ML12080A202

Calculation OSC-9510, Revision 1, FMEA for Ssf 4.16kV Alternate Power Feed from Psw EC91876 (OD500928)

ML12080A202
Person / Time
Site:	Oconee
Issue date:	02/21/2012
From:	Hohenstein J Duke Energy Carolinas
To:	Office of Nuclear Reactor Regulation
References
OSC-9510, Rev 1
Download: ML12080A202 (18)

Text

Farm 101.1 (RO2-12'CERTIFICATION OF ENGINEERING CALCULATION Station and Unit Number: Oconee 1. 2. 3 and common Revision No.: I Title of Calculation:

FMEA for SSF 4.16kV Alternate Power Feed from PSW EC91876 (OD500928)

Calculation Number: OSC-9l ACTIVE: Yes Z No E]Microfic~he Attmchment List: 510 TYPE I: Yes [] No 0 QA CONDITION of items covered: IF No I Farm 101 DSD List: Yes ['l No (See Form Calculation Body Pages (Vol.) Supporting Documents (Vol.) Volumes Revised Deleted Added Revised Deleted Added Deleted Added Form 101.2, 2. 3. Forms 101.1, Iv 4. 5. 6. 7. 8, 9.10. 11 The signatures below certify that this calculation has been originated, checked, inspected and approved in accordance with established procedures.

Originated By: See Vendor Cover Sheet Date: Date: Checked By: See Vendor Cover Sheet Verification Method: Method 1 R M lethod 2 ] Method 3E] Other Ii Approved By: Issued to DCRM: Date: OX1,4-5 Received_ Date: by DCRM: Date:_Complete the Spaces Below for Documentation of Multiple Originators (Odg.) or Checkers (Chk.)Pages: A11 Orig.: Date: Verif. Method 1IM 2E1 3[1 Other-] Chk. / Date: ZI-.- /12-Pages: Orig.: Date: Verif. Method 1[-' 2E] 3E] Other[] Chk.: Date:

Form 101.1 (AO2-12 CERTIFICATION OF ENGINEERING CALCULATION Station and Unit Number:. Oconee 1,2, 3 and common Revision No.: 1 Title of Calculation:

FMEA for SSF 4.16kV Alternate Power Feed from PSW EC91 876 (OD500928)

Calculation Number. OSC-9 ACTIVE: Yes [0 No []Microfiche Attarchment List: 510 TYPE I: Yes El No 0 QA CONDITION of items covered: 1 Yes 7-l Nn Ptvm loltdl DSD) List: YAs F-l No IRI (SeA Form iet.7'I Calculation Body Pages (Vol.) Supporting Documents (Vol.) Volumes*Revised Deleted :Added Revised Deleted Added Deleted Added Form 101.2, 2, 3, Forms 101.1, iv 4. 5, 6, 7, 8,9.10.11 The signatures below certify that this calculation has been originated, checked, inspected and approved in accordance with established procedures.

Originated By: John Hohenstein (S&tLra-Q..-.... Date: 2/20/12 Checked By: Frank Calebrese (S&) .-.. ,.. Date:4'/ 12/2O112 Verification Method: Method 1 0 Method 2 f Method 3 El Other El Approved By:. Mike Mortarulo (S&L)/6.- i. ..--,--- Jk p.-. Date: 2/20/12 Issued Received to DCRM: Date: by DCRM_: Date: Complete the Spaces Below for Documentation of Multiple Originators (Odg.) or Checkers (Chk.)Pages: Org.:.. Date: Verif. Method 1[-E 2- 3rE] Other[] Chk.: Date: Pages: Orig.:. Date: Verif. Method 1ir 2[] 3[3 Other[] Chk.: Date:

P.orn 101.1 (R08441 CERTIFICATION OF ENGINEERING CALCULATION Station And Unit Number Oconee 1,2,3 and common Title Of Calculation FMEA for SSF 4.16KVAltemate power feed from PSW EC 91876 (0D500928)

Calculation Number OSC-9510 Total Original Pages i, I Through iii, II Total Supporting Documentation Attachments 0 Total Microfiche Attachments 0 Total Volumes I Active Calculation IAnalysis Yes 0 No 0 Microfiche Attachment List o Yes 0It No If Active is this a Type I Calculabon/Analysis Yes ONo r0 (See Form 101.4)These engineering Calculations cover QA Condilion

-_L_. Items. In accordance with established procedures, the quality has been assured and I certify that the above Calculation has been Originated, Checked, or Approved as noted below.Originated By SEE VENDOR COVERSHEET Date Checked By SEE VENDOR COVERSHEET Date Verification Method: Method 1 .Methodflhi),,jAethod 3 El Approved By dVFP -Ad- '44 601 Date Other -l Issued To Document Management Date Received By Document Date f Complete The Spaces Below For Documenlalltn Of Multiple Originators Or Chedck&(Pages Originated By Checked By Verification Method-Through Date Date Method 2 El Method 3 El Method 1 El Other El Pages Originated By Checked By Verification Method: Pages Originated By Checked By Verification Method: Through Date Date Method 3 El Method 1 El Method 2 El Through Other Ql Date Date Method 3 [1 Other El Method 1 El Method 2 El l'lauRIZ101-i CEl~rlFlCA'r0N Or ENGiW~5iNO CALCtJLA loN

• 4 IflA~h1 CFRTIP'ICZTION OF ENGINEBRING CALCULATION Station And Unit Number Oconee 1.2,3 and common Thie O Calculation FMEA for SSF 4.16KV Alternate power feed ftrom PSW EC 91876(00500928)

Calculation Number OSC-9610 Total Original Pages 1. 1 Through lii. I]Total Supporting Documentation Attachments 0 Total Microfiche Attachments 0 Total Volumes ! Active Calculation I Analysis Yes Cl No M]Microfche Attachment List O Yes 0i No If Active Is this a Type I Calcutatlon/Analyals Yes CtNo rl (See Form 101.4)Thse eonglneering Calculations cover QA Condition

t. Items. In accofdance with estblished procedures.

the quaitiy has been assured end I cenily that the above Calculation has been Originated, Checked, or .pproved as noted beloyr Originated By Chris San Pedro & IJ414.) Date 11112)10 Checkted By Frank Calabrese

-~ i Dat 1112 Verification Method: Method 1 0 d 2 E) Method 3 [0 other []Approved By C. A. Stasunas DF/ DaIe 1111210 Issued To Document Management Date Received By Document Management Date Complete The Spaces Below For Documonation Of Multiple Olighlators or chedcers Pages Through Originated By Date Checked By Date Verlication Method: Method I [D Method 2 [3 Method 3 E" Other El Pages Through Originated By Date Checked By Date Verification Method: Method 1 C] Method 2 C] Method 3 [3 Other C: Pages Through_Originated By Date Checked By _Date Verifieatlon Method: Method 1 El Method 2 [3 Method 3 E] Other nl FIOCI 101-i CERTMCArTIONOP ENGINEEIUNIOCALCULATION PapO I Form 101.2 (R3-03)Calculation Number REVISION DOCUMENTATION SHEET OSC-9510 Revision Revision Description Number 0 Initial Issue per EC 91876 (0D500928)

I Revised to address new failure mode: a 4.16 kV breaker spuriously closing. Incorporate niidor comments to existing revision 0 document.Fmwiou 101 -2 RJIvISION DOCUMENTATrION SHEIrT e4leek -mrh)a CALCULATION IMPACT ASSESSMENT (CIA)Slalon I/ Unt Oconee J 1. 2. 3 Caleuailion No. OSC-9510 QGv. 0 Page CIA .1 PIP No. 6if applicable) 0-04-04733-008 By Chis San Pedro Date, 1/1% -'-Prob. No. (stress ask use only) N/A Checked By Frank Calabrese r* vwee ,o NEOL raowed to Identify calculations?

El YES EINO INote: a NEOL search is NOT required for Icalculialon originations (I.e.. Rev. 0's)Identify In the blocks below, the groups consultod for an lmpact Assessment of this calculation ortglnatlonlrevislon.

E'i RES (Power. I & C, ERRT.ReactorJ MCIC I Pdmay Systems. Balance of Plant. Rolaltng EQmUpmenL, Vatvas & Heat Exdiangera.

Cii I El moo I Mechanical 11gr., Electrical Engr.. Civl Engr. I ope] Oratons

• OPS Support L. Maintenance

• Tech. Suppori.] Work Control

• Program. Supp.[I oohr Group Indlv. ContaSWed~lsli C_1 NGO I GA Tech. Services (151).Severe Accident Analysis.Elect. Sys. & Equip.. Design& Reactor Supp. Civil Sltuctural , Core Mech. &T/I Analysis.

Mech. Sys. &Equip.. Nuclear Design and Safety Analysis, MallMelatluigylPiping I LI Training Local IT_. Regulatory Compliance Li Chemistry I Radiation Protection No Group roqulrod to be cow.Mlivd. Cerrt~aAcieDate tulied Listed below are the Identifled documents (ex- "FCIIINICAL SPECIFICATION SEC1IONS, tIvSAR S.C'rlONS, I)ISIGN BASIS STATION DIAWINGS, OTHIER CALCULATIONS, ETC.)that may require revision as a result of the calculation origination or revision, the document ownergroup and the change required (Including any necessary PIP Corrective Actions).'Note. Any desqnf changes. which requite chanses 1o Station Procedures.

must he Irnismillarl as Design Deliveable Docutnmivus.

DOCUMENT GROUP CHANGE REQUIRED Page It CALCULATION IMPACT ASSESSMENT (CIA)Station I Unit Oconee I / 2 / 3 and common Calculation No.PIP No. (if applicable)

Originated By Prob. No. (stress & s/r use only) Checked By OSC-9510 Rev. 1 a e, IV John Hohenstein (S&L) Date 211:/2* -'F. Calabrese (S&L) Date 2a16112 NEDL reviewed to Identify calculations?

Yes "]No N.ote: a NEDL search is NOT required for calculation originations (i.e., Rev. 0)Identify In the blocks below, the groups consulted for an Impact Assessment of U's-ca r ::ation.-mndiv. Contacted/Date Indiv. Contacted/Dat/

0 SYS Travis Bryant 2/2/12 El NCO[Power, I & C, Primary, [Section XI Inspection, Reactor, BOP.] Safety Analysis, Nuclear Fuel Mgmt & Design, Corporate Design Support, Fuel Mech. & TI/H r PCE Analysis, Nuclear Design][Mech. Comp., Bloc. Comp, Programs]F DES[Mechanical Engr., Electrical Engr., Civil Engr.] F Training F Local rr El Operations

-OPS Support F Regulatory Compliance F] Maintenance

-Tech. Support f" Chemistry F Work Control -Program. Supp. IF Radiation Protection 0 Other Group r- No Group required to be consulted Listed below are the identified documents (ex: TECHNICAL SPECIFICATION SECTIONS, UFSAR SECTIONS, DESIGN BASIS DOCUMENTS, STATION PROCEDURFS*, DRAWINGS, OTHER CALCULATIONS, ETC.)that may require revision as a result of the calculation origination or revision, the document owner/group and the change required (including any necessary PIP Corrective Actions).*Note: Any design changes, which require changes to Station Procedures, must be transmitted as Design Deliverable Documents.

M DOCUMENT GROUP CHANGE REOUIRED (Attach Additional Sheets As Required)

Calculation:

OSC-9510 Rev. I Failure Modes and Effects Analysis for the Alternate Power Feeds to Standby Shutdown Facility (SSF) 4.16 KV Switchgear OTS1 from PSW Electrical System 1.0 Purpose The purpose of this calculation is to document the failure modes and effects analysis resulting from the addition of an alternate power source to Standby Shutdown Facility (SSF) 4.16 KV Switchgear OTS I from PSW electrical systems. This design change is instituted under EC 91876 (OD500928)-"SSF 4.16KV Alternate Power Feed from PSW". This analysis is limited to determining new failure modes or effects and significant increases in the probability of existing failures resulting from the design changes. Single failure analysis will not need to be performed since the PSW System as well as Standby Shutdown System is not intended to be single failure proof. Common mode failure assessment is reviewed to ensure that components and circuits introduced into existing systems (which are analyzed for single failure vulnerability) can not cause undesirable effects and /or consequences on existing failure analysis.2.0 Scope The scope of this analysis is limited to the failures and effects on the Standby Shutdown Facility Electrical System, introduced to this system from changes implemented by the modification listed above. The components (addition of a compartment section and associated 1200A main supply breaker to the existing SSF 4.16 KV Switchgear OTS 1) installed under the design change are related to supplying alternate power from the PSW 4.16 KV Switchgear B7T to SSF Switchgear OTS 1 in the event of loss of existing normal power feed from Switchgear B2T concurrent with the loss of SSF diesel generator.

The analysis will focus on components added to the systems by the design change, their failures and the effects the failures have on the existing equipment, which usually have significant event mitigation functions.

In general, it will not address failures of existing equipment or failures of existing power feeds including relaying trip schemes and interlock schemes which are identical in function to the existing design. Similarly, relocation of 150 KVA isolation transformer does not introduce any new type of failure. For example, this analysis will not address the effects of failure of SSF emergency diesel, but will limit the scope to the failure of the alternative (PSW) components and the effect they have on that function.

Since the PSW System is not intended nor designed to be single failure proof, a Page I of I I Calculation:

OSC-9510 Rev. 1I single failure analysis need not be performed.

3.0 References

1. EDM-105, Rev. 1, Guidelines for Performing a Failure Modes and Effects Analysis and Single Failure Analysis 2. Oconee Nuclear Station UFSAR Chapters 3, 8, 9, 15 3. OSS-0254.00-00-2014, Rev.7, Design Basis Specification for the 4160/600/120V SSF Essential AC Power System 4. OSS-0254.00-00-2020, Rev. 8, Design Basis Specification for the Standby Shutdown Facility 125 VDC Essential Power System 5. OSS-0254.00-00-1053, Draft Rev. 0, Design Basis Specification for the Protected Service Water System 6. OSS-0254.00-00-4005, Rev. 21, Design Basis Specification for the Oconee Design Basis Events 7. OSS-0254.00-00-4013, Rev. 4, Design Basis Specification for the Oconee Single Failure Criteria 8. OSC-10008 Rev. 0 Failure Modes and Effects Analysis.

Protected Service Water (PSW) System -Electrical

& Mechanical Equipment 9. 0-6700, Rev. M, One Line Diagram- Main PSW Switchgear and load centre 13.Bkv/4.16Kv/600V system Switchgear B6Tand B7T Load Center LCPSW 1 10. 0-6700-02 Rev. D One Line Diagram PSW 125V DC Power Panelboard for PSW Building 11. 0-702-B, Rev. 19C, One Line Diagram -4160 and 600V Essential Load Centers Auxiliary Power Systems Standby Shutdown Facility 12. 0-702-A2, Rev. 14, One Line Diagram 6900V & 4160 Station Auxiliary Sys.13. OEE-I17-92-0A,Rev 2A, Elementary Diagram SSF 4160V Switchgear OTSl Comp. No. 1 4KV Feeder Breaker 14. OEE-1 17-92-OB,Rev 2A, Elementary Diagram SSF 4160V Switchgear OTS I Comp. No. 1 4KV Feeder Breaker 15. OEE-i17-93-OBRev 5A, Elementary Diagram SSF 4160V Switchgear OTSI Comp. No. 2 Motor Feeder 16. OEE-117-95-OB,Rev 3A, Elementary Diagram SSF 4160V Switchgear OTSI Comp. No. 4 & 5 Diesel Generator 17. OEE-117-95-OD,Rev 4A, Elementary Diagram SSF 4160V Switchgear OTSI Page 2 of I I Calculation:

OSC-9510 I Rev. I Comp. No. 4 & 5 Diesel Generator 18. OEE-I17-97,Rev IA, Elementary Diagram 4160V, SSF Essential Switchgear OTSI Heater Circuit 19. OEE-615, Rev. B , Elementary Diagram 4.16kV PSW Switcbgear B7T Unit# 4 Alternate Feed For SSF Loads 20. OEE-615-01, Rev. C , Elementary Diagram 4.16kV PSW Switchgear B7T Unit# 4 Alternate Feed For SSF Loads 21. OEE-615-02, Rev. C, Elementary Diagram 4.16kV PSW Switchgear B7T Unit# 4 Alternate Feed For SSF Loads 22. OEE-615-03, Rev. A , Elementary Diagram 4.16kV PSW SWGR B7T Unit# 4 Alternate Feed For SSF Loads 23. OEE-615-04, Rev. C, Elementary Diagram 4.16kV PSW Switchgear B7T Unit# 4 Alternate Feed For SSF Loads 24. OEE-616, Rev. A , Elementary Diagram SSF 4160V Switchgear OTSI Unit 0 Feeder Breaker 25. OEE-616-01, Rev. A, Elementary Diagram SSF 4160V Switchgear OTSI Unit 0 Feeder Breaker 26. OEE-616-02, Rev. A, Elementary Diagram SSF 4160V Switchgear OTSI Unit 0 Feeder Breaker 27. OEE-616-03, Rev. A, Elementary Diagram SSF 4160V Switchgear OTSI Unit 0 Feeder Breaker 4.0 Assumptions

4.1 Certain

references used in the calculation have not yet been approved.

This assumption tracks those references to ensure information used in this calculation from those references is not altered in a way that affects the references being tracked is identified below: 3.5 OSS-025400-00-1053 Draft Rev. 0 5.0 Methodology The methodology is in keeping with the worksheet in Appendix A of EDM- 105 and the failure modes for components given in Appendix B of EDM-105, except where judgment dictates an additional failure mechanism should be included.Page 3 of I I Calculation:

OSC-9510 I Rev. I 6.0 Analysis'Faidie Moie ani asffect: nalysis'Worksheet System: Protected Service Water (PSW)Subsystem:

SSF Switchgeor Alternate Feeder Prepared by: John I. Hohenstein Equipment:

B7T-4 Date: February 15, 2012 Diagram: 0,6700. OEE-615. OEE-6I5-Oi, Rev. No. I_OEE-615-02..:OEE-615-03 and OE.B-615-04

._:.Effects on" Method of Comp Failure Failure Train Mto t Identification

3) Mode Mechanism and/or Detection (8)(2) (4) (5) System: __ (6)4 KV Breaker Supplies rails to Elcetrical or Lossof Breakor Note: this breaker Is normally 0 .PsW Alternate Close. mechanical Alhernate Indication closed.Switchgear PSW Power failure. feed to (10cal -B7T-4. to SSF (7T31. and MCR)V tad Normal: 100 KV APS power Swlchgenr QAC in via new 13.8 KV line and (0.6700) oSwrI the main PSW transformer CM'7.(OEE-615) control room Emergency.

13.8.KV line from either Keowee unit via transformer C77/CT6(Tie.

breaker closed).This is within the Design Basis of PSW (not single failure proof), is detectable, and may he remedied by replacing the breaker with the available spare breaker.Page 4 of 11 Calculation:

OSC-9510 I Rev. II* .-."... " FailureM .de.and'Effects Anal sis W orksheet System: Protected Service Water (PSWP Subsystem:-

SSF Switcheear Alternate Feeder Pared by 15H2 ntn Date : Fe~bruary 15, 20_]2 Equipment:

HTT-4 Rev. No. I Diagram: 0-6700. OEE-615, OBE-615-01. OEE-615-03 and OF-15-04 Effects on Component Failure Failure Train Method.Identification

() Mode Mechanism and/or of Failure Remarks and Other Effects (I) (2) (4) (5) System Detection (8)(6) (7)Fails Electrical Loss of Breaker Same as above.Open failure. Alternate indication (trips). feed to (local -(yr.9 I. and MCR)OAC in the main control room Fails to Electrical or Upstream Breaker Loss of multiple PSW system trip mechanical Main indication equipment and components if when failure. Switchgear (local -B7T Is powered from B6T required breaker will and MCR) through BTT-I tie breaker.isolate the No impact if BiT is aligned respective OAC in normally to B7T-2 main SwItchgear the main breaker.causing the c aintl 1This is within the Design Basis causing the control of PSW (not single failure failure of ro connected room proof), is detectable, and may be equipmnent.

remedied by replacing the affcted components with available spores.Spurious Electrical PSW Power Breaker This failure has no effect on Closure Failure available to indication PSW or SSF operation as SSF SSF (local -Swltchgear breaker OTS 1-0 is Switchge and MCR) normally open.OTSI OAC in the main control room Page 5 of l I Calculation:

OSC-9510 Rev.]I J,3Filure Mode and Effects Analysis Worksheet

, System: Protected Service Water (PSWI Prepared by: Zohn J. Hohenstein Subsystem:

PSW Electrical System Date: February 15.2012 Equipment:

PSWPL2DC Breaker 6 Rev. No. I Dia ram: O-67(0X0)-..

EE-6 1 5- 1, Component Failure Failure Effccts on Method of Remarks and Other Identification F Train and/or Failure R e cts (2) (3) Mode Mechanism System Detection (8)(4) (5) (6) (7)PSWPL2DC 125V DC Loss of Electrical or PSW 125V PSW SWGR This device is also 2 Breaker #6 Control DC mechanical DC control Breaker Status evaluated in calculation (0-6700-02)

Power for control failure, power Indication OSC-1 0008. The 4.16KV Bkr power, unavailable to Ught. (local following remarks ame (OEE-615.01)

PSWB7T.4 PSWITr-4 and remote repeated from that (Alternate breaker. operator panel) calculation:

feed to SSF Breaker will extinguish.

Assuming PSW System OTSI cannot be is in normal alignment Switchgear) operated (BTT.4 is closed) and electrically does not need to be exercised, PSW power to OTSi-0 will be available.

Alternatively If B7T-4 is open, BT-4 has manual chtarging capability to effect breaker closure upon Joss of control power.See item number I for failure to close B7r-4.Page 6 of II Calculation:

OSC-9510 Rev. I.*. :-Faiire Mode and Effects Analysis Workhee ;.System: -Standby Shutdown Facility Subsystem:

SSF Switchgear PSW Sponly Breaker Equipent:OTSIBreaer 0Prepared by: John 1. Hcihenstcin Equipm ent: O T SIBreak cr Q D ae0e r ar 5 2 1 Date : IFebruary

! 5,2012 Diagram: 0-6700. 0-702-D. 0-702-A2.Rcy. No., I 0E13- 1 17-92-OA.OEB-117-92-0B.

OEE-616.O -l-616-01.

OEE-616-02, OEE616-03 Effects on Method of Remarks and Other No. Component Function Faile M Failure Train and/or Failure Effects No. Identification Mode Mechanism System Detection (8)(2) (3) (4) (5) (6) (7)4 KV Breaker Connects Fails to Electrical or Loss of Local and Note: this breaker is 3 @ SSF alternate Close. mechanical Alternate SSF CR normally open and switchgear PSW failure. feed to Swgr. Breaker interlocked to prevent OTS 1-0 Power OTSI from indicating paralleling the PSW (0-6700) source to PSW Swgr. lights, power source with (ORE-616)

SSF existing normal power switchgear source (from B2"T) or OTS I back-up power source (SSF diesel).Since this alternate source is utilized when both normal and back-up diesel feed are unavailable, failure to connect alternate PSW power source to o'rSl would mean the SSF electrical system is unavailable..

However, failure of this hreaker in open position has no impact on existing sources.This is within the Design Basis of SSF system (not single failure proot), is detectable, and may be remedied by replacing the breaker with the available spare breaker.I I Page 7 of I I Calculation:

OSC-9510 I Rev. 1 S .. .Failure Mode and Effects Analysis.Worksheet.

System: Standby Shutdown Facility Subsystem:

SSP Switchear PSW Supplv Breaker Prepared by: John J. Hohcnstein Equipment:

OTS] Breaker 0 Date: February 15. 2012 Diagram: 0-6700, 0-702-B. O-702-A2.

OEE- 117 Rev. No. I OA, EE-I 17-92-OB.

OEH-616. OEE-616-01, OEE-616-2 and OER-616-03 Method Remarks and Other No. Component Function Failure Failure Effects on Train of Effects (o. Identification Mode Mechanism and/or System Failure (1) (2) (4) (5) (6) Detection (8)(7)Fails Electrical Loss of Alternate feed Local and Some as above.Open failure. to OTS I. SSF CR (trips). Breaker indicating lights.Fails to Electrical or Upstream Swltchgcar Local and Manual operation would trip mechanical B7T (PSW) breaker SSF CR be required to trip the when failure, will isolate the SSF Breaker breaker or clear the required Switchgear OTS I indicating interlocks.

causing the failure of lights.connected equIpment.

Keeps OTSI-I and OTS 1-4 from closing il."Trip" interlock to OTS 1-2 (ASW Pump) not initiated OTS 1-0 space heaters will not energize Spurious Electrical A spurious closure of Local and Inadvertent closure of Closure Failure orS 1-0 could cause SSF CR OTS 1-0 would place paralleling of PSW & Breaker 4.16KV power from SSF power sources, indicating both PSW and SSF lights, sources on the SSF Switchgear OTS I simultaneously.

Recommend keeping B7T-4 Beaker open to prevent this failure.Page 8 of II Calculation:

OSC-9510 I Rev. 1 FAilu're -Mode and Efects. Anýlysis Worksheet.

.System: Standby Shutdown Facility Subsystem:

SSF DC Control Power Prepared by: John J. Hohenstein Date: February 15.2012 Equipmentu DC Breaker 5CR Rev. No. I Diram: OEf,616-0

1. --759-K No Component Function Failure Failure Effects on Method of Remarks and Other Identification i Mode Mechanism Train and/or Failure Effects (1) (2) (3) System Detection (2)L.___ J(4) ((6) (7) (s)DCSF breaker 125V DC Loss of Electrical Breaker SSF CR Assming PSW system is 4 5CR control DC failure, cannot be Breaker in its normal alignment power for control Operated indicating (OTS 1-0 Is open), PSW 4.16kV power. electrically lights and power will not be (OEE-616-01) breaker Local light available to switchgear Indication on OT1S .However. OTS1 -0 OTSI-0 switchgear has manual charging PSW power OTSI .0 is capability to effect source lost, breaker closure.supply Assuming the breker is breaker closed or closed once (assuming spring charge happened before lie control power failure), this failure would not compromise the ability of the system to finction if required.

The breaker could still be opened manually.This failure would also render the breaker protective features inoperable; a fault down stream not isolated by the load feeder brcakcr will cause PSW swirchgear breaker to isolate the switehgear OTS I rendering other connected equipment inoperable.

This is within the Design B,asis of SSF system (not single fiilure proof), is detectable, and may be remedied by repairing the I control power feed.Page 9 of I I Calculation:

OSC-9510 Rev. I-,' " .' FaWilureMoe iandEffects Analysis Worksheet System: Standby Shutdown Facilily Prepared by: John J. Hohenstein Subsystem:_SSF Swiichgear OTSI Date: Februnry 15,2012 Equipment:

OTS I- I and OTS 1-4 Rev. No. I Diagram: Effects__n E ffec s o n M e th o d o f No. Component

..Failure Failure rrain M e Remarks and Other i) Identification FunctiOnran Failure Effects Mode Mechanism and/or Detection (2) (3) (4) (5) System (8)(6)(7)4kV breakers Primary Spurious Electrical A spurious Local and This line item identifies the 5 @Switchgear and closure failure, closure of SSF CR minor condition of a OTS] Emergency when OTSI-I or Breaker spurious breaker closure'I'S I-I Diesel system OTS 1-4 Indicating addressed in Item 3 for Generator is could cause lights, these specific SSF breakers OTS1-4 aligned paralleling when orS I is aligned to the feeds to to PSW of PSW & PSW power source.OTSI power SSF power source sources. Inadvertent closure of OTSI-I or OTS.-4 would place 4.16KV power from both PSW and SSP sources Ot the SSF Swltchgear OTSI simultaneously.

Recommend keeping OTSI-I and OTS 1-4 breakers racked out when SSF switchgear OTS1 is aligned to PSW to prevent this failure.Page 10orlI Calculation:

OSC-9510 Rev. 1 7.0 Conclusions The failure effects of the PSW System and SSF System equipment analyzed in this calculation are provided in the work sheets in section 6.0. There are certain equipment failures that are significant to the SSF switchgear operation.

These are discussed below: Powering the OTS I switchgcar from both PSW and SSF power sources is possible on a spurious closure of breaker OTS 1-0 (when OTS I is aligned to the primary SSF source) or a spurious closure of breaker OTS 1-1 or OTS 1-4 (when OTS I is aligned to PSW source).This calculation recommends changing the normal state of breaker B7T-4 to normally open. This calculation also recommends that procedural controls be established to rack out breakers OTSI-1 and OTS 1-4 when the SSF OTSI switchgear is aligned to the PSW power source.Page I I of 11