaming RA E.1 to I.1 is an administrative change.Renaming Condition F to Condition J is an administrative change. Renaming RA F.1 to J.1 is an administrative change.Renaming Condition G to Condition K is an administrative change.All of the proposed revisions to new Condition K reflect instances where the RA and associated CT of a Condition (or RA) are not met.Renaming RAs G.1 and G.2 to K.1 and K.2 is an administrative change.
Renaming Condition H to Condition L is an administrative change.Adding "LCO 3.8.1.a and LCO 3.8.1.b" to new Condition L clarifies that the Condition corresponds to a level of degradation in which all redundancy in the unit-specific (i.e., LCO 3.8.1.a and LCO 3.8.1.b) AC electrical power supplies has been lost.The new NOTE added to the SURVEILLANCE REQUIREMENTS section of CNS TS 3.8.1 clarifies that not all of the SRs are applicable to all the components described in the LCO.New SR 3.8.1.21 lists the SRs that are applicable to new LCO 3.8.1.c and new LCO 3.8.1.d.These SRs are 3.8.1.1, 3.8.1.2, 3.8.1.4, 3.8.1.5 and 3.8.1.6. The Frequency of new SR 3.8.1.21 is to be in accordance with the CNS Surveillance Frequency Control Program.
U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 222.2McGuire Evaluation of the TS 3.8.1 Change Request  In order to continue to meet Criterion 3 of 10 CFR 50.36with the removal of the requirement fromthe MNS TS Bases to maintain both normal and emergency power for operability of the shared systems (NSWS, CRAVS, CRACWS and ABFVES), the opposite unit's AC power sources that are necessary to support the NSWS, CRAVS, CRACWS and ABFVES are incorporated into TS 3.8.1 within new LCOs 3.8.1.c and 3.8.1.d.Eachtrain of NSWS, CRAVS, CRACWS and ABFVES is connected to an onsite Class 1E electrical power distribution subsystem from either unit.The word "necessary" used in LCO 3.8.1.c and LCO 3.8.1.d clarifies that the respective AC power source is aligned to the opposite unit Onsite Essential Auxiliary Power System that is supplying power to a train of shared systems.For example, in a normal alignment at MNS, Unit 1 Essential Bus 1ETA supplies Train Aof shared systemsandUnit 2 Essential Bus 2ETB supplies Train B of shared systems.Thus for this normal plant configuration, the 2B offsite circuit and 2B DG, both of which supply power to 2ETB, would be LCO 3.8.1.c and LCO 3.8.1.d AC sources for Unit 1 TS 3.8.1.Similarly, the 1A offsite circuit and 1A DG, both of which supply power to 1ETA, would be LCO 3.8.1.c and LCO 3.8.1.d AC sources for Unit 2 TS 3.8.1.However, since the 2A offsite circuit and 2A DG are not necessary to supply power to a train of shared systems in the normal plant configuration, they would not be LCO 3.8.1.c and LCO 3.8.1.d AC sources.And since the 1B offsite circuit and 1B DG are not necessary to supply power to a train of shared systems in the normal plant configuration, they would not be LCO 3.8.1.c and LCO 3.8.1.d AC sources.It is important to note that if desired or required to maintain operability, Train A shared equipment can be swapped to receive power from Unit 2 Essential Bus 2ETA. Similarly, Train B shared equipment can be swapped to receive power from Unit 1 Essential Bus 1ETB.The Note that is added to the Applicability section takes exception to the requirements for the required AC sources in LCO 3.8.1.c and LCO 3.8.1.d provided the associated shared systems are inoperable. This exception is intended to allow declaring the shared systems supported by the opposite unit inoperable either in lieu of declaring the LCO 3.8.1.c and LCO 3.8.1.d AC sources inoperable, or at any time subsequent to entering ACTIONS for an inoperable LCO 3.8.1.c or LCO 3.8.1.d AC source. This exception is acceptable since, with the shared systems supported by the opposite unit inoperable and the associated ACTIONS entered, the LCO 3.8.1.c and LCO 3.8.1.d AC sources provide no additional assurance that acceptable fuel design limits and reactor coolant pressure boundary limits are not exceeded as a result of abnormal transients and also provide no additional assurance that adequate core cooling is provided and containment operability and other vital functions are maintained in the event of a postulated design basis accident (DBA).Adding "LCO 3.8.1.a" to Condition A clarifies that the Condition pertains to a qualified circuit between the offsite transmission network and the Onsite Essential Auxiliary Power System rather than a qualified circuit between the offsite transmission network and the opposite unit's Onsite Essential Auxiliary Power System.Changing "OPERABLE offsite circuit" to "required OPERABLE offsite circuit(s)" in RA A.1 reflects that it could be necessary to verify the operability of more than one offsite circuit when a LCO 3.8.1.a offsite circuit is inoperable, since an offsite circuit may be aligned to the opposite unit Onsite Essential Auxiliary Power System that is supplying power to a train of the NSWS, CRAVS, CRACWS and ABFVES (i.e., a LCO 3.8.1.c offsite circuit).The proposed maximum CT of 17 days for RA A.3 limits the total time that LCO 3.8.1.a or LCO 3.8.1.b is not met while concurrently or simultaneously in Conditions A and B.The existing CT U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 23is the sum of the CT for RA A.3 (i.e., 72 hours) and existing RA B.4 (i.e., 72 hours).MNS is proposing to increase the CT for existing RA B.4 to 14 days; thus the maximum CT for RA A.3 will be increased from 6 days to 17 days.Adding "LCO 3.8.1.b" to Condition B clarifies that the Condition pertains to a unit-specific DGrather than a DG from the opposite unit necessary to supply power to the NSWS, CRAVS, CRACWS andABFVES.New RA B.1 provides assurance that the LCO 3.8.1.d DG is operablewhen a LCO 3.8.1.b DG is inoperable.Renaming RAs B.1, B.2, B.3.1, B.3.2 and B.4 are administrative changes."OPERABLE DG" is changed to "OPERABLE DG(s)" in new RAs B.4.1 and B.4.2 to reflect that the RAs are to be performed for a LCO 3.8.1.d DG in addition to the OPERABLE LCO 3.8.1.b DG.New RA B.5 is added as a prerequisite for entering the extended CT of new RA B.6 (i.e., 14 days).As specified in the TS Bases markups (Attachment 3), Emergency Supplemental Power Source (ESPS) availability requires that:1.The load test has been performed within 30 days of entry into the extended CT.2.The ESPS fuel tank is verified locally to be greater than or equal to a 24 hour supply.
3.The ESPS supporting system parameters for starting and operating are verified to be within limits for functional availability (e.g., battery state of charge).The CT of 72 hours from discovery of unavailable ESPS of new RA B.6 (formerly RA B.4) is based on the existing CT for an inoperable DG.The 24 hour CT of new RA B.6 is based on Branch Technical Position 8-8 and indicates that if the ESPS unavailability occurs sometime after 72 hours of continuous DG inoperability (i.e., after entering the extended CT for an inoperable DG), then the remaining time to restore the ESPS to available status or restore the DG to operable status is limited to 24 hours. The 14 day CT of new RA B.6 is in accordance with Branch Technical Position 8-8, which indicates that operation may continue when a DG is inoperable for a period that should not exceed 14 days, provided a supplemental AC power source is available.The ESPS is the supplemental AC power source for MNS.The 17 day CT of new RA B.6 limits the total time that LCO 3.8.1.a or LCO 3.8.1.b is not met while concurrently or simultaneously in Conditions A and B.The existing CT is the sum of the CT for RA A.3 (i.e., 72 hours) and existing RA B.4 (i.e., 72 hours).MNSis proposing to increase the CT for existing RA B.4 to 14 days; thus the maximum CT for new RA B.6 will be increased from 6 days to 17 days.New Condition C reflects that with a LCO 3.8.1.dDG inoperable, the remaining operable unit-specific DG and the required offsite circuits are adequate to supply power to the onsite Class 1E Distribution System.The CT of new RAs C.1.1 and C.1.2 are in accordance with Regulatory Guide 1.93, which indicates operation may continue in this condition for a periodthat should not exceed 72 hours. The 72 hour CT takes into account the capacity and capability of the remaining AC power sources, a reasonable time for repairs and the low probability of a DBA occurring during the period.New Condition D is added foran inoperable qualified circuit between the offsite transmission network and the opposite unit's Onsite Essential Auxiliary Power System necessary to supply U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 24power to the NSWS, CRAVS, CRACWS and ABFVES.The Note above new RA D.1 indicates that when Condition D is entered with no AC source to a train, the Conditions and RAs for LCO 3.8.9, "Distribution Systems -Operating," must be immediately entered.This allows new Condition D to provide requirements for the loss of a LCO 3.8.1.c offsite circuit and LCO 3.8.1.d DG without regard to whether a train is de-energized.LCO 3.8.9 provides the appropriate restrictions for a de-energized train.New RA D.1 ensures a highly reliable power source remains with the one necessaryLCO 3.8.1.c offsite circuit ("necessary" only when the offsite circuit is aligned to the opposite unit Onsite Essential Auxiliary Power System that is supplying power to a train of the NSWS, CRAVS, CRACWS and ABFVES) inoperable by verifying the operability of the remaining required offsite circuits. The CT for new RA D.1 is consistent with NUREG-1431andthe CT for existing RA A.1.New RA D.2 only applies if the train cannot be powered from an offsite source and is intended to provide assurance that an event coincident with a single failure of the associated DG will not result in a complete loss of safety function for the NSWS, CRAVS, CRACWS or the ABFVES. The 24 hour CT for new RA D.2 is considered acceptable because it minimizes risk while allowing time for restoration before subjecting the unit to transients associated with shutdown. The remaining operable offsite circuits and DGs are adequate in this condition to supply power to the Class 1E Distribution System. The 24 hour CT also takes into account the component operability of the redundant counterpart to the inoperable NSWS, CRAVS, CRACWS or ABFVES, the capacity and capability of the remaining AC sources, a reasonable time for repairs and the low probability of a DBA occurring during this period.New RA D.3 reflects that if the inoperable qualified circuit between the offsite transmission network and the opposite unit's Onsite Essential Auxiliary Power System necessary to supply power to the NSWS, CRAVS, CRACWS and ABFVEScannot be restoredto operable status within 72 hours, then the NSWS, CRAVS, CRACWS and ABFVES components associated with the inoperable offsite circuit must be declared inoperable. The ACTIONS associated with the LCOs for those shared systems will ensure that appropriate action is taken.The 72 hour CT for new RA D.3 takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs and the low probability of a DBA occurring during this period.New Condition E is added for an opposite unit DG necessary to supply power to the NSWS, CRAVS, CRACWS and ABFVES inoperable.The Note above new RA E.1 indicates that when Condition E is entered with no AC source to a train, the Conditions and RAs for LCO 3.8.9, "Distribution Systems -Operating," must be immediately entered. This allows new Condition E to provide requirements for the loss of a LCO 3.8.1.c offsite circuit and LCO 3.8.1.d DG without regard to whether a train is de-energized.LCO 3.8.9 provides the appropriate restrictions for a de-energized train.The new RA E.1 to verify both unit-specific DGs are operableand the ESPS is available forms the basis for the 14 day CT of new RA E.5.The verification in this RA provides assurance that the LCO 3.8.1.bsafety-related DGs and the ESPS are capable of supplying the Class 1E AC Electrical Power Distribution System.New RA E.2 ensures a highly reliable power source remains with the one necessary LCO 3.8.1.d  DG ("necessary" only when the DG is aligned to the opposite unit Onsite Essential Auxiliary Power System that is supplying power to a train of the NSWS, CRAVS, CRACWS and U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 25ABFVES) inoperable by verifying the operability of the remaining required offsite circuits. The CTfor new RA E.2 is consistent with NUREG-1431andthe CT for existing RA A.1.New RA E.3 is intended to provide assurance that a loss of offsite power, during the period a LCO 3.8.1.d DG is inoperable, does not result in a complete loss of safety function for the NSWS, CRAVS, CRACWS or the ABFVES. Four hours (i.e., the CT for new RA E.3) from discovering the LCO 3.8.1.d DG inoperable coincident with one train of NSWS, CRAVS, CRACWS or ABFVES inoperable that is associated with the other train that has emergency poweris acceptable because it minimizes risk while allowing time for restoration before subjecting the unit to transients associated with shutdown. The four hour CT also takes into account the capacity and capability of the remaining NSWS, CRAVS, CRACWS and ABFVES train, a realistic time for repairs and the low probability of a DBA occurring during this period. The remaining operable DGs and offsite circuits are adequate in this condition to supply electrical power to the onsite Class 1E Distribution System. Thus, on a component basis, single failure protection for the NSWS, CRAVS, CRACWS or ABFVES may have been lost; however, function has not been lost.New RA E.4.1 provides an allowance to avoid unnecessary testing of operable DGs. If it can be determined that the cause of the inoperable LCO 3.8.1.d DG (opposite unit DG necessary to supply power to the NSWS, CRAVS, CRACWS and ABFVES) does not exist on the operable DGs, then SR 3.8.1.2 does not have to be performed. In accordance with new RA E.4.2, if the cause of the initial inoperable LCO 3.8.1.d DG cannot be confirmed not to exist on the remaining DGs, then performance of SR 3.8.1.2 suffices to provide assurance of continued operability of the DGs. According to Generic Letter 84-15, the 24 hour CT is reasonable to confirm that the operable DGs are not affected by the same problem as the inoperable LCO 3.8.1.d DG.New RA E.5 reflects that if the opposite unit DG that is needed to supply power to the NSWS, CRAVS, CRACWS and ABFVES cannot be restoredto operable status within 14 days, then the NSWS, CRAVS, CRACWS and ABFVES components associated with the inoperable DG must be declared inoperable.The Actions associated with the NSWS, CRAVS, CRACWS and ABFVES will ensure the appropriate actions are taken.The CT of 14 days is justified by new RA E.1 (verify both unit-specific DGs are operableand the ESPS is available).The 14 day CT is also consistent with the proposed CT in ACTION B when ESPS is available.New Condition F is added to indicate that with an additional LCO 3.8.1.b safety-related DG inoperable or the ESPS unavailable, the remaining operable LCO 3.8.1.b DG and qualified circuits are adequate to supply electrical power to the onsite Class 1E Distribution System.New RA F.1.1 is provided to restore both of the unit-specific DGs to operable and the ESPS to available. New RA F.1.2 is provided to restore the LCO 3.8.1.d DG to operable.Either of the new RAs F.1.1 and F.1.2 must be completed within 72 hours.The 72 hour CT for RAs F.1.1 and F.1.2 is consistent with Regulatory Guide 1.93. The 72 hour CT also takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs and the low probability of a DBA occurring during the period.New RA F.1.3 reflects that if the opposite unit DG that is necessaryto supply power to the NSWS, CRAVS, CRACWS and ABFVES cannot be restoredto operable status within 72 hours, then the NSWS, CRAVS, CRACWS and ABFVES components associated with the inoperable DG must be declared inoperable.The ACTIONS associated with the LCOs for those shared systems will ensure that appropriate action is taken.The 72 hour CT for new RA F.1.3 takes U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 26into account the capacity and capability of the remaining AC sources, a reasonable time for repairs and the low probability of a DBA occurring during this period.Renaming Condition C to Condition G is an administrative change.Adding "LCO 3.8.1.a" to new Condition G  clarifies that the portion of the Condition pertains to the qualified circuits between the offsite transmission network and the Onsite Essential Auxiliary Power System rather than a qualified circuit between the offsite transmission network and the oppositeunit's Onsite Essential Auxiliary Power System.The second part of Condition G after the "OR" connector is added to reflect when the offsite circuit required by LCO 3.8.1.c and one offsite circuit required by LCO 3.8.1.a are concurrently inoperable, if the LCO 3.8.1.a offsite circuit is credited with providing power to the NSWS, CRAVS, CRACWS and ABFVES.Renaming RAs C.1 and C.2 to G.1 and G.2 is an administrative change. Changing "Condition C" to "Condition G" in the CT for new RA G.1 is an administrative change. Renaming Condition D to Condition H is an administrative change.Adding "LCO 3.8.1.a" and"LCO 3.8.1.b" to new Condition H clarifies that the Condition pertains to a qualified circuit between the offsite transmission network and the Onsite Essential Auxiliary Power System (rather than a qualified circuit between the offsite transmission network and the opposite unit's Onsite Essential Auxiliary Power System) and to a DG capable of supplying the Onsite Essential Auxiliary Power Systems (rather than a DG from the opposite unit necessary to supply power to the NSWS, CRAVS, CRACWS and ABFVES).Changing "Condition D" to "Condition H" in the NOTE above new RA H.1 is an administrative change. Renaming RAs D.1 and D.2 to H.1. and H.2 is an administrative change. Renaming Condition E to Condition I is administrative change.Adding "LCO 3.8.1.b" to new Condition I clarifies that the portion of the Condition pertains to the unit-specific DGsrather than a DG from the opposite unit necessary to supply power to the NSWS, CRAVS, CRACWS and ABFVES.The second part of Condition I after the "OR" connector is added to reflect that with one LCO 3.8.1.d DG inoperable and the LCO 3.8.1.b DG that provides power to the NSWS, CRAVS, CRACWS and ABFVES inoperable, there are no remaining standby AC sources to the NSWS, CRAVS, CRACWS and ABFVES.Renaming RA E.1 to I.1 is an administrative change.
Renaming Condition F to Condition J is an administrative change. Renaming RA F.1 to J.1 is an administrative change.Renaming Condition G to Condition K is an administrative change.All ofthe proposed revisions to new Condition K reflect instances where the RA and associated CT of a Condition (or RA) are not met.Renaming RAs G.1 and G.2 to K.1 and K.2 is an administrative change.Renaming Condition H to Condition L is an administrative change.Adding "LCO 3.8.1.a and LCO 3.8.1.b" to new Condition L clarifies that the Condition corresponds to a level of degradation in which all redundancy in the unit-specific (i.e., LCO 3.8.1.a and LCO 3.8.1.b) AC electrical power supplies has beenlost.
U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 27The new NOTE added to the SURVEILLANCE REQUIREMENTS section of MNSTS 3.8.1 clarifies that not all of the SRs are applicable to all the components described in the LCO.New SR 3.8.1.21 lists the SRs that are applicable to new LCO 3.8.1.c andnew LCO 3.8.1.d.These SRs are 3.8.1.1, 3.8.1.2, 3.8.1.4, 3.8.1.5 and 3.8.1.6. The Frequency of new SR 3.8.1.21 is to be in accordance with the MNSSurveillance Frequency Control Program.3.ADDITIONAL TECHNICAL JUSTIFICATION FORCATAWBA PROPOSEDCHANGEBased on the September20, 2017 public meeting forthe subject LAR, Duke Energy is also providing in the following sections additional discussion regarding theCNS NSWSdesign basisandaclarification of statements pertaining to the NSWS that are located in Chapter 9 of the CNS UFSAR.3.1Discussion of NSWS Design BasisThere are six NSWSheaders at Catawba: Essential 1A, Unit 1 Nonessential, Essential 1B, Essential 2A, Unit 2 Nonessential and Essential 2B. There are four NSWStrains, correspondingto the four essential headers. There are two essential NSWSloops at Catawba:
A and B, each consisting of a Unit 1 and a Unit 2 essential train. The term "channel" is used interchangeably with "loop". To understand NSWSoperation,the NSWS layout must be understood. Each essential NSWSloop has a single supply line and a single return line that serves both units. This effectively makes components in the NSWSPumphouse not unit related.
The only characteristicthat ties a NSWS pumpto a particular unit is the Class 1E electrical bus from which the pumpreceives power.The common A and B NSWS supply lines and the crossovers between units allows flow from any NSWSpump to be directed to any NSWS header. This gives the station flexibility in normal NSWSoperation, but also makes possible system faults that affect the operability of both units (discussed further in Table 1 below).The NSWS design basis specifies that the systemshould be operated in a manner such that itcan perform itssafety function in mitigating the consequences of a design basis event accounting for a single failure in the system. The worst single failure can eliminate one loop of NSWS pumps. With that design basis conceptin mindand the NSWSflow balanced to one-pump analysis values, the following statements are relevant regarding the NSWS at Catawba:1.Four NSWSpumps are needed to operate both units without entering aTechnical Specification Action statement.2.Two operating NSWS pumps are required to mitigate theconsequences of a design basis event if both units are operating. In other words, two NSWSpumps have sufficient capacity to supply post-LOCA loads on one unit and shutdown and cooldown loads on the other unit.3.One pump is required to mitigate the consequences of a design basis event if one unit is operating and the other unit is in Mode 5 or 6. Specifically, one NSWSpump has U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 28sufficient capacity to maintain a unit indefinitely in Cold Shutdown (commencing 36 hours following a trip from full power) while supplying the post-LOCA loads on the other unit.Nuclear service water capacity capabilities are as follows:1.One operating NSWSpump can supply one essential loop in the one-pump analysis mode.2.Two operating NSWSpumps can supply one essential loop (twoessential headers) and both nonessential headers, or two NSWS pumps can supply the total flow demands of one unit with limited flow to the other unit. Note that the NSWSSingle Supply Header Operation (SSHO) Evaluation calculation was performed to verifythe NSWSSingle Supply Header alignment and demonstrated that while the NSWS is aligned in SSHO, two NSWSpumps have adequate capacity to supply all four NSWSessential headers and all four diesel generators, assuming a design-basis event on one unit, a LOOP on both units, a loss of Lake Wylie resulting in isolation of both NSWSnon-essential headers, and one NSWSpump pit suction transfer failureresulting in the loss of two NSWSpumps.3.Three operating NSWSpumps can supply flow to all six NSWSheaders.The scenarios belowin Table 1 represent the possible combinations of events and failures in the Catawba NSWSfor the proposed change.Not all possible combinations are described, but the combinations that are presented bound other possible combinations (i.e.,failure of valve 1RN3A is presented, which bounds the corresponding opposite train failure of valve 1RN4B).Two figures (simplified diagrams) are provided following Table 1 for each Case Number provided in Table 1.The first diagram for each Case Number represents the NSWS alignment with the initial conditions and the second diagram represents the NSWS alignment post event.To understand the NSWSresponse to the various scenarios and failurespresented in Table 1,the single failure considerations for the NSWSsystem must be explained.Per the Design Basis Specification for the NSWS, single failure considerations regarding the NSWS are as follows:If both units are operable, the NSWSshall be capable of mitigating the consequences of a design basis event on one unit, concurrent with a Loss of Offsite Power affecting both units, assuming a single failure on the system.  (Two failures, i.e.,one per unit, is not assumed.)  The design basis event may be assumed concurrent with worse case conditions (e.g., Loss of Lake Wylie).If one unit is in an action statement and the other unit is operable, the NSWSshall be capable of mitigating the consequences of a design basis event on the operating unit, concurrent with a Loss of Offsite Power assuming a single failure of any unit related component required to support operation of the operable unit. Failures of shared system components are not postulated.The diesel generators are shared components with regard to their supporting function of NSWS.A single failure is not postulated on the unit in an action statement or either of that unit's diesel generators.
U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 29If one unit is operable and the other unit is shut down, the NSWSshall be capable of mitigating the consequences of a design basis event on the operating unit, concurrent with a Loss of Offsite Power assuming a single failure of any unit related or shared component required to support operation of the operable unit.If both units are in action statements, single failures are not postulated on any NSWSunit related or shared component. Please refer to the following definitions for Table 1:ECCS -Emergency Core Cooling SystemsEDG -Emergency Diesel GeneratorESPS-Emergency Supplemental Power SourceHX -HeatExchangerLOCA -Loss of Coolant AccidentLOOP -Loss of Offsite PowerSNSWP -Standby Nuclear Service Water PondSp -High High Pressure Signal in Containment U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 30Table 1 -NSWSScenarios and System ResponseCase Number /Initial ConditionsEventSingle FailureDescription of NSWSResponsePost Event NSWSFlow Demands(1)NSWSaligned to Lake WylieUnit 1 -Mode 1Unit 2 -Mode 1 All equipment OperableUnit 1 LOCA (Sp)LOOP Both Units"Sp" = High High Pressure Signal in ContainmentNo failuresThe NSWSremains aligned to Lake Wylie. The Unit 1 NSWScrossover valves and non-essential header supply valves close, isolating the Unit 1 NSWSNon-Essential Header.The Unit 2 NSWScrossover valves remain open, allowing NSWSflow between loops A and B and to the Unit 2 NSWS Non-Essential header. This provides non-assured NSWSbackup flow to non-essential components.Loop A NSWSPumps 1A and 2A supply NSWS flowto EDGs 1A and2A, 1A and 2A NSWS Essential Headersand cross-train through Unit 2crossover valves, as required.Loop B NSWSPumps 1B and 2B supply NSWS flowto EDGs 1B and 2B, 1B and 2B NSWSEssential Headersand cross-train through Unit 2crossover valves, as required.Summary -The NSWS iscapable of supporting the required LOCA loads on Unit 1 and Hot Standby loads on Unit 2.NSWSPump motor demands 1A, 1B, 2A, 2BNSWSStrainer backwash1A, 1B, 2A, 2BComponent Cooling (CC)HX 1A, 1B, 2A, 2BContainment Spray (CS)HX 1A, 1BDiesel Jacket Water CoolingHX 1A, 1B, 2A, 2BAuxiliary FeedwaterMakeup 1A, 1B, 2A, 2BCRACWSChiller A or BU2 NSWSNon-Essential Header U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 31Case Number /Initial ConditionsEventSingle FailureDescription of NSWSResponsePost Event NSWSFlow Demands(2)NSWSaligned to Lake WylieUnit 1 -Mode 1Unit 2 -Mode 1All equipment OperableUnit 1 LOCA (Sp)LOOP Both UnitsLoss of Lake WylieNo failuresThe NSWSaligns to the Standby Nuclear Service Water Pond (SNSWP).The NSWSloops are isolated from each other by closure of crossover valves. The LoopA NSWSPumps 1A and 2A supply NSWS flow to EDGs 1A and 2A and tothe 1A and 2A NSWSEssential Headers.The Loop B NSWSPumps 1B and 2B supply NSWS flowto EDGs 1B and 2B andto the 1B and 2B NSWSEssential Headers.The Unit 1 and 2 NSWSNon-Essential Headers are isolated due to closure of crossover valves during swap to the SNSWP.Summary -The NSWS is capable of supporting the required LOCA loads on Unit 1 and Hot Standby loads on Unit 2.NSWSPump motor demands 1A, 1B, 2A, 2BNSWSStrainer backwash1A, 1B,2A, 2BCCHX 1A, 1B, 2A, 2BCSHX 1A, 1B Diesel Jacket Water CoolingHX 1A, 1B, 2A, 2BAuxiliary FeedwaterMakeup 1A, 1B, 2A, 2BCRACWSChiller A or B(3)
NSWSaligned to the SNSWPUnit 1 -Mode 1Unit 2 -Mode 1All equipment OperableUnit 1 LOCA (Sp)LOOP Both UnitsNo FailuresThe NSWSremains aligned to the SNSWP. The Unit 1 NSWScrossover valves and non-essential header supply valves close, isolating the Unit 1 NSWSNon-Essential Header.NSWSPump motor demands 1A, 1B, 2A, 2BNSWSStrainer backwash 1A, 1B, 2A, 2B U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 32Case Number /Initial ConditionsEventSingle FailureDescription of NSWSResponsePost Event NSWSFlow DemandsThe Unit 2 NSWScrossover valves remain open, allowing NSWSflow between loops A and B and to the Unit 2 NSWSNon-Essential header. This provides non-assured NSWSbackup flow to Unit 2 non-essential components.The Loop A NSWSPumps 1A and 2A supply NSWS flow to EDGs 1A and2A, 1A and 2A NSWSEssential Headersand cross-train through the Unit 2crossover valves, as required.The Loop B NSWSPumps 1B and 2B supply NSWS flow to EDGs 1B and 2B, the1B and 2B NSWS Essential Headersand cross-train through the Unit 2 crossover valves, as required.Summary -The NSWS iscapable of supporting the required LOCA loads on Unit 1 and Hot Standby loads on Unit 2.CCHX 1A, 1B, 2A, 2BCSHX 1A, 1BDiesel Jacket Water Cooling HX 1A, 1B, 2A, 2BAuxiliary Feedwater Makeup 1A, 1B, 2A, 2BCRACWSChiller A or BUnit 2 NSWSNon-Essential Header U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 33Case Number /Initial ConditionsEventSingle FailureDescription of NSWSResponsePost Event NSWSFlow Demands(4)
NSWSAligned to the SNSWPUnit 1 -Mode 1Unit 2 -Mode 1All Equipment OperableUnit 1 LOCA (Sp)LOOP Both UnitsEDG 1A Fails, resulting in 1A NSWSpump failure and 1A ECCS failureThe NSWSremains aligned to the SNSWP. The Unit 1 NSWScrossover valve 1RN48B and NSWSNon-Essential header supply valves close, isolating the Unit 1 NSWSNon-Essential Header.The Unit 2 NSWScrossover valves remain open, allowing NSWSflow between loops A and B and to the Unit 2 NSWS Non-Essential header. This provides non-assured NSWSbackup flow to Unit 2 non-essential components.The Loop A NSWSPump 2A supplies NSWS flow to EDG2A, the 1A and 2A NSWSEssential Headersand cross-train through the Unit 2crossover valves, as required.The Loop B NSWSPumps 1B and 2B supply NSWS flowto EDGs 1B and 2B, the 1B and 2B NSWS Essential Headers and cross-train through the Unit 2crossover valves, as required.CCHX 1A receives NSWSflow since the flow control valve fails open. However, CCTrain 1A is not powered or available.Summary -The NSWS iscapable of supporting the required LOCA loads on NSWSPump motor demands 1B, 2A, 2BNSWSStrainer backwash1B, 2A, 2BCCHX 1A, 1B, 2A, 2BCSHX 1B Diesel Jacket Water CoolingHX 1B, 2A, 2BAuxiliary FeedwaterMakeup 1B, 2A, 2BCRACWSChiller BUnit 2NSWSNon-Essential Header U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 34Case Number /Initial ConditionsEventSingle FailureDescription of NSWSResponsePost Event NSWSFlow DemandsUnit 1 and Hot Standby loads on Unit 2.(5)NSWSaligned to Lake WylieUnit 1 -Mode 1Unit 2 -Mode 1 All equipment OperableUnit 1 LOCA (Sp)LOOP Both UnitsLoss of Lake WylieValve 1RN3A fails to open, resulting in loss of Pit A, failure of 1A and 2A NSWSPumps, 1A and 2A EDGs, 1A and 2A ECCSThe NSWSaligns to the SNSWP.Since there are not any TSentries on Unit 1 or Unit 2, a failure of the shared A Train NSWSsuction pit valve 1RN3A is postulated.The NSWSessential loops are isolated from each otherby closure of the crossover valves. This isolates the failed A loop from the B loop.No power is available to A Train essential equipment due to loss of the A train EDGs. The Loop B NSWSPumps 1B and 2B supply NSWS flowto EDGs 1B and 2B andthe 1B and 2B NSWSEssential Headers. NSWSPump motor demands 1B, 2BNSWSStrainer backwash1B, 2BCCHX 1B, 2BCSHX 1BDiesel Jacket Water CoolingHX 1B, 2BAuxiliary FeedwaterMakeup 1B, 2B U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 35Case Number /Initial ConditionsEventSingle FailureDescription of NSWSResponsePost Event NSWSFlow DemandsThe Unit 1 and 2 NSWSNon-Essential Headers are isolated due to closure of valves during swap to the SNSWP.Summary -The NSWS iscapable of supporting the required LOCA loads on Unit 1 and Hot Standby loads on Unit 2.CRACWSChiller B(6)NSWSaligned to Lake WylieUnit 1 -Mode 1Unit 2 -Mode 1EDG 2Bis inoperable,resulting in isolation of theUnit 2Non-EssentialHeader andclosure of thecrossover valveNSWSPump 2B is operableLOOP Both UnitsEDG 1A Fails, resulting in 1A NSWSPump failure NOTE -This eventassumes a failure (EDG1A) while a shared component (EDG 2B) is inoperable. The NSWSremains aligned to Lake Wylie. A single failure can occur onaUnit 1 component since aUnit 2 component is inoperable. No failures are postulated on shared components.The NSWSPump 2B is not credited, since offsite power is lost and ESPS power is not immediately available. The Unit 1 NSWScrossover valves remain open, allowing NSWSflow between loops A and B and to the Unit 1 NSWSNon-Essential header. This provides non-assured NSWSbackup flow to Unit 1 non-essential components.Each NSWSLoop has one NSWSPump (1B, 2A) to supply NSWS flowto EDGs NSWSPump motor demands 1B, 2ANSWSStrainer backwash 1B, 2ACCHX 1A, 1B, 2A, 2BDiesel Jacket Water CoolingHX 1B, 2AAuxiliary FeedwaterMakeup 1B, 2ACRACWSChiller BUnit 1NSWSNon-Essential Header U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 36Case Number /Initial ConditionsEventSingle FailureDescription of NSWSResponsePost Event NSWSFlow Demands1B and 2A, the 1B and 2A NSWS Essential Headersand the Unit 1 Non-Essential Header.Since EDG 2B is inoperable, valves 2RN48B and 2RN50B are closed.CCHXs 1A and 2B receive NSWSflow since the flow control valve fails open. However, CCTrains 1A and 2B are not powered or available.Summary -The NSWS iscapable of supporting the required Hot Standby loads on Units 1 and 2.(7)NSWSaligned to Lake WylieUnit 1 -Mode 1 Unit 2 -Mode 1EDG 2Bisinoperable, resulting in isolation of the Unit 2Non-EssentialHeader and closure of the crossover valveNSWSPump 2B is operableUnit 1 LOCA (Sp)LOOP Both UnitsEDG 1A Fails, resulting in 1A NSWSPump failure and 1A ECCS failureNOTE -This event assumes a failure (EDG1A) while a shared component (EDG 2B) is inoperable.The NSWSremains aligned to Lake Wylie. A single failurecan occur on aUnit 1 component since aUnit 2 component is inoperable. No failures are postulated on shared components.The NSWSPump 2B is not credited, since offsite power is lost and ESPS power is not immediately available. Each NSWSLoop has one NSWSPump (1B, 2A) to supply NSWS flowto EDGs NSWSPump motor demands 1B, 2ANSWSStrainer backwash1B, 2ACCHX 1A, 1B, 2A, 2BCSHX 1BDiesel Jacket Water CoolingHX 1B, 2AAuxiliary U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 37Case Number /Initial ConditionsEventSingle FailureDescription of NSWSResponsePost Event NSWSFlow Demands1B and 2A, the 1B and 2A NSWS Essential Headers.Since EDG 2B is inoperable, valves 2RN48B and 2RN50B are closed.CCHXs 1A and 2B receive NSWSflow since the flow control valve fails open. However, CCTrains 1A and 2B are not powered or available.The Unit 1 and Unit 2 NSWSNon-Essential Headers are isolated.Summary -The NSWS iscapable of supporting the required LOCA loads on Unit 1 and Hot Standby loads on Unit 2.FeedwaterMakeup 1B, 2ACRACWSChiller B(8)NSWSaligned to Lake WylieUnit 1 -Mode 1Unit 2 -ShutdownEDG 2Bisinoperable, resulting in isolation of the Unit 2Non-Essential Header and closure of the crossovervalveNSWSPump 2B is operableUnit 1 LOCA (Sp)LOOP Both UnitsEDG 1B Fails, resulting in 1B NSWSPump failure and 1B ECCS failureNOTE -This event assumes a failure (EDG 1B) while a shared component (EDG 2B) is inoperable.The NSWSremains aligned to Lake Wylie. A single failurecan occur on EDG 1B since aUnit 2 component is inoperable. No failures are postulated on shared components.The NSWSPump 2B is not credited, since offsite power is lost and ESPS power is not immediately available.NSWSPump motor demands 1A, 2ANSWSStrainer backwash1A, 2ACCHX 1A, 2ACSHX 1ADiesel Jacket Water CoolingHX 1A, 2A U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 38Case Number /Initial ConditionsEventSingle FailureDescription of NSWSResponsePost Event NSWSFlow DemandsThere are no operable NSWSpumps or EDGs on Loop B.Since EDG 2B is inoperable, valves 2RN48B and 2RN50B are closed.Only 1A Auxiliary FeedwaterMakeup.The Unit 1 and Unit 2 NSWSNon-Essential Headers are isolated.Summary -The NSWS iscapable of supporting the required LOCA loads on Unit 1 and Shutdown loads on Unit 2.Auxiliary FeedwaterMakeup 1ACRACWSChiller A(9)NSWSaligned to Lake WylieUnit 1 -Mode 1Unit 2 -Mode 1EDG 2B is inoperable, resulting in isolation of the Unit 2Non-EssentialHeader and closure of the crossover valveNSWSPump 2B is operableUnit 1 LOCA (Sp)LOOP Both UnitsLoss of Lake WylieEDG 1A Fails, resulting in failure of valve 1RN3A to open. This results in loss of Pit A, failure of 1A and 2A NSWSPumps, 1A and 2A EDG, 1A and 2A ECCSNOTE -This event assumes a failure (EDG 1A) while a shared component (EDG 2B) is inoperable. The NSWSaligns to the SNSWP.The NSWSPump 2B is not credited, since offsite power is lost and ESPS power is not immediately available. Since EDG 2B is inoperable,valves2RN48B and 2RN50B are closed.No power is available to A Train essentialequipment due to loss of A train EDGs. NSWSLoop B has one operating NSWSpump (1B) to supply NSWS flowto EDG 1B, the 1B NSWSEssential Header, and NSWSPump motor demands 1BNSWSStrainer backwash1BCCHX 1B, 2BCSHX 1BDieselJacket Water CoolingHX 1BAuxiliary FeedwaterMakeup 1B U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 39Case Number /Initial ConditionsEventSingle FailureDescription of NSWSResponsePost Event NSWSFlow DemandsCCHXs 1B and 2B.CCHX 2B receives NSWSflow since the flow control valve fails open. However, CCTrain 2B is not powered or available.Unit 2 has no Component Coolinguntil ESPS is aligned.The Unit 1 and Unit 2 NSWSNon-Essential Headers are isolated.Summary -The NSWS iscapable of supporting the required LOCA loads on Unit 1 and Hot Standby loads on Unit 2. Unit 2 must have ESPS aligned to power the 2B Essential Busfor this scenario.CRACWSChiller B(10)NSWSaligned to Lake WylieUnit 1 -Mode 1Unit 2 -Mode 1EDG 2B is inoperable, resulting in isolation of the Unit 2Non-Essential Header and closure of the crossover valveNSWSPump 2B is operableUnit 1 LOCA (Sp)LOOP Both UnitsLoss of Lake WylieEDG 1B Fails, resulting in failure of valve 1RN4B to open. This results in loss of Pit B, failure of 1B and 2B NSWSPumps, 1B and 2B ECCSNOTE -This event assumes a failure (EDG 1B) while a shared component (EDG 2B) is inoperable.The NSWS aligns to theSNSWP.NSWSPump 2B is not credited, since offsite power is lost and ESPS power is not immediately available.Since EDG 2B is inoperable,valves2RN48B and 2RN50B are closed.The NSWSessential loops are isolated from each other by closure of crossover NSWSPump motor demands 1A, 2ANSWSStrainer backwash1A, 2A,CCHX 1A, 2ACSHX 1ADiesel Jacket Water CoolingHX 1A, 2A U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 40Case Number /Initial ConditionsEventSingle FailureDescription of NSWSResponsePost Event NSWSFlow Demandsvalves. This isolates NSWScooling water to 1B and 2B EDGs and the NSWSTrain 1B and 2B supplied essential components. No power is available to B Train essential equipment due to loss of the B train EDGs. The Loop A NSWSPumps 1A and 2A supply NSWS flowto EDGs 1A and 2A andto the 1A and 2A NSWSEssential Headers.The Unit 1 and Unit 2 NSWSNon-Essential Headers are isolated.Summary -The NSWS iscapable of supporting the required LOCA loads on Unit 1 and Hot Standby loads on Unit 2.Auxiliary FeedwaterMakeup 1A, 2ACRACWSChiller A(11)NSWSaligned to Lake WylieUnit 1 -Mode 1Unit 2 -Shutdown EDG 2B is operableNSWSPump 2B is inoperable Unit 1 LOCA (Sp)LOOP Both UnitsLoss of Lake WylieValve 1RN3A fails to open, resulting in loss of Pit A, failure of 1A and 2A NSWSPumps, 1A and 2A EDGs, 1A and 2A ECCSThe NSWSaligns to the SNSWP.Since Unit 2 is shutdown, the inoperable 2B NSWSPump does notrequire TS entry per TS 3.7.8. Therefore, a failure of the shared A Train NSWSsuction pit valve 1RN3A is postulated.The NSWSessential loops are isolated from each other by closure of crossover valves, but NSWSLoop A has no NSWSflow.NSWSPump motor demands 1BNSWSStrainer backwash1BCCHX 1B, 2BCSHX 1B U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 41Case Number /Initial ConditionsEventSingle FailureDescription of NSWSResponsePost Event NSWSFlow DemandsNo power is available to A Train essential equipment due to lossof the A train EDGs. NSWSLoop B has one operating NSWSpump (1B) to supply NSWS flowto EDGs 1Band 2B. ECCS 2B has power from 2B EDG and cooling water from 1B NSWSPump. No Auxiliary FeedwaterMakeup on shutdown Unit 2. The Unit 1 and 2 NSWSNon-Essential Headers are isolated due to closure of crossover valves during swap to the SNSWP.Summary -This scenario models the NSWS "One Pump Flow Balance."  The NSWS is capable of supporting the required LOCA loads on Unit 1 and Shutdown loads on Unit 2.Diesel Jacket Water CoolingHX 1B, 2BAuxiliary FeedwaterMakeup 1BCRACWSChiller B(12)NSWSaligned to Lake WylieUnit 1 -Mode 1Unit 2 -ShutdownEDG 2B is inoperable, resulting in isolation of the Unit 2Non-EssentialUnit 1 LOCA (Sp)LOOP Both UnitsLoss of Lake WylieValve 1RN3A fails to open, resulting in loss of Pit A, failure of 1A and 2A NSWSPumps, 1A and 2A EDGs, 1A and 2A ECCSNOTE -This event assumes a failure (1RN3A) while a shared component (EDG 2B) is inoperable. The NSWSaligns to the SNSWP.Since Unit 2 is shutdown, the inoperable 2B EDG does notrequire TSentry per TS NSWSPump motor demands 1BNSWSStrainer backwash 1B U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 42Case Number /Initial ConditionsEventSingle FailureDescription of NSWSResponsePost Event NSWSFlow DemandsHeader and closure of the crossover valveNSWSPump 2B                is operable3.8.2(only 1 EDG is required on the shutdown unit). Since EDG 2B is inoperable,valves2RN48B and 2RN50B are closed.No power is available to A Train essential equipment due to loss of the A train EDGs. The NSWSLoop B has one operating NSWSpump(1B).The NSWSPump 2B is not credited, since offsite power is lost and ESPS power is not immediately available. CCHX 2B receives NSWSflow since the flow control valve fails open. However, CCTrain 2B is not powered or available until and unless ESPS is aligned. No Auxiliary FeedwaterMakeup on shutdown Unit 2. The Unit 1 and Unit 2 NSWSNon-Essential Headersareisolated. Summary -The NSWS iscapable of supporting the required LOCA loads on Unit 1 and Shutdown loads on Unit 2. However, Unit 2 must have ESPS aligned to power the 2B Essential Bus.CCHX 1B, 2BCSHX 1BDiesel Jacket Water CoolingHX 1BAuxiliary FeedwaterMakeup 1BCRACWSChiller B U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 43Figure 1a -Case Number 1 (Initial Conditions)Case 1 -Initial Conditions Aligned to Lake Wylie SNSW PONO 1RN5A IRN6B I I I OFF Unit 1 -Mode 1 28 DIG Unit 2 -Mode 1 OFF All Equipment Operable 18 0/G 28 DIG IRN848B 2RN848B IRN58B ,, "'' ~msMe IRN69B SNSW PONO~ OFF 18 28 ESS 18 ESS o-----1"JRN538 2B ESS !RN4B HEADER HEADER HEADER OFF 2RN47A IRN47A I I w !-, I I UNIT 2 NON-ESS UN IT I NON-ESS U2 NON-ESS HEADER 2RN50B 2RN49A !RN49A IRN50B HEADER 1RN51A1RN528 2RN52B 2RN51A HEADER "" <I: _J I I I 2RN488 1RN48B SNSW PONO *I I OFF 2A ESS IA ESS 2A ESS *1 2A 0/G HEADER HEADER HEADER IRN3A 1 2RN67A IRN67A [J-:l( IRN8438 OFF 2A 0/G 2RN846A t-.1~ 1 IRN57A SNSW PONO IRN846A , IA~/G L IA 0/G 180/G !RNIA 1RN2B I I OFF 28 0/G 8 2RN8498 ON 2A D/G___l_J F!AD/G A 2RN847A LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 44Figure 1b -Case Number 1 (Event Response)Case 1 -Event Response Unit 1 LOCA SNSW PONO 1RN5A 1 RNGB I , / I I ON LOOP_ both Units 28 IJ/G No failures ON , 18 D/G ---l,.-~14---9illl--28 IJ/G IRN848B 2RN848B -2RN69B i=-IRN58B 18 DIG JAN69B SNSW PONO ,___,__ _____ __, ON 18 28 ESS 18 ESS 2B ESS HEADER~ HEADER o---1 HEADER ON JRN53B 2RN47A I I w _J 2;1 II UNIT 2 NON-ESS
* UNIT I NON-ESS~ U2 NON-ESS HEADER HEADER HEADER 2RN50B 2RN49A 1RN49A 1RN50B JRN51A IRN52B 2RN52B 2RN51A 2RN48B "'" "'"' I (;:) I ON ,0 '" + IA ESS _ I _______J.____ 2A ESS t 2RN67A IOOA
* 2A *1 2A 0/G HEADER HEADER 't' -1-HEADER ON I I [J-:l( 1RN843B 2A 0/G 2RN84VA -l IRN57A SNSW POND -IRN63A r IRN846A L IA 0/G IA D/G 1B 0/G !RNJA IRN2B I \,_ / I ON 2B 0/G IRN849B 2RN849B ON 9 I F!AO/G 2A D/G A 2RN847A LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 45Figure 2a -Case Number 2 (Initial Conditions)Case 2 -Initial Conditions Aligned to Lake Wylie Unit 1 -Mode 1 SNSW PONO 1RN5A IRN6B I I I OFF Unit 2 -Mode 1 28 DIG All Equipment Operable OFF 1B D/G 28 DIG IRN848B 2RNB48B IRN58B ,, "'' ~msMe IRN69B SNSW PONO~ OFF 18 28 ESS 18 ESS o-----1"JRN53B 2B ESS !RN4B HEADER HEADER HEADER OFF 2RN47A IRN47A I I w !-, I I UNIT 2 NON-ESS UN IT I NON-ESS U2 NON-ESS HEAOER 2RN50B 2RN49A !RN49A IRN508 HEADER 1RN51A1RN528 2RN528 2RN51A HEADER "" <I: _J I I I 2RN48B 1RN488 SNSW PONO *I I OFF 2A ESS IA ESS 2A ESS *1 2A 0/G HEADER HEADER HEADER IRN3A 1 2RN67A IRN67A [J-:l( IRN8438 OFF 2A 0/G 2RN846A t-.1~ 1 IRN57A SNSW PONO IRN846A , IA~/G L IA 0/G 1B0/G !RNIA 1RN28 I I OFF 28 0/G B 2RN849B ON 2A D/G__l_J F!AO/G A 2RN847A LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 46Figure 2b -Case Number 2 (Event Response)Case 2 -Event Response Unit 1 LOCA ~N<;w PnNn lRN5A I \. / I ON LOOP both Units lRNGB 28 0/ G Loss of Lake Wylie, RN System aligns to SNSWP ON No failurf's 18 0/G 28 DIG 1RN8488 2RN8488 2RN69B 1=--JRN5BB 1B 0/G JRN69B SNSW POND \~--+------.eJ ON IB 28 ESS 1B ESS 2B ESS =oc, -----=-I """' _______ _...,,__ _____ HEADER ON I I o-i 2RN47A w -..JI II UNIT 2 NON-ESS
* UNIT l NON-ESS U2 NON-ESS HEADER HEADER H AD R 2RN508 2RN49A '1RN49A 1RN50B lR~A E E 2RN48B "" '&deg;~ _J,____.J I ON " ess + IA ESS _ I ______J,.___ 2A ESS l~N;A
* 1 2A *1 2A DIG HEADER HEADER 't' T HEADER i 2RN67A A ON 2A 0/G 2RN84:E4A SNSW PONO
* 1RN63A lRN846A lA .DIG JA 0/G i.-w-1B DIG lRNJA IRN2B I ci I ON 2B DIG *1 I lRN849B ON 2RN8498 9 l ritlAO/G 2A 0/G A 2RN847A LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 47Figure 3a -Case Number 3 (Initial Conditions)Case 3 -Initial Conditions Aligned to SNSWP SNSW POND lHN;A JRNG.B I I OFF Unit 1 -Mode 1 28 0/G Unit 2 -Mode 1 All Equipment Operable 18 0/G 28 DIG 1RN848B 2RN848B 1RN58B 18 DIG 1RN69B SNSW PONO~ OFF JJRN53B 28 ESS 1B ESS 2B ESS !RN48 HEADER HEADER HEADER OFF 2RN47A 1RN47A I I w ~7 I I UNIT 2 NON-ESS UNIT l NON-ESS U2 NON-ESS HEADER 2RN508 2RN49A IRN49A IRN508 HEADER JRN51A IRN528 2RN528 2RN51A HEADER "' ([ _J I I I 2RN488 1RN48B SNSW POND I OFF 2A ESS IA ESS--++--2A ESS *1 2A DIG HEADER HEADER HEADER i 2RN67A !RN67A OFF 2A 0/G .l. 2RN84f-A SNSW PONO _ _ 1RN63A t 1RN846A !A 0/G lA 0/G 1B0/G 1HN1'A tHN)R I \d I OFF 2B DIG B 2RN8498 ON 2A 0/G -1-J ~"~' A 2RN847A LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 48Figure 3b -Case Number 3 (Event Response)Case 3 -Event Response Unit 1 LOCA ~N<;w PnNn I \. / 1 ON LOOP both Units lRN5A 1RN6B 28 1J1 G No failures ON 18 0/G ---t"<l-----.!4---D'<J--28 IJ/G 1RN8488 2RN8488 2RN69B i=-JRN588 18 DIG JRN698 SNSW POND \ ___ _. ______ __, ON 18 28 ESS 18 ESS 28 ESS HEADER~ HEADER J HEADER ON !RN53B I I 2RN47A w UNIT 2 NON-ESS
* UNIT l NON-ESS U2 NDN-ESS HEADER HEADER HEADER 2RN50B 2RN49A 1RN49A 1RN50B lR~A ~I II ' 2RN488 "" '&deg;~ _J,____.J I ON " ess + IA ESS _ I ______J,.____ 2A ESS l~N;A
* 1 2A *1 2A DIG HEADER HEADER 't' T HEADER i 2RN67A A ON 2A 0/G 2RN84:E4A SNSW PONO
* 1RN63A lRN846A lA .IJ/G JA 0/G 1B 0/G lRNJA IRN2B I ci I ON 2B 0/G *1 I 1RN8498 ON 2RN~t9B l bit IA 0/G 2A 0/G A 2RN847A LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 49Figure 4a -Case Number 4 (Initial Conditions)Case 4 -Initial Conditions Aligned to SNSWP SNSW POND lHN;A JRNG.B I I OFF Unit 1 -Mode 1 28 0/G Unit 2 -Mode 1 All Equipment Operable 18 0/G 28 DIG 1RN848B 2RN848B 1RN58B 18 DIG 1RN69B SNSW PONO~ OFF JJRN53B 28 ESS 1B ESS 2B ESS !RN48 HEADER HEADER HEADER OFF 2RN47A 1RN47A I I w ~7 I I UNIT 2 NON-ESS UNIT l NON-ESS U2 NON-ESS HEADER 2RN508 2RN49A IRN49A IRN508 HEADER JRN51A IRN528 2RN528 2RN51A HEADER "' ([ _J I I I 2RN488 1RN48B SNSW POND I OFF 2A ESS IA ESS--++--2A ESS *1 2A DIG HEADER HEADER HEADER i 2RN67A !RN67A OFF 2A 0/G .l. 2RN84f-A SNSW PONO _ _ 1RN63A t 1RN846A !A DIG lA 0/G 1B0/G 1HN1'A tHN)R I \d I OFF 2B DIG B 2RN8498 ON 2A 0/G -1-J ~"~' A 2RN847A LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 50Figure 4b -Case Number 4 (Event Response)Case 4 -Event Response Unit 1 LOCA ~Nc;\,o,,.! PnNn I I ON LOOP both Units 1RN5A 1RN6B EOG 1A failure causes RN 1A Pump failure and 1A. ECCS failure 28 IJ/G ON RN remains aligned to SNSWP 18 0/G 28 IJ/ G 1RN8488 2RN848B JRN58B 18 DIG 1RN69B SNSW POND~ ON JIRN53B 28 ESS 18 ESS 2B ESS 1RN48 HEADER HEADER HEADER ON I I 2RN47A 1RN47A w :1 II UNIT 2 NON-ESS UNIT l NON-ESS~ U2 NDN-ESS HEADER HEADER HEADER 2RN50B 2RN49A B !RN51A 1RN528 2RN528 2RN51A 2RN488 1RN48B SNSW PONO I ON 2A ESS IA ESS--++--2A ESS *1 2A DIG HEADER HEADER HEADER i 2RN67A IRN67A ON 2A 0/G _,.:E4 SNSW PONO
* IRN63A lRN846A 1 G JA 0/G 1B0/G IRNIA 1RN2B I I OFF 2B 0/G *1 8 ?RNR4~R OFF i.------w-I A 0/ G 2A 0/G ol IRN847A 2RN847A LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 51Figure 5a -Case Number 5 (Initial Conditions)Case 5 -Initial Conditions Aligned to Lake Wylie SNSW POND 1RN5A JRNGB I 'd I OFF Unit 1 -Mode 1 28 0/G Unit 2 -Mode 1 All Equipment Operable 18 0/G 28 DIG 1RN848B 2RN848B 1RN58B 18 DIG 1RN69B SNSW PONO~ OFF JJRN53B 28 ESS 1B ESS 2B ESS !RN48 HEADER HEADER HEADER OFF 2RN47A 1RN47A I I w ~7 I I UNIT 2 NON-ESS UNIT l NON-ESS U2 NON-ESS HEADER 2RN508 2RN49A IRN49A IRN508 HEADER JRN51A IRN528 2RN528 2RN51A HEADER "' ([ _J I I I 2RN488 1RN48B SNSW POND I OFF 2A ESS IA ESS--++--2A ESS *1 2A DIG HEADER HEADER HEADER i 2RN67A !RN67A I D------!\ I RN843B OFF 2A 0/G 2RN846A 1 D----i I RN57A SNSW PONO 1RN63A t 1RN846A L !A 0/G lA 0/G 1B0/G lRNlA IRN:>R I \-d I OFF 2B DIG R 2RN8498 ON 2AD/G~ F"~' A 2RN847A LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 52Figure 5b -Case Number 5 (Event Response)1RN5A 1RN6B I I ON SNSW POND~ 1RN48 ON I I w :1 II SNSW PONO IRNIA 1RN2B I I OFF Case 5 -Event Response Unit 1 LOCA LOOP both Units ~Nc;\,o,,.! PnNn ON Loss of Lake Wylie, RN System aligns to SNSWP 28 0/G 1RN3A Failure results in loss of pit A, lA and 2A RN Pumos, lA and 2A EDGs, lA and 2A ECCS 18 0/G 28 DIG 1RN8488 2RN8488 JRN588 .. ~, 1RN69B ON 28 ESS 18 ESS J 2B ESS HEADER HEADER HEADER JRN53B 2RN47A 1RN47A UNIT 2 NON-ESS HEADER 2RN50B 2RN49A 2RN48B 2A ESS 2 G HEADER i 2RN67A 1 G OFF UNIT l NON-ESS~ U2 NON-ESS HEADER H AD R B IRN51A 1RN528 2RN52B 2RN51A E E 1RN48B IA ESS--+-+--2A ESS HEADER HEADER IRN67A 2A 0/G .... 2RN84f-A SNSW PONO 1 ..... IRN63A lRN846A JA 0/G 2B DIG ?RNR4~R 2A 0/G 2RN847A *1 lBDIG B l+------cki----I A 0/ G IRN847A LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 53Figure 6a -Case Number 6 (Initial Conditions)1RN5A JRNGB I 'd I OFF SNSW POND~ !RN48 OFF I I w :1 II SNSW PONO I *1 OFF lRNlA IRN2R I \-d I ON Case 6 -Initial Conditions Aligned to Lake Wylie Unit 1 -Mode 1 ~Nc;\,o,,.! PnNn Unit 2 -Mode 1 2 G EOG 2B Inoperable so close 2RN48B and 2RN50B RN Pump 2B Operable 18 DIG OFF 28 ESS HEADER 2RN47A UNIT 2 NON-ESS HEADER 2RN508 2RN49A 2RN488 OFF 2A ESS 2A DIG HEADER i 2RN67A t !A DIG OFF 18 0/G 28 DIG 1RN848B 2RN848B 1RN58B 1RN69B 1B ESS JJRN53B 2B ESS HEADER HEADER 1RN47A UNIT l NON-ESS U2 NDN-ESS 1RN49A IRN508 HEADER JRN51A IRN528 2RN528 2RN51A HEADER 1RN48B IA ESS--++--2A ESS HEADER HEADER !RN67A I D------!\ I RN843B 2A 0/G 2RN846A 1 D--i IRN57A SNSW PONO 1RN63A 1RN846A L lA 0/G 2B DIG 2RN8498 2A 0/ G ----cJ<J..----1 2RN847A 1B0/G R I A 0/ G IRNA474 LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 54Figure 6b -Case Number 6 (Event Response)1RN5A JRNGB I I SNSW POND~ !RN48 ON I I w :1 II SNSW PONO I *1 ON lRNlA IRN2R I I OFF Case 6 -Event Response LOOP both Units RN System remains aligned to Lake Wylie ~N<:;\,o,,.! PflNn RN Pump 2B not available since Offsite Power lost and EDG2B lnop 2 G EDG 1A failure causes RN Pump 1A failure, 1A ECCS failure 18 0/G 28 0/G 1RN848B 2RN8488 1RN58B 18 DIG 1RN69B ON 28 ESS 18 ESS o-JJRN538 28 ESS HEADER HEADER HEADER 2RN47A 1RN47A UNIT 2 NON-ESS UNIT 1 NON-ESS U2 NON-ESS HEADER 1RN49A IRN508 HEADER JRN51A IRN528 2RN528 2RN51A HEADER 2RN50B 2RN49A 2RN488 ON 2A ESS 2A DIG HEADER i 2RN67A ' 1~ OF 1RN48B IA ESS--++--2A ESS HEADER HEADER 1RN67A I D------!( I RN843B 2A 0/G 2RN846A l D---i I RN57A SNSW PONO 1RN63A 1RN846A L lA 0/G 2B 0/G 2RNA49R 2A 0/G 2RN847A 1B0/G R f.-----i,L::J-1 A 0/ G IRNA474 LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 55Figure 7a -Case Number 7 (Initial Conditions)1RN5A JRNGB I 'd I OFF SNSW POND~ !RN48 OFF I I w :1 II SNSW PONO I *1 OFF lRNlA IRN2R I \-d I ON Case 7 -Initial Conditions Aligned to Lake Wylie Unit 1 -Mode 1 ~Nc;\,o,,.! PnNn Unit 2 -Mode 1 2 G EOG 2B Inoperable so close 2RN48B and 2RN50B RN Pump 2B Operable 18 DIG OFF 28 ESS HEADER 2RN47A UNIT 2 NON-ESS HEADER 2RN508 2RN49A 2RN488 OFF 2A ESS 2A DIG HEADER i 2RN67A t !A DIG OFF 18 0/G 28 DIG 1RN848B 2RN848B 1RN58B 1RN69B 1B ESS JJRN53B 2B ESS HEADER HEADER 1RN47A UNIT l NON-ESS U2 NON-ESS 1RN49A IRN508 HEADER JRN51A IRN528 2RN528 2RN51A HEADER 1RN48B IA ESS--++--2A ESS HEADER HEADER !RN67A I D------!\ I RN843B 2A 0/G 2RN846A 1 D----i I RN57A SNSW PONO 1RN63A 1RN846A L lA 0/G 1B0/G 2B DIG R 2RN8498 2A 0/G 2RN847A I A 0/ G IRNA474 LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 56Figure 7b -Case Number 7 (Event Response)1RN5A JRNGB I I SNSW POND~ !RN48 ON I I w :1 II SNSW PONO I *1 ON lRNlA IRN2A I I OFF Case 7-Event Response Unit 1 LOCA LOOP both Units ~Nc;\,o,,.! PnNn RN System remains aligned to Lake Wylie 2 G RN Pump 2B not available since Offsite Power lost and EDG 2B lnop EDG 1A failure causes RN Pump 1A failure, 1A ECCS failure 18 0/G 28 0/G 1RN848B 2RN848B 1RN58B 18 DIG 1RN69B ON 28 ESS 1B ESS JJRN53B 2B ESS HEADER HEADER HEADER 2RN47A 1RN47A UNIT 2 NON-ESS UNIT l NON-ESS U2 NON-ESS HEADER 2RN508 2RN49A 2RN488 ON 2A ESS 2A DIG HEADER i 2RN67A ' 1~ OF 1RN49A 1RN508 HEADER 1RN51A IRN528 2RN528 2RN51A HEADER 1RN48B IA ESS--++--2A ESS HEADER HEADER 1RN67A I D------!\ 1 RN843B 2A 0/G 2RN846A 1 D--i IRN57A SNSW PONO 1RN63A 1RN846A L lA 0/G 2B 0/G 2RNA49R 2A 0/ G -----cJ<J...---2RN847A 1B0/G R I A 0/ G IRNA474 LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 57Figure 8a -Case Number 8 (Initial Conditions)1RN5A JRNGB I 'd I OFF SNSW PONO~ !RN48 OFF I I w :1 II SNSW PONO I *1 OFF lRNlA IRN2R I \-d I ON Case 8 -Initial Conditions Aligned to Lake Wylie Unit 1 -Mode 1 ~Nc;\,o,,.! PnNn Unit 2 -Shutdown 2 G EDG 2B Inoperable so close 2RN48B and 2RNS0B RN Pump 2B Operable 18 DIG OFF 28 ESS HEADER 2RN47A UNIT 2 NON-ESS HEADER 2RN508 2RN49A 2RN488 OFF 2A ESS 2A DIG HEADER i 2RN67A t !A DIG OFF 18 0/G 28 DIG 1RN848B 2RN848B 1RN58B 1RN69B 1B ESS JJRN53B 2B ESS HEADER HEADER 1RN47A UNIT l NON-ESS U2 NON-ESS 1RN49A IRN508 HEADER JRN51A IRN528 2RN528 2RN51A HEADER 1RN48B IA ESS--++--2A ESS HEADER HEADER !RN67A I D------!\ I RN843B 2A 0/G 2RN846A 1 D----i I RN57A SNSW PONO 1RN63A 1RN846A L lA 0/G 1B0/G 2B DIG R 2RN8498 2A 0/G 2RN847A I A 0/ G IRNA474 LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 58Figure 8b -Case Number 8 (Event Response)1RN5A JRNGB I I SNSW POND~ !RN48 OFF I I w :1 II SNSW PONO I *1 ON lRNlA IRN2R I \-::::{ I ON Case 8 -Event Response Unit 1 LOCA LOOP both Units ~Nc;\,o,,.! PnNn RN System remains aligned to Lake Wylie 2 G RN Pump 2B not available since Offsite Power lost and EDG 2B lnop EDG 1B failure causes RN Pump 1B failure, 1B ECCS failure 18 0/G 28 0/G 1RN848B 2RN848B
* 1RN58B 2RN698 1~ i=--FF 28 ESS 18 ESS JJRN538 28 ESS HEADER HEADER HEADER 2RN47A UNIT 2 NON-ESS UNIT l NON-ESS~ U2 NON-ESS HEADER 2RN508 2RN49A 2RN48B ON 2A ESS 2A DIG HEADER i 2RN67A !A 0/G ON HEADER HEADER B 1RN51A IRN528 2RN52B 2RN51A + " ess-----+-+-,-,ss HEADER HEADER I D------!\ 1 RN843B 2A 0/G 2RN846A 1 D--i IRN57A SNSW PONO 1RN63A 1RN846A L lA 0/G 2B 0/G 2RNA49R 2A 0/ G ----cJ<J..---.l 2RN847A 1B0/G R 1 A 0/ G IRNA47A LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 59Figure 9a -Case Number 9 (Initial Conditions)1RN5A JRNGB I 'd I OFF SNSW POND~ !RN48 OFF I I w :1 II SNSW PONO I *1 OFF lRNlA IRN2R I \-d I ON Case 9 -Initial Conditions Aligned to Lake Wylie Unit 1 -Mode 1 ~Nc;\,o,,.! PnNn Unit 2 -Mode 1 2 G EDG 2B Inoperable so close 2RN48B and 2RN50B RN Pump 2B Operable 18 DIG OFF 28 ESS HEADER 2RN47A UNIT 2 NON-ESS HEADER 2RN508 2RN49A 2RN488 OFF 2A ESS 2A DIG HEADER i 2RN67A t !A DIG OFF 18 0/G 28 DIG 1RN848B 2RN848B 1RN58B 1RN69B 1B ESS JJRN53B 2B ESS HEADER HEADER 1RN47A UNIT l NON-ESS U2 NON-ESS 1RN49A IRN508 HEADER JRN51A IRN528 2RN528 2RN51A HEADER 1RN48B IA ESS--++--2A ESS HEADER HEADER !RN67A I D------!\ I RN843B 2A 0/G 2RN846A 1 D----i I RN57A SNSW PONO 1RN63A 1RN846A L lA 0/G 1B0/G 2B DIG R 2RN8498 2A 0/G 2RN847A I A 0/ G IRNA474 LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 60Figure 9b -Case Number 9 (Event Response)w ..J ;. w "' "i 1RN5A 1RN68 SNSW PONO 1RN48 SNSW PONO *I IRN:iA lRNlA IRN2R OFF ON OFF OFF 2"G 18 0/G ON Case 9 -Event Response Unit 1 LOCA LOOP both Units Loss of Lake Wylie, RN System aligns to SNSWP RN Pump 2B not available since Offsite Power lost and EDG 2B lnop EDG 1A failure causes 1RN3A failure, RN pit A loss, RN Pumps 1A, 2A failure SNS~1 POND 18 0/G 28 0/G 28 ESS--------i HEADER ;>RN1''lR 2RN47A 1RN1''lR 1RN47A 18 ESS HEADER 1RN848B 2RN8488 JRN588 28 ESS HEADER UNIT 2 NON-ESS HEADER UNIT 1 NON-ESS HEADER HEADER 1RN51A IRN528T2RN528 2RN5lA U2 NDN-ESS 2RN50B 2RN49A 2RN488 ~OFF 2 G 2A ESS HEADER
* I l~,G OF 1RN49A. 1R.N508 1RN488 IA ESS >-------<~ HEADER 2A ESS ~----<-----HEADER 1RN67A 2A 0/G ..... 2RNR4f-A ' SNSW POND " I 1RN63A 1RN846A JA 0/G 28 0/G 2RNA49A 2A 0/ G ----cJ::i----l 2RN847A 1R rvr, f.---t,L::J-1 A 0/ G IRNR47A LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 61Figure 10a -Case Number 10 (Initial Conditions)1RN5A JRNGB I 'd I OFF SNSW POND~ !RN48 OFF I I w :1 II SNSW PONO I *1 OFF lRNlA IRN2R I \-d I ON Case 10 -Initial Conditions Aligned to Lake Wylie Unit 1 -Mode 1 ~Nc;\,o,,.! PnNn Unit 2 -Mode 1 2 G EDG 2B Inoperable so close 2RN48B and 2RN50B RN Pump 2B Operable 18 DIG OFF 28 ESS HEADER 2RN47A UNIT 2 NON-ESS HEADER 2RN508 2RN49A 2RN488 OFF 2A ESS 2A DIG HEADER i 2RN67A t !A DIG OFF 18 0/G 28 DIG 1RN848B 2RN848B 1RN58B 1RN69B 1B ESS JJRN53B 2B ESS HEADER HEADER 1RN47A UNIT l NON-ESS U2 NON-ESS 1RN49A IRN508 HEADER JRN51A IRN528 2RN528 2RN51A HEADER 1RN48B IA ESS--++--2A ESS HEADER HEADER !RN67A I D------!\ I RN843B 2A 0/G 2RN846A 1 D--i IRN57A SNSW PONO 1RN63A 1RN846A L lA 0/G 1B0/G 2B DIG R 2RN8498 2A 0/G 2RN847A I A 0/ G IRNA474 LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 62Figure 10b -Case Number 10 (Event Response)1RN5A 1RN6B I I SNSW POND~ !RN48 OFF I I w :1 II SNSW PONO I *1 ON IRNIA IRN28 I I ON Case 10 -Event Response Unit 1 LOCA LOOP both Units Loss of Lake Wylie, RN System aligns to SNSWP ~Nc;\,o,,.! PnNn RN Pump 28 not available since Offsite Power lost and EDG 28 lnop 2 G EDG 1B failure causes 1RN48 failure, RN pit 8 loss, RN Pump 1B failure 18 0/G 28 0/G 1RN8488 2RN8488
* 1RN588 2RN69B 1~ i=--FF 28 ESS 18 ESS JJRN53B 2B ESS HEADER HEADER HEADER 2RN47A UNIT 2 NON-ESS UNIT l NON-ESS~ U2 NON-ESS HEADER 2RN488 ON 2A ESS 2A DIG HEADER i 2RN67A !A 0/G ON B HEADER 1RN51A IRN52B 2RN52B 2RN51A HEADER +""'-t-=!::-'"'~ HEADER HEADER IRN843B 2A 0/G 2RN846A 1 D----l 1RN57A SNSW PONO 1RN63A lRN846A 1 A 0/ G L 28 0/G 2RNA49R 2A 0/G ol 2RN847A 1B0/G R i.-------w-I A 0/ G IRN847A LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 63Figure 11a -Case Number 11 (Initial Conditions)1RN5A JRNGB I I SNSW POND~ !RN48 OFF I I w :1 II SNSW POND I *1 OFF lRNlA IRN2R I \-d I ON Case 11 -Initial Conditions Aligned to Lake Wylie SNSW POND OFF Unit 1 -Mode 1 28 0/G Unit 2 -Shutdown EOG 2B Operable 18 0/G 28 DIG RN Pump 2B inoperable with Unit 2 shutdown 1RN848B 2RN848B 18 DIG OFF 28 ESS HEADER 2RN47A UNIT 2 NON-ESS HEADER 2RN508 2RN49A 2RN488 OFF 2A ESS 2A DIG HEADER i 2RN67A t !A 0/G OFF 1RN58B 1RN69B JJRN53B 1B ESS 2B ESS HEADER HEADER 1RN47A UNIT l NON-ESS U2 NON-ESS 1RN49A IRN508 HEADER JRN51A IRN528 2RN528 2RN51A HEADER 1RN48B IA ESS--++--2A ESS HEADER HEADER !RN67A I D------!\ I RN843B 2A 0/G 2RN846A 1 D----i I RN57A SNSW PONO 1RN63A 1RN846A L lA 0/G 2B DIG 2RN8498 2A 0/ G ----cJ<J..----l 2RN847A 1B0/G R I A 0/ G IRNA474 LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 64Figure 11b -Case Number 11 (Event Response)1RN5A I I 1RN6B SNSW PONO~ 18 !RN48 ON I I w :1 II SNSW PONO I *1 OFF IRNJA IRN28 I I OFF Case 11
* Event Response Unit 1 LOCA 1RN3A failure causes RN pit A loss, RN Pumps lA& 2A failure, EOG 1A.&2A failure Loss of Lake Wylie, RN System aligns to SNSWP ~N<:;\,o,,.! PflNn LOOP both Units ON RN Pump 28 inoperable with Unit 2 shutdown 28 0/G 18 0/G 28 0/G 1RN848B 2RN848B 1RN58B t-. rn*~, ______:J~~~ ON 28 ESS 18 ESS 2B ESS HEADER HEADER HEADER _ o--i 2RN47A UNIT 2 NON-ESS HEADER 2RN508 2RN49A 2RN488 2A ESS 2 G HEADER i 2RN67A 1 G OFF J 1RN47A UNIT 1 NON-ESS~ U2 NON-ESS HEADER HEADER B 1RN51A IRN52B 2RN528 2RN51A 1RN488 !A ESS-+--+---2A ESS HEADER HEADER JRN67A 2A 0/G .... 2RN84f-A SNSW PONO 1 ..... 1RN63A lRN846A lA0D/G 4 28 0/G 2RN849B 2A 0/ G ----c,k::J...-. 2RN847A i.-W-1Rrvr, 1 A 0/ G IRN847A LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 65Figure 12a -Case Number 12 (Initial Conditions)1RN5A JRNGB I 'd I OFF SNSW PONO~ !RN48 OFF I I w :1 II SNSW PONO I *1 OFF lRNlA IRN2R I \-d I ON Case 12 -Initial Conditions Aligned to Lake Wylie Unit 1 -Mode 1 ~Nc;\,o,,.! PnNn Unit 2 -Shutdown 2 G EDG 2B Inoperable so close 2RN48B and 2RNS0B RN Pump 2B Operable 18 DIG OFF 28 ESS HEADER 2RN47A UNIT 2 NON-ESS HEADER 2RN508 2RN49A 2RN488 OFF 2A ESS 2A DIG HEADER i 2RN67A t !A DIG OFF 18 0/G 28 DIG 1RN848B 2RN848B 1RN58B 1RN69B 1B ESS JJRN53B 2B ESS HEADER HEADER 1RN47A UNIT l NON-ESS U2 NDN-ESS 1RN49A IRN508 HEADER JRN51A IRN528 2RN528 2RN51A HEADER 1RN48B IA ESS--++--2A ESS HEADER HEADER !RN67A I D------!\ I RN843B 2A 0/G 2RN846A 1 D--i IRN57A SNSW PONO 1RN63A 1RN846A L lA 0/G 1B0/G 2B DIG R 2RN8498 2A 0/G 2RN847A I A 0/ G IRNA474 LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 66Figure 12b -Case Number 12 (Event Response)I I 1RN5A 1RNhR OFF SNSW POND~ IRN48 ON I I w :1 II <:;N<:;W PONO I ~I OFF lRNJA IHNdB I I OFF Case 12
* Event Response Unit 1 LOCA LOOP both Units Loss of Lake Wylie, RN System aligns to SNSWP SNSW PONO 1RN3A failure causes RN pit A loss, RN Pumps lA& 2A failure, EOG 1A.&2A failure 2 , G .. " . ~, _____:]''"'"" ON 2B ESS HEADER o--i 2RN4 7A UNIT 2 NON-ESS HEADER 2RN508 2RN49A 2RN48B 2A ESS 2 G HEADER i 2RN67A 1 G OFF 18 0/G 28 0/G 1RN848B 2RN848B 1=--JRN58B 1B ESS 2B ESS HFADFR HFAOFR J lRN47A UNIT l NON-ESS U2 NON-ESS HEADER IRN49A IRN50B HEADER JRN51A IRN528 2RN52B 2RN51A 1RN48B 1 A ESS 2A ESS HEADER HEADER 1RN67A I f7-.--C"r' JRN8438 2A 0/G """~ l D-i 1RN57A SNSW PONO lRN63A 1RN846A JA 00/G ----l--., 2B DIG 2RN8498 2A 0/ G -----c,lo----+i 2RN847A ~180/G B l A 0/ G IANA47A LAKE WYLIE U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 67Table 2 belowshows the NSWSflow rates(in gallons per minute)to essential components based on the twelve scenarios described in Table 1 above. In all cases, the NSWSflow is within required ranges, and the minimum number of essential components are available to achieve the required heat removal requirements to support the required Safety Function.Additionally, the NSWSpump flow rates and NSWSEssential Header pressures are within the required range.As previously discussed, not all possible combinations are shown, but the combinations that are presented bound other possible combinations (i.e.,failure of valve 1RN3A is presented, which bounds the corresponding opposite train failure of valve 1RN4B).Please refer to the following definitions for Table 2:
CA -Auxiliary FeedwaterHX -Heat ExchangerKD -Diesel Jacket Water CoolingNS -Containment SprayYC -Control Room Chilled WaterNW -Containment Penetration Valve EjectionKF -Spent Fuel Cooling U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 68Table 2-NSWS Scenarios and Flow Rates to Essential ComponentsComponentRequired Flow Range*Case1Case2Case3Case4Case5Case6Case7Case8Case9Case10Case11Case 12NSWSPump 1A Discharge Flow8600-2580013427136831434000001342801365300NSWSPump 1B Discharge Flow8600-258001363115077156401715315785196031951702061502114720615NSWSPump 2A Discharge Flow8600-2580011776122271334216838017096156991177801217400NSWSPump 2B Discharge Flow8600-258008636914893511159794030000000NSWSTrain A Strainer Backwash600-1600166917331715854081282916680173300NSWSTrain B Strainer Backwash600-16001313135613511323135072272407420730742KC HX 1A4925-14000641878957647763406550669578600790700KC HX 1B4925-14000688779107872741976396637648406954066976954KC HX 2A4925-14000616978637607753106317642878100787200KC HX 2B4925-14000702680888033756178796808669707193069287193KD HX 1A600-140010441016987000010690101700KD HX 1B600-140011881033102897810071078108209170883917KD HX 2A600-1400107411421114108701057108711600114300KD HX 2B600-1400155414651458139114320000012540NS HX 1A2200-5000290930562961000031470305600NS HX 1B2200-5000264730413026286729520250502687025882687NS HX 2A2200-5000000000000000NS HX 2B2200-5000000000000000NSWSCA, NW, KF Makeup 1A6006006006000000600060000NSWSCA, NW, KF Makeup 1B60060060060060060060060006000600600NSWSCA, NW, KF 60060060060060006006000060000 U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 69ComponentRequired Flow Range*Case1Case2Case3Case4Case5Case6Case7Case8Case9Case10Case11Case 12Makeup 2ANSWSCA, NW, KF Makeup 2B6006006006006006000000000YC Chiller Cond 'A'1100-1600152918831823000017600177100YC Chiller Cond 'B'1100-1600000156116081397136501463014091463Unit 1 Non Ess Header**0-3400000003400000000Unit 2 Non Ess Header**0-34003400034003400000000001A Essential Header Press 1RNPT5020Min 35 PSIG72.578.376.471.4064.06772.3078.4001B Essential Header Press 1RNPT5030Min 35 PSIG72.677.476.772.376.359.659.7062.9060.662.92A Essential Header Press 2RNPT5020Min 35 PSIG72.678.665.571.4064.167.172.7078.7002B Essential Header Press 2RNPT5030Min 35 PSIG72.377.176.271.276.359.459.8063060.763* Range of allowable flow values is from an approved Catawba Calculation (Nuclear Service Water System Test Acceptance Criteria)**NSWSflow to Non-Essential Headers is not required and is not set per NSWSFlow Balance Procedures, so required minimum is zero. Flow value reflects total nominal flow rates of components, from Design Basis Document for the NSWS(Design Basis Specification for the Nuclear Service Water System (RN).
U.S.Nuclear Regulatory CommissionRA-17-0051, Enclosure Page 703.2Clarification of CNS UFSAR StatementsThe following is a clarification of CNS UFSAR Section 9.2.1.2, RN(i.e., NSWS)Pumphouse Section:UFSAR Statement: "The operation of any two pumps on either or both supply lines is sufficient to supply all cooling water requirements for unit startup, cooldown, and refueling and post-accident operation of two units."Explanation: While the NSWS has four pumps, any combination of two pumps is adequate for all modes of operation for both units, including post-accident conditions. It takes two pumps (any unit or train, just any two pumps), to supply cooling water to any combination of the four operations listed. This is possible due to the design of the NSWS, which allows NSWS flow between units and between trains, depending upon the system alignment. This capability is evident in the above Case Numbers 5-8 in Table 1, which depict the accident response of the NSWS and show that two NSWS pumps have adequate capacity to support LOCA loads on one unit and hot standby loads on the other unit. In the preceding scenarios, the "Initial Conditions" diagram depicts the 1A NSWS Pump in operation supplying flow toall four NSWS Essential Headers (1A, 1B, 2A, 2B). This system alignment is typical for normal operation. During the summer months, it is typical to start a second NSWS pump to support cooling water flow demands. Any other pump can be in service to supply this coolingwater flow demand.UFSAR Statement: "However, one pump has sufficient capacity to supply all cooling water requirements during normal power operation of both units or during post accident conditions if the unaffected unit is already in cold shutdown."Explanation: As described above, the NSWS will typically have one pump in operation supplying cooling water flow demands for both units during normal operation. The second part of the statement concerns the accident response of the NSWS which results in one remaining NSWS supplying both units (the NSWS "one pump flow balance"), and is depicted in Case Number 11 in Table 1. With one unit shutdown and the other unit in Mode 1, one NSWS pump has sufficient capacity to supply the flow demands for both the shutdown unit and the accident unit. toRA-17-0051Attachment 1Revised Catawba Technical Specification Marked Up Pages AC Sources - Operating3.8.1Catawba Units 1 and 23.8.1-1 Amendment Nos. 253/2483.8  ELECTRICAL POWER SYSTEMS3.8.1  AC Sources-Operating LCO  3.8.1The following AC electrical sources shall be OPERABLE:a.Two qualified circuits between the offsite transmission network and the Onsite Essential Auxiliary Power System; andb.Two diesel generators (DGs) capable of supplying the Onsite Essential Auxiliary Power Systems;andc. One qualified circuit between the offsite transmission network and the opposite unit's Onsite Essential Auxiliary Power System necessaryto supply power to the Nuclear Service Water System (NSWS), Control Room Area Ventilation System (CRAVS), Control Room Area Chilled Water System (CRACWS) and Auxiliary Building Filtered Ventilation Exhaust System (ABFVES); andd.One DG from the opposite unit necessaryto supplypower to the NSWS, CRAVS, CRACWS and ABFVES;  ANDThe automatic load sequencers for TrainA and TrainB shall be OPERABLE.APPLICABILITY:MODES1, 2, 3, and4.---------------------------------------------NOTE------------------------------------------- The opposite unit electrical power sources in LCO 3.8.1.c and LCO 3.8.1.d are not required to be OPERABLE when the associated shared systems areinoperable.--------------------------------------------------------------------------------------------------
AC Sources - Operating3.8.1Catawba Units 1 and 23.8.1-2 Amendment Nos. 253/248ACTIONS-----------------------------------------------------------NOTE----------------------------------------------------------
LCO 3.0.4.b is not applicable to DGs.
-----------------------------------------------------------------------------------------------------------------------------CONDITIONREQUIRED ACTIONCOMPLETION TIMEA.One LCO 3.8.1.a offsite circuit inoperable.A.1Perform SR3.8.1.1 for required OPERABLE offsite circuit(s). ANDA.2Declare required feature(s) with no offsite power available inoperable when its redundant required feature(s) is inoperable.ANDA.3Restore offsite circuit to OPERABLE status.1 hourANDOnce per 8hours thereafter24hours from discovery of no offsite power to one train concurrent with inoperability of redundant required feature(s)72hoursAND6 17days from discovery of failure to meet LCO3.8.1.a or LCO 3.8.1.b AC Sources - Operating3.8.1ACTIONSCatawba Units 1 and 23.8.1-3 Amendment Nos. 173/165CONDITIONREQUIRED ACTIONCOMPLETION TIMEB.One LCO 3.8.1.b DG inoperable.B.1Verify both DGs on the opposite unit OPERABLE.ANDB.12Perform SR3.8.1.1 for the required offsite circuit(s).ANDB.23Declare required feature(s) supported by the inoperable DG inoperable when its required redundant feature(s) is inoperable.ANDB.34.1Determine OPERABLE DG(s)is not inoperable due to common cause failure.ORB.34.2Perform SR3.8.1.2 for OPERABLE DG(s). AND1 hourANDOnce per 12 hours thereafter1 hourANDOnce per 8hours thereafter4 hours from discovery of ConditionB concurrent with inoperability of redundant required feature(s)24hours24hours(continued)
AC Sources - Operating3.8.1ACTIONSCatawba Units 1 and 23.8.1-4 Amendment Nos. 253/248CONDITIONREQUIRED ACTIONCOMPLETION TIMEB.(continued)B.5Ensure availability of Emergency Supplemental Power Source (ESPS).ANDB.4B.6Restore DG to OPERABLE status. Prior to entering the extended Completion Time of ACTION B.6ANDOnce per 12 hours thereafter72hoursfrom discovery of unavailableESPSAND6 days from discovery of failure to meet LCO24 hoursfrom discovery of unavailable ESPS when in extended Completion TimeAND14 daysAND17 days from discovery of failure to meet LCO3.8.1.a or LCO 3.8.1.b AC Sources - Operating3.8.1ACTIONSCatawba Units 1 and 23.8.1-5 Amendment Nos. 253/248C.Required Action and associated Completion Time of Required Action B.1 not met.C.1.1Restore both DGs on the opposite unit to OPERABLE status. ORC.1.2Restore LCO 3.8.1.b DG to OPERABLE status.72 hoursD. LCO 3.8.1.c offsite circuit inoperable. -------------------NOTE------------------Enter applicable Conditions and Required Actions of LCO3.8.9, "Distribution Systems-Operating," when Condition D is entered with no AC power source to a train.---------------------------------------------D.1Perform SR3.8.1.1 for the required offsite circuit(s).ANDD.2Declare NSWS, CRAVS, CRACWS or ABFVES with no offsite power available inoperable when the redundant NSWS, CRAVS, CRACWS or ABFVES is inoperable.ANDD.3Declare NSWS, CRAVS, CRACWS and ABFVES supported by the inoperable offsite circuit inoperable.1 hourANDOnce per 8hours thereafter24 hours from discovery of no offsite power to one train concurrent with inoperability of redundant required feature(s)72 hours AC Sources - Operating3.8.1ACTIONSCatawba Units 1 and 23.8.1-6 Amendment Nos. 253/248E. LCO 3.8.1.d DG inoperable.-------------------NOTE------------------Enter applicable Conditions and Required Actions of LCO3.8.9, "Distribution Systems-Operating," when Condition E is entered with no AC power source to a train.---------------------------------------------E.1Verify both LCO 3.8.1.b DGs OPERABLE, the opposite unit's DG OPERABLEand ESPS available. ANDE.2Perform SR3.8.1.1 for the required offsite circuit(s).ANDE.3 Declare NSWS, CRAVS, CRACWS or ABFVES supported by the inoperable DG inoperable when the redundant NSWS, CRAVS, CRACWS or ABFVES is inoperable. AND1 hourANDOnce per 12 hours thereafter1 hourANDOnce per 8 hours thereafter4 hours from discovery of Condition E concurrent with inoperability of redundant required feature(s)
AC Sources - Operating3.8.1ACTIONSCatawba Units 1 and 23.8.1-7 Amendment Nos. 253/248E. (continued)E.4.1Determine OPERABLE DG(s) is not inoperable due to common cause failures.ORE.4.2Perform SR 3.8.1.2 for OPERABLE DG(s).ANDE.5Declare NSWS, CRAVS, CRACWS andABFVES supported by the inoperable DG inoperable.24 hours24 hours14 daysF. Required Action and associated Completion Time of Required Action E.1 not met.F.1.1Restore both LCO 3.8.1.b DGs and opposite unit's DG to OPERABLE status and ESPS to available status.ORF.1.2Restore LCO 3.8.1.d DG to OPERABLE status.ORF.1.3Declare NSWS, CRAVS, CRACWS and ABFVES supported by the inoperable DG inoperable.72 hours AC Sources - Operating3.8.1ACTIONSCatawba Units 1 and 23.8.1-8 Amendment Nos. 253/248CG. Two LCO 3.8.1.a offsite circuits inoperable.OROne LCO 3.8.1.a offsitecircuit that provides power to the NSWS,CRAVS, CRACWS andABFVES inoperable andthe required LCO 3.8.1.coffsite circuit inoperable.CG.1Declare required feature(s) inoperable when its redundant required feature(s) is inoperable.ANDCG.2Restore one offsite circuit to OPERABLE status.12hours from discovery of ConditionCG concurrent with inoperability of redundant required features24hours(continued)
AC Sources - Operating3.8.1ACTIONS  (continued)Catawba Units 1 and 23.8.1-9 Amendment Nos. 173/165CONDITIONREQUIRED ACTIONCOMPLETION TIMEDH. One LCO 3.8.1.a offsite circuit inoperable.ANDOne LCO 3.8.1.b DG inoperable.-------------------NOTE------------------Enter applicable Conditions and Required Actions of LCO3.8.9, "Distribution Systems-Operating," when ConditionDH is entered with no AC power source to any train.---------------------------------------------DH.1Restore offsite circuit to OPERABLE status.ORDH.2Restore DGto OPERABLE status.12hours12hoursEI. Two LCO 3.8.1.b DGs inoperable.ORLCO 3.8.1.b DG thatprovides power to theNSWS, CRAVS,CRACWS and ABFVESinoperable and LCO3.8.1.d DG inoperable.EI.1Restore one DG to OPERABLE status.2 hoursFJ. One automatic load sequencer inoperable.FJ.1Restore automatic load sequencer to OPERABLE status.12hours AC Sources - Operating3.8.1ACTIONS  (continued)Catawba Units 1 and 23.8.1-10Amendment Nos. 173/165GK. Required Action and associated Completion Time of ConditionA, BC,C, D,E, orF,G, H, I, or Jnot met.ORRequired Action and associated Completion Time of RequiredAction B.2, B.3, B.4.1,B.4.2, or B.6not met.ORRequired Action and associated CompletionTime of RequiredAction E.2, E.3,E.4.1, E.4.2, or E.5not met.GK.1Be in MODE3.ANDGK.2Be in MODE5.6 hours36hoursHL. Three or more LCO 3.8.1.a and LCO 3.8.1.b AC sources inoperable.HL.1Enter LCO3.0.3.Immediately AC Sources - Operating3.8.1Catawba Units 1 and 23.8.1-11Amendment Nos. 263/259SURVEILLANCE REQUIREMENTS--------------------------------------------------------NOTE-------------------------------------------------------------SR 3.8.1.1 through SR 3.8.1.20 are only applicable to LCO 3.8.1.a and LCO 3.8.1.b AC sources. SR 3.8.1.21 is only applicable to LCO 3.8.1.c and LCO 3.8.1.d AC sources.-----------------------------------------------------------------------------------------------------------------------------SURVEILLANCEFREQUENCYSR  3.8.1.1Verify correct breaker alignment and indicated power availability for each offsite circuit.In accordance with the Surveillance Frequency Control ProgramSR  3.8.1.2---------------------------------NOTES-------------------------------1.Performance of SR3.8.1.7 satisfies this SR.2.All DG starts may be preceded by an engine prelube period and followed by a warmup period prior to loading.3.A modified DG start involving idling and gradual acceleration to synchronous speed may be used for this SR as recommended by the manufacturer.
When modified start procedures are not used, the time, voltage, and frequency tolerances of SR3.8.1.7 must be met.  ---------------------------------------------------------------------------Verify each DG starts from standby conditions and achieves steady state voltage > 3950V and < 4580V, and frequency > 58.8 Hzand< 61.2Hz.In accordance with the Surveillance Frequency Control Program(continued)
AC Sources - Operating3.8.1SURVEILLANCE REQUIREMENTS  (continued)Catawba Units 1 and 23.8.1-21Amendment Nos. 263/259SURVEILLANCEFREQUENCYSR  3.8.1.20--------------------------------------NOTE----------------------------All DG starts may be preceded by an engine prelube period.  ---------------------------------------------------------------------------Verify when started simultaneously from standby condition, each DG achieves, in < 11seconds, voltage of > 3950V and frequency of > 57 Hz and maintains steady state voltage > 3950V and < 4580V, and frequency > 58.8Hz and < 61.2Hz.In accordance with the Surveillance Frequency Control ProgramSR  3.8.1.21  For the LCO 3.8.1.c and LCO 3.8.1.d AC electrical sources, SR 3.8.1.1, SR 3.8.1.2, SR 3.8.1.4, SR 3.8.1.5, and SR 3.8.1.6 are required to be met.In accordance with the Surveillance Frequency Control Program  toRA-17-0051Attachment 2Revised McGuireTechnical Specification Marked Up Pages AC Sources -Operating3.8.1McGuire Units 1 and 23.8.1-1Amendment No. 221/2033.8  ELECTRICAL POWER SYSTEMS3.8.1  AC Sources-OperatingLCO  3.8.1The following AC electrical sources shall be OPERABLE:a.Two qualified circuits between the offsite transmission network and the Onsite Essential Auxiliary Power System; andb.Two diesel generators (DGs) capable of supplying the Onsite Essential Auxiliary Power Systems; andc.One qualified circuit between the offsite transmission network and the opposite unit's Onsite Essential Auxiliary Power System necessaryto supply power to the Nuclear Service Water System (NSWS), Control Room Area Ventilation System (CRAVS), Control Room Area Chilled Water System (CRACWS) and Auxiliary Building Filtered Ventilation Exhaust System (ABFVES); andd.One DG from the opposite unit necessaryto supply power to the NSWS, CRAVS, CRACWS and ABFVES;ANDThe automatic load sequencers for TrainA and TrainB shall be OPERABLE.APPLICABILITY:MODES1, 2, 3, and4.---------------------------------------------NOTE----------------------------------------------The opposite unit electrical power sources in LCO 3.8.1.c and LCO 3.8.1.d are not required to be OPERABLE when the associated shared systems areinoperable.---------------------------------------------------------------------------------------------------
AC Sources -Operating3.8.1McGuire Units 1 and 23.8.1-2Amendment No. 221/203ACTIONS---------------------------------------------------------NOTE-------------------------------------------------------------
LCO 3.0.4.b is not applicable to DGs.-------------------------------------------------------------------------------------------------------------------------------CONDITIONREQUIRED ACTIONCOMPLETION TIMEA.One LCO 3.8.1.a offsite circuit inoperable.A.1Perform SR3.8.1.1 for required OPERABLE offsite circuit(s).ANDA.2Declare required feature(s) with no offsite power available inoperable when its redundant required feature(s) is inoperable.ANDA.3Restore offsite circuit to OPERABLE status.1hourANDOnce per 8hours thereafter24hours from discovery of no offsite power to one train concurrent with inoperability of redundant required feature(s)72 hoursAND617days from discovery of failure to meet LCO3.8.1.a or LCO 3.8.1.b AC Sources -Operating3.8.1ACTIONSMcGuire Units 1 and 23.8.1-3Amendment No. 184/166CONDITIONREQUIRED ACTIONCOMPLETION TIMEB.One LCO 3.8.1.b DG inoperable.B.1Verify LCO 3.8.1.d DGOPERABLE.ANDB.12Perform SR3.8.1.1 for the required offsite circuit(s).ANDB.23Declare required feature(s) supported by the inoperable DG inoperable when its required redundant feature(s) is inoperable.ANDB.34.1Determine OPERABLE DG(s)is not inoperable due to common cause failure.ORB.34.2Perform SR3.8.1.2 for OPERABLE DG(s).AND1 hourANDOnce per 12 hours thereafter1hourANDOnce per 8hours thereafter4hours from discovery of ConditionBconcurrent with inoperability of redundant required feature(s)24hours24hours(continued)
AC Sources -Operating3.8.1ACTIONSMcGuire Units 1 and 23.8.1-4Amendment No. 293/272CONDITIONREQUIRED ACTIONCOMPLETION TIMEB.(continued)B.5Ensure availability of Emergency Supplemental PowerSource (ESPS).ANDB.4B.6Restore DG to OPERABLE status.Prior to entering the extended Completion Time of ACTION B.6ANDOnce per 12 hours thereafter72hoursfrom discovery of unavailable ESPS**AND6days from discovery of failure to meet LCO 24 hours from discovery of unavailable ESPS when in extended Completion TimeAND14 daysAND17 days from discovery of failure to meet LCO 3.8.1.a or LCO 3.8.1.b AC Sources -Operating3.8.1ACTIONSMcGuire Units 1 and 23.8.1-5Amendment No. 293/272C.Required Action and associated Completion Time of Required Action B.1 not met.C.1.1Restore LCO 3.8.1.d DGto OPERABLE status.ORC.1.2Restore LCO 3.8.1.b DG to OPERABLE status.72 hoursD.LCO 3.8.1.c offsite circuit inoperable.------------------NOTE--------------------Enter applicable Conditions and Required Actions of LCO 3.8.9, "Distribution Systems -Operating," when Condition D is entered with no AC power source to a train.----------------------------------------------D.1Perform SR 3.8.1.1 for the required offsite circuit(s).ANDD.2Declare NSWS, CRAVS, CRACWS or ABFVES with no offsite power available inoperable when the redundant NSWS, CRAVS, CRACWS or ABFVES is inoperable.ANDD.3Declare NSWS, CRAVS, CRACWS and ABFVES supported by the inoperable offsite circuit inoperable.1 hourANDOnce per 8 hours thereafter24 hours from discovery of no offsite power to one train concurrent with inoperability of redundant required feature(s)72 hours AC Sources -Operating3.8.1ACTIONSMcGuire Units 1 and 23.8.1-6Amendment No. 293/272E.LCO 3.8.1.d DG inoperable.------------------NOTE--------------------Enter applicable Conditions and Required Actions of LCO 3.8.9, "Distribution Systems -Operating," when Condition E is entered with no AC power source to a train.----------------------------------------------E.1Verify both LCO 3.8.1.b DGs OPERABLE and ESPS available.ANDE.2Perform SR 3.8.1.1 for the required offsite circuit(s).ANDE.3DeclareNSWS, CRAVS, CRACWS or ABFVES supported by the inoperable DG inoperable when the redundant NSWS, CRAVS, CRACWS or ABFVES is inoperable.AND1 hourANDOnce per 12 hours thereafter1 hourANDOnce per 8 hours thereafter4 hours from discovery of Condition E concurrent with inoperability of redundant required feature(s)(continued)
AC Sources -Operating3.8.1ACTIONSMcGuire Units 1 and 23.8.1-7Amendment No. 293/272E.(continued)E.4.1Determine OPERABLE DG(s) is not inoperable due to common cause failures.ORE.4.2Perform SR 3.8.1.2 for OPERABLE DG(s).ANDE.5Declare NSWS, CRAVS, CRACWS andABFVES supported by the inoperable DG inoperable.24 hours24 hours14 daysF.Required Action and associated CompletionTime of Required Action E.1 not met.F.1.1Restore both LCO 3.8.1.b DGs to OPERABLE status and ESPS to available status.ORF.1.2Restore LCO 3.8.1.d DG to OPERABLE status.ORF.1.3Declare NSWS, CRAVS, CRACWS and ABFVES supported by the inoperable DG inoperable.72 hours AC Sources -Operating3.8.1ACTIONSMcGuire Units 1 and 23.8.1-8Amendment No. 293/272C.GTwo LCO 3.8.1.a offsite circuits inoperable.OROne LCO 3.8.1.a offsitecircuit that providespower to the NSWS,CRAVS, CRACWS andABFVES inoperable andthe required LCO 3.8.1.coffsite circuit inoperable.CG.1Declare required feature(s) inoperable when its redundant required feature(s) is inoperable.ANDCG.2Restore one offsite circuit to OPERABLE status.12hours from discovery of ConditionCGconcurrent with inoperability of redundant requiredfeature(s)24hours(continued)** 'A' Train EDGs are allowed to be inoperable for a total of 14 days for the correction of a degraded condition on the 'A' Train supply piping from the Standby Nuclear Service Water Pond (SNSWP). The 14 daysmay be taken consecutively or in parts until completion of the activity, or by March 1,2017whichever occurs first. During the period in which the 'A' Train NSWS supply piping from the SNSWP is not available, the 'A' Train NSWS will remain aligned to Lake Norman until the system is ready for post maintenance testing. Any maintenance that is performed on the remaining portions of 'A' Train NSWS during the period in which the 'A' NSWS from the SNSWP supply piping is not available will be limited to a 72 hour completion time. The latter will not count against the 14 day completion time. Allowance of the extended Completion Time is contingent on meeting the Compensatory Measures and Commitments as described in MNS LAR submittal correspondence letter MNS-16-005.
AC Sources -Operating3.8.1ACTIONS  (continued)McGuire Units 1 and 23.8.1-9Amendment No. 184/166CONDITIONREQUIRED ACTIONCOMPLETION TIMEDH.One LCO 3.8.1.a offsite circuit inoperable.ANDOne LCO 3.8.1.b DG inoperable.------------------NOTE-------------------Enter applicable Conditions and Required Actions of LCO3.8.9, "Distribution Systems-Operating," when ConditionDHis entered with no AC power source to any train.---------------------------------------------DH.1Restore offsite circuit to OPERABLE status.ORDH.2Restore DG to OPERABLE status.12hours12hoursEI.Two LCO 3.8.1.b DGs inoperable.ORLCO 3.8.1.b DG thatprovides power to the NSWS, CRAVS,CRACWS and ABFVESinoperable and LCO3.8.1.d DG inoperableEI.1Restore one DG to OPERABLE status.2hoursFJ.Oneautomatic load sequencer inoperable.FJ.1Restore automatic load sequencer to OPERABLE status.12hours AC Sources -Operating3.8.1ACTIONS  (continued)McGuire Units 1 and 23.8.1-10Amendment No. 184/166GK.Required Action and associated Completion Time of ConditionA, B, C, D,E, orC,F, G, H, I, or Jnot met.ORRequired Action andassociatedCompletionTime of Required Action B.2, B.3, B.4.1,B.4.2, or B.6 not met.ORRequired Action andassociated CompletionTime of RequiredAction E.2, E.3,E.4.1, E.4.2, or E.5not met.GK.1Be in MODE3.ANDGK.2Be in MODE5.6hours36hoursHL.Three or more LCO 3.8.1.a and LCO 3.8.1.b AC sources inoperable.HL.1Enter LCO3.0.3.Immediately AC Sources -Operating3.8.1McGuire Units 1 and 23.8.1-11Amendment No. 261/241SURVEILLANCE REQUIREMENTS-------------------------------------------------------NOTE----------------------------------------------------------------SR 3.8.1.1 through SR 3.8.1.20 are only applicable to LCO 3.8.1.a and LCO 3.8.1.b AC sources. SR 3.8.1.21 is only applicable to LCO 3.8.1.c and LCO 3.8.1.d AC sources.-------------------------------------------------------------------------------------------------------------------------------SURVEILLANCEFREQUENCYSR  3.8.1.1Verify correct breaker alignment and indicated power availability for each offsite circuit.In accordance with the Surveillance Frequency Control ProgramSR  3.8.1.2--------------------------------NOTES--------------------------------1.Performance of SR3.8.1.7 satisfies this SR.2.All DG starts may be preceded by an engine prelube period and followed by a warmup period prior to loading.3.A modified DG startinvolving idling and gradual acceleration to synchronous speed may be used for this SR as recommended by the manufacturer. When modified start procedures are not used, the time, voltage, and frequency tolerances of SR3.8.1.7 must be met.---------------------------------------------------------------------------Verify each DG starts from standby conditions and achieves steady state voltage 3740V and 4580V, and frequency 58.8 Hzand61.2Hz.In accordance with the Surveillance Frequency Control Program(continued)
AC Sources -Operating3.8.1SURVEILLANCE REQUIREMENTS  (continued)McGuire Units 1 and 23.8.1-21Amendment No. 261/241 SURVEILLANCEFREQUENCYSR  3.8.1.20--------------------------------NOTES--------------------------------All DG starts may be preceded by an engine prelube period.--------------------------------------------------------------------------Verify when started simultaneously from standby condition, each DG achieves, in 11seconds, voltage of 3740 V and frequency of 57 Hz and maintains steady state voltage 3740V and 4580V, and frequency 58.8Hz and 61.2Hz.In accordance with the Surveillance Frequency Control ProgramSR  3.8.1.21For the LCO 3.8.1.c andLCO 3.8.1.d AC electrical sources, SR 3.8.1.1, SR 3.8.1.2, SR 3.8.1.4, SR 3.8.1.5, and SR 3.8.1.6 are required to be met.In accordance with the Surveillance Frequency Control Program  toRA-17-0051Attachment 3Revised Catawba Technical Specification Bases Marked Up Pages(For Information Only)
Catawba Units 1 and 2B 3.8.1-1Revision No. 6AC Sources-OperatingB 3.8.1B 3.8  ELECTRICAL POWER SYSTEMSB 3.8.1  AC Sources-OperatingBASESBACKGROUNDThe unit Essential Auxiliary Power Distribution System AC sources consist of the offsite power sources (preferred power sources, normal andalternate(s)), and the onsite standby power sources (TrainA and TrainB diesel generators (DGs)). As required by 10CFR50, AppendixA, GDC17 (Ref.1), the design of the AC electrical power system provides independence and redundancy to ensure an available source of power to the Engineered Safety Feature (ESF) systems.The onsite Class1E AC Distribution System is divided into redundant load groups (trains) so that the loss of any one group does not prevent the minimum safety functions from being performed. Each train has connections to two preferred offsite power sources and a single DG.At the 600V level of the onsite Class 1E AC Distribution System, each unit has one motor control center (MCC), 1EMXG and 2EMXH, that each supply power to a train ofshared systems. The term shared systems is defined as the shared components of Train A or Train B of Nuclear Service Water System (NSWS), Control Room Area Ventilation System (CRAVS), Control Room Area Chilled Water System (CRACWS) and Auxiliary BuildingFiltered Ventilation Exhaust System (ABFVES). The MCC 1EMXG is normally aligned to receive power from load center 1ELXA but if desired or required to maintain operability of the Train A shared systems, can be swapped to receive power from load center 2ELXA. The MCC 2EMXH is normally aligned to receive power from load center 2ELXB but if desired or required to maintain operability of the Train B shared systems, can be swapped to receive power from load center 1ELXB.There are also provisions to accommodate the connecting of the Emergency Supplemental Power Source (ESPS) to one train of either unit's Class 1E AC Distribution System. The ESPS consists of two 50% capacity non-safety related commercial grade DGs. Manual actions are required to align the ESPS to the station and only one of the station's four onsite Class 1E Distribution System trains can be supplied by the ESPS at any given time. The ESPS is made available to support extended Completion Times in the event of an inoperable DG as well as a defense-in-depth source of AC power to mitigate a station blackout event. The ESPS would remain disconnected from the Class 1E AC Distribution System unless required for supplemental power to one of the four 4.16 Catawba Units 1 and 2B 3.8.1-2Revision No. 6kV ESF buses.From the transmission network, two electrically and physically separated circuits provide AC power, through step down station auxiliary transformers, to the 4.16kV ESF buses. A detailed description of the offsite power network and the circuits to the Class1E ESF buses is found in the UFSAR, Chapter8 (Ref.2).A qualified offsite circuit consists of all breakers, transformers, switches, interrupting devices, cabling, and controls required to transmit power from the offsite transmission network to the onsite Class1E ESF bus(es).Certain required unit loads are returned to service in a predetermined sequence in order to prevent overloading the transformer supplying offsite power to the onsite Class1E Distribution System. Within 1minute after the initiating signal is received, all automatic and permanently connected loads needed to recover the unit or maintain it in a safe condition are returned to service via the load sequencer.The onsite standby power source for each 4.16kV ESF bus is a dedicated DG. DGsA andB are dedicated to ESF busesETA andETB, respectively. A DG starts automatically on a safety injection (SI) signal (i.e., low pressurizer pressure or high containment pressure signals) or on an ESF bus degraded voltage or undervoltage signal (refer to LCO3.3.5,"Loss of Power (LOP) Diesel Generator (DG) Start Instrumentation"). After the DG has started, it will automatically tie to its respective bus after offsite power is tripped as a consequence of ESF bus undervoltage or degraded voltage, independent of or coincident with an SI signal. With no SI signal, there is a 10 minute delay between degraded voltage signal and the DG start signal. The DGs will also start and operate in the standby mode without tying to the ESF bus on an SI signal alone. Following thetrip of offsite power, a sequencer strips loads from the ESF bus. When the DG is tied to the ESF bus, loads are then sequentially connected to its respective ESF bus by the automatic load sequencer. The sequencing logic controls the permissive and starting signals to motor breakers to prevent overloading the DG by automatic load application.In the event of a loss of preferred power, the ESF electrical loads are automatically connected to the DGs in sufficient time to provide for safe reactor shutdown and to mitigate the consequences of a Design Basis Accident (DBA) such as a loss of coolant accident (LOCA).Certain required unit loads are returned to service in a predetermined sequence in order to prevent overloading the DG in the process.
Approximately 1minute after the initiating signal is received, all loads needed to recover the unit or maintain it in a safe condition are returned to service.Ratings for TrainA and TrainB DGs satisfy the requirements of Regulatory Guide1.9 (Ref.3). The continuous service rating of each DG Catawba Units 1 and 2B 3.8.1-3Revision No. 6is 7000kW with 10% overload permissible for up to 2hours in any 24hour period. The ESF loads that are powered from the 4.16kV ESF buses are listed in Reference2.APPLICABLEThe initial conditions of DBA and transient analyses in the UFSAR, SAFETY ANALYSESChapter6 (Ref.4) and Chapter15 (Ref.5), assume ESF systems are OPERABLE. The AC electrical power sources are designed to provide sufficient capacity, capability, redundancy, and reliability to ensure the availability of necessary power to ESF systems so that the fuel, Reactor Coolant System (RCS), and containment design limits are not exceeded.
These limits are discussed in more detail in the Bases for Section3.2, Power Distribution Limits; Section3.4, Reactor Coolant System (RCS);
and Section3.6, Containment Systems.The OPERABILITY of the AC electrical power sources is consistent with the initial assumptions of the Accident analyses and is based upon meeting the design basis of the unit. This resultsin maintaining at least one train of the onsite or offsite AC sources OPERABLE during Accident conditions in the event of:a.An assumed loss of all offsite power or all onsite AC power; and b.A worst case single failure.
The AC sources satisfy Criterion3 of 10 CFR 50.36 (Ref. 6).LCOTwo qualified circuits between the offsite transmission network and the onsite Essential Auxiliary Power System and separate and independent DGs for each train ensure availability of the required power to shut down the reactor and maintain it in a safe shutdown condition after an anticipated operational occurrence (AOO) or a postulated DBA.Additionally, one qualified circuit between the offsite transmission network and the opposite unit onsite Essential Auxiliary Power System whennecessary to power shared systems and one opposite unit DG when necessary to power shared systems ensure availability of the requiredpower to shut down the reactor and maintain it in a safe shutdowncondition after an AOO or a postulated DBA.Qualified offsite circuits are those that are described in the UFSAR and are part of the licensing basis for the unit.In addition, one required automatic load sequencer per train must be OPERABLE.Each offsite circuit must be capable of maintaining rated frequency and voltage, and accepting required loads during an accident, while connected to the ESF buses.
Catawba Units 1 and 2B 3.8.1-4Revision No. 6The 4.16 kV essential system is divided into two completely redundant and independent trains designated A and B, each consisting of one4.16 kV switchgear assembly, three 4.16 kV/600 V transformers, two 600 V load centers, and associated loads.Normally, each Class 1E 4.16 kV switchgear is powered from its associated non-Class 1E train of the 6.9 kV Normal Auxiliary Power System as discussed in "6.9 kV Normal Auxiliary Power System" in Chapter 8 of the UFSAR (Ref. 2). Additionally, a standbysource of power to each 4.16 kV essential switchgear, not required by General Design Criterion 17,is provided from the 6.9 kV system via two separate and independent 6.9/4.16 kV transformers. These transformers are shared between units and provide the capabilityto supply a standbysource of preferred power to each unit's 4.16 kV essential switchgear from either unit's 6.9 kV system. A key interlock scheme is provided to preclude the possibility of connecting the two units together at either the 6.9 or 4.16 kV level.Each train of the 4.16 kV Essential Auxiliary Power System is also provided with a separate and independent emergency diesel generator to supply the Class 1E loads required to safely shut down the unit following a design basis accident. Additionally, each diesel generator is capable of supplying its associated 4.16 kV blackout switchgear through a connection with the 4.16 kV essential switchgear. Each DG must be capable of starting, accelerating to rated speed and voltage, and connecting to its respective ESF bus on detection of bus undervoltage. This will be accomplished within 11seconds. Each DG must also be capable of accepting required loads within the assumed loading sequence intervals, and continue to operate until offsite power can be restored to the ESF buses. These capabilities are required to be met from a variety of initial conditions such as DG in standby with the engine hot and DG in standby with the engine at ambient conditions.
Additional DG capabilities must be demonstrated to meet required Surveillance, e.g., capability of the DG to revert to standby status on an ECCS signal while operating in parallel test mode. Proper sequencing of loads, including tripping of nonessential loads, is a required function for DG OPERABILITY.The AC sources in one train must be separate and independent (to the extent possible) of the AC sources in the other train. For the DGs, separation and independence are complete.For the offsite AC sources, separation and independence are provided to the extent practical.LCO 3.8.1.c and LCO 3.8.1.d both use the word "necessary" to clarify when and how to apply these LCOs on a per unit basis. The word "necessary" clarifies that the qualified offsite circuit in LCO 3.8.1.c and the one DG from the opposite unitin LCO 3.8.1.d are aligned to the Catawba Units 1 and 2B 3.8.1-5Revision No. 6opposite unit Onsite Essential Auxiliary Power System that is supplying power to a train of shared systems.LCO 3.8.1.c specifies thatone qualified circuit between the offsite transmission network and the opposite unit's Onsite Essential Auxiliary Power System be OPERABLE when necessaryto supply power to the shared systems.LCO3.8.1.d specifies thatone DG from the opposite unit be OPERABLE when necessaryto supply power to the shared systems. The qualified circuit in LCO 3.8.1.c must be separate and independent (to the extent possible) of the qualified circuit which provides power to the other train of shared systems. These requirements, in conjunction with the requirements for the applicable unit AC electrical power sources in LCO 3.8.1.a and LCO 3.8.1.b, ensure that power is available to two trains of the shared NSWS, CRAVS, CRACWS and ABFVES.For example, with both units in MODE 1, the normal power alignment per plant procedures with no inoperable equipment is to have the Train A shared systems powered from Unit 1 (1EMXG) and the Train B shared systems powered from Unit 2 (2EMXH). In this normal alignment, Unit 1 LCO 3.8.1.c is met by an OPERABLE 2B offsite circuit and LCO 3.8.1.d is met by an OPERABLE 2B DG. Since the 2A offsite circuit and 2A DG are not necessary to supply power to a train of shared systems in the normal power alignment, they are not Unit 1 LCO 3.8.1.c and LCO 3.8.1.d AC sources for this example. For Unit 2, LCO 3.8.1.c is met by an OPERABLE 1A offsite circuit and LCO 3.8.1.d is met by an OPERABLE 1A DG.Since the 1B offsite circuit and 1B DG are not necessary to supply power to a train of shared systems in the normal power alignment, they are not Unit 2 LCO 3.8.1.c and LCO 3.8.1.d AC sources for this example.APPLICABILITYTheAC sources and sequencers are required to be OPERABLE in MODES1, 2, 3, and4 to ensure that:a.Acceptable fuel design limits and reactor coolant pressure boundary limits are not exceeded as a result of AOOs or abnormal transients; andb.Adequate core cooling is provided and containment OPERABILITY and other vital functions are maintained in the event of a postulated DBA.A Note has been added taking exception to the Applicability requirements for the requiredAC sources in LCO 3.8.1.c and LCO 3.8.1.d provided the associated shared systems areinoperable. This exception is intended to allow declaring the shared systemssupported by the opposite unitinoperable either in lieu of declaring the opposite unit AC sources inoperable, or at any time subsequent to entering ACTIONS for an inoperable opposite unit AC source.
Catawba Units 1 and 2B 3.8.1-6Revision No. 6This exception is acceptable since, with the shared systemssupported by the opposite unitinoperable and the associated ACTIONS entered, the opposite unit AC sources provide no additional assurance of meeting the above criteria.The AC power requirements for MODES5 and6 are covered inLCO3.8.2, "AC Sources-Shutdown."ACTIONSA Note prohibits the application of LCO 3.0.4.b to an inoperable DG. There is an increased risk associated with entering a MODE or other specified condition in the Applicability with an inoperable DG and the provisions of LCO 3.0.4.b, which allow entry into a MODE or other specified condition in the Applicability with the LCO not met after performance of a risk assessment addressing inoperable systems and components, should not be applied in this circumstance.When entering Required Actions for inoperable offsite circuit(s) and/or DG(s), it is also necessary to enter the applicable Required Actions of any shared systems LCOs when either normal or emergency power to shared components governed by these LCOs becomes inoperable. These LCOs include 3.7.8, "Nuclear Service Water System (NSWS)"; 3.7.10, "Control Room Area Ventilation System (CRAVS)"; 3.7.11, "Control Room Area Chilled Water System (CRACWS)"; and 3.7.12, "Auxiliary Building Filtered Ventilation Exhaust System (ABFVES)".A.1To ensure a highly reliable power source remains with one LCO 3.8.1.a offsite circuit inoperable, it is necessary to verify the OPERABILITY of the remaining required offsite circuitson a more frequent basis. Since the Required Action only specifies "perform," a failure of SR3.8.1.1 acceptance criteria does not result in a Required Action not met.
However, if a second required circuitsfails SR3.8.1.1, the second offsite circuit is inoperable, and ConditionCG, for two offsite circuits inoperable, is entered.A.2Required ActionA.2, which only applies if the train cannot be powered from an offsite source, is intended to provide assurance that an event coincident with a single failure of the associated DG will not result in a complete loss of safety function of critical redundant required features. These features are powered from the redundant AC electrical powertrain. This includes motor driven auxiliary feedwater pumps. The turbine driven auxiliary feedwater pump is required to be considered a redundant required feature, and, therefore, required to be determined OPERABLE by this Required Action. Three independent AFW pumps are required to ensure the availability of decay heat removal capability for all events Catawba Units 1 and 2B 3.8.1-7Revision No. 6accompanied by a loss of offsite power and a single failure. System design is such that the remaining OPERABLE motor driven auxiliary feedwater pump isnot by itself capable of providing 100% of the auxiliary feedwater flow assumed in the safety analysis.The Completion Time for Required ActionA.2 is intended to allow the operator time to evaluate and repair any discovered inoperabilities. This Completion Time also allows for an exception to the normal "time zero" for beginning the allowed outage time "clock."  In this Required Action, the Completion Time only begins on discovery that both:a.The train has no offsite power supplying it loads; and b.A required feature on the other train is inoperable.If at any time during the existence of ConditionA (one LCO 3.8.1.a offsite circuit inoperable) a redundant required feature subsequently becomes inoperable, this Completion Time begins to be tracked.Discovering no offsite power to one train of the onsite Class1E Electrical Power Distribution System coincident with one or more inoperable required support or supported features, or both, that are associated with the other train that has offsite power, results in starting the Completion Times for the Required Action. Twenty-four hours is acceptable because it minimizes risk while allowing time for restoration before subjecting the unit to transients associated with shutdown.The remaining OPERABLE offsite circuitsand DGs are adequate to supply electrical power to TrainA and TrainB of the onsite Class1E Distribution System. The 24hour Completion Time takes into account the component OPERABILITY of the redundant counterpart to the inoperable required feature. Additionally, the 24hour Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.A.3According to Regulatory Guide1.93 (Ref.7), operation may continue inConditionA for a period that should not exceed 72hours. With one offsite circuit inoperable, the reliability of the offsite system is degraded, and the potential for a loss of offsite power is increased, with attendant potential for a challenge to the unit safety systems. In this Condition, however, the remaining OPERABLE offsite circuit and DGs are adequate to supply electrical power to the onsite Class1E Distribution System.The 72hour Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.The second Completion Time for Required ActionA.3 establishes a limit Catawba Units 1 and 2B 3.8.1-8Revision No. 6on themaximum time allowed for any combination of required AC power sources to be inoperable during any single contiguous occurrence of failing to meet the LCOLCO 3.8.1.a or LCO 3.8.1.b. If ConditionA is entered while, for instance, a LCO 3.8.1.bDG is inoperable and that DG is subsequently returned OPERABLE, the LCO may already have been not met for up to 72hours14 days. This could lead to a total of 144hours17 days, since initial failure to meet the LCOLCO 3.8.1.a or LCO 3.8.1.b, to restore the offsite circuit. At this time, a DG could again become inoperable, the circuit restored OPERABLE, and an additional 72hours14 days(for a total of 931days) allowed prior to complete restoration of the LCOLCOs 3.8.1.a and 3.8.1.b. The 617day Completion Time provides a limit on the time allowed in a specified condition after discovery of failure to meet the LCOLCO 3.8.1.a or LCO 3.8.1.b. This limit is considered reasonable for situations in which ConditionsA andB are entered concurrently. The "AND" connectorbetween the 72hour and 617day Completion Times means that both Completion Times apply simultaneously, and the more restrictive Completion Time must be met.As in Required ActionA.2, the Completion Time allows for an exception to the normal "time zero" for beginning the allowed outage time "clock."
This will result in establishing the "time zero" at the time that the LCOLCO 3.8.1.a or LCO 3.8.1.bwas initially not met, instead of at the time ConditionA was entered.B.1It is required to administratively verify both opposite-unit DGs OPERABLE within 1 hour and to continue this action once per 12 hours thereafter until restoration of the required LCO 3.8.1.b DG is accomplished. This verification provides assurance that both opposite-unit DGs are capable of supplying the onsite Class 1E AC Electrical Power Distribution System.B.12To ensure a highly reliable power source remains with an inoperable LCO 3.8.1.b DG, it is necessary to verify the availability of the required offsite circuits on a more frequent basis. Since the Required Action only specifies "perform," a failure of SR3.8.1.1 acceptance criteria does not result in a Required Action being not met. However, if a circuit fails to pass SR3.8.1.1, it is inoperable. Upon offsite circuitinoperability, additional Conditions and Required Actions must then be entered.B.23Required ActionB.23is intended to provide assurance that a loss of offsite power, during the period that a LCO 3.8.1.b DG is inoperable, does not result in a complete loss of safety function of critical systems. These features are designed with redundant safety related trains. This includes motor driven auxiliary feedwater pumps. The turbine driven auxiliary feedwater pump is required to be considered a redundant Catawba Units 1 and 2B 3.8.1-9Revision No. 6required feature, and, therefore, required to be determined OPERABLE by this Required Action. Three independent AFW pumps are required to ensure the availability of decay heat removal capability for all events accompanied by a loss of offsite power and a single failure. System design is such that the remaining OPERABLE motor driven auxiliary feedwater pump is not by itself capable of providing 100% of the auxiliary feedwater flow assumed in the safety analysis. Redundant required feature failures consist of inoperable features associated with a train, redundant to the train that has an inoperable LCO 3.8.1.b DG.The Completion Time for Required ActionB.23is intended to allow the operator time to evaluate and repair any discovered inoperabilities. This Completion Time also allows for an exception to the normal "time zero" for beginning the allowed outage time "clock."  In this Required Action, the Completion Time only begins on discovery that both:a.An inoperable LCO 3.8.1.b DG exists; andb.A required feature on the other train (TrainA or TrainB) is inoperable. If at any time during the existence of this Condition (one LCO 3.8.1.b DG inoperable) a required feature subsequently becomes inoperable, this Completion Time would begin to be tracked.Discovering one required LCO 3.8.1.b DG inoperable coincident with one or more inoperable required support or supported features, or both, that are associated with the OPERABLE DG, results in starting the Completion Time for the Required Action. Four hours from the discovery of these events existing concurrently is Acceptable because it minimizes risk while allowing time for restoration before subjecting the unit to transients associated with shutdown.In this Condition, the remaining OPERABLE DGsand offsite circuits are adequate to supply electrical power to the onsite Class1E Distribution System. Thus, on a component basis, single failure protection for the required feature's function may have been lost; however, function has not been lost.The 4hour Completion Time takes into account the OPERABILITY of the redundant counterpart to the inoperable required feature. Additionally, the 4hour Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.B.34.1 and B.34.2Required ActionB.34.1 provides an allowance to avoid unnecessary testing of OPERABLE DG(s). If it can be determined that the cause of the inoperable DG does not exist on the OPERABLE DG, SR3.8.1.2 does not have to be performed. If the cause of inoperability exists on other DG(s), the other DG(s) would be declared inoperable upon discovery and ConditionEand/or I of LCO3.8.1, as applicable,would be Catawba Units 1 and 2B 3.8.1-10Revision No. 6entered. Once the failure is repaired, the common cause failure no longer exists, and Required ActionB.34.1 is satisfied. If the cause of the initial inoperable DG cannot be confirmed not to exist on the remaining DG(s), performance of SR3.8.1.2 suffices to provide assurance of continued OPERABILITY of that DG.In the event the inoperable DG is restored to OPERABLE status prior to completing either B.34.1 or B.34.2, the problem investigation process will continue to evaluate the common cause possibility. This continued evaluation, however, is no longer under the 24 hour constraint imposed while in Condition B.These Conditions are not required to be entered if the inoperability of the DG is due to an inoperable support system, an independently testable component, or preplanned testing or maintenance. If required, these Required Actions are to be completed regardless of when the inoperable DG is restored to OPERABLE status. According to Generic Letter84-15 (Ref.8), 24hours is reasonable to confirm that the OPERABLE DG(s) is not affected by the same problem as the inoperable DG.B.5In order to extend the Completion Time for an inoperable DG from 72 hours to 14 days, it is necessary to ensure the availability of the ESPS prior to entering the extended Completion Time of Required Action B.6 (i.e., 14 days) and every 12 hours thereafter. The "extended Completion Time of ACTION B.6" is defined as 14 days. ESPS availability requires that:1) The load test has been performed within 30 days of entry into the extended Completion Time. The Required Action evaluation is met with an administrative verification of this prior to testing; and2) ESPS fuel tank level is verified locally to be 3) ESPS supporting system parameters for starting and operating are verified to be within required limits for functional availability (e.g., battery state of charge).On discovery of an unavailable ESPS, the Completion Time for Required Action B.6 starts the72 hour or 24 hour clock.The ESPS is not used to extend the Completion Time for more than one inoperable DG at any one time. B.46According to Regulatory Guide1.93 (Ref.7), operation may continue in ConditionB for a period that should not exceed 72hours.
Catawba Units 1 and 2B 3.8.1-11Revision No. 6In accordance with Branch Technical Position 8-8 (Ref. 14), operation may continue in Condition B for a period that should not exceed 14 days,provided a supplemental AC power source is available.In ConditionB, theremaining OPERABLE DGs, available ESPSandoffsite circuits are adequate to supply electrical power to the onsite Class1E DistributionSystem. The 72hour14 dayCompletion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.If the ESPS is or becomes unavailable with an inoperable LCO 3.8.1.b DG, then action is required to restore the ESPS to available status or to restore the DG to OPERABLE status within 72 hours from discovery of an unavailable ESPS. However, if the ESPS unavailability occurs sometime after 72 hours of continuous DG inoperability(i.e., after entering the extended Completion Time for an inoperable DG), then the remaining time to restore the ESPS to available status or to restore the DG to OPERABLE status is limited to 24 hours.The 72 hour and 24 hour Completion Times allow for an exception to the normal "time zero" for beginning the allowed outage time "clock."  The 72 hour Completion Time only begins on discovery that both an inoperable DG exists and the ESPS is unavailable. The 24 hour Completion Time only begins if the extended Completion Time for the inoperable DG has been entered and the ESPS is unavailable.Therefore, when one LCO 3.8.1.b DG is inoperable due to either preplanned maintenance (preventive or corrective) or unplanned corrective maintenance work, the Completion Time can be extended from 72 hours to 14 days if it is ensured that ESPS is availablefor backup operation.The second fourth Completion Time for Required ActionB.46establishes a limit on the maximum time allowed for any combination of required AC power sources to be inoperable during any single contiguous occurrence of failing to meet the LCOLCO 3.8.1.a or LCO 3.8.1.b. If ConditionB is entered while, for instance, ana LCO 3.8.1.a offsite circuit is inoperable and that circuit is subsequently restored OPERABLE, the LCO may already have been not met for up to 72hours. This could lead to a total of 144hours17 days, since initial failure to meet the LCOLCO 3.8.1.a or LCO 3.8.1.b, to restore the DG. At this time, ana LCO 3.8.1.a offsite circuit could again become inoperable, the DG restored OPERABLE, and an additional 72hours (for a total of 920days) allowed prior to complete restoration of the LCOLCO 3.8.1.a and LCO 3.8.1.b.The 617day Completion Time provides a limit on time allowed in a specified condition after discovery of failure to meet the LCOLCO 3.8.1.a or LCO 3.8.1.b.This limit is considered reasonable for situations in which ConditionsA andB are entered concurrently. The "AND" connector between the 72hour14 dayand617day Completion Times means that both Completion Times apply simultaneously, and the more restrictive Catawba Units 1 and 2B 3.8.1-12Revision No. 6Completion Time must be met.As in Required ActionB.23, the Completion Time allows for an exception to the normal "time zero" for beginning the allowed time "clock."  This will result in establishing the "time zero" at the time that the LCOLCO 3.8.1.a or LCO 3.8.1.bwas initially not met, instead of at the time ConditionBwas entered.C.1.1 and C.1.2In Condition C with an opposite-unit DG inoperable, the remaining OPERABLE unit-specific DG and required qualified circuits are adequate to supply electrical power to the onsite Class 1E Distribution System. According to Regulatory Guide 1.93 (Ref. 7), operation may continue in Condition C for a period that should not exceed 72 hours. The 72 hour Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs and the low probability of a DBA occurring during this period.D.1Pursuant to LCO 3.0.6, the DistributionSystem ACTIONS would not be entered even if all AC sources to it were inoperable, resulting in de-energization. Therefore, the Required Actions of Condition D are modified by a Note to indicate that when Condition D is entered with no AC source to any train, the Conditions and Required Actions for LCO 3.8.9 must be immediately entered. This allows Condition D to provide requirements for the loss of aLCO 3.8.1.c offsite circuit and LCO 3.8.1.d DG without regard to whether a train is de-energized. Limiting Condition for Operation 3.8.9 provides the appropriate restrictions for ade-energized train.To ensure a highly reliable power source remains with the one required LCO 3.8.1.c offsite circuit inoperable, it is necessary to verify the OPERABILITY of the remaining required offsite circuitson a more frequent basis. Since the Required Action only specifies "perform," a failure of SR 3.8.1.1 acceptance criteria does not result in a Required Action not met. However, if a second required circuit fails SR 3.8.1.1, the second offsite circuit is inoperable, and Condition A andG, as applicable, for the two offsite circuits inoperable, is entered.D.2Required Action D.2, which only applies if the train cannot be powered from an offsite source, is intended to provide assurance that an event coincident with a single failure of the associated DGwill not result in a complete loss of safety function for the NSWS, CRAVS, CRACWS or the ABFVES. The Completion Time for Required Action D.2 is intended to allow the operator time to evaluate and repair any discovered inoperabilities. This Completion Time also allows for an exception to the normal "time zero" for beginning the allowed outage time "clock."  In this Catawba Units 1 and 2B 3.8.1-13Revision No. 6Required Action, the Completion Time only begins on discovery that both:a.The train has no offsite power supplying its loads: andb.NSWS, CRAVS, CRACWS or ABFVES on the other train that has offsite power is inoperable.If at any time during the existence of Condition D (one required LCO 3.8.1.c offsite circuit inoperable) a train of NSWS, CRAVS, CRACWS or ABFVES becomes inoperable, this Completion Time begins to be tracked.Discovering no offsite power to one train of the onsite Class 1E Electrical Power Distribution System coincident with one train of NSWS, CRAVS, CRACWS or ABFVES that is associated with the other train that hasoffsite power, results in starting the Completion Times for the Required Action. Twenty-four hours is acceptable because it minimizes risk while allowing time for restoration before subjecting the unit to transients associated with shutdown.The remaining OPERABLE offsite circuits and DGs are adequate to supply electrical power to Train A and Train B of the onsite Class 1E Distribution System. The 24 hour Completion Time takes into account the component OPERABILITY of the redundant counterpart to the inoperable NSWS, CRAVS, CRACWS or ABFVES. Additionally, the 24 hour Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.D.3Consistent with the time provided in ACTION A, operation may continue in Condition D for a period that should not exceed 72 hours. With one required LCO 3.8.1.c offsite circuit inoperable, the reliability of the offsite system is degraded, and the potential for a loss of offsite power is increased, with attendant potential for a challenge to the unit safety systems. In this Condition, however, the remaining OPERABLE offsite circuits and DGs are adequate to supply electrical power to the onsite Class 1EDistribution System.If the LCO 3.8.1.c required offsite circuit cannot be restored to OPERABLE status within 72 hours, the NSWS, CRAVS, CRACWS and ABFVES components associated with the offsite circuitmust be declared inoperable. The ACTIONS associatedwith the NSWS, CRAVS, CRACWS and ABFVES will ensure the appropriate actions are taken. The 72 hour Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, andthe low probability of a DBAoccurring during this period.E.1 Catawba Units 1 and 2B 3.8.1-14Revision No. 6Pursuant to LCO 3.0.6, the Distribution System ACTIONS would not be entered even if all AC sources to it were inoperable, resulting in de-energization. Therefore, the Required Actions of Condition E are modified by a Note to indicate that when Condition E is entered with no AC source to any train, the Conditions and Required Actions for LCO 3.8.9 must be immediately entered. This allows Condition E to provide requirements for the loss of the LCO 3.8.1.c offsite circuitand LCO 3.8.1.d DG without regard to whether a train is de-energized. Limiting Condition for Operation 3.8.9 provides the appropriate restrictions for a de-energized train.The 14 day Completion Time for Required Action E.5 is based on the OPERABILITY of the other three safety-related DGs and the availability of the ESPS. The ESPS is available to power the inoperable DG bus loads in the event of a station blackout or loss of offsite power event. It is required to administrativelyverify the three safety-related DGs OPERABLE and the ESPS available within one hour and to continue this action once per 12 hours thereafter until restoration of the required DG is accomplished. This verification provides assurance that the three safety-related DGs and the ESPS are capable of supplying the onsite Class 1E AC Electrical Power Distribution System.E.2To ensure a highly reliable power source remains with the one required LCO 3.8.1.d DG inoperable, it is necessary to verify the OPERABILITYof the required offsite circuits on a more frequent basis.Since the Required Action only specifies "perform," a failure of SR 3.8.1.1 acceptance criteria does not result in a Required Action not met. However, if a circuit fails to pass SR 3.8.1.1, it is inoperable. Upon offsite circuit inoperability, additional Conditions and Required Actions must then be entered.E.3Required Action E.3 is intended to provide assurance that a loss of offsite power, during the period the LCO 3.8.1.d DG is inoperable, does not result in a complete loss of safety function for the NSWS, CRAVS, CRACWS or the ABFVES. The Completion Time is intended to allow the operator time to evaluate and repair any discovered inoperabilities. This Completion Time also allows for an exception to the normal "time zero" for beginning the allowed outage time "clock."  In this Required Action, the Completion Time only begins on discovery that both:a.An inoperable LCO 3.8.1.d DG exists; and b.NSWS, CRAVS, CRACWS or ABFVES on the other train that has emergency power isinoperable.If at any time during the existence of this Condition (the LCO 3.8.1.d DG inoperable) a train of NSWS, CRAVS, CRACWS or ABFVES becomes inoperable, this Completion Time begins to be tracked.
Catawba Units 1 and 2B 3.8.1-15Revision No. 6Discovering the LCO 3.8.1.d DG inoperablecoincident with one train of NSWS, CRAVS, CRACWS or ABFVES that is associated with the other train that has emergency powerresults in starting the Completion Time for the Required Action. Four hours from the discovery of these events existing concurrentlyis acceptable because it minimizes risk while allowing time for restoration before subjecting the unit to transients associated with shutdown.In this Condition, the remaining OPERABLE DGs and offsite circuits are adequate to supply electrical power tothe onsite Class 1E Distribution System. Thus, on a component basis, single failure protection for the NSWS, CRAVS, CRACWS or ABFVES may have been lost; however, function has not been lost. The four hour Completion Time also takes into account the capacity and capability of the remaining NSWS, CRAVS, CRACWS and ABFVES train, a reasonable time for repairs, and the low probability of a DBA occurring during this period.E.4.1 and E.4.2Required Action E.4.1 provides an allowance to avoid unnecessary testing of OPERABLE DGs. If it can be determined that the cause of the inoperable DG does not exist on the OPERABLE DG(s), SR 3.8.1.2 does not have to be performed. If the cause of inoperability exists on other DG(s), the other DG(s) would be declared inoperable upon discovery and Condition B and I of LCO 3.8.1, as applicable, would be entered. Once the failure is repaired, the common cause failure no longer existsandRequired Action E.4.1 is satisfied. If the cause of the initial inoperable DG cannot be confirmed not to exist on the remaining DG(s), performance of SR 3.8.1.2 suffices to provide assurance of continued OPERABILITY of the DG(s).In the event the inoperable DG is restoredto OPERABLE status prior to completing either E.4.1 or E.4.2, the problem investigation process will continue to evaluate the common cause possibility. This continued evaluation, however, is no longer under the 24 hour constraint imposed while in Condition E.According to Generic Letter 84-15 (Ref. 8), 24 hours is reasonableto confirm that the OPERABLE DG(s) is not affected by the same problem as the inoperable DG.E.5Consistent with the time provided in ACTION B, operation may continue in Condition E for a period that should not exceed 14 days. In Condition E, the remaining OPERABLE DGs, available ESPS and offsite power circuits are adequate to supply electrical power to the Class 1E Distribution System.If the LCO 3.8.1.d DG cannot be restored to OPERABLE status within 14 Catawba Units 1 and 2B 3.8.1-16Revision No. 6days, then the NSWS, CRAVS, CRACWS and ABFVES components associated with this DG must be declared inoperable. The Actions associated with the NSWS, CRAVS, CRACWS and ABFVES will ensure the appropriate actions are taken.The 14 day Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, andthe low probability of a DBA occurring during this period.F.1.1 and F.1.2In Condition F, with an additional safety-related DG inoperable or the ESPS unavailable, the remaining OPERABLE DG and qualified circuits are adequate to supply electrical power to the onsite Class 1E Distribution System. According to Regulatory Guide 1.93 (Ref. 7), operation may continue in Condition F for a period that should not exceed 72 hours. The 72 hour Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs,and the low probability of a DBA occurring during this period.F.1.3If the LCO 3.8.1.d DG cannot be restored to OPERABLE status within 72 hours, then the NSWS, CRAVS, CRACWS and ABFVES components associated with this DG must be declared inoperable. The Required Actions associated with the NSWS, CRAVS, CRACWS and ABFVES will ensure that the appropriate actions are taken.The 72 hour Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, andthe low probability of a DBA occurring during this period.CG.1 and CG.2Condition G is entered when both offsite circuits required by LCO3.8.1.a are inoperable, or when the offsite circuit required by LCO 3.8.1.c and one offsite circuit required by LCO 3.8.1.a are concurrently inoperable, if the LCO 3.8.1.a offsite circuit is credited with providing power to the NSWS, CRAVS, CRACWS and ABFVES.Required ActionCG.1, which applies when two offsite circuits are inoperable, is intended to provide assurance that an event with a coincident single failure will not result in a complete loss of redundant required safety functions. The Completion Time for this failure of redundant required features is reduced to 12hours from that allowed for one train without offsite power (Required ActionA.2). The rationale for the reduction to 12hours is that Regulatory Guide1.93 (Ref.7) allows a CompletionTime of 24hours for two required offsite circuits inoperable, based upon the assumption that two complete safety trains are OPERABLE. When a concurrent redundant required feature failure exists, this assumption is not the case, and a shorter Completion Time of Catawba Units 1 and 2B 3.8.1-17Revision No. 612hours is appropriate. These features are powered from redundant AC safety trains. This includes motor driven auxiliary feedwater pumps.
Single train features, such as turbine driven auxiliary pumps, are not included in the list.The Completion Time for Required ActionCG.1 is intended to allow the operator time to evaluate and repair any discovered inoperabilities. This Completion Time also allows for an exception to the normal "time zero" for beginning the allowed outage time "clock."  In this Required Action the Completion Time only begins on discovery that both:a.All required offsite circuits are inoperable; andb.A required feature is inoperable.If at any time during the existence of ConditionCG(two LCO 3.8.1.a offsite circuits inoperableor one LCO 3.8.1.a offsite circuit that provides power to the NSWS, CRAVS, CRACWS and ABFVES inoperable and the required LCO 3.8.1.c offsite circuit inoperable) a required feature becomes inoperable, this Completion Time begins to be tracked.According to Regulatory Guide1.93 (Ref.7), operation may continue in ConditionCGfor a period that should not exceed 24hours. This level of degradation means that the offsite electrical power system does not have the capability to effect a safe shutdown and to mitigate the effects of an accident; however, the onsite AC sources have not been degraded. This level of degradation generally corresponds to a total loss of the immediately accessible offsite power sources.Because of the normally high availability of the offsite sources, this level of degradation may appear to be more severe than other combinations of two AC sources inoperable that involve one or more DGs inoperable.
However, two factors tend to decrease the severity of this level of degradation:a.The configuration of the redundant AC electrical power system that remains available is not susceptible to a single bus or switching failure; andb.The time required to detect and restore an unavailable offsite power source is generallymuch less than that required to detect and restore an unavailable onsite AC source.With both of the required offsite circuits inoperable, sufficient onsite AC sources are available to maintain the unit in a safe shutdown condition in the event of a DBAor transient. In fact, a simultaneous loss of offsite AC sources, a LOCA, and a worst case single failure were postulated as a part of the design basis in the safety analysis. Thus, the 24hour Completion Time provides a period of time to effect restoration of one of the offsite circuits commensurate with the importance of maintaining an AC electrical power system capable of meeting its design criteria.
Catawba Units 1 and 2B 3.8.1-18Revision No. 6According to Reference6, with the available offsite AC sources, two less than required by the LCO, operation may continue for 24hours. If two offsite sources are restored within 24hours, unrestricted operation may continue. If only one offsite source is restored within 24hours, power operation continues in accordance with ConditionAor D, as applicable.DH.1 and DH.2Pursuant to LCO3.0.6, the Distribution System ACTIONS would not be entered even if all AC sources to it were inoperable, resulting in de-energization. Therefore, the Required Actions of ConditionDHare modified by a Note to indicate that when ConditionDHis entered with no AC source to any train, the Conditions and Required Actions for LCO3.8.9, "Distribution Systems-Operating," must be immediately entered. This allows ConditionDHto provide requirements for the loss of one offsite circuit and one DG, without regard to whether a train is de-energized. LCO3.8.9 provides the appropriate restrictions for a de-energized train.According to Regulatory Guide1.93 (Ref.7), operation may continue in ConditionDHfor a period that should not exceed 12hours.In ConditionDH, individual redundancy is lost in both the offsite electrical power system and the onsite AC electrical power system. Since power system redundancy is provided by two diverse sources of power, however, the reliability of the power systems in this Condition may appear higher than that in ConditionCG(loss of both two required offsite circuits). This difference in reliability is offset by the susceptibility of this power system configuration to a single bus or switching failure. The 12hour Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.EI.1With TrainA and TrainBDGstwo LCO 3.8.1.b DGsinoperable, there are no remaining standby AC sourcesto provide power to most of the ESF systems.With one LCO 3.8.1.d DG inoperable and the LCO 3.8.1.b DG that provides power to the NSWS, CRAVS, CRACWS and ABFVES inoperable, there are no remaining standby AC sources to the NSWS, CRAVS, CRACWS and ABFVES. Thus, with an assumed loss of offsite electrical power, insufficient standby AC sources are available to power the minimum required ESF functions. Since the offsite electrical power system is the only source of AC power for this level of degradation, the risk associated with continued operation for a very short time could be less than that associated with an immediate controlled shutdown (the immediate shutdown could cause grid instability, which could result in a total loss of AC power). Since any inadvertent generator trip could also result in a total loss of offsite AC power, however, the time allowed for continued operation is severely restricted. The intent here is to avoidthe Catawba Units 1 and 2B 3.8.1-19Revision No. 6risk associated with an immediate controlled shutdown and to minimize the risk associated with this level of degradation.According to Reference7, with both LCO 3.8.1.b DGs inoperable,or with the LCO 3.8.1.b DG that provides power to the NSWS, CRAVS, CRACWS and ABFVES and the LCO 3.8.1.d DGinoperable,operation may continue for a period that should not exceed 2hours.FJ.1The sequencer(s) is an essential support system to both the offsite circuit and the DG associated with a given ESF bus. Furthermore, the sequencer is on the primary success path for most major AC electrically powered safety systems powered from the associated ESF bus.
Therefore, loss of an ESF bus sequencer affects every major ESF system in the train. When a sequencer is inoperable, its associated unit and train related offsite circuit and DG must also be declared inoperable and their corresponding Conditions must also be entered. The 12hour Completion Time provides a period of time to correct the problem commensurate with the importance of maintaining sequencer OPERABILITY. This time period also ensures that the probability of an accident (requiring sequencer OPERABILITY) occurring during periods when the sequencer is inoperable is minimal.GK.1 and GK.2If the inoperable AC electric power sources cannot be restored to OPERABLE status within the required Completion Time,If any Required Action and associated Completion Time of Conditions A, C, F, G, H, I, or J are not met,the unit must be brought to a MODE in which the LCO does not apply.Furthermore, if any Required Action and associated Completion Time of Required Actions B.2, B.3, B.4.1, B.4.2, B.6, E.2, E.3, E.4.1, E.4.2, or E.5 are not met, the unit must be brought to a MODE in which the LCO does not apply.To achieve this status, the unit must be brought to at least MODE3 within 6hours and to MODE5 within 36hours. The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging plant systems.HL.1ConditionHLcorresponds to a level of degradation in which all redundancy in the LCO 3.8.1.a and LCO 3.8.1.b AC electrical power supplies has been lost. At this severely degraded level, any further losses in the AC electrical power system will cause a loss of function.
Therefore, no additional time is justified for continued operation. The unit is required by LCO3.0.3 to commence a controlled shutdown.SURVEILLANCEThe AC sources are designed to permit inspection and testing of all Catawba Units 1 and 2B 3.8.1-20Revision No. 6REQUIREMENTSimportant areas and features, especially those that have a standby function, in accordance with 10CFR50, AppendixA, GDC18 (Ref.9). Periodic component tests are supplemented by extensive functional tests during refueling outages (under simulated accident conditions). The SRs for demonstrating the OPERABILITY of the DGs are in accordance with the recommendations of Regulatory Guide1.9 (Ref.3), Regulatory Guide1.108 (Ref.10), and Regulatory Guide1.137 (Ref.11), as addressed in the UFSAR.Where the SRs discussed herein specify voltage and frequency tolerances, the following is applicable. The minimum steady state output voltage of 3950V is 95% of the nominal 4160V output voltage. Thisvalue allows for voltage drop to the terminals of 4000V motors whose minimum operating voltage is specified as 90% or 3600V. It also allows for voltage drops to motors and other equipment down through the 120V level where minimum operating voltage isalso usually specified as 90%
of name plate rating.The specified maximum steady state output voltage of 4580 V is equal to the maximum operating voltage specified for 4000V motors. It ensures that for a lightly loaded distribution system, the voltageat the terminals of 4000V motors is no more than the maximum rated operating voltages.
The specified minimum and maximum frequencies of the DG are 58.8Hz and 61.2Hz, respectively. These values are equal to +/-2% of the 60Hz nominal frequency and are derived from the recommendations given in Regulatory Guide1.9 (Ref.3).The SRs are modified by a Note which states that SR 3.8.1.1 through SR3.8.1.20 are applicable to LCO 3.8.1.a and LCO 3.8.1.b AC sources. TheNote also states that SR 3.8.1.21 is applicable to LCO 3.8.1.c and LCO3.8.1.d AC sources. This Note clarifies that not all of the SRs areapplicable to all the components described in the LCO.
AC Sources-OperatingB 3.8.1BASESCatawba Units 1 and 2B 3.8.1-35Revision No. 6SURVEILLANCE REQUIREMENTS  (continued)allow portions of the Surveillance to be performed for the purpose of reestablishing OPERABILITY (e.g. post work testing following corrective maintenance, corrective modification, deficient or incomplete surveillance testing, and other unanticipated OPERABILITY concerns)provided an assessment determines plant safety is maintained or enhanced. This assessment shall, at a minimum, consider the potential outcomes and transients associated with a failed partial Surveillance, a successful partial Surveillance, and a perturbation of the offsite or onsite system when they are tied together or operated independently for the partial Surveillance; as well as the operator procedures available to cope with these outcomes. These shall be measured against the avoided riskof a plant shutdown and startup to determine that plant safety is maintained or enhanced when portions of  the Surveillance are performed in MODE 1, 2, 3, or 4. Risk insights or deterministic methods may be used for this assessment. Credit may be taken for unplanned events that satisfy this SR.SR3.8.1.20This Surveillance demonstrates that the DG starting independence has not been compromised. Also, this Surveillance demonstrates that each engine can achieve proper speed within the specified time when the DGs are started simultaneously.The Surveillance Frequency is based on operating experience, equipment reliability, and plant risk and is controlled under the Surveillance Frequency Control Program.This SR is modified by a Note. The reason for the Note is to minimize wear on the DG during testing. For the purpose of this testing, the DGs must be started from standby conditions, that is, with the engine coolant and oil continuously circulated and temperature maintained consistent with manufacturer recommendations.SR 3.8.1.21This SR lists the SRs that are applicable to LCO 3.8.1.c and LCO 3.8.1.d (SRs 3.8.1.1, 3.8.1.2, 3.8.1.4, 3.8.1.5 and 3.8.1.6). Meeting any single SR for LCO 3.8.1.c and LCO 3.8.1.d will satisfy both Unit 1 and Unit 2 requirements for that SR.
AC Sources-OperatingB 3.8.1BASESCatawba Units 1 and 2B 3.8.1-36Revision No.6REFERENCES1.10CFR50, AppendixA, GDC17.2.UFSAR, Chapter8.3.Regulatory Guide1.9, Rev.2, December 1979.
4.UFSAR, Chapter6.5.UFSAR, Chapter15.
6.10 CFR 50.36, Technical Specifications, (c)(2)(ii).7.Regulatory Guide1.93, Rev.0, December1974.
8.Generic Letter84-15, "Proposed Staff Actions toImprove and Maintain Diesel Generator Reliability," July2,1984.9.10CFR50, AppendixA, GDC18.
10.Regulatory Guide1.108, Rev.1, August1977 (Supplement September 1977).11.Regulatory Guide1.137, Rev.1, October 1979.
12.ASME, Boiler and Pressure Vessel Code, SectionXI.
13.Response to a Request for Additional Information (RAI) concerning the June 5, 2006 License Amendment Request (LAR) Applicable to Technical Specification (TS) 3.8.1, "AC Sources-Operating,"
Surveillance Requirement (SR) 3.8.1.13, (TAC NOS. MD3217, MD3218, MD3219, and MD3220), April 4, 2007.14.Branch Technical Position 8-8, February 2012. toRA-17-0051Attachment 4Revised McGuireTechnical Specification Bases Marked Up Pages(For Information Only)
McGuire Units 1 and 2B 3.8.1-1                            Revision No. 115AC Sources-OperatingB 3.8.1B 3.8  ELECTRICAL POWER SYSTEMSB 3.8.1  AC Sources-OperatingBASESBACKGROUNDThe unit Essential Auxiliary or Class1E AC Electrical Power Distribution System AC sources consist of the offsite power sources (preferred power sources, normal and alternate(s)), and the onsite standby power sources (TrainA and TrainB diesel generators (DGs)). As required by 10CFR50, AppendixA, GDC17 (Ref.1), the design of the AC electrical power system provides independence and redundancy to ensure an available source of power to the Engineered Safety Feature (ESF) systems.The onsite Class1E AC Distribution System is divided into redundant load groups (trains) so that the loss of any one group does not prevent the minimum safety functions from being performed. Each train has connections to two preferred offsite power sources and a single DG.At the 600V level of the onsite Class 1E AC Distribution System, there are two motor control centers (MCC) per train(for a total of four MCCs) that supply alloftheshared systemson both units.The MCCs 1EMXG and 1EMXH supply Train A shared systems. The MCCs 2EMXG and 2EMXH supply Train B shared systems. The term shared systems is defined as the shared components of Train A or Train B of Nuclear Service Water System (NSWS), Control Room Area Ventilation System (CRAVS), Control Room Area Chilled Water System (CRACWS)and Auxiliary Building Filtered Ventilation Exhaust System (ABFVES). The MCCs 1EMXG and 1EMXH are normally aligned to receive power from load centers1ELXA(1EMXH) and 1ELXC (1EMXG)but if desired or required to maintain operability of the Train A shared systems, can be swapped to receive power from load centers2ELXA(1EMXH) and 2ELXC (1EMXG). The MCCs 2EMXG and 2EMXH are normally aligned to receive power from load centers2ELXB(2EMXH) and 2ELXD (2EMXG)but if desired or required to maintain operability of the Train B shared systems, can be swapped to receive power from load centers1ELXB(2EMXH) and 1ELXD (2EMXG).There arealso provisions to accommodate the connecting of the Emergency Supplemental Power Source (ESPS) to one train of either unit's Class 1E AC Distribution System. The ESPS consists of two 50% capacity non-safety related commercial grade DGs. Manual actions are required to align the ESPS to the station and only one of the station's four onsite Class 1E Distribution System trains can be supplied by the ESPS at any given time. The ESPS is made available to support extended Completion Times in the event of an inoperable DG as well as a defense-in-depth source of AC power McGuire Units 1 and 2B 3.8.1-2                            Revision No. 115BACKGROUND  (continued)to mitigate a station blackout event. The ESPS would remain disconnected from the Class 1E AC Distribution System unless required for supplemental power to one of the four 4.16kV ESF buses.Offsite power is supplied to the unit switchyard(s) from the transmission network by two transmission lines. From the switchyard(s), two electrically and physically separated circuits provide AC power, through step down station auxiliary transformers, to the 4.16kV ESF buses. A detailed description of the offsite power network and the circuits to the Class1E ESF buses is found in the UFSAR, Chapter8 (Ref.2).A qualified offsite circuit consists of all breakers, transformers, switches, interrupting devices, cabling, and controls required to transmit power from the offsite transmission network to the onsite Class1E ESF bus(es).The offsite transmission systems normally supply their respective unit's onsite power supply requirements. However, in the event that one or both buslines of a unit become unavailable, or by operational desire, it is acceptable to supply that unit's offsite to onsite power requirements by aligning the affected 4160V bus of the opposite unit via the standby transformers, SATA and SATBin accordance with Regulatory Guides 1.6 and 1.81 (Ref. 12 and 13). In this alignment, each unit's offsite transmission system could simultaneously supply its own 4160V buses and one (or both) of the buses of the other unit.Although a single auxiliary transformer (1ATA, 1ATB, 2ATA, 2ATB) is sized to carry all of the auxiliary loads of its unit plus both trains of essential 4160V loads of the opposite unit, the LCO would not be met in this alignment due to separation criteria.
AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-3                            Revision No. 115BACKGROUND  (continued)Each unit's Train A and B 4160V bus must be derived from separate offsite buslinesqualified offsite circuits. The first offsite power supplyqualified offsite circuitcan be derived from any of the four buslines (1A, 1B, 2A, or 2B). The second offsite power supplyqualified offsite circuitmust not derive its power from the same busline qualified offsite circuit as the first.Additionally, the Train A and Train B Class 1E AC Distribution Systems providing power to the Train Aand Train B shared systems must not derive their power from the same qualified offsite circuit.Acceptable train and unit specific breaker alignment options are described below: Unit 1 A Train 1.BL1A-1ATA-1TA-1ATC-1ETA2.BL1B-1ATB-1TA-1ATC-1ETA3.BL1A-1ATA-1TC-SATA-1ETA 4.BL1B-1ATB-1TC-SATA-1ETA5.BL2A-2ATA-2TC-SATA-1ETA6.BL2B-2ATB-2TC-SATA-1ETAUnit 1 B Train 1.BL1B-1ATB-1TD-1ATD-1ETB2.BL1A-1ATA-1TD-1ATD-1ETB3.BL1B-1ATB-1TB-SATB-1ETB4.BL1A-1ATA-1TB-SATB-1ETB5.BL2B-2ATB-2TB-SATB-1ETB6.BL2A-2ATA-2TB-SATB-1ETBUnit2 A Train 1.BL2A-2ATA-2TA-2ATC-2ETA2.BL2B-2ATB-2TA-2ATC-2ETA3.BL2A-2ATA-2TC-SATA-2ETA4.BL2B-2ATB-2TC-SATA-2ETA5.BL1A-1ATA-1TC-SATA-2ETA6.BL1B-1ATB-1TC-SATA-2ETAUnit 2 B Train 1.BL2B-2ATB-2TD-2ATD-2ETB2.BL2A-2ATA-2TD-2ATD-2ETB3.BL2B-2ATB-2TB-SATB-2ETB 4.BL2A-2ATA-2TB-SATB-2ETB5.BL1B-1ATB-1TB-SATB-2ETB6.BL1A-1ATA-1TB-SATB-2ETB AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-4                            Revision No. 115BACKGROUND  (continued)Certain required unit loads are returned to service in a predetermined sequence in order to prevent overloading the transformer supplying offsite power to the onsite Class1E Distribution System. Typically (via accelerated sequencing), within 1 minute after the initiating signal is received, all loads needed to recover the unit or maintain it in a safe condition are returned to service.The onsite standby power source for each 4.16kV ESF bus is a dedicated DG. DGsA andB are dedicated to ESF busesETA andETB, respectively. A DG starts automatically on a safety injection (SI) signal (i.e., low pressurizer pressure or high containment pressure signals) or on an ESFbus degraded voltage or undervoltage signal (refer to LCO3.3.5, "Loss of Power (LOP) Diesel Generator (DG) Start Instrumentation"). After the DG has started, it will automatically tie to its respective bus after offsite power is tripped as a consequenceof ESF bus undervoltage or degraded voltage, independent of or coincident with an SI signal. The DGs will also start and operate in the standby mode without tying to the ESF bus on an SI signal alone. Following the trip of offsite power, a sequencer strips loads from the ESF bus. When the DG is tied to the ESF bus, loads are then sequentially connected to its respective ESF bus by the automatic load sequencer. The sequencing logic controls the permissive and starting signals to motor breakers to prevent overloading the DG by automatic load application.In the event of a loss of preferred power, the ESF electrical loads are automatically connected to the DGs in sufficient time to provide for safe reactor shutdown and to mitigate the consequences of a Design Basis Accident (DBA) such as a loss of coolant accident (LOCA).Certain required unit loads are returned to service in a predetermined sequence in order to prevent overloading the DG in the process. Typically (via accelerated sequencing), within 1 minute after the initiating signal is received, all loads needed to recover the unit or maintain it in a safe condition are returned to service.Ratings for TrainA and TrainB DGs satisfy the requirements of Regulatory Guide1.9 (Ref.3). The continuous service rating of each DG is 4000kW with 10% overload permissible for up to 2hours in any 24hour period. The ESF loads that are powered from the 4.16kV ESF buses are listed in Reference2.APPLICABLEThe initial conditions of DBA and transient analyses in the UFSAR, SAFETY ANALYSESChapter6 (Ref.4) and Chapter15 (Ref.5), assume ESF systems are OPERABLE. The AC electrical power sources are designed to provide sufficient capacity, capability, redundancy, and reliability to ensure the availabilityof necessary power to ESF systems so that the fuel, Reactor AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-5                            Revision No. 115APPLICABLE SAFETY ANALYSES (continued)Coolant System (RCS), and containment design limits are not exceeded. These limits are discussed in more detail in the Bases for Section3.2, Power Distribution Limits; Section3.4, Reactor Coolant System (RCS); and Section3.6, Containment Systems.The OPERABILITY of the AC electrical power sources is consistent with the initial assumptions of the Accident analyses and is based upon meeting the design basis of the unit. This results in maintaining at least one train of the onsite or offsite AC sources OPERABLE during Accident conditions in the event of:a.An assumed loss of all offsite power or all onsite AC power; and b.A worst case single failure.
The AC sources satisfy Criterion3 of 10 CFR 50.36 (Ref. 6).LCOTwo qualified circuits between the offsite transmission network and the onsite Class1E Electrical Power System and separate and independent DGs for each train ensure availability of the required power to shut down the reactor and maintain it in a safe shutdown condition after an anticipated operational occurrence (AOO) or a postulated DBA.Additionally, one qualified circuit between the offsite transmission network and the opposite unit onsite Essential Auxiliary Power System whennecessary to power shared systems and one opposite unit DG when necessary to power shared systems ensure availability of the requiredpower to shut down the reactor and maintain it in a safe shutdowncondition after an AOO or a postulated DBA.Qualified offsite circuits are those that are described in the UFSAR and are part of the licensing basis for the unit.In addition, one required automatic load sequencer per train must be OPERABLE.Each offsite circuit must be capable of maintaining rated frequency and voltage, and accepting required loads during an accident, while connected to the ESF buses.The 4.16 kV essential system is divided into two completely redundant and independent trains designated A and B, each consisting of one 4.16 kV switchgear assembly, two 4.16 kV/600 V load centers, and associated loads.
AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-6                            Revision No. 115LCO  (continued)Normally, each Class 1E 4.16 kV switchgear is powered from its associated non-Class 1E train of the 6.9 kV Normal Auxiliary Power System as discussed in "6.9 kV Normal Auxiliary Power System" in Chapter 8 of the UFSAR (Ref. 2). Additionally, an alternate source of power to each 4.16 kV essential switchgear is provided from the 6.9 kV system via a separate and independent 6.9/4.16 kV transformer. Two transformers are shared between units and provide the capability to supply an alternate source of power to each unit's 4.16 kV essential switchgear from either unit's 6.9 kV system. A key interlock scheme is provided to precludethe possibility of connecting the two units together at either the 6.9 or 4.16 kV level.Each train of the 4.16 kV Essential Auxiliary Power System is also provided with a separate and independent emergency diesel generator to supply the Class 1E loads required to safely shut down the unit following a design basis accident.Each DG must be capable of starting, accelerating to rated speed and voltage, and connecting to its respective ESF bus on detection of bus undervoltage. This will be accomplished within 11seconds. Each DG must also be capable of accepting required loads within the assumed loading sequence intervals, and continue to operate until offsite power can be restored to the ESF buses. These capabilities are required to be met from a variety of initial conditions such as DG in standby with the engine hot and DG in standby with the engine at ambient conditions. Additional DG capabilities must be demonstrated to meet required Surveillance, e.g., capability of the DG to revert to standby status on an ECCS signal while operating in parallel test mode. Proper sequencing of loads is a function of Sequencer OPERABILITY. Proper load shedding is a function of DG OPERABILITY. Proper tripping of non-essential loads is a function of AC Bus OPERABILITY (Condition A of Technical Specification 3.8.9).The AC sources in one train must be separate and independent (to the extent possible) of the AC sources in the other train. For the DGs, separation and independence are complete.LCO 3.8.1.c and LCO 3.8.1.d both use the word "necessary" to clarify when and how to apply these LCOs on a per unit basis. The word "necessary" clarifies that the qualified offsite circuit in LCO 3.8.1.c and the one DG from the opposite unit in LCO 3.8.1.d are aligned to the opposite unit Onsite Essential Auxiliary Power System that is supplying power to a train of shared systems.LCO 3.8.1.c specifies thatone qualified circuit between the offsite transmission network and the opposite unit's Onsite Essential Auxiliary Power System be OPERABLE when necessary to supply power to the AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-7                            Revision No. 115LCO  (continued)shared systems.LCO 3.8.1.d specifies thatone DG from the opposite unit be OPERABLE when necessary to supply power to the shared systems.The qualified circuit in LCO 3.8.1.c mustbe separate and independent (to the extent possible) of the qualified circuit which provides power to the other train of sharedsystems. These requirements, in conjunction with the requirements for the applicable unit AC electrical power sources in LCO 3.8.1.a and LCO 3.8.1.b, ensure that power is available to two trains of the shared NSWS, CRAVS, CRACWS and ABFVES.For example, with both units in MODE 1, the normal power alignment per plant procedures with no inoperable equipment is to have the Train A shared systems powered from Unit 1 (1EMXG and 1EMXH) and the Train B shared systems powered from Unit 2 (2EMXG and 2EMXH). In this normal alignment, Unit 1 LCO 3.8.1.c is met by an OPERABLE 2B offsite circuit and LCO 3.8.1.d is met by an OPERABLE 2B DG. Since the 2A offsite circuit and 2A DG are not necessary to supply power to a train of shared systems in the normal power alignment, they are not Unit 1 LCO 3.8.1.c and LCO 3.8.1.d AC sources for this example. For Unit 2, LCO 3.8.1.c is met by an OPERABLE 1A offsite circuit and LCO 3.8.1.d is met by an OPERABLE 1A DG.Since the 1B offsite circuit and 1B DG are not necessary to supply powerto a train of shared systems in the normal power alignment, they are not Unit 2 LCO 3.8.1.c and LCO 3.8.1.d AC sources for this example.Both normal and emergency power must be OPERABLE for a shared component to be OPERABLE. If normal or emergency power supplying a shared component becomes inoperable, then the Required Actions of the affected shared component LCO must be entered independently for each unit that is in the MODE of applicability of the shared componentLCO. The shared component LCOsare:3.7.7 -Nuclear Service Water System (NSWS),3.7.9 -Control Room Area Ventilation System (CRAVS),3.7.10 -Control Room Area Chilled Water System (CRACWS), and3.7.11 -Auxiliary Building Filtered Ventilation Exhaust System (ABFVES).
AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-8                            Revision No. 115APPLICABILITYThe AC sources and sequencers are required to be OPERABLE in MODES1, 2, 3, and4 to ensure that:a.Acceptable fuel design limits and reactor coolant pressure boundary limits are not exceeded as a result of AOOs or abnormal transients; andb.Adequate core cooling is provided and containment OPERABILITY and other vital functions are maintained in the event of a postulated DBA.A Note has been added taking exception to the Applicability requirementsfor the required AC sources in LCO 3.8.1.c and LCO 3.8.1.d provided theassociated shared systems are inoperable. This exception is intended to allow declaring the shared systems supported by the opposite unitinoperable either in lieu of declaring the opposite unit AC sources inoperable, or at any time subsequent to entering ACTIONS foran inoperable opposite unit AC source.This exception is acceptable since, with the shared systems supported bythe opposite unit inoperable and the associated ACTIONS entered, theopposite unit AC sources provide no additional assurance of meeting theabove criteria.The AC power requirements for MODES5 and6 are covered inLCO3.8.2, "AC Sources-Shutdown."ACTIONS A Note prohibits the application of LCO 3.0.4.b to an inoperable DG. There is an increased risk associated with entering a MODE or other specified condition in the Applicability with an inoperable DG and the provisions of LCO 3.0.4.b, which allow entry into a MODE or other specified condition in the Applicability with the LCO not met after performance of a risk assessment addressing inoperable systems and components, should not be applied in this circumstance.A.1To ensure a highly reliable power source remains with one LCO 3.8.1.a offsite circuit inoperable, it is necessary to verify the OPERABILITY of the remaining required offsite circuitson a more frequent basis. Since the Required Action only specifies "perform," a failure of SR3.8.1.1 acceptance criteria does not result in a Required Action not met. However, if a second required circuit fails SR3.8.1.1, the second offsite AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-9                            Revision No. 115ACTIONS  (continued)circuit is inoperable, and ConditionCG, for two offsite circuits inoperable, is entered.A.2Required ActionA.2, which only applies if the train cannot be powered from an offsite source, is intended to provide assurance that an event coincident with a single failure of the associated DG will not result in a complete loss of safety function of critical redundant required features. These features are powered from the redundant AC electrical power train. This includes motor driven auxiliary feedwater pumps. The turbine driven auxiliary feedwater pump is required to be considered a redundant required feature, and, therefore, required to be determined OPERABLE by this Required Action. Three independent AFW pumps are required to ensure the availability of decay heat removal capability for all events accompanied by a loss of offsite power and a single failure. System design is such that the remaining OPERABLE motor driven auxiliary feedwater pump is not by itself capable of providing 100% of the auxiliary feedwater flow assumed in the safety analysis.The Completion Time for Required ActionA.2 is intended to allow the operator time to evaluate and repair any discovered inoperabilities. This Completion Time also allows for an exception to the normal "time zero" for beginning the allowed outage time "clock."  In this Required Action, the Completion Time only begins on discovery that both:a.The train has no offsite power supplying its loads; andb.A required feature on the other train is inoperable.If at any time during the existence of ConditionA (one LCO 3.8.1.a offsite circuit inoperable) a redundant required feature subsequently becomes inoperable, this Completion Time begins to be tracked.Discovering no offsite power to onetrain of the onsite Class1E Electrical Power Distribution System coincident with one or more inoperable required support or supported features, or both, that are associated with the other train that has offsite power, results in starting the Completion Times for the Required Action. Twenty-four hours is acceptable because it minimizes risk while allowing time for restoration before subjecting the unit to transients associated with shutdown.The remaining OPERABLE offsite circuitsand DGs are adequate tosupply electrical power to TrainA and TrainB of the onsite Class1E Distribution System. The 24hour Completion Time takes into account the component OPERABILITY of the redundant counterpart to the inoperable required feature. Additionally, the 24hour Completion Time takes into account the AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-10                            Revision No. 115ACTIONS  (continued)capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.A.3According to Regulatory Guide1.93 (Ref.7), operation may continue in ConditionA for a period that should not exceed 72hours. With one offsite circuit inoperable, the reliability of the offsite system is degraded, and the potential for a loss of offsite power is increased, with attendantpotential for a challenge to the unit safety systems. In this Condition, however, the remaining OPERABLE offsite circuit and DGs are adequate to supply electrical power to the onsite Class1E Distribution System.The 72hour Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.The second Completion Time for Required ActionA.3 establishes a limit on the maximum time allowed for any combination of required AC power sources to be inoperable during any single contiguous occurrence of failing to meet the LCOLCO 3.8.1.a or LCO 3.8.1.b. If ConditionA is entered while, for instance, a LCO 3.8.1.b DG is inoperable and that DG is subsequently returned OPERABLE, the LCO may already have been not met for up to 72hours14 days. This could lead to a total of 144hours17 days, since initial failure to meet the LCOLCO 3.8.1.a or LCO 3.8.1.b, to restore the offsite circuit. At this time, a DG could again become inoperable, the circuit restored OPERABLE, and an additional 72hours14 days(for a total of 931days) allowed prior to complete restoration of the LCOLCOs 3.8.1.a and 3.8.1.b. The 617day Completion Time provides a limit on the time allowed in a specified condition after discovery of failure to meet the LCOLCO 3.8.1.a or LCO 3.8.1.b. This limit is considered reasonable for situations in which ConditionsA andB are entered concurrently. The "AND" connector between the 72hourand 617day Completion Times means that both Completion Times apply simultaneously, and the more restrictive Completion Time must be met.As in Required ActionA.2, the Completion Time allows for an exception to the normal "time zero" for beginning the allowed outage time "clock."
This will result in establishing the "time zero" at the time that the LCOLCO 3.8.1.a or LCO 3.8.1.bwas initially not met, instead of at the time ConditionA was entered.B.1It is required to administratively verify the LCO3.8.1.d DG OPERABLEwithin onehour and to continue this action once per 12 hours thereafter AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-11                            Revision No. 115ACTIONS  (continued)until restoration of the required LCO 3.8.1.b DG is accomplished. This verification provides assurance that the LCO 3.8.1.d DG is capable of supplying the onsite Class 1E AC Electrical Power Distribution System.B.12To ensure a highly reliable power source remains with an inoperable LCO 3.8.1.b DG, it is necessary to verify the availability of the required offsite circuits on a more frequent basis. Since the Required Action only specifies "perform," a failure of SR3.8.1.1 acceptance criteria does not result in a Required Action being not met. However, if a circuit fails to pass SR3.8.1.1, it is inoperable. Upon offsite circuit inoperability, additional Conditions and Required Actions must then be entered.B.23Required ActionB.23is intended to provide assurance that a loss of offsite power, during the period that a LCO 3.8.1.b DG is inoperable, does not result in a complete loss of safety function of critical systems. These features are designed with redundant safety related trains. This includes motor driven auxiliary feedwater pumps. The turbine driven auxiliary feedwater pump is required to be considered a redundant required feature, and, therefore, required to be determined OPERABLE by this Required Action. Three independent AFW pumps are required to ensure the availability of decay heat removal capability for all events accompanied by a loss of offsite power and a single failure. System design is such that the remaining OPERABLE motor driven auxiliary feedwater pump is not by itself capable of providing 100% of the auxiliary feedwater flow assumed in the safety analysis. Redundant required feature failures consist of inoperable features associated with a train, redundant to the train that has an inoperable LCO 3.8.1.b DG.The Completion Time for Required ActionB.23is intended to allow the operator time to evaluate and repair any discovered inoperabilities. This Completion Time also allows for an exception to the normal "time zero" for beginning the allowed outage time "clock."  In this Required Action, the Completion Time only begins on discovery that both:a.An inoperable LCO 3.8.1.b DG exists; andb.A requiredfeature on the other train (TrainA or TrainB) is inoperable.
AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-12                            Revision No. 115ACTIONS  (continued)If at any time during the existence of this Condition (one LCO 3.8.1.b DG inoperable) a required feature subsequently becomes inoperable, this Completion Time would begin to be tracked.Discovering one required LCO 3.8.1.b DG inoperable coincident with one or more inoperable required support or supported features, or both, that are associated with the OPERABLE DG, results in starting the Completion Time for the Required Action. Four hours from the discovery of these events existing concurrently is Acceptable because it minimizes risk while allowing time for restoration before subjecting the unit to transients associated with shutdown.In this Condition, the remaining OPERABLE DGsand offsite circuits are adequate to supply electrical power to the onsite Class1E Distribution System. Thus, on a component basis, single failure protection for the required feature's function may have been lost; however, function has not been lost. The 4hour Completion Time takes into account the OPERABILITY of the redundant counterpart to the inoperable required feature. Additionally, the 4hour Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.B.34.1 and B.34.2Required ActionB.34.1 provides an allowance to avoid unnecessary testing of OPERABLE DG(s). If it can be determined that the cause of the inoperable DG does not exist on the OPERABLE DG, SR3.8.1.2 does not have to be performed. If the cause of inoperability exists on other DG(s), the other DG(s) would be declared inoperable upon discovery and ConditionEand/or I of LCO3.8.1, as applicable,would be entered. Once the failure is repaired, the common cause failure no longer exists, and Required ActionB.34.1 is satisfied. If the cause of the initial inoperable DG cannot be confirmed not to exist on the remaining DG(s), performance of SR3.8.1.2 suffices to provide assurance of continued OPERABILITY of that DG.In the event the inoperable DG is restored to OPERABLE status prior to completing either B.34.1 or B.34.2, the problem investigation process will continue to evaluate the common cause possibility. This continued evaluation, however, is no longer under the 24 hour constraint imposed while in Condition B. These Conditions are not required to be entered if the inoperability of the DG is due to an inoperable support system, an independently testable component, or preplanned testing or maintenance. If required, these AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-13                            Revision No. 115ACTIONS  (continued)Required Actions are to be completed regardless of when the inoperable DG is restored to OPERABLE status.According to Generic Letter84-15 (Ref.8), 24hours is reasonable to confirm that the OPERABLE DG(s) is not affected by the same problem as the inoperable DG.B.5In order to extend the Completion Time for an inoperable DG from 72 hours to 14 days, it is necessary to ensure the availability of the ESPS prior to entering the extended Completion Time of Required Action B.6 (i.e., 14 days) and every 12 hours thereafter. The "extended Completion Time of ACTION B.6" is defined as 14 days. ESPS availability requires that:1) The load test has been performed within 30 days of entry into the extended Completion Time. The Required Action evaluation is met with an administrative verification of this prior to testing; and2) ESPS fuel tank level is verified locally to be 24 hour supply; and3) ESPS supporting system parameters for starting and operating are verified to be within required limits for functional availability (e.g., battery state of charge).On discovery of an unavailable ESPS, the Completion Time for Required Action B.6 starts the 72 hour or 24 hour clock.The ESPS is not used to extend the Completion Time for more than one inoperable DG at any one time.B.46According to Regulatory Guide1.93 (Ref.7), operation may continue in ConditionB for a period that should not exceed 72hours.In accordance with Branch Technical Position 8-8 (Ref.14), operation may continue in Condition B for a period that should not exceed 14 days, provided a supplemental AC power source is available.In ConditionB, the remaining OPERABLE DGs, available ESPSandoffsite circuits are adequate to supply electrical power to the onsite Class1E Distribution System. The 72hour14 dayCompletion Time takes into account the capacity and capability of the remaining AC sources, a AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-14                            Revision No. 115ACTIONS  (continued)reasonable time for repairs, and the low probability of a DBA occurring during this period.If the ESPS is or becomes unavailable with an inoperable LCO 3.8.1.b DG, then action is required to restore the ESPS to available status or to restore the DG to OPERABLE status within 72 hours from discovery of an unavailable ESPS. However, if the ESPS unavailability occurs sometimeafter 72 hours of continuous DG inoperability (i.e., after entering the extended Completion Time for an inoperable DG), then the remaining time to restore the ESPS to available status or to restore the DG to OPERABLE status is limited to 24 hours.The 72 hour and 24 hour Completion Times allow for an exception to the normal "time zero" for beginning the allowed outage time "clock."  The 72 hour Completion Time only begins on discovery that both an inoperableDG exists and the ESPS is unavailable. The 24 hour Completion Time only begins if the extended Completion Time for the inoperable DG has been entered and the ESPS is unavailable.Therefore, when one LCO 3.8.1.b DG is inoperable due to either preplanned maintenance (preventive or corrective) or unplanned corrective maintenance work, the Completion Time can be extended from 72 hours to 14 days if it is ensured that ESPS is available for backup operation.The second fourth Completion Time for Required ActionB.46establishes a limit on the maximum time allowed for any combination of required AC power sources to be inoperable during any single contiguous occurrence of failing to meet the LCOLCO 3.8.1.a or LCO 3.8.1.b. If ConditionB is entered while, for instance, an a LCO 3.8.1.a offsite circuit is inoperable and that circuit is subsequently restored OPERABLE, the LCO may already have been not met for up to 72hours. This could lead to a total of 144hours17 days, since initial failure to meet the LCOLCO 3.8.1.a or LCO 3.8.1.b, to restore the DG. At this time, an a LCO 3.8.1.a offsite circuit could again become inoperable, the DG restored OPERABLE, and an additional 72hours (for a total of 920days) allowed prior to complete restoration of the LCOLCO 3.8.1.a and LCO 3.8.1.b. The 617day Completion Time provides a limit on time allowed in a specified condition after discovery of failure to meet the LCOLCO 3.8.1.a or LCO 3.8.1.b.This limit is considered reasonable for situations in which ConditionsAandB are entered concurrently. The "AND" connector between the 72hour14 dayand617day Completion Times means that both Completion Times apply simultaneously, and the more restrictive Completion Time must be met.As in Required ActionB.23, the Completion Time allows for an exception to the normal "time zero" for beginning the allowed time "clock."  This will AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-15                            Revision No. 115ACTIONS  (continued)result in establishing the"time zero" at the time that the LCOLCO 3.8.1.a or LCO 3.8.1.bwas initially not met, instead of at the time ConditionBwas entered.C.1.1 and C.1.2In Condition C with a LCO 3.8.1.d DG inoperable, the remaining OPERABLE unit-specific DG and required qualified circuits are adequate to supply electrical power to the onsite Class 1E Distribution System. According to Regulatory Guide 1.93 (Ref. 7), operation may continue in Condition C for a period that should not exceed 72 hours. The 72 hour Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs and the low probability of a DBA occurring during this period.D.1Pursuant to LCO 3.0.6, the Distribution System ACTIONS would not be entered even if all AC sources to it were inoperable, resulting in de-energization. Therefore, the Required Actions of Condition D are modified by a Note to indicate that when Condition D is entered with no AC source to any train, the Conditions and Required Actions for LCO 3.8.9 must be immediately entered. This allows Condition D to provide requirements for the loss of a LCO 3.8.1.c offsite circuit and LCO 3.8.1.d DG without regard to whether a train is de-energized. Limiting Condition for Operation 3.8.9 provides the appropriate restrictions for a de-energized train.To ensure a highly reliable power source remains with the one required LCO 3.8.1.c offsite circuit inoperable, it is necessary to verify the OPERABILITY of the remaining required offsite circuitson a more frequent basis. Since the Required Action only specifies "perform," a failure of SR 3.8.1.1 acceptance criteria does not result in a Required Action not met. However, if a second required circuit fails SR 3.8.1.1, the second offsite circuit isinoperable, and Condition A and G, as applicable, for the two offsite circuits inoperable, is entered.D.2Required Action D.2, which only applies if the train cannot be powered from an offsite source, is intended to provide assurance that an event coincident with a single failure of the associated DG will not result in a complete loss of safety function for the NSWS, CRAVS, CRACWS or the ABFVES.The Completion Time for Required Action D.2 is intended to allow the operator time to evaluate and repair any discovered inoperabilities. This Completion Time also allows for an exception to the AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-16                            Revision No. 115ACTIONS  (continued)normal "time zero" for beginning the allowed outage time "clock."  In this Required Action, the Completion Time only begins on discovery that both:a.The train has nooffsite power supplying its loads; andb.NSWS, CRAVS, CRACWS or ABFVES on the other train that has offsite power is inoperable.If at any time during the existence of Condition D (one required LCO 3.8.1.c offsite circuit inoperable) a train of NSWS, CRAVS, CRACWS or ABFVES becomes inoperable, this Completion Time begins to be tracked.Discovering no offsite power to one train of the onsite Class 1E Electrical Power Distribution System coincident with onetrain of NSWS, CRAVS, CRACWS or ABFVES that is associated with the other train that has offsite power, results in starting the Completion Time for the Required Action.Twenty-four hours is acceptable because it minimizesrisk while allowing time for restoration before subjectingthe unit to transients associated with shutdown.The remaining OPERABLE offsite circuits and DGs are adequate to supply electrical power to Train A and Train B of the onsite Class 1E Distribution System. The 24 hour Completion Time takes into account thecomponent OPERABILITY of the redundant counterpart to the inoperable NSWS, CRAVS, CRACWS or ABFVES. Additionally, the 24 hour Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.D.3Consistent with the time provided in ACTION A, operation may continue in Condition D for a period that should not exceed 72 hours. With one required LCO 3.8.1.c offsite circuit inoperable, the reliability of the offsite system is degraded, and the potential for a loss of offsite power is increased, with attendant potential for a challenge to the unit safety systems. In this Condition, however, the remaining OPERABLE offsite circuits and DGs are adequate to supply electrical power to the onsite Class 1E Distribution System.If the LCO 3.8.1.c required offsite circuit cannot be restored to OPERABLE status within 72 hours, the NSWS, CRAVS, CRACWS and ABFVES components associated with the offsite circuit must be declared inoperable. The ACTIONS associated with the NSWS, CRAVS, CRACWS and ABFVES will ensure the appropriate actions are taken. The 72 hour Completion Time takes into account the capacity and AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-17                            Revision No. 115ACTIONS  (continued)capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.E.1Pursuant to LCO 3.0.6, the Distribution System ACTIONS would not be entered even if all AC sources to it were inoperable, resulting inde-energization. Therefore, the Required Actions of Condition E are modified by a Note to indicate that when Condition E is entered with no AC source to any train, the Conditions and Required Actions for LCO 3.8.9 must be immediately entered. This allows Condition E to provide requirements for the loss of the LCO 3.8.1.c offsite circuit and LCO 3.8.1.d DG without regard to whether a train is de-energized. Limiting Condition for Operation 3.8.9 provides the appropriate restrictions for a de-energized train.The 14 day Completion Time for Required Action E.5 is based on the OPERABILITY of both LCO 3.8.1.b safety-related DGs and the availability of the ESPS. The ESPS is available to power the inoperable DG bus loads in the event of a station blackout or loss of offsite power event. It is required to administratively verify the LCO 3.8.1.b safety-related DGs OPERABLE and the ESPS available within one hour and to continue this action once per 12 hours thereafter until restoration of the required DG is accomplished. This verification provides assurance that the LCO 3.8.1.b safety-related DGs and the ESPS are capable of supplying the onsite Class 1E AC Electrical Power Distribution System.E.2To ensure a highly reliable power source remains with the one required LCO 3.8.1.d DG inoperable, it is necessary to verify the OPERABILITY of the required offsite circuits on a more frequent basis. Since the Required Action only specifies "perform," a failure of SR 3.8.1.1 acceptance criteria does not result in a Required Action not met. However, if a circuit fails to pass SR 3.8.1.1, it is inoperable. Upon offsite circuit inoperability, additional Conditions and Required Actions must then be entered.E.3Required Action E.3 is intended to provide assurance that aloss of offsite power, during the period the LCO 3.8.1.d DG is inoperable, does not result in a complete loss of safety function for the NSWS, CRAVS, CRACWS or the ABFVES. The Completion Time is intended to allow the operator time to evaluate and repair any discovered inoperabilities. This Completion Time also allows for exception to the normal "time zero" for beginning the allowed outage time "clock."  In this Required Action, the Completion Time only begins on discovery that both:
AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-18                            Revision No. 115ACTIONS  (continued)a.An inoperable LCO 3.8.1.d DG exists; andb.NSWS, CRAVS, CRACWS or ABFVES on the other train that has emergency power is inoperable.If at any time during the existence of this Condition (the LCO 3.8.1.d DG inoperable) a train of NSWS, CRAVS, CRACWS or ABFVES becomes inoperable, this Completion Time begins to be tracked.Discovering the LCO 3.8.1.d DG inoperable coincident with one train of NSWS, CRAVS, CRACWS or ABFVES that is associated with the other train that has emergency power results in starting the Completion Time for the Required Action. Four hours from the discovery of these events existing concurrently is acceptable because it minimizes risk while allowing time for restoration before subjecting the unit to transients associated with shutdown.In this Condition, the remaining OPERABLE DGs and offsite circuits are adequate to supply electrical power to the onsite Class 1E Distribution System. Thus, on a component basis, single failure protection for the NSWS, CRAVS, CRACWS or ABFVES may have been lost; however, function has not been lost. The four hour Completion Time also takes into account the capacity and capability of the remaining NSWS, CRAVS, CRACWS andABFVEStrain, a reasonable time for repairs, and the low probability of a DBA occurring during this period.E.4.1 and E.4.2Required Action E.4.1 provides an allowance to avoid unnecessary testing of OPERABLE DGs. If it can be determined that the cause of the inoperable DG does not exist on the OPERABLE DG(s), SR 3.8.1.2 does not have to be performed. If the cause of inoperability exists on other DG(s), the other DG(s) would be declared inoperable upon discovery and Condition B and I of LCO 3.8.1, as applicable, would be entered. Once the failure is repaired, the common cause failure no longer exists and Required Action E.4.1 is satisfied. If the cause of the initial inoperable DG cannot be confirmed not to exist on the remaining DG(s), performance of SR 3.8.1.2 suffices to provide assurance of continued OPERABILITY of the DG(s).In the event the inoperable DG is restored to OPERABLE status prior to completing either E.4.1 or E.4.2, the problem investigation process will continue to evaluate the common cause possibility. This continued evaluation, however, is no longer under the 24 hour constraint imposed while in Condition E.
AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-19                            Revision No. 115ACTIONS  (continued)According to Generic Letter 84-15 (Ref. 8), 24 hours is reasonable to confirm that the OPERABLE DG(s) is not affected by the same problem as the inoperable DG.E.5Consistent with the time provided in ACTION B, operation may continue in Condition E for a period that should not exceed 14 days. In Condition E, the remaining OPERABLE DGs, available ESPS and offsite power circuitsare adequate to supply electrical power to the Class 1E Distribution System.If the LCO 3.8.1.d DG cannot be restored to OPERABLE status within 14 days, then the NSWS, CRAVS, CRACWS and ABFVES components associated with this DG must be declared inoperable. The Actions associated with the NSWS, CRAVS, CRACWS and ABFVES will ensure the appropriate actions are taken.The 14 day Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.F.1.1 and F.1.2In Condition F, with an additional LCO 3.8.1.b safety-related DG inoperable or the ESPS unavailable, the remaining OPERABLE LCO 3.8.1.b DG and qualified circuits are adequate to supply electrical power to the onsite Class 1E Distribution System. According to Regulatory Guide 1.93 (Ref. 7), operation may continue in Condition F for a period that should not exceed 72 hours. The 72 hour Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.F.1.3If the LCO 3.8.1.d DG cannot be restored to OPERABLE status within 72 hours, then the NSWS, CRAVS, CRACWS and ABFVES components associated with this DG must be declared inoperable. The Required Actions associated with the NSWS, CRAVS, CRACWS and ABFVES will ensure that the appropriate actions are taken.The 72 hour Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.
AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-20                            Revision No. 115ACTIONS  (continued)CG.1 and CG.2Condition G is entered when both offsite circuits required by LCO 3.8.1.a are inoperable, or when the offsite circuit required by LCO 3.8.1.c and one offsite circuit required by LCO 3.8.1.a are concurrently inoperable, if the LCO 3.8.1.a offsite circuit is credited with providing power to the NSWS, CRAVS, CRACWS and ABFVES.Required ActionCG.1, which applies when two offsite circuits areinoperable, is intended to provide assurance that an event with a coincident single failure will not result in a complete loss of redundant required safety functions. The Completion Time for this failure of redundant required features is reduced to 12hours from that allowed for one train without offsite power (Required ActionA.2). The rationale for the reduction to 12hours is that Regulatory Guide1.93 (Ref.7) allows a Completion Time of 24hours for two required offsite circuits inoperable, basedupon the assumption that two complete safety trains are OPERABLE. When a concurrent redundant required feature failure exists, this assumption is not the case, and a shorter Completion Time of 12hours is appropriate. These features are powered from redundant AC safety trains. This includes motor driven auxiliary feedwater pumps. Single train features, such as turbine driven auxiliary pumps, are not included in the list.The Completion Time for Required ActionCG.1 is intended to allow the operator time to evaluate and repair any discovered inoperabilities. This Completion Time also allows for an exception to the normal "time zero" for beginning the allowed outage time "clock."  In this Required Action the Completion Time only begins on discovery thatboth:a.All required offsite circuits are inoperable; and b.A required feature is inoperable.If at any time during the existence of ConditionCG(two LCO 3.8.1.a offsite circuits inoperableor one LCO 3.8.1.a offsite circuit that provides power to the NSWS, CRAVS, CRACWS and ABFVES inoperable and the required LCO 3.8.1.c offsite circuit inoperable) a required feature becomes inoperable, this Completion Time begins to be tracked.According to Regulatory Guide1.93 (Ref.7), operation may continue in ConditionCGfor a period that should not exceed 24hours. This level of degradation means that the offsite electrical power system does not have the capability to effect a safe shutdown and to mitigate the effects of an accident; however, the onsite AC sources have not been degraded. This level of degradation generally corresponds to a total loss of the immediately accessible offsite power sources.
AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-21                            Revision No. 115ACTIONS  (continued)Because of the normally high availability of the offsite sources, this level of degradation may appear to be more severe than other combinations of two AC sources inoperable that involve one or more DGs inoperable. However, two factors tend to decrease the severity of this level of degradation:a.The configuration of the redundant AC electrical power system that remains available is not susceptible to a single bus or switching failure; andb.The time required to detect and restore an unavailable offsite power source is generally much less than that required to detect and restore an unavailable onsite AC source.With both of the required offsite circuits inoperable, sufficient onsite AC sources are available to maintain the unit in a safe shutdown condition in the event of a DBA or transient. In fact, a simultaneous loss of offsite ACsources, a LOCA, and a worst case single failure were postulated as a part of the design basis in the safety analysis. Thus, the 24hour Completion Time provides a period of time to effect restoration of one of the offsite circuits commensurate with theimportance of maintaining an AC electrical power system capable of meeting its design criteria.According to Reference6, with the available offsite AC sources, two less than required by the LCO, operation may continue for 24hours. If two offsite sources are restored within 24hours, unrestricted operation may continue. If only one offsite source is restored within 24hours, power operation continues in accordance with ConditionAor D, as applicable.DH.1 and DH.2Pursuant to LCO3.0.6, the Distribution System ACTIONS would not be entered even if all AC sources to it were inoperable, resulting in de-energization. Therefore, the Required Actions of ConditionDHare modified by a Note to indicate that when ConditionDHis entered with no AC source to any train, the Conditions and Required Actions for LCO3.8.9, "Distribution Systems-Operating," must be immediately entered. This allows ConditionDHto provide requirements for the loss of one offsite circuit and one DG, without regard to whether a train is de-energized. LCO3.8.9 provides the appropriate restrictions for a de-energized train.According to Regulatory Guide1.93 (Ref.7), operation may continue in ConditionDHfor a period that should not exceed 12hours.
AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-22                            Revision No. 115ACTIONS  (continued)In ConditionDH, individual redundancy is lost in both the offsite electrical power system and the onsite AC electrical power system. Since power system redundancy is provided by two diverse sources of power, however, the reliability of the power systems in this Condition may appear higher than that in Condition CG(loss of both two required offsite circuits). This difference in reliability is offset by the susceptibility of this power system configuration to a single bus or switching failure. The 12hour Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.EI.1With TrainA and TrainB DGstwo LCO 3.8.1.b DGsinoperable, there are no remaining standby AC sourcesto provide power to most of the ESF systems.With one LCO 3.8.1.d DG inoperable and the LCO 3.8.1.b DG that provides power to the NSWS, CRAVS, CRACWS and ABFVES inoperable, there are no remaining standby AC sourcesto the NSWS, CRAVS, CRACWS and ABFVES. Thus, with an assumed loss of offsite electrical power, insufficient standby AC sources are available to power the minimum required ESF functions. Since the offsite electrical power system is the only source of AC power for this level of degradation, the risk associated with continued operation for a very short time could be less than that associated with an immediate controlled shutdown (the immediate shutdown could cause grid instability, which could result in a total loss of AC power). Since any inadvertent generator trip could also result in a total loss of offsite AC power, however, the time allowed for continued operation is severely restricted. The intent here is to avoid the risk associated with an immediate controlled shutdown and to minimize the risk associated with this level of degradation.According to Reference7, with both LCO 3.8.1.b DGs inoperable,or with the LCO 3.8.1.b DG that provides power to the NSWS, CRAVS, CRACWS and ABFVES and the LCO 3.8.1.d DG inoperable,operation may continue for a period that should not exceed 2hours.FJ.1The sequencer(s) is an essential support system to both the offsite circuit and the DG associated with a given ESF bus. Furthermore, the sequencer is on the primary success path for most major AC electrically powered safety systems powered from the associated ESF bus.
Therefore, loss of an ESF bus sequencer affects every major ESF system in the train. The 12hour Completion Time provides a period of time to correct the problem commensurate with the importance of maintaining AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-23                            Revision No. 115ACTIONS  (continued)sequencer OPERABILITY. This time period also ensures that the probability of an accident (requiring sequencer OPERABILITY) occurring during periods when the sequencer is inoperable is minimal.GK.1 and GK.2If the inoperable AC electric power sources cannot be restored to OPERABLE status within the required Completion Time,If any Required Action and associated Completion Time of Conditions A, C, F, G, H, I, or J are not met,the unit must be brought to a MODE in which the LCO does not apply. Furthermore, if any Required Action and associated Completion Time of Required Actions B.2, B.3, B.4.1, B.4.2, B.6, E.2, E.3, E.4.1, E.4.2, or E.5 are not met, the unit must be brought to a MODE in which the LCO does not apply. To achieve this status, the unit must be brought to at least MODE3 within 6hours and to MODE5 within 36hours. The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging plant systems.HL.1ConditionHLcorresponds to a level of degradation in which all redundancy in the LCO 3.8.1.a and LCO 3.8.1.b AC electrical power supplieshas been lost. At this severely degraded level, any further losses in the AC electrical power system will cause a loss of function. Therefore, no additional time is justified for continued operation. The unit is required by LCO3.0.3 to commence a controlled shutdown.
AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-24                            Revision No. 115SURVEILLANCEThe AC sources are designed to permit inspection and testing of all REQUIREMENTSimportant areas and features, especially those that have a standby function, in accordance with 10CFR50, AppendixA, GDC18 (Ref.9). Periodic component tests are supplemented by extensive functional tests during refueling outages (under simulated accident conditions). The SRs for demonstrating the OPERABILITY of the DGs are in accordance with the recommendations of Regulatory Guide1.9 (Ref.3) and Regulatory Guide1.137 (Ref.11), as addressed in the UFSAR.Since the McGuire DG manufacturer, Nordberg, is no longer in business, McGuire engineering is the designer of record. Therefore, the term "manufacturer's or vendor's recommendations"is taken to mean the recommendations as determined by McGuire engineering, with specific Nordberg input as it is available, that were intended for the DGs, taking into account the maintenance, operating history, and industry experience, when available. Where the SRs discussed herein specify voltage and frequency tolerances, the following is applicable. The minimum steady state output voltage of 3740V is 90% of the nominal 4160V output voltage. This value allows for voltage drop to the terminals of 4000V motors whose minimum operating voltage is specified as 90% or 3600V. It also allows for voltage drops to motors and other equipment down through the 120Vlevel where minimum operating voltage is also usually specified as 90%
of name plate rating. The specified maximum steady state output voltage of 4580 V is equal to the maximum operating voltage specified for 4000Vmotors. It ensures that for a lightly loaded distribution system, the voltage at the terminals of 4000V motors is no more than themaximum rated operating voltages. The specified minimum and maximum frequencies of the DG are 58.8Hz and 61.2Hz, respectively. These values are equal to 2% of the 60Hz nominal frequency and are derived from the recommendations given in Regulatory Guide1.9 (Ref.3).The SRs are modified by a Note which states that SR 3.8.1.1 through SR 3.8.1.20 are applicable to LCO 3.8.1.a and LCO 3.8.1.b AC sources. The Note also states that SR 3.8.1.21 is applicable to LCO 3.8.1.c and LCO 3.8.1.d AC sources. This Note clarifies that not all of the SRs are applicable to all the components described in the LCO.SR3.8.1.1This SR ensures proper circuit continuity for the offsite AC electrical power supply to the onsite distribution network and availability ofoffsite AC electrical power. The breaker alignment verifies that each breaker is in its correct position to ensure that distribution buses and loads are connected to their preferred power source, and that appropriate AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-37Revision No. 115SURVEILLANCE REQUIREMENTS  (continued)adequately shows the capability of the DG system to perform these functions is acceptable. This testing may include any series of sequential, overlapping, or total steps so that the entire connection and loading sequence is verified.The Surveillance Frequency is based on operating experience, equipment reliability, and plant risk and is controlled under the Surveillance Frequency Control Program.This SR is modified by two Notes. The reason for Note1 is to minimize wear and tear on the DGs during testing. For the purpose of this testing, the DGs must be started from standby conditions, that is, with the engine  coolant and oil continuously circulated and temperature maintained consistent with manufacturer recommendations for DGs. The reason for Note2 is that the performance of the Surveillance would remove a required offsite circuit from service, perturb the electrical distribution system, and challenge safety systems.SR3.8.1.20This Surveillance demonstrates that the DG starting independence has not been compromised. Also, this Surveillance demonstrates that each engine can achieve proper speed within the specified time when the DGs are started simultaneously.The Surveillance Frequency is based on operating experience, equipment reliability, and plant risk and is controlled under the Surveillance Frequency Control Program.This SR is modified by a Note. The reason for the Note is to minimize wear on the DG during testing. For the purpose of this testing, the DGs must be started from standby conditions, that is, with the engine coolant and oil continuously circulated and temperature maintained consistent with manufacturer recommendations.SR 3.8.1.21This SR lists the SRs that are applicable to LCO 3.8.1.c and LCO 3.8.1.d (SRs 3.8.1.1, 3.8.1.2, 3.8.1.4, 3.8.1.5 and 3.8.1.6). Meeting any single SR for LCO 3.8.1.c and LCO 3.8.1.d will satisfy both Unit 1 and Unit 2 requirements for that SR.____________________________________________________________________________
AC Sources-OperatingB 3.8.1BASESMcGuire Units 1 and 2B 3.8.1-38Revision No. 115REFERENCES1.10CFR50, AppendixA, GDC17.2.UFSAR, Chapter8.3.Regulatory Guide1.9, Rev.3, July 1993.
4.UFSAR, Chapter6.
5.UFSAR, Chapter15.
6.10 CFR 50.36, Technical Specifications, (c)(2)(ii).7.Regulatory Guide1.93, Rev.0, December1974.8.Generic Letter84-15, "Proposed Staff Actions to Improve and Maintain Diesel Generator Reliability," July2,1984.9.10CFR50, AppendixA, GDC18.10.Regulatory Guide1.137, Rev.1, October 1979.
11.IEEE Standard308-1971.
12.Regulatory Guide 1.6, Rev. 0, March 1971.
13.Regulatory Guide 1.8.1, Rev. 1, January 1975.14.Branch Technical Position 8-8, February 2012.
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