Text

Tornado and High Energy Line Break Mitigation License Amendment Requests - Supplemental Responses to Request for Additional Information Nos. 70, 76, and 106
	ML12080A199
Person / Time
Site:	Oconee
Issue date:	03/01/2012
From:	Gillespie T; Duke Energy Carolinas
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	Download: ML12080A199 (55)
	v • d • e

Duke T. PRESTON Vice GILLESPIE, JR.

President Energye Oconee Nuclear Station 0CFR 50.90 Duke Energy 10 FONOJ VP / 7800 Rochester Hwy.

Seneca. SC 29672 March 1, 2012 864-873 4478 864-873-4208 fax Document Control Desk T.Gillespie@duke-energy:corn U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Duke Energy Carolinas, LLC Oconee Nuclear Station, Units 1, 2, and 3 Docket Numbers 50-269, 50-270, and 50-287, Renewed Operating Licenses DPR-38, DPR-47, and DPR-55 Tornado and High Energy Line Break Mitigation License Amendment Requests - Supplemental Responses to Request for Additional Information Nos. 70, 76, and 106 By letter dated December 16, 2011, Duke Energy Carolinas, LLC (Duke Energy) responded to a Nuclear Regulatory Commission (NRC) Request for Additional Information (RAI). As contained in that response, Duke Energy communicated that supplemental information would be provided for:

" RAI 70 - Remaining design change package information as they are approved for field implementation, and

" RAI 76 - PSW Failure Modes and Effects Analysis.

Additionally, supplemental information was added to the RAI 106 response associated with the licensing basis of actions required to achieve cold shutdown conditions following a High Energy Line Break (HELB) in the Turbine Building. The Enclosure to this letter contains Duke Energy's supplemental information.

Based on the status of the HELB licensing actions and the Protected Service Water (PSW) modifications, Duke Energy believes the next course of action would be to meet with the Staff for follow-up discussions. This meeting should expedite resolution of additional questions that may be raised by the Staff from earlier RAI responses.

If you have any questions in regard to this letter, please contact Stephen C. Newman, Regulatory Compliance Senior Engineer, Oconee Nuclear Station, at (864) 873-4388.

I declare under penalty of perjury that the foregoing is true and correct. Executed on March 1, 2012.

Sincerely,

r-UILLC_5Ia T. Preston Gillespie, Jr.

Vice President Oconee Nuclear Station Enclosure/Attachment www.duke-energy corn

Nuclear Regulatory Commission Supplemental Responses to Request for Additional Information Nos. 70, 76, and 106 March 1, 2012 Page 2 cc: (w/enclosure/attachment)

Mr. John F. Stang, Project Manager Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 8 G9A Washington, D. C. 20555 Mr. Victor M. McCree, Administrator, Region II U.S. Nuclear Regulatory Commission Marquis One Tower 245 Peachtree Center Ave., NE, Suite 1200 Atlanta, GA 30303-1257 Mr. Andrew T. Sabisch NRC Senior Resident Inspector Oconee Nuclear Station Ms. Susan E. Jenkins, Manager Radioactive & Infectious Waste Management SC Dept. of Health and Environmental Control 2600 Bull St.

Columbia, SC 29201

Enclosure Supplemental Responses to RAI Nos. 70, 76, and 106

Enclosure - Supplemental Responses to RAI Nos. 70, 76, and 106 March 1, 2012 Page 2

RAI 70

Confirm that all electrical design calculations, analyses, and drawings associated with the proposed PSW electrical power system are approved and final.

Duke Energy Response The PSW project (electrical, civil and mechanical scope) contains thirty nine (39) Design Change Packages (DCPs):

Seven (7) of these DCPs are being implemented utilizing the 50.59 process.

" Twenty-five additional DCPs are within the scope of the PSW LAR and have been approved and released for field implementation. Design documents including electrical design calculations, analyses and drawings associated with these released DCPs have been approved. In some instances, there will be some subsequent calculations, analyses or drawings and revisions to these documents to close out open items that are being tracked.

" Seven (7) remaining DCPs have not been released for implementation. The remaining seven: (7) DCPs will be released on a schedule that supports future field implementation start dates for the scope of these DCPs. Calculations, analyses and drawings will be available for NRC audit as these DCPs are completed.

In regard to the seven (7) remaining DCPs, previously communicated vendor equipment delivery and document completion schedules have resulted in challenges to engineering change package preparation. These challenges have caused Duke Energy to revise the Protected Service Water System implementation schedule. The basis for this change was discussed with NRC management on February 9, 2012, and documented in a commitment change letter dated February 21, 2012. Based on the revised PSW implementation schedule, the remaining DCPs are expected to be released for field implementation, with the exception of EC 91878 (new PSW pump tie-in), by May 31, 2012. Auxiliary Building temperature analyses necessary to demonstrate equipment qualification are impacting completion of this EC. Regardless, available design information associated with this EC will be provided for Staff review by May 31, 2012.

As discussed previously, Duke Energy will notify the Staff when a DCP is field released and uploaded to the SharePoint site. The revised implementation schedule coordinates the removal of the Station Auxiliary Service Water (ASW) pump and switchgear, replacement with the Protected Service Water (PSW) system pumps, and post-modification testing of the PSW system with Unit l's Fall 2012 refueling outage. Much of the major infrastructure elements of the PSW system remain in-progress and are scheduled to be completed by July 31, 2012, i.e.,

the PSW building equipment installation and power up, followed by completion of the backup power feed to the Standby Shutdown Facility.

RAI 76

By letter dated October 8, 2010 the NRC issued RAI 42. The licensee responded to the RAI by letter dated December 7, 2010. The response stated that a Failure Modes and Effects Analysis/Single Failure Analysis (FMEA/SFA) will be performed for the PSW electrical system.

Provide the results of the FMEA/SFA for the PSW system.

Enclosure - Supplemental Responses to RAI Nos. 70, 76, and 106 March 1, 2012 Page 3 Duke Energy Response The following three (3) FMEA calculations are provided in Attachment 1:

1. Keowee Hydro Station Units I & 2

2. Protected Service Water System (PSW) and

3. SSF 4.16 kV Alternate Power Feed from PSW The FMEA calculations were performed in accordance with Duke Energy Engineering Directive:

"Guidelines for Performing a Failure Modes and Effects Analysis and Single Failure Analysis."

Documentation of these analyses is in accordance with Duke Energy Engineering Directive:

"Engineering Calculations I Analyses," with a preparer, checker and approver. The FMEA calculations that were prepared, checked, and approved by vendors, were also reviewed and approved by Duke Energy.

The Duke Energy FMEA process utilizes numerous internal and external documents and standards. The external documents/standards include:

ANSI/ANS-58.9-1981, "Single Failure Criteria for Light Water Reactor Safety-Related Fluid Systems".

" Safety Series No. 50-P-1, "Application of the Single Failure Criterion', International Atomic Energy Agency, Vienna, 1990, "Application of the Single Failure Criterion," a publication within the NUSS Program.

" IEEE Std. 603-1998, "IEEE Standard Criteria for Safety Systems for Nuclear Power Generating Stations"

" IEEE Std. 379-1994, "IEEE Standard Application of the Single-Failure Criterion to Nuclear Safety Systems"

" IEEE Std. 352-1987, "IEEE Guide for General Principles of Reliability Analysis of Nuclear Safety Systems"

" IEEE Std. 1028-1997, "IEEE Standard for Software Reviews"

" NUREG 492 "Fault Tree Handbook"

Regulatory Guide 1.53 "Application of the Single-Failure Criterion to Safety Systems"

Regulatory Guide 1.168 "Verification, Validation, Reviews, and Audits for Digital Software used in Safety Systems of Nuclear Power Plants"

" BTP-19 "NUREG 0800 - Standard Review Plan Chapter 7, Branch Technical Position HICB 7-19" Guidance for Evaluation of Defense-in-Depth and Diversity in Digital Computer based Instrumentation and Control Systems."

The FMEA calculations evaluated the effects of failures of each element of the PSW system and address:

Essential functions

Components needed for those essential functions

How each component can conceivably fail. For instrumentation, failure modes other than "on" or "off" are considered.

" What are the effects if the failure does occur

Is the failure in the safe or unsafe direction

Enclosure - Supplemental Responses to RAI Nos. 70, 76, and 106 March 1, 2012 Page 4

" How the failure is detected

Inherent provisions provided in the design to compensate for the failure

Operating errors that should be considered.

As identified in the calculations, there are certain equipment failures that are important to PSW operation. Recommended resolution of these failures is included in the FMEA calculations. In accordance with established Duke Engineering processes, the items from the calculations are under further evaluation for disposition. Results from the FMEA calculations and the disposition of items will be tracked in the Oconee Nuclear Station's Corrective Action Program.

RAI 106 Please provide under one cover all documentation associated with the tornado and HELB mitigation strategies. This should include an update to the original application as appropriate, updated regulator commitments, all updated RAIs, diagrams, figures and any other associated documentation. This request is being made because some documentation associated with the LARs has been superseded. The updated documentation will allow the NRC to accelerate the review of the LARs.

In addition, the Staff verbally requested that a definitive statement be made to ensure that prior 2009 to 2011 RAI issues have been appropriately addressed concerning responses containing the verbiage "common understanding," "previously discussed," "previously agreed to," or "previously addressed," and the licensing basis of actions required to achieve cold shutdown conditions following a High Energy Line Break (HELB) in the Turbine Building.

Duke Ener-gy Response Refer to Enclosure 3 (of Duke Energy's December 16, 2011, RAI responses) for the updated HELB LAR package. As stated in the December 16, 2011, cover letter, Duke Energy will update the Tornado LAR by March 31, 2012.

The following Duke Energy RAI responses given in column 1 of Table-1 contain the verbiage "1common understanding," "previously discussed," "previously agreed to," or "previously addressed." Duke Energy has evaluated the original RAI as well as the subsequent responses given in columns 2 and 3, and has concluded that the set of responses provided to the Staff has addressed the information requested.

Enclosure - Supplemental Responses to RAI Nos. 70, 76, and 106 March 1, 2012 Page 5 Table-1 1 2 .3 Original RAI 1st Supplemental 2nd Supplemental Response No. :RAI Response No. 2 RAI Response No. 3 2 13 [H] 79, 80, and 81 3(a) 14 [H]

3(b) 14 [H]

3(c) 14 [H] -

6(a) 17 [H]

9(c) 20 [H] _

10(a) 20 [H] 87 Additionally, Duke Energy has evaluated the Staff's RAls, as contained in Table-2, on the use of primary and alternate repair paths following a Turbine Building HELB. As part of this earlier, RAI response, damage repair/restoration procedures were requested by the Staff and subsequently posted to the SharePoint site for information purposes only. Duke Energy is not requesting Staff approval of these restoration procedures since they involve transition to cold shutdown activities, which are not part of the current or proposed HELB licensing basis.

Specifically, as stated on page 1 of the December 15, 1972, Giambusso letter 4:

"Thus, a nuclearplantshould be designed so that the reactorcan be shutdown and maintainedin a safe shutdown condition in the event of a postulatedrupture, outside containment, of a pipe containinga high energy fluid, including the double ended rupture of the largestpipe in the main steam and feedwater systems. Plantstructures,systems and components important to safety should be designed and located in the facility to accommodate the effects of such a postulatedpipe failure to the extent necessaryto assure that a safe shutdown condition of the reactor can be accomplished and maintained."

Also described in question 10 (of 21) from the same December 15, 1972, letter:

"Verification that failure of any structures,including nonseismic Category I structures, caused by the accident, will not cause failure of any other 1 Letter from Dave Baxter, Vice President, Oconee Nuclear Station, to the U. S. Nuclear Regulatory Commission, titled "Responses to Request for Additional Information for the License Amendment Request to Revise the Oconee Nuclear Station Current Licensing Basis for High Energy Line Break Events Outside of the Containment Building;"

License Amendment Request No. 2008-007, dated October 23, 2009.

Letter from Dave Baxter, Vice President, Oconee Nuclear Station, to the U. S. Nuclear Regulatory Commission, titled "High Energy Une Break License Amendment Request - Response to Request for Additional Information,"

dated December 7, 2010.

3 Letter from T. Preston Gillespie, Vice President, Oconee Nuclear Station, to the U. S. Nuclear Regulatory Commission, titled "Tornado and High Energy Line Break (HELB) Mitigation License Amendment Requests (LARs)

- Responses to Request for Additional Information," dated December 16, 2011.

Letter from A. Giambusso. Deputy Director for Reactor Projects, Directorate of Licensing, United States Atomic Energy Commission, to Mr. Austin C. Thies, Senior Vice President, Production & Transmission, Duke Power Company (ref: letter regarding the postulated pipe failures outside of the containment structure), dated December 15, 1972.

Enclosure - Supplemental Responses to RAI Nos. 70, 76, and 106 March 1, 2012 Page 6 structuresin a manner to adversely affect: (a) Mitigation of the consequences of the accidents; and (b) Capabilityto bring the unit(s) to a cold shutdown condition."

Duke Energy understands the criteria established by the information above requires that structural failures do not preclude the ability to access and perform damage repair, if necessary, of components needed to achieve a cold shutdown condition. Further, the incorporation of damage repairs needed to achieve cold shutdown in the license basis is not required by the above. As such, Duke Energy is not requesting NRC Staff review and approval of component damage repair plans and procedures necessary to transition from Mode 4 to Mode 5 and did not address this issue as part of this RAI response.

Table-2 RAI:Response No.5 TB Structure Involved 6 [H] Restoration activities for column G-17.

7 [H] Restoration activities for column G-23.

8 [H] Restoration activities for column Ga-24.

9 [H] Restoration activities for column K-23.

10 [H] Restoration activities for columns H-32 or H-33a.

11 [H] Failure of 2-ES-024-R.

12 [H] Restoration activities for Column H-39.

Letter from Dave Baxter, Vice President, Oconee Nuclear Station, to the U. S. Nuclear Regulatory Commission, titled "Responses to Request for Additional Information for the License Amendment Request to Revise the Oconee Nuclear Station Current Licensing Basis for High Energy Une Break Events Outside of the Containment Building;"

License Amendment Request No. 2008-007, dated October 23, 2009.

ATTACHMENT 1 Failure Modes and Effects Analysis (FMEA) Calculations for:

1. Keowee Hydro Station Units 1 & 2

2. Protected Service Water System (PSW) and

3. SSF 4.16 kV Alternate Power Feed from PSW

Failure Modes and Effects Analysis For Keowee Hydroelectric Units

Form 101.1 (RO2-12' CERTIFICATION OF ENGINEERING CALCULATION Station and Unit Number. Keowee Hydro Station Units 1&2 Revision No.: 0 Titse of Calculation: Failure Mode and Effects Analysis (FMEA) for the Keowee 13.8kV Switchgear (KPF)

Power Feeds to Protected Service Water System (PSW) Swltchgear (B6T/B7T)

,m Calculation Number: KC-219)0 ACTIVE: Yes Z No [] TYPE I: Yes [] No 0 QA CONDITION of items covered: I Mi-mflrchA Attachment List: Y*q Fl No r* (nan Fanmi 1O1.4* DSD List Yes Fl1 No [* (See Forrm 101.7*

Calculation Body Pages (Vol. 1 of 1) Supporting Documents (Vol) Volumes Revised Deleted Added Revised Deleted Added Deleted Added

.. - CIA-I, - -... .

I1through 15, - -.. .

Al through A26 The signatures below certify that this calculation has been originated, checked, Inspected and approved in accordance with established procedures. */)

Originated By: Dinesh R. Patel Date: 2121112

, " Date:

Checked By. V. K. Puri I Verification Method: Method I1 " Method 2 [] Method 3 El Other E)

Approved By: Donald E. Taylor A' Issued Received A-" ut *-T£ to DCRM: Date: by DCRM: Date:

Complete the Spaces Below for Documentation of Multiple Originators (Oig.) or Checkers (Chk.)

Pages: 41i/ Odg.:_ Date:

Venf. Method I R] 20- 3F- OtherE] Chk.: 7" &Ws .. 20y6"t zL -*' ,, -Date:A/2//12.

Pages: Orig.:_ Date:

Verif. Method 1[] 2E] 3[] Other[] Chk.: Date:

Form 101.2 (R3-03) Calculation Number KC-2190 REVISION DOCUMENTATION SHEET Revision Revision Descrption Number 0 (Calculation Owner. O-SYS)

Initial Issue per EC91875 (OD500927)

I I.

1~

I.

__ I

E.M. 4.9 Kevision 12 CALCULATION IMPACT ASSESSMENT (CIA)

Station / Unit: Keowee I and 2 Calculation No. KC-2190 Rev. 0 , /7 Page CIA-I PIP No. (if applicable) WA Originated By: Dinesh R. Patel ,§& -J Date: 2/16/12 Prob. No. (stres &sr use only) Cheded By: V. K. PurI Date: P-.j lp/r Note: a NEDL search is NOT required for NEDL reviewed to Identify calculations? YES W NO calculation originations (i.., Rev. 0's) I l

Identify In the blocks below, the groups consulted for an Impact Assessment of this calculation orlginatlon/revson.

Indiv. ContatedVat In'. Contacted/Date SYS Darla King / 2-1-142 - NGO

[Power, I & C, Primary, Travis L. Bryant / 2-13-12 [Section XI Inspection, Safety Reactor, BOP,] Analysis, Nuclear Fuel Mgmt

& Design, Corporate Design Support, Fuel Mech. & T/H QPCE Analysis, Nuclear Design]

[Mech. Comp., MCC. Comp, Programs]

DES

[Mechanical Engr., Electrical Training Engr. Civil Engr.) _ _ _ Local IT Q Operations - OPS Support _ _ _ Regulatory Compliance Maintenance - Tech. Support [_ Chemistry Work Control - Program. Supp. _ _ _ Radiation Protection .

___Other _roup [_ No Group required to be consulted Listed below are the Identified documents (e=: TECHNICAL SPECIFICATION SECTIONS, UFSAR SECTIONS, DESIGN BASIS DOCUMENTS, STATION PROCEDURES*, 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 requirechanges to Station Procedures,must be transnmiedas Design Debrable Documents DOCUMENT GROUP CHANGE PERFORMED (Attach Additional Sheets As Required)

Keowee Hydro Units I & 2 Calculation: KC-2190 Failure Mode and Effects Analysis (FMEA) for the Keowee Revision: 0 13.8kV Switchgear (KPF) Power Feeds to Protected Service Date: 2/16/12 Water System (PSW) Switchgear (B6T/B7T)

TABLE OF CONTENTS SECTION TITLE PAGE NO.

1.0 Purpose 2 2.0 Scope 3 3.0 References 6 4.0 Assumptions 11 5.0 Methodology 12 6.0 Analysis/Matrices (Ref. Appendix A) 13 7.0 Conclusions 14 Appendix A Failure Mode and Effects Analysis Worksheet A-1 Page 1

Keowee Hydro Units I & 2 Calculation: KC-2190 Failure Mode and Effects Analysis (FMEA) for the Keowee Revision: 0 13.8kV Switchgear (KPF) Power Feeds to Protected Service Date: 2/16/12 Water System (PSW) Switchgear (B6T/B7T) 1.0 Purpose The purpose of this calculation Is to perform the Failure Mode and Effects Analysis (FMEA) for changes made to the Keowee Hydro Units (KHU I and 2) under Engineering Change EC 91875 (OD500927), Keowee AC Power Tie-Ins (KPF switchgear) to the Protected Service Water (PSW) system. This qualitative analysis is limited to determining failure modes and their effects as well as any increases in the probability of existing system failures resulting from the design change. Single failure analysis is not needed to be performed since the PSW System itself Is not designed as a single failure proof system (Ref. 4). Failures identified in the PSW components added per this Engineering Change shall be reviewed to assure that they are acceptable. The Keowee system feeds as well as the new KHU/PSW AC power feeds being supported by this modification are designed to satisfy QA Condition I requirements. EC 91875 supports the PSW System for Oconee Units 1, 2, and 3.

Since the KHU-1 and KHU-2 are QA-1 safety related generation Systems, the new equipment KPF I & 2 Switchgear and associated systems meet the criteria for performing a FMEA per EDM-105 requirements.

This is an Active" calculation because it will be kept updated for the life of the plant.

Page 2

Keowee Hydro Units I & 2 Calculation: KC-2190 Failure Mode and Effects Analysis (FMEA) for the Keowee Revision: 0 13.8kV Switchgear (KPF) Power Feeds to Protected Service Date: 2/16/12 Water System (PSW) Switchgear (B6T/B7T) 2.0 Scope The scope of this FMEA qualitative analysis only covers the KPF switchgear, protective relays, and 125V DC power. This analysis is limited to identifying new failure modes and effects and determining the acceptability of those failures or significant increases in the probability of existing system failures due to equipment installed under EC 91875 (OD500927).

The Protected Service Water System is designed as a standby system for use under emergency conditions. The PSW system provides added "defense in depth" protection by serving as a backup to existing safety systems and as such the system is not required to comply with single failure criteria. The PSW system is provided as an alternate means to achieve and maintain a stable Reactor Coolant System (RCS) pressure and temperature for one, two, or three units following postulated events; Tornado and High Energy Line Break (HELB), and a loss of Lake Keowee Event. The PSW system is also capable of cooling the RCS to 2500 F and maintaining this condition until damage repairs can be implemented to proceed to cold shutdown.

The safety function provided by the PSW system Is to supply cooling water for decay heat removal at full system pressure to all six (6) steam generators following postulated event scenarios. A second safety function of the PSW electrical power system, in combination with the High Pressure Injection System, is providing borated water to the RCS pump seals and to provide primary RCS makeup.

EC 91875 Is part of the PSW Project and is in support of the installation of two additional parallel QA Condition I (Safety Related) 13.8 kV underground power feeds from either KPF1 or KPF2 switchgear to the new PSW System switchgears B6T and B7T (Ref. 5 &6). These new underground KHU feeds are Independent of the existing Keowee emergency underground power feed to transformer CT-4. The PSW system is also receiving a fully redundant and independent power feed thru a new overhead 13.8 kV distribution line from the 100/13.8KV Fantline Substation (Ref. 79). The 13.8 kV overhead feed (from the 100 kV Alternate Power Source will be the normal power supply for the PSW system. The new PSW underground feeds from KHU 1 & 2 will provide a safety related power backup option following postulated event scenarios.

The scope for EC 91875 is to install two (2) bus taps from KHU-1 & 2 13.8 kV non-segregated bus to two (2) 13.8KV Switchgears KPF-1 & 2. The 13.8 kV non-segregated bus taps are made outside the Keowee Generators I and 2 walls and in a transition box. Generator I and 2 outputs to KPF I & 2 switchgears are provided with 6-1/C 750 Kcmil cables each. The cables are routed to KPF-1 & 2 switchgear via cable trays. KPF-2 switchgear enclosure will have two (2) 13.8 kV 1200A vacuum circuit breakers (KPF-10 & KPF-12) with one breaker ready space without protective relays. KPF-1 switchgear will have three (3) 13.8 kV Page 3

Keowee Hydro Units 1 & 2 Calculation: KC-2190 Failure Mode and Effects Analysis (FMEA) for the Keowee Revision: 0 13.8kV Switchgear (KPF) Power Feeds to Protected Service Date: 2/16/12 Water System (PSW) Switchgear (B6T/B7T) 1200A vacuum circuit breakers (KPF-9, KPF-1 1, and a fully functional spare less protective relays KPF-13).

Circuit breakers KPF-9 (fed from Keowee Unit 1) and KPF-10 (fed from Keowee Unit 2) are electrically interlocked so only one breaker can be closed at any given time. KPF-9 and KPF-1 0 are normally open. Each breaker's operation Is controlled either from the Oconee Unit 2 main control room or Keowee control room. When Keowee has control of these breakers for maintenance purposes there will be an alarm indication at the Oconee Control Room. Breakers KPF-1 I and KPF-12 are normally closed and under control of the Keowee Operators.

KPF-1 and KPF-2 switchgear buses are connected by a "cable bus tie" consisting of 3-1/C 750 Kcmil cables, and this allows breakers KPF-1 1 and KPF-12 to be fed from either breaker KPF-9 (Keowee Unit 1) or KPF-10 (Keowee Unit 2) when closed. This arrangement and the PSW underground feeder cables, provides a Safety Related backup power source option for the PSW System switchgear, breaker KPF-1 Ito switchgear B6T via CT-6 transformer and breaker KPF-12 to switchgear B7T via CT-7 transformer respectively.

By design, the PSW circuit breakers (KPF-9, KPF-10, KPF-11 and KPF-12) are not electrically interlocked with the existing Keowee breakers ACB 1, ACB 2, ACB 3 and ACB 4. The PSW circuit breakers are manually operated and under administrative control of Keowee and Oconee operators.

Engineering Change (EC) 91875 provides electrical interlock logic to prevent breakers KPF-9 (KHU I supply) and KPF-1 0 (KHU 2 supply) from being closed simultaneously and installs the necessary protective relaying for breakers KPF-9, KPF-10, KPF-1 1 and KPF-12. This EC also provides inputs to computer points (OAC), Sequence Events recorder (SER) at Keowee and the necessary Stat alarms both at Keowee and Oconee main control room.

EC 91875 also installs six new 125 VDC power circuits from Keowee's DC distribution centers for the new 13.8 kV breaker switchgear, Panel EB20 and Keowee-Oconee interface cabinets per drawing K-704 (Ref. 7). Three (3) new DC circuit breakers are being installed in spare compartments of each of the existing 125 VDC distribution centers (1DA and 2DA).

This modification will also disconnect one of the two 0.45 ohm resistors from each of the KHU Generator Grounding Transformer Secondary Circuits to allow a higher ground fault current to flow to compensate for additional capacitance added by PSW electrical system. This change has been evaluated and found to be acceptable by calculation KC-0094 (Ref. 14). Protective relay (59GN1 &2) settings will remain same as present. The basic function of the grounding transformer circuit remains the same with no new failure modes or effects identified due to this change in resistance.

Page 4

Keowee Hydro Units 1 & 2 Calculation: KC-2190 Failure Mode and Effects Analysis (FMEA) for the Keowee Revision: 0 13.8kV Switchgear (KPF) Power Feeds to Protected Service Date: 2/16/12 Water System (PSW) Switchgear (B6T/B7Tr)

Electrical Instrumentation and Controls

Description:

Keowee Control Room -Four (4) control switches and indication are provided in the Keowee control room to control breakers KPF-9, KPF-10, KPF-1 I and KPF-

12. Two Local/Remote selector switches (one each for breakers KPF-9 and KPF-10) in the Keowee control room are provided for required operation from either Oconee Control or Keowee Control Rooms. These transfer switches are normally set in the remote position to allow Oconee Operations to control breakers KPF-9 and KPF-10 operation. In addition, inputs are provided to computer points, SER points and alarms as required. Finally, ammeters, ground sensing protective relaying, time overcurrent relays, differential relays, lockout relays, and breaker failure relays for the breakers and circuits are provided for primary and backup protection as required. All these devices/equipment will be installed In existing Keowee Control Boards (CB) and Electrical Boards (EB) with a new EB20 added to house KPF-1 & 2 protective relays and also facilitate common termination points for field wirings.

Oconee Unit 2 Main Control Room (MCR) - These changes are in support of EC 91875 and are being performed by EC 91853 (OD200942). The specifics of the changes Includes installation of two (2) Breaker Control Switches (one for KPF-9 and one for KPF-1 0) and indicating lamps on 2AB3 (Remote Section of the Oconee MCR ) for Oconee Operations to verify the status and operation of KPF-9 and KPF-10 breakers. In addition, Stat alarms in the Oconee MCR will alert the operator to the abnormal position of Local position of Remote/Local selector switch at Keowee control room.

Protective relaying is being installed on all new circuit breakers with a breaker failure scheme in place should any one breaker not operate as designed.

Protective relay functions have been properly selected and coordinated based on issued calculation KC-2217 (Ref. 12). The electrical impact from this engineering change on the existing Keowee 125V DC system (Ref. 7) has been evaluated and found to be acceptable by calculation KC-2152 (Ref.10). The new 13.8 kV breakers have been properly sized and rated per Electrical Transient Analysis Program (ETAP) Calculation OSC-9370 (Ref. 13). Seismic analysis has been performed for equipment being installed by this modification with no adverse findings per calculations KC-2026 and KC-2195 (Ref. 9 and 11).

This design change will make no connections to the PSW Switchgear or Oconee MCR equipment as that work is part of separate PSW Design Change Packages.

However, inputs will be provided to computer points, Sequence of Events Recorder (SER) points and necessary Stat alarms including wiring for the new circuit breakers (Circuit Breakers KPF-9 and KPF-10) that will be controlled from the Oconee MCR. This modification will utilize existing spare power and control cables that were previously installed underground from the Keowee Hydro Station to the Oconee Station.

Page 5

Keowee Hydro Units 1 & 2 Calculation: KC-2190 Failure Mode and Effects Analysis (FMEA) for the Keowee Revision: 0 13.8kV Switchgear (KPF) Power Feeds to Protected Service Date: 2116/12 Water System (PSW) Switchgear (B6T/B7T) 3.0 References

1. EDM-105, Rev. 1, Guidelines for Performing a Failure Mode and Effects Analysis and Single Failure Analysis

2. Not Used

3. O8S-0254.00-00-2005, Rev. 20, Design Basis Specification for the Keowee Emergency Power

4. O8S-0254.00-00-1053, Design Basis Specification for the Protected Service Water System (Not Issued)

5. KEE-17 Rev. 19 Elementary Diagram Gen ACB Backup Control Disc Sw Indicating Lights

6. K-700, Rev. 32A, Keowee One Line Diagram, Relays and Meters, 13.8-230 kV (Not issued)

7. K-704, Rev. 38A, One Une Diagram, 125 VDC Station Auxiliary Circuits (Not Issued)

8. FMEA-29412516-1 Rev. 2 Failure Mode and Effects Analysis (FMEA) for Eaton / Cutler-Hammer 15kV Switchgear Breakers from NLI (SQAD 4465).

9. KC-2026, Rev. 0, Seismic Qualification Documentation for Keowee Units 1 and 2

10. KC-2152, Rev. 1, Keowee U 1/2 125VDC Power System ETAP Model Base File

11. KC-21 95, Rev. 0, Keowee 13.8 kV Breakers Equipment Mounting and Cable Tray Supports Qualification

12. KC-2217 Rev. 0, Protective Relaying Calculation For Keowee 13.8 kV KPF Switchgear

13. OSC-9370, Rev. 0B, UI/2/3, PSW AC Power System Voltage And Short Circuit Analyses

14. KC-0094, Rev. 1, Keowee Generator Neutral Grounding

15. Licensing Amendment Request (LAR) No. 2008-005, Proposed LAR to Revise the Oconee Nuclear Station Current Licensing Basis for HELB events outside of the Containment Buildings

16. OEE-218-33 ,Rev 11, List Statalarm No 2SA17 Vertical Board 2VB3

17. OEE-218-34 ,Rev 9, List Statalarm No 2SA17 Vertical Board 2VB3

18. KEE-6, R1 9A, Tabulation Statalarm No, SA1 Station Alarms (Not Issued)

Page 6

Keowee Hydro Units I & 2 Calculation: KC-2190 Failure Mode and Effects Analysis (FMEA) for the Keowee Revision: 0 13.8kV Switchgear (KPF) Power Feeds to Protected Service Date: 2/16/12 Water System (PSW) Switchgear (B6T/B7T)

19. KEE-106, Rev 10A, Tabulation Statalarm List ISAI T-G System Condition Alarm (Not Issued)

20. KEE-1 06-03, Rev 8C, Status Point Summary Oconee I Keowee Supervisory System (Not Issued)

21. KEE-208, Rev 8A, Tabulation Statalarm List 2SAI T-G System Condition Alarm (Not Issued)

22. Not Used

23. KEE-8-03 Rev I1A, Sequence of Event Recorder List ONKOELKCRO127 Contacts Ust (Not Issued)

24. KEE-8-03-OA Rev A, Sequence of Event Recorder List ONKOELKCRO127 Contacts List (Not Issued)

25. K-707 Rev 26A, Elementary:Diagram AC Circuits Generators Number I & 2 Transformer Number I (Not Issued)

26. K-707-C Rev A, Elementary Diagram AC Circuits Generator Number I Transformer Number 1 (Not Issued)

27. K-707-D Rev A, Elementary Diagram AC Circuits Generator Number 2 Transformer Number I (Not Issued)

28. K-707-E Rev A, Elementary Diagram AC Circuits Generator Number 1&2 Transformer Number I (Not Issued)

29. KEE-1 11 Rev 32A, Elementary Diagram Turbine & Governor Systems Startup Control (Not Issued)

30. KEE-1 12-16 Rev 1A, Elementary Diagram Excitation System Exciter Start &

Lockout (ECTB) (Not Issued)

31. KEE-1 13 Rev 23A, Elementary Diagram Master Control System Startup Controls (Not Issued)

32. KEE-1 13-1 Rev 15A, Elementary Diagram Master Control System Auto-Manual Control (Not Issued)

33. Not Used

34. KEE-1 14 Rev 30A, Elementary Diagram Generator Control ACB-1 Control Circuit (Not Issued)

35. KEE-1 14-1 Rev 24A, Elementary Diagram Generator Control ACB-3 Control Circuit (Not Issued)

36. KEE-1 14-03-0A, Rev. A, Elementary Diagram, Generator Control Normal &

Emergency Lockout (Not Issued)

Page 7

Keowee Hydro Units I & 2 Calculation: KC-2190 Failure Mode and Effects Analysis (FMEA) for the Keowee Revision: 0 13.8kV Switchgear (KPF) Power Feeds to Protected Service Date: 2/16/12 Water System (PSW) Switchgear (B6T/B7T)

37. KEE-114-4 Rev 17A, Elementary Diagram, Generator Control & Relaying (Not Issued)

38. KEE-1 17-01-OA Rev A, Keowee Oconee Elementary Diagrams Remote Controls (Not Issued)

39. KEE-119 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-9 Control Circuit (Not Issued)

40. KEE-1 19-001 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-9 Control Circuit (Not Issued)

41. KEE-1 19-002 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-9 Protective Relay Circuit (Not Issued)

42. KEE-1 19-003 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-9 Contact & Switch Development (Not Issued)

43. KEE-1 19-004 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-9 Contact &Switch Development (Not Issued)

44. KEE-121 Rev A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-9, 10, 11 & 12 Protective Relay Control (Not Issued)

45. KEE-121-001 Rev A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-9, 10, 11 & 12 Protective Relay Control (Not Issued)

46. KEE-122 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-1 I Control Circuit (Not Issued)

47. KEE-122-001 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-1 1 Control Circuit (Not Issued)

48. KEE-122-002 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-1 1 Protective Relays (Not Issued)

49. KEE-122-003 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-1 I Contact & Switch Development (Not Issued)

50. KEE-122-004 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-1 1 Contact & Switch Development (Not Issued)

51. KEE-211 Rev 28A, Elementary Diagram Turbine & Governor Systems Startup Control (Not Issued)

52. KEE-212-16 Rev 2A, Elementary Diagram Excitation System Exciter Start &

Lockout (ECTB) (Not Issued)

Page 8

Keowee Hydro Units I &2 Calculation: KC-2190 Failure Mode and Effects Analysis (FMEA) for the Keowee Revision: 0 13.8kV Switchgear (KPF) Power Feeds to Protected Service Date: 2/16112 Water System (PSVV) Switchgear (B6T/B7T)

53. KEE-213 Rev 24A, Elementary Diagram Master Control System Startup Controls (Not Issued)

54. KEE-213-1 Rev 14A, Elementary Diagram Master Control System Auto-Manual Control (Not Issued)

55. KEE-213-9 Rev 9A, Elementary Diagram Master Control System (Not Issued)

56. KEE-214 Rev 29A, Elementary Diagram Generator Control ACB-2 Control Circuit (Not Issued)

57. KEE-214-1 Rev 20A, Elementary Diagram Generator Control ACB-4 Control Circuit (Not Issued)

58. KEE-214-03-OA, Rev. A, Elementary Diagram, Generator Control Normal &

Emergency Lockout (Not Issued)

59. KEE-214-4 Rev 14A, Elementary Diagram, Generator Control & Relaying (Not Issued)

60. KEE-217-01-OA Rev B, Keowee Oconee Elementary Diagrams Remote Controls (Not Issued)

61. KEE-219 Rev, A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-10 Control Circuit (Not Issued)

62. KEE-219-001 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-10 Control Circuit (Not Issued)

63. KEE-219-002 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-10 Control Circuit (Not Issued)

64. KEE-219-003 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-10 Contact & Switch Development (Not Issued)

65. KEE-219-004 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-10 Contact & Switch Development (Not Issued)

66. KEE-222 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-12 Control Circuit (Not Issued)

67. KEE-222-001 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-12 Control Circuit (Not Issued)

68. KEE-222-002 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-12 Protective Relay (Not Issued)

69. KEE-222-003 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-12 Contact &Switch Development (Not Issued)

Page 9

Keowee Hydro Units 1 & 2 Calculation: KC-2190 Failure Mode and Effects Analysis (FMEA) for the Keowee Revision: 0 13.8kV Switchgear (KPF) Power Feeds to Protected Service Date: 2/21/12 Water System (PSW) Switchgear (B6T/B7T)

70. KEE-222-004 Rev. A, Elementary Diagram PSW Emergency Power 13.8kV Feeder Bkr KPF-12 Contact & Switch Development (Not Issued)

71. Oconee Nuclear Station Scope Description for EC91 875 (OD500927)

Keowee AC Power Tie-Ins

72. OEE-1 14-01-OA Rev A, Elementary Diagram Keowee-Oconee Interposing Relays (Not Issued)

73. OEE-214-01-OA Rev A, Elementary Diagram Keowee-Oconee Interposing Relays (Not Issued)

74. IEEE 352-1987 IEEE Guide for General Principles of Reliability Analysis of Nuclear Power Generating Station Safety Systems

75. KM-303-0037.001 Rev. 2 (NLI QR-29412518-1 Rev. 2) Qualification Report for Cutler-Hammer 15kV Switchgear (SQAD 4273)

76. KM-303-0036.001 Rev. 5 (NLI IM-29412516-1 Rev. 5) Instruction Manual for 15KV Cutler-Hammer Switchgear (SQAD 4531) (Not Issued)

77. Duke Power specification KSR-0267.00-00-0001, Rev. 2, "Procurement Specification for the Design, Fabrication and Testing of QA-1, Keowee Hydro Station, 13.8kV Medium Voltage (KPF) Switchgear, Protective Relay Electrical Board (EB20) and Non-QA-1 Electrical Support Equipment for the Protected Service Water (PSW) System."

78. EC91853 (OD200942) Unit 2 Pre-outage Main Control Room Board Additions for PSW

79. EC91874 (OD500923) 13.8kV Feed to PSW System from 100kV APS

80. EC91852 (OD200945) Unit 2 Outage Main Control Board Additions Page 10

Keowee Hydro Units I & 2 Calculation: KC-2190 Failure Mode and Effects Analysis (FMEA) for the Keowee Revision: 0 13.8kV Switchgear (KPF) Power Feeds to Protected Service Date: 2/16/12 Water System (PSW) Switchgear (B6T/B7T) 4.0 Assumptions A. Concurrent random failures are excluded from the scope of analysis since they are considered non-credible.

B. Ifa single failure results in cascading multiple failures, the analysis considers these to be a single failure.

C. Failure of the cables is considered non-credible and excluded from the scope of the analysis.

D. Environmental effects such as temperature, radiation, and steam impingement are considered to be non-credible because the equipment Is located in an environmentally controlled location (Ref. 75).

E. Manufacturing errors are not considered because of post modification and maintenance testing as well as quality control programs.

F. Human error is not considered since there are programs in place to prevent human errors.

G. Wiring, wiring terminations are not considered credible once they are secured and tested (post modification testing).

H. Equipment has been qualified for seismic mounting (Ref. 11)

1. The analysis includes only the most probable component failure. Good engineering judgment (not analysis or statistical data) is used in determining the credibility of the causes of the failure. Unlikely failures are omitted from the analysis.

J. Active failure on the contact side of a relay will not propagate across relay.

K. Two independent hardware failures of safety related components is not considered a credible failure mode.

Page 11

Keowee Hydro Units I & 2 Calculation: KC-2190 Failure Mode and Effects Analysis (FMEA) for the Keowee Revision: 0 13.8kV Switchgear (KPF) Power Feeds to Protected Service Date: 2/16/12 Water System (PSW) Switchgear (B6T/B7T) 5.0 Methodology The methodology is in keeping with the worksheet In Appendix A of EDM-1 05 and the failure modes for components given in Appendix B of EDM-1 05, except where judgment dictates an additional failure mechanism should be included.

The following basic questions are considered in the evaluation of components provided in Appendix A of this calculation:

" What are the essential functions of the system?

" What components are needed for the essential functions?

" How can each component credibly fail?

" What mechanisms might produce these modes of failure?

What could the effects be if the failures did occur?

" Is the failure in a safe or unsafe direction?

How is the failure detected?

" What Inherent provisions are provided in the design to compensate for the failure?

" What redundant provisions exist to provide an equivalent function?

" If no redundant provisions exist, then what repair options exist?

Generally, the "Remarks and Other Effects" column has considered the worst case failure result from the "Failure Mode" column. Failure modes that result in effects that are non-significant to Keowee Emergency power supply to PSW or equipment functionality were not considered.

Page 12

Keowee Hydro Units 1 & 2 Calculation: KC-2190 Failure Mode and Effects Analysis (FMEA) for the Keowee Revision: 0 13.8kV Switchgear (KPF) Power Feeds to Protected Service Date: 2/16/12 Water System (PSW) Switchgear (B6T/B7T) 6.0 Analysis I Matrices (Ref. Appendix A)

1) System/Component Description The purpose of Keowee electrical feed to PSW system is to provide emergency power to mitigate the PSW event (HELB/Tomado) thus enabling to achieve and maintain all three Oconee Units in Safe Shutdown state. Keowee emergency supply to PSW is not a single failure proof design. However, all critical equipment/components are procured QA-lcondition and redundancy of power supplies is maintained for a reliable power supply. Normally PSW power is provided by 13.8kV overhead tie line from Fantline Substation and Keowee will be used as an emergency backup power to PSW.

2) Boundary and Analysis The FMEA discusses credible Keowee Emergency power supply and related equipment/components during PSW event under emergency and normal operating modes.

3) Depth of Analysis The FMEA evaluates major functional failures of Keowee emergency power supplies, individual equipment/component failures and related consequential failures of Keowee supplies to perform safety function and also, the failures that impact the functionality of existing equipment

4) Failure Modes Identification Failure modes of equipment/component are depicted in column 4 of FMEA worksheets (Appendix A).

5) Operational condition of system Keowee is required to provide emergency backup power to Fantline overhead power supply to PSW system under a PSW event and PSW building 'House Loads' under normal operational condition. The alignment of all MV and LV breakers are manually performed by Oconee and Keowee operations.

6) Methods of detecting failure Methods of detecting the failure are provided in column 7 of the FMEA worksheets provided in Appendix A of this calculation.

7) Evaluation of Failure Effects Evaluation of the failure effects are provided in column 8 of the FMEA worksheets provided in Appendix A of this calculation.

Page 13

Keowee Hydro Units I & 2 Calculation: KC-2190 Failure Mode and Effects Analysis (FMEA) for the Keowee Revision: 0 13.8kV Switchgear (KPF) Power Feeds to Protected Service Date: 2/16112 Water System (PSW) Switchgear (B6T/B7T) 7.0 Conclusions A. Overall system reliability EC 91875 provides design changes that improve the overall PSW system reliability by providing a backup power feed option from Keowee following postulated HELB and Tornado scenarios for Oconee. The normal power feed for the PSW system is by the 13.8 kV overhead feed from the 100/13.8KV Fantline Substation. The PSW system is not required to support normal operation of Oconee or to mitigate a design basis accident. The PSW system is designed as a standby system for use under emergency conditions. The Keowee Hydro Units 1 and 2 supply power to PSW via KPF-1 and KPF-2 switchgears respectively, using underground separate circuits Inductbank provides added "defense in depth" protection. This configuration serves as a backup to existing safety systems even though the system is not required to comply with the single failure criteria.

The PSW system is not single failure proof. The redundancy (parallel paths and 100% redundant pieces of equipment) provide defense in depth and a highly reliable system B. Assessment of failure significance A total 18 cases of failures In equipment installed per EC-91875 (13.8 kV breakers with associated relaying and control devices) have been evaluated with two adverse impacts identified (Cases 17 & 18). This conclusion is based on the following discussion:

" All equipment failures postulated by the analysis documented in Appendix A were evaluated with no adverse impact identified except cases 17 and 18.

" The PSW system is not required to be single failure proof and is used in emergency situations when all normal or emergency feedwater systems are lost. The PSW system is not required to support normal operation of the facility or to mitigate a design basis accident.

" The Keowee Emergency AC Feed to PSW is normally not connected and is under administrative control of Oconee operators, and will only be utilized in emergency or testing scenarios.

Proposed Tech Spec Surveillance Requirements SR 3.7.10.2 will verify that the KHU emergency underground power feed can be aligned to and power the PSW electrical system on a 92 days frequency.

The equipment and control components procured under EC91875 are standard electrical equipment for power distribution and are procured as QA Condition I (Ref. 77).

Page 14

Keowee Hydro Units 1 & 2 Calculation: KC-2190 Failure Mode and Effects Analysis (FMEA) for the Keowee Revision: 0 13.8kV Switchgear (KPF) Power Feeds to Protected Service Date: 2/21/12 Water System (PSW) Switchgear (B6TIB7T)

Electrical breakers being Installed were analyzed for proper selection, sizing, and impact on the existing AC and DC power systems and found to be acceptable (Refs. 10, 12,13 and 14).

, Seismic Analysis was performed for the 13.8 kV breakers, Electrical Boards (EB 20) and Keowee control room hardware impacts with no adverse findings (Refs. 9 and 11).

C. Suggestions:

1. Appendix A cases 17 and 18 events identified in column 8 could be mitigated by the following corrective actions:

Add Reverse Power Protection.

Add a cable tie with a breaker and protective relaying between load side of breaker KPF-9 and 10.

e Remove the cable tie between KPF-1 and 2 switchgear buses. In the event If power to PSW Is available only from one path then close the bus-tie breaker at PSW B6T/B7T switchgear (PSW building).

If one breaker KPF-9 (10) is closed then keep, administratively or procedurally, the other breaker KPF-1 0 (9) in disconnected position.

Consider providing a mechanical Kirkkey interlock between breakers KPF-9 and 10.

2. Based on the normally de-energized protective trip relays it is prudent that the trip circuit relays added per EC91875 be included in the system surveillance to validate the functionality of the desired protective functions.

Page 15

Calculation No.: KC-2190 Revision No.: 0 APPENDIX- A PAGE: A-1 Appendix A Failure Mode and Effects Analysis Worksheet

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW-Keowee Emergency Backup Power Revision No: 0 Subsystem: N/A Prepared by: Dinesh R. Patel Equipment: Keowee 13.8 kV KPF-Switchgear Breaker for PSW Emergency Feed Date : 2/16/12 Drawings:- (-700 & K-704 Case Component Failure Failure Effects on Train FMethod of No. Identification Function Mode Mechanism and/or System Failure Remarks and Other Effects (1)(3) (4) (5) (6) (7)D.. .. (8)

KI ELK BK KPFI I Provide Fail open Electrical Loss of Keowee as an Operator Failure is Detectable and Circuit Breaker Keowee (Tripped) failure or alternate emergency Detection - Acceptable. Diverse redundant KPF-1 1 Emergency mechanical power supply to PSW Oconee U2 means of supplying power are Backup Power failure transformer CT6 ( B6T MCR available (See Note 1).

K-700 to PSW CT6 Switcbgear) located at STATALARM transformer PSW Building (See 2SA17-18 Note 1) (See Note 2)

Fail Electrical Closed is normal Operator Failure is Detectable and Closed failure or position of breaker. Detection (See Acceptable. Upstream breaker mechanical Faults would be Note 2) will open circuit on downstream failure cleared by upstream breaker failure to trip.

circuit breaker (See Note 3). Operator Open Breaker closed Detection (See 13.8KV Breaker 'A' is open at duen due trecanrcaloe to mechanicalAcetb. Note 2) PSW. Failure is Detectable and failurefailur Acceptable.

Partial trip Electrical See Fail Closed Operator Failure is Detectable and failure or Discussion above and Detection (See Acceptable (See Fail Closed mechanical Note 8 Note 8) Discussion above and Note 8) failure Partial Electrical See Fail Open Operator Failure is Detectable and closure failure or Discussion above and Detection (See Acceptable (See Fail Open mechanical Note 8 Note 8) Discussion above and Note 8) failure

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW-Keowee Emergencv Backup Power Revision No: 0 Subsystem: N/A Prepared by: Dinesh R. Patel Equipment: Keowee 13.8 kV KPF-Switchgear Breaker for PSW EmerRency Feed Date: 2/16/12 Drawings: K-700 & K-704 I

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW--Keowee Emergency Backup Power Revision No:..

Subsystem: NIA Prepared by: Dinesh R. Patel Equipment: Keowee 13.8 kV KPF-Switchgear Breaker for PSW Emergency Feed Date: 2/16/12 Drawings: K-700 & K-704 Case Component Funto Failure Failure Effects on Train Method Failure of No.

(1) identification (2) (3) Mode (4) Mechanism (5) and/or (6) System Detection Deecio (8)

(8) 2 K2 ELK"BK KPFI2 Provide Fail open Electrical Loss of Keowee as an Operator Failure is Detectable and Keowee (Tripped) failure or alternate emergency Detection - Acceptable. Diverse redundant Circuit Breaker Emergency mechanical power supply to PSW Oconee U2 means of supplying power are Backup Power failure transformer C77 ( B7T MCR available (See Note I)

K-700 to PSW CT7 Switchgear) located at STATALARM transformer PSW Building (See 2SA17-18 Note 1) (See Note 2)

Fail Closed Electrical Closed is normal Operator Failure is Detectable and failure or position of breaker. Detection (See Acceptable. Upstream breaker mechanical Faults would be cleared Note 2) will open circuit on breaker failure by upstream circuit failure to trip.

breaker (See Note 3) 13.8KV Breaker 'C' is open at Open Breaker closed operator PSW. Failure is Detectable and due to mechanical Detection (See Acceptable.

failure Note 2)

Partial trip Electrical See Fail Closed Operator Failure is Detectable and failure or Discussion above and Detection (See Acceptable (See Fail Closed mechanical Note 8 Note S) Discussion above and Note 8) failure Partial Electrical See Fail Open Operator Failure is Detectable and closure failure or Discussion above and Detection (See Acceptable (See Fail Open mechanical Note 8 Note 8) Discussion above and Note 8) failure Loss of Electrical See Note 4 Operator Failure is Detectable and control failure Detection (See Acceptable power Note 5)

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW-Keowee Emergency Backup Power Revision No: 0 Subsystem: N/A Prepared by- Dinesh R. Patel Equipment: Keowee 13.8 kV KPF-Switchgear Breaker for PSW Emenzency Feed Date: 2/16/12 Drawings: K-700 & K-704 Method of Case Component Function Failure Failure Effects on Train Failure No. Identification Mode Mechanism and/or System Detection Remarks and Other Effects (1) (2) (3)J(4) (5) (6) .. t(7) 1.

(8) 3 KI ELK BK KPF09 Provide PSW Fail open Electrical PSW Emergency 13.8 Operator Failure is Detectable and emergency (Tripped) failure or kV power feed from Detection (See Acceptable. Diverse redundant Cirui Breaker Circuit 13.8 kV Power mechanical Unit I is lost. (See Note 2) means ofsupplying power are from Keowee failure Note 6) available (See Note 1)

K-700 Unit I Fail Closed Electrical Open is normal Operator Failure is Detectable and failure. position of breaker. Detection (See Acceptable'(See Note 7)

Failure to trip would Note 2)

See Case-il for result in loss of Mechanical Keowee Unit 1 Failure. Generator (See Note 7)

Partial trip Electrical See Fail Closed: Operator Failure is Detectable and failure or Discussion above and Detection (See Acceptable (See Fail Closed mechanical Note 8 Note 8) Discussion above and Note 8) failure Partial Electrical See Fail Open Operator Failure is Detectable and closure failure or Discussion above and Detection (See Acceptable (See Fail Open mechanical Note 8 Note 8) Discussion above and Note 8) failure Loss of Electrical See Note 4 Operator Failure is Detectable and control failure Detection (See Acceptable power Note 5)

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW-Keowee Emergency Backup Power Revision No: 0 Subsystem: N/A Prepared by: DineAsh R. Patel Equipment: Keowee 13.8 kV KPF-Switchnear Breaker for PSW Emergency Feed Date: 2/16/12 Drawings: K-700 & K-704 case "ase component c atpon Function Failure Failure Effects on Train fMethod°of Failure No. Identification (3) (3Mode Mechanism and/or system: Demtectionhr (8)ection ffct (1) (2) (4) (5) (6) ".(7) (8) 4 K2 ELK BK KPFI Provide PSW Fail open Electrical PSW Emergency 13.8 Operator Failure is Detectable and emergency (Tripped) failure or kV power feed from Detection (See Acceptable. Diverse redundant Circuit Breaker 13.8 kV Power mechanical Unit 2 is lost. (See Note 2) means of supplying power are KPF-I from Keowee failure Note 6) available (See Note 1)

K-700 Unit 2 Fail Closed Electrical Open is normal Operator Failure is Detectable and failure, position ofbreaker. Detection (See Acceptable (See Note 7)

See Case-18 for Failure to trip would Note 2)

Seechacasl f result in loss of Mechanical Keowee Unit 2 Failure. Generator (See Note 7)

Partial trip Electrical See Fail Closed Operator Failure is Detectable and failure or Discussion above and Detection (See Acceptable (See Fail Closed mechanical Note 8 Note 8) Discussion above and Note 8) failure Partial Electrical See Fail Open Operator Failure is Detectable and closure failure or Discussion above and Detection (See Acceptable (See Fail Open mechanical Note 8 Note 8) Discussion above and Note 8) failure Loss of Electrical See Note 4 Operator Failure is Detectable and control failure Detection (See Acceptable power Note 5)

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW-Keowee EmerRency Backup Power Revision No: 0 Subsystem: N/A Prepared by: Dinesh R. Patel Equipment: Keowee 13.8 kV KPF-Switchgear Breaker for psW Emergency Feed Date : 2/16/12 Drawings: K-700 & K-704

... Method of Case Component Function Failure Failure Effects on Train Failure No. Identification uno Mode Mechanbm and/or System Detection Remarks and Other Effects (1) (2) (3) (4) (5) 1(6) j t (8) .

5 KI ELK RL Provide breaker Contact Electrical KPF-1 1 fails to open Operator Failure is Acceptable - Backup 96KPF1 1 trip signal Set - fails failure or on faults - but Detection (See overcurrmt relay protection is in F1 r initiated by open mechanical upstrem breakerb9wiil Note 1:1) place to trip upstream breaker circuit for breaker (50/cu5)ent failure operate to clear fault should this 86-KPFI I trip c -ircuifr breater (50151) and (circuit fail to operate.

KPF-lground fault (See Note 9) Redundant diverse power

9) (510) protective sources are still available (See K-700 & KEE- relays for KPF- Note 9) 0122-002 11 Contact Electrical False trips ( contact Operator Failure is Detectable and Set - fails failure or closures) could result Detection (See Acceptable - Diverse Power closed mechanical in loss of one PSW Note 11) Feeds are still available (See failure emergency feed Note 1) through KPF- 1I Relay fails Electrical False Trip of breaker Operator.. Failure is Detectable and to failure or KPF-11 Detection (See Acceptable - Diverse Power energized mechanical Note 11) Feeds are still available if state failure needed (See Note 1)

Relay fails Electrical KPF-1 1 fails to open Operator Failure is Acceptable - Diverse to de- failure or on faults - but Detection (See Protection and Breaker Failure energized mechanical upstream breaker 9 will Note 11) Scheme will provide protection state failure operate to clear fault via KPF-9. Redundant diverse power sources are still available.

(See Note 9) (See Note 9)

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 tlSvstem:

6 * -

PSW-KenweeEme JIlA encvBarkun Power Revision No: 0 W Yký Prepared by: Dinesh R. Patel Equipment: Keowee 13.8 kV KPF-Switchgear Breaker for PSW Emergency Feed Date: 2/16/12 Drawings: K-700 & K-704 Case Component F Failure Failure Effects on Train fMethod Failure of n No. Identification Function Mode Mechanism and/or System Detec in Remarks and Other Effects (1) (2) (4) (5) (6) (7) (8) 6 K2 ELK RL Provide b r Contact Electrical KPF-12 fails to.open Operator Failure isAcceptable - Backup 86KPF12 trip signal Set - fails failure or on faults - but Detection (See overcurrent relay protection is in 86-KPF12 trip initiated by open mechanical upstream breaker 10 Note 11) place to trip upstream breaker circuit for breaker overcurrent failure will operate to clear should this 86-KPF12 trip KPF-12 (See Note (50/51) and fault circuit fail to operate.

9) 1ground o) fault (See Note Redundant diverse power

9) (51G) protective (See No 9) sources are still available (See K-700 & KEE- relays for KPF- Note 9) 0222-002 12 Contact Electrical False trips (contact Operator Failure is Detectable and Set - fails failure or closures) could result Detection (See Acceptable - Diverse Power closed mechanical in loss of one PSW Note 11) Feeds are still available (See failure emergency feed Note 1) through KPF-12 Relay fails Electrical False Trp of breaker Operator Failure is Detectable and to failure or KPF-12 Detection (See Acceptable - Diverse Power energized mechanical Note 11) Feeds are still available if state failure needed (See Note 1)

Relay fails Electrical KPF-12 fai to open Operator Failure is Acceptable - Diverse to de- failure or on faults - but Detection (See Protection and Breaker Failure energized mechanical upstream breaker 10 Note 11) Scheme will provide protection state failure will operate to clear via KPF-10. Redundant diverse fault (See Note 9) power sources are still available.

(See Note 9)

APPENDIX-A PAGE A9 APPENDX - APAGTA Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW-Keowee EmerRencv Backup Power C. *S1--+a- MIA Revision No: 0 JUU~ay*II B. 1Wo M

Prepared by: Dinesh R. Patel Equipment: Keowee 13.8 kV KPF-Switchgear Breaker for PSW Emergency Feed Date: 2/16/12 Drawings: K-700 & K-704

,, ,. ..... Meho of, ,,

Case Component Failure Failure Effects on TinMethdof No. Identification Mode Mechanism and/or Systemr Remarks and Other Effects (1) (2) (3) (4) (5) (6) Detection (8) 7 KO ELK RL 86KPF Provide Contact Electrical Generator protective Operator Failure is Detectable and briakersuit breaker trip Set - fails failure or relays operate and trip Detection - Acceptable - Existing Generator for breakers KPF-9, signal initiated open mechanical the connected KIU Loss of an Protective relay circuits will KPF-lO, KPF-I 1, & by overcurrent failure generator as well as operating unit, protect the connected generator.

KPF-J2 (See Note (51 for KPF 9 connected 13.8 kV would provide Power can be supplied from the

& KPF 10), output breakers numerous MCR other Unit or overhead power

10) differential through 86El86E2 trip indications(See feed options as scussed in K-700 & KEE-0 121 (87KPF), and circuits for fault Note 2) Note I ground fault protective relays for KPF switchgear breakers Contact Electrical Trip of breakers KPF-9 STATALARM Failure is Detectable and Set - fails failure or or 10 and loss of PSW via Oconee Acceptable. Diverse redundant closed mechanical emergency feeds to 2SA17-6 and means of supplying power are failure CT6 and CT7 Keowee SAI- available (See Note 1) 35 Relay fails Electrical Same as contact set- Same as contact Failure is Detectable and to failure or fails closed discussed set - fails Acceptable - Same as contact set energized mechanical above closed fails closed discussed above state failure discussed above Relay fails Electrical Same as contact set Same as contact Failure is Detectable and to de- failure or fails open discussed set fails open Acceptable - Same as contact set energized mechanical above discussed above fails open discussed above state failure

Station: Keowee Hydro Units 1&2 System: PSW-Keowee Emeraencv Backup Power Calculation: KC-2190 Revision No: 0 Subsystem: N/A Equipment: Keowee 13.8 kV KPF-Swltchgear Breaker for PSW Emergency Feed Prepared by: Dinesh R.Patel Drawings: K-700 & K-704 Date: 2/16/12 Case Component Function Failure Failure Effects on Train Method Fai .lureof No. Identification Fni Mode Mechanism and/or System Detection Remarks and Other Effects (1) (2) (3) (4) (5) (6) (7)j (8) 8 KI ELK BK Provide125V Fails Open Electrical Loss of breaker 9 status Operator Failure is Detectable and IDA2CC DC Control Failure or indication lights on Detection- Acceptable - Loss of power to Unit I 125VDC Power for Mechanical Oconee 2AB3,and Loss of breaker these relays result in loss of Distribution Center interposing Failure 2EFS panels. status lights for indicating lights and Statalarm relays 52-9RD breaker 9 is only. No control functions am and 52-9RC detectable by lost.

K-704 mounted in operator Keowee- observation.

Oconee Interface Cabinet No.

KOIC-A OEE-114 OA Fails Electrical Fault would be cleared Operator Failure is Detectable and Closed Failure or by supply breaker to Detection - Acceptable - Power can be (Fails to Mechanical Distribution Center Loss of status supplied from Keowee Unit 2 trip) Failure IDA - resulting in loss lights for through breaker 10 and 12 to of Distribution Center breakers, PSW transformer CT 7 (See and loss ofUnit I Note 1)

Generator due to loss of Generator DC control power circuits

API)NfNIfI - A PAMF: Al1I Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW.-Keowee Emergency Backup Power Revision No: 0 Subsystem: N/A Prepared by: Dinesh R. Patel Equipment: Keowee 13.8 kV KPF-Switchgear Breaker for PSW Emergency Feed Date:. 2/16/12 Drawings: K-700 & K-704 Method of Case Component Failure Failure FunctionFailure Effects on Train No. Identification Fni Mode Mechanism and/or System Detection Remarks and Other Effects (1) (2) (3) ((5) (6) . (7) .:_ (8) _ _ _

. 9 KI ELK BK Provide125V Fails Open Electrical Loss of breaker KPF-9 Operator Failure is Detectable and IDA2CL DC Control Failure or Remote control from Detection Acceptable - Power can be U Power to Mechanical Oconee Control Room Keowee supplied from Keowee Unit 2 Diti Center Protective Failure Control Board through breaker 10 and 12 IDAiBreaker 2CL Relay Circuits 3 Breaker KPF- through PSW transformer CT 7 for Breakers 9 09 Red Light (See Note 1)

K-704 &l1 goes oft KEE-01 17 0A KEE- 119 Fails Electrical Fault would be cleared Operator Failure is Detectable and Closed Failure or by supply breaker to Detection- Acceptable - Power can be (Fails to Mechanical Distribution Center Loss of breaker supplied from Keowee Unit 2 trip) Failure IDA- resulting in loss through breaker 10 and 12to of Distribution Center Kislaow KeoweeNoe1 PSW transformer CT 7 (See and loss of Unit I Control Board Note 1)

Generator due to loss CB3.

of Generator DC control power circuits

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW-Keowee Emergency Backup Power Revision No: 0 Subsystem: N/A Prepared by: Dinesh R.Patel Equipment: Keowee 13.8 kV KPF-Switchgear Breaker for PSW Emergency Feed Date: 2/16/12 Drawings: K-700 & K-704 Case Component Function Failure Failure Effects on Train Method of No. Identification Fni Mode Mechanism and/or System Detection Remarks and Other Effects (1) (2) (3) (4) (5) (6) (7) (8) 10 KI ELK BK Provide125V Fails Open Electrical Loss of Control Power Operator Failure is Detectable and IDA2CR DC Control Failure-or and protective relay Detection - Acceptable - Power can be Unit I 125VDC Power to Trppe Mechanical operation for KPF 9 DC Power supplied from Keowee Unit 2 to Disbution Cente CircuitDistibuion 9 l Iwoul entr Failure Brakes and I. nedBreakers tobe Available raeP8W breakers 10 and 12CT tranaorme through 7 (See IDA Breaker 2CR Breakers 9 &1 inoperabl woudeclarneed be White Light on Note 1 7 K-704 KEF-I19 KEE-122 resulting in loss of PSW Emergency Keowee CB2 Nt Howeverbased p) on potential KEo-12 fromKergen silent failures ofnormally de-power from Keowee energized protective trip relays, Und lOne Gffenertor It is recommended that the new and loss ofUl feed t trip circuits from EC 91875 be PSW transformer CT6 accounted for in system surveillances to validate the functionality of the desired protective functions.

Fails Electrical Fault would be cleared Operator Failure is Detectable and Closed Failure or by supply breaker to Detection- Acceptable - Power can be (Fails to Mechanical Distribution Center Via loss of DC supplied from Keowee Unit 2 trip) Failure IDA- resulting in loss Power through breaker 10 and 12 to of Distribution Center Available PSW transfbrmer CT 7 (See and loss of Unit I Whit Note 1)

Generator due to loss White Light on of Generator DC control power circuits

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW-Keowee Emergency Backup Power Revision No: 0 Subsystem: N/A Prepared by: Dinesh R.,Patel Equipment: Keowee 13.8 kV KPF-Switchgear Breaker for PSW Emergency Feed Date: 2/16/12 Drawings: K-700 & K-704 Method of Case Component Function Failure Failure Effects on Train Failure RO No.

(1)

Identifcation (2) (3)

Mode (4)

Mechanism (5) and/or System (6) 1(7) iRemarks (8) and Other Effects 11 KI ELK BK Providel25V Fails Open Electrical Loss of breaker 10 Operator Failure is Detectable and 2DA4CC DC Control Failure or status indication lights Detection - Acceptable - Loss of power to Power for (Tripped) Mechanical on Oconce 2AB3 and Loss of breaker these relays result in loss of Unit 2 125VDC interposing Failure 2EFS panels. status lights for indicating lights and Statalarm Distribution Center breaker 10 is only. No control functions are relays 52-2DA Breaker 4CC 1ORD and 52- detectable by lost K-704 1ORC mounted operator in Keowee- observation.

Oconee Interface Cabinet No.

KOIC-B OEE-214 OA S 1. 1 Fails Electrical Fault would be cleared Operator Failure is Detectable and Closed Failure or by supply breaker to Detection - Acceptable - Power can be (Fails to Mechanical Distribution Center Loss ofstatus supplied from Keowee Unit 1 trip) Failure 2DA - resulting in loss lights for through breaker 9 and 11 to of Distribution Center breakers PSW transformer CT 6 (See and loss of Unit 2 Note I)

Generator due to loss of Generator DC control power circuits

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW -Keowee Emergencv Backup Power Revision No: 0 Subsystem: N/A Prepared by: Dinesh R. Patel Equipment: Keowee 13.8 kV KPF-SwItchRear Breaker for PSW Emergency Feed Date : 2/16/12 Drawings: K-700 & K-704 Effects on Train Method of Case No.

(1)

Component Identification (2)

Function (3)

Failure Mode (4)

Failure Mechanism (5) and/or System (6)

Failure Detection D7) j Remarks and Other Effects (8) 12 K2 ELK BK Providel25V Fails Open Electrical Loss of breaker KPF- Operator Failure is Detectable and 2DA4CL DC Control Failure or 10 Remote control Detection Acceptable - PSW Emergency Power Keoweecan be supplied I throughfrom RoomOconee Control Power to (TjJpped) Mechanical from Keowee Control Board Unit breaker Distriu2on Center Protective Failure Distr eaker Relay Circuits 8 Breaker KPF- 9 and l I through PSW 2DA Breaker 4CL for Breaker 10 10 Red Light transformer CT 6 (See Note 1)

K-704 & 12 goes off.

KEE-0217 OA KEE-219 Fails Electrical Fault would be cleared Operator Failure is Detectable and Closed Failure or by supply breaker to Detection - Acceptable - PSW Emergency (Fails to Mechanical Distribution Center Loss of breaker Power can be supplied from trip) Failure 2DA - resulting In loss sKeowee Unit I through breaker of Distribution Center lights on 9 and 11 through PSW and loss of Unit 2 Kowetrsformer CT 6 (See Note )

Generator due to loss Control Board trnfreCT6(eNoe)

CBS of Generator DC control power circuits

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW-IKeowee Emermency Backup Power Revision No: 0 Subsystem: N/A Eauinment: Keowee 13.8 kV KPF-Switchnear Breaker for PSW Emereencv Feed Prepared by: Dinesh R. Patel Date: 2/16/12 Drawings: K-700 & K-704 Case No. Component Identification Function (3)

IFailure Mode Failure Mechanism Effects on Train and/or Systemretection Failure M'ethod of R Remarks and other Effects (1) (2) 1 (4) (5) (6) (7) (8) 13 KI ELK BK Provide125V Fails Open Electrical Loss of Control Power Operator Failure is Detectable and 2DA4CR DC Control Failure or and protective relay Detection - Acceptable - Power can be Unit 2Di2srbuCo C r Power to (Tripped) Mechanical Failure operation and for KPF 10

12. Breakers DC Power supplied 9from breakers andKeowee Unit 1 through I to PSW intcutFiuead 2 raeAvailable Distr e nter Breakers 10 would need to be White Light on transformer CT 6 (See Note 1) 2DA Breaker 4CR and 12 declared inoperable WieLgto K-704 resulting in loss of Keowee CB9 However, based on potential KEE-219 PsW Emergency E-2 Ewergoeoe goes ofE silent failures of normally de-energized protective trip relays, KEE-222 power from Keowee it is recommended that the new Unit Two Generator trip circuits from EC 91875 be and loss of feed to accounted for in system PSW transformer CT7 survemlances to validate the functionality of the desired protective finctions.

Fails Electrical Fault would be cleared Operator Failure is Detectable and Closed Failure or by supply breaker to Detection- Acceptable - Power can be (Fails to Mechanical Distnrbution Center Via loss of DC supplied from Keowee Unit I trip) Failure 2DA - resulting in loss Powe through breaker 9 and 11 to ofDistribution Center Power PSW transformer CT 6 (See and loss of Unit 2 vite Light Note )

Generator due to loss WhiteLgo of Generator DC Keowee CB9 control power circuits

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW-Keowee Emermency Backup Power Revision No: _O Subsystem: N/A Prepared by: Dinesh R. Patel Equipment: Keowee 13.8 kV KPF-Switchgear Breaker for PSW Emergency Feed Date: 2/16/12 Drawings: K-700 & K-704

,I,, ,, Method of CaseFailure Failure Effects on Train Noas e nC aionent Function Failure Remarks and Other Effects No. Identification (3) Mode Mechanism and/or System Detection R (1) (2) (4) (5) (6) (7) (8) 14 125VDC Provide power Fail Open Electrical or Same as Itrns 8, 9 and Same as Items Same as Items 8, 9 and 10.

Distribution IDA. Center for controlrelay protective & (Tripped) Mechanical 10. 8,9 and 10. Results in loss of DC power to I prtectivfor breaker Failure the affected Unit.

K1ELK-PL.-1DA fobrae KPF-9 and However, this is the same failure (K-704) KPF-1 1 scenario for the existing breakers (ACB-1 through 4) in the current design and does not present a new failure mode Fail Close Electrical or Same as Items 8, 9 and Same as Items Same as Items 8,9 and 10.

(Fails to Mechanical 10. 8, 9 and 10. However, this is the same failure trip) Failure scenario for the existing breakers (ACB-1 through 4) in the current design and does not present a new failure mode

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW -Keowee Emergency Backup Power Revision No: 0 Subsystem: N/A Prepared by: Dinesh R. Patel Equipment: Keowee 13.8 kV KPF-Switchgear Breaker for PSW Emergency Feed Date: 2/16/12 Drawings: K-700 & K-704 Case Component Failure Failure Effects on Train No. (1)o. (2 Idn~ictio ()

Identification Function 4)Mode Maioure ()Mechanism Fechaniure 6)and/orsonTri Ef System ()Detection Failure (8 Remarks and Other Effects (1) (2) (3)I4 (5) (6) Det(7)io 1(8) 15 125VDC Provide power Fail Open Electrical or Same as Items 11, 12, Same as Items Same as Items 11, 12 and 13.

Distribution Center for control & Mechanical and 13 11, 12, and 13 Resultsin loss of DC power to 2DA protective relay pped) Failure the affected Unit.

for breaker K2ELK-PL-2DA KPF-10 and However, this is the same failure (K-704) KPF-12 scenario for the existing breakers (ACB- I through.4) in the current design and does not present a new failure mode Fail Close Electrical or Same as Items 11, 12, Same as Items Same as Items 11, 12, and 13 (Fails to Mechanical and 13 11, 12, and 13 However, this is the same failure trip) Failure scenario for the existing breakers (ACB-I through 4) in the current design and does not present a new failure mode

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW-Keowee Emergencv Backup Power Revision No: 0 Subsystem: N/A Prepared by: Dinesh R. Patel Equipment: Keowee 13.8 kV KPF-Switchfgear Breaker for PSW Emergency Feed Date: 2/1.6/12 Drawings: K-700 & K-704

... Method of Case Component Failure Failure Effects on Train No.

(1) identification (2)d(3) Mode (3 (4) Mechanism (5) and/or System (6) Detection (8 Remarkes (8)(7)

ReasanOtrEfes

_8) 16 KOELK-RL-87KPF Provides Loss of Electrical or This failure would Detection of However, to improve the protection for 12SVDC Mechanical. jeopardize the loss of DC reliability of the design, critical KPF-], and 2 Power capability of using power is easily shared protective relays are KOELK-RL- Switchgears either Keowee detectable powered through an existing 59GNPX and KHU-l, Generator Unit during through power transfer switch used for KJELK-1D- and 2 emergency conditions Keowee control KHU I and 2 relaying shown on 62BKPFI I Generators until DC power was room drawing K-704 (Re£ 7). The restored. indications power transfer switch shown on K2ELK-TD- (White light on drawing. K-704 enables 62BKPF12 the control 125VDC power to these relays Dwgs: K-700 board 2 & 9) either from DC distribution and required center IDA or 2DA.

K-704 corrective It takes two hardware failures KEE-0121 action will be for complete loss ofDC power KEE-0122-002taken to restore which is not considered a DC control credible failure mode.

KEE-0222-002 power.

KEE-017

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW-Keowee Emergency Backup Power Revision No: 0 Subsystem: N/A Prepared by: Dinesh R. Patel Equipment: Keowee 13.8 IkV KPF-Switchlear Breaker for PSW Emergency Feed Date: 2/16/12 Drawings: K-700 & K-704 FFailure IIMethod( Failure Effects an Train FMe of Case Component No. Identification Function Mode Mechanism and/or Systern Failure Remarks and Other Effects (1) (2) (3) (4) (5) (6) (7) (8) 17 KI ELK BK KPF09 Provide PSW Bkr. KPF- Mechanical Depending upon the: Operator The KHU-2 is running and Circuit Breaker emergency 10 is failure KHU and PSW Detection (See breaker KPF-10 is closed which Cirui 13.8 kV Power closed, operating Note 2) energizes the KPF-l and 2 KPF-9 from Keowee Normally configuration. switchgears due to cable tie K70UnIOpn Sbetween two switchgears and K-700 Un Open B See Remarks provides power to PSW B6T Breaker and B7T switchgear via CT6 KPF-09 and CT7 transformers SCloses, respectively.

See It is very unlikely but remotely Remarks possible that due to mechanical failure (closing shaft linkage, associated component with cams) could close KPF-9 breaker which is supposed to be in the open position. Under this condition following may happen:

I. If Generator KHU-1 is off line then Generator KHIU-I wiU start running as an induction motor load from the Generator KHU-2 uniL This is not desirable.

This could result in severe damage and loss

__of both KHU Units.

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW-Keowee EmerRency Backup Power Revision No: 0 Subsystem: N/A Prepared by: Dinesh R. Patel Equipment: Keowee 13.8 kV KPF-Switchgear Breaker for PSW Emergency Feed Date : 2/16/12 Drawings: K-700 & K-704 T ... Method of Case Component Funcon Failure Failure Effects on Train Failure R a No.

(1)

Identification (2) 1.(3) Mode (3).*

(4)

Mechanism (5) and/or System (6)

Detection 1(....________(8)

(7 ) .,:

and Other Effects Remarks 17 2. If Generator KHU-I (Contd) powers CT-4 and both KHU units are connected to the 230KV overhead tie, then inadvertent closing of the Breaker KPF-9 will not create electrical damage, since both Units are synchronized.

3. If Generator powers CT-4 KHU-I and both KHU units are not connected to 230KV overhead tie then inadvertently closure of KPF-9 will connect two generators which may probably be out-of-synchronism resulting in severe damage and loss of both KHU units and associated equipment.

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW--Keowee Emergency Backup Power Revision No: .Q Subsystem: N/A, Prepared by: Dinesh R. Patel Equipment: Keowee 13.8 kV KPF-Switchgear Breaker for PSW Emergency Feed Date : 2116112 Drawings:, K-700 & K-704 Failure Failure ST Effects on TrainFailure r Method of Case Component No. Identification Function Mode Mechanism and/or System Detection (8)Remarks and Other Effects (1) (2) (3) (4) (6) (7).. ,() (..... .

is KI ELK BK KPF10 Provide PSW Blk. KPF- Mechanical Depending upon the Operator The KHU-I is running and emergency 09 is failure KHU and PSW Detection (See breaker KPF-09 is closed which Circuit Breaker 13.8 kV Power closed. operating Note 2) energizes the KPF-l and 2 KPF-10 from Keowee configuration. switchgears due to cable tie Normally between two switchgears and K-700 Unit 2 See Remarks Open provides power to PSW B6T Breaker and B7T switchgear via CT6 KPF-10 and CT7 transformers Closes. respectively.

See It is very unlikely but remotely Remarks possible that due to mechanical fkilure (closing shaft linkage, associated component with cams) could close KPF-] 0 breaker which is supposed to be in the open position. Under this condition following may happen:

I. If Gcnerator KHU-2 is off line then Generator KHU-2 will start running as an induction motor load from the Generator KHU-l unit.

This could result in severe damage and loss of both KHU Units.

L_____________________________.1.______________________ .L....................... J £ _______________________

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW -Keowee Emenzency Backup Power Revision No: 0 Subsystem: N/A Prepared by: Dinesh R. Patel Equipment: Keowee-13.8 W KPF-Switchpear Breaker for PSW Emergencv Feed Date: 2/16/12 Drawings: K-700 & K-704 Case Component Failure Failure Effectson Train MFailure No. Identification (3) Mode Mechanism. and/or System Detecion Remarks and Other Effects (1) (2) 3(4) (5) (6) (7) (8) 18 2. If Generator KI-IU-2 (Contd) powers CT-4 and both KHU units are connected to the 230KV overhead tie, then inadvertent closing of the Breaker KPF-1O will not create electrical damage, since both Units are synchronized.

3. If Generator KHU-2 powers CT-4 and both KHU units are not connected to 230KV overhead tie then inadvertently closure of KPF-10 will connect two generators which may probably be out-of-synchronism resulting in severe damage and loss of both KHU units and associated equipment.

APPENDIX -.A. PAGE A23 APPENDIX -A PAGE A23 Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW-Keowee Emergencv Backup Power C 16 MIA Revision No: 0

~uuJyJt~aI,. fln Prepared by: Dinesh R. Patel Equipment: Keowee 13.8 kV KPF-Switchgear Breaker for PSW Emergency Feed Date: 2/16/12 Drawings: K-700 & K-704 Remarks and Other Effects Notes:

1. Keowee Circuit Breakers KPF-11 and KPF-12 are In normally closed positions and their operation is controlled by Keowee Operations. The Keowee underground circuits from each breaker to Its respective PSW transformer (KPF-11 powers CTS while KPF-12 powers CT7) is one of two alternate emergency power supplies as shown on drawing KC-700. A spare breaker module (Breaker 13) Is also available at the Keowee station should breaker module replacement be required for any of the four breakers (KPF-9, KPF-10, KPF-11, or KPF-12). Both PSW Transformers (CT6 and CTV) are each sized to carry all PWS loads in the event one PSW transformer Is not functional for any reason. Also, there is a tie breaker for PSW buses B6T and BMT. Based on this diversity of power feed options and compatible equipment ratings, a single failed open KPF-11 and 12 breaker Is acceptable.

13.8KV overhead supply from 100113.8KV Fant line substation Is the normal power supply to PSW loads with Keowee KHU-1 and KHU-2 as emergency backup power source.

2. Breaker (open and close) status lights and an associated ammeter are provided In the Keowee control room to verify proper breaker position and related current flow for all four breakers (KPF-9, 10, 11, and 12). Local breaker status lights (open and close) are also provided for each breaker at the switchgear enclosure. Breakers (KPF-11 and KPF-12) are normally closed and alarmed in the Oconee U2 MCR via STATALARM should either breaker be opened. Power path verification is also part of a 90 day technical specification surveillance requirement (TS SR 3.7.10.2) that verifies breaker operability by closing the Keowee to PSW feeder breakers as Identified in License Amendment Request No.

2008-005. Breaker Status Lights and Control Switches will also be Installed In Oconee U2 main control room for circuit breakers KPF-9 and KPF-10 under EC 91853 and EC 91852.

3. These PSW transformer feeder breakers KPF-11 and KPF-12 are each in series with the upstream breaker KPF-9 or KPF-10 and are of equal size, interrupting rating and having redundant protective devices. A breaker failure scheme Is being provided for a fault on either feeder breaker (KPF-11 or KPF-12) that would initiate a trip of breakers KPF-9 or 10 should breakers KPF-11 or KPF-12 fall to clear a fault. Operator action would be required to verify the fault and cleared or isolated prior to restoring power from either KHU unit to prevent subsequent trips from the original fault. Protective relay settings for breakers, buses and cables protection system Installed by EC 91875 as well as a review for Impacts on existing protective relays has been performed by calculation KC-2217 (Ref.12).

Ct~4nt; Vawa MAP "nif 12.2J

..,-, .Calculation: KC-2190 System: PSW-Keowee Emerfencv Backup Power No:R PreparedPby:

Revision t Subsystem: N/A Equipment: Keowee 13.8 kV KPF-Switchfear Breaker for PSW Emergencv Feed ae by: DineshR. Patel Drawings: K-700 & K-704 Date: .2/16/12 Failure Failure Effects on Train Mead Failure rEeof Case Component No. Identification Funion Mode Mechanism and/or SystiemO DeteCtion Remarks and Other Effects No. Idntfian (3) (6)Detecti (1) (2)(4(5(6

4. Loss of control power would result in the inability to operate the affected breaker (open or close) and the loss of breaker protective functions.

Breakers KPF-9, 10. 11 and 12 are controllable from the Keowee control room with breakers KPF-9 and KPF-10 normally controlled from the Oconee control room. Based on drawing K-704, breakers KPF-9 and KPF-11 (CTS feed) are powered from the U1 125V DC distribution panel and breakers KPF-10 and KPF-12 (CT7 feed) are powered from the U2 125V DC distribution panel. Until DC power Is restored, the affected breakers should be considered Inoperable and removed from service due to loss of protective features. This would result in loss of the Keowee emergency power feed to one transformer CTSICT7 (depending on which Units DC power was lost) at the time of power failure. This Is acceptable as explained in note I above due to diverse means to feed both PSW transformers (CT6 and CT?) from the 13.8 kV overhead feed from the 100113.8KV Fantline Substation and the fact that either PSW transformer (CTG/CT7) can feed all PSW loads.

8. Loss of DC breaker control power is alarmed via stat alarm In Keowee control room. Two White indicating lights are also provided In the Keowee control room to monitor the availability of the 125V DC breaker feeds. Functionality of control circuit is also verified during 90 day technical specification surveillance requirements as discussed In note 2 above.

Also, if the 125V DC control power Is lost and an emergency breaker open or close operation Is required then manual triplclose function at the breaker front could be achieved. If the closingltripplng springs need charging for the operation then, manual (maintenance) handle could be used. All these operations need to be performed with proper PPE equipment.

6. Keowee PSW emergency power can be supplied from either the Keowee Unit I (KPF-9) or Unit 2 (KPF-10) connection. Upon failure of either connecting breaker for any reason, the entire PSW emergency power feed loads can be supplied by the other Keowee Unit. KPF-9 and 10 are interlocked so only one Keowee Unit can be connected at any time. PSW loads could be supplied from the 13.8 kV overhead line as discussed In note I above.

7. Failure of this breaker (KPF-9 or KPF-1O) to trip (fall closed) due to faults when supplying emergency PSW power would result In operation of a breaker failure relay (50B-KPF9 or 50B.KPFIO) which would trip the affected generator via a lockout relay (86E-1 or 88E-2). Operator action would be required to ensure the faulted line was Identified and cleared/isolated prior to restoring power from unaffected KHU unit to prevent subsequent trips from the original faulL Since both KHU generators can each supply 100% emergency P8W loads, and only one generator is ever connected to PSW loads, the loss of one generator Is acceptable. If this breaker were to fall close (spurious closure) and the related Hydro Unit was running - then the PSW emergency power feeds through unaffected unit breakers KPF-11 or KPF-12 would be energized down to PSW Breaker A or Breaker C on PSW switchgear SOT or BTT respectively. Since these PSW breakers (A & C) are normally open this should have no adverse impact on the power system. If the associated Hydro Unit was not in operation, this breaker failure (spurious closure) would not energize the emergency power feeds. in either case, the breaker status would be detectable by operator status lights In the

Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System:. PSW -Keowee Emergency Backup Power Revision No: 0 Subsystem: N/A Prepared by- Dinesh R. Patel Equipment: Keowee 13.8 kV KPF-Switchgear Breaker for PSW Emergency Feed * -% ffI Drawings: K-700 & K-704 Uate : ZL&o6L, Method of Case Component Function Failure Failure Effects on Train Failure No. Identification (3) Mode Mechanism and/or System Detection (8)Remarks and Other Effects (1) (2) (4) (5) (6) (7)

Oconee Unit 2 main control room as well as in the Keowee control room which also can confirm current flow or the lack of current flow by the Installed Keowee ammeters. This is within the design basis of the PSW system (not single failure proof), Is detectable and may be also be remedied by replacement of the failed breaker with a spare breaker (If needed due to spurious breaker operation).

8. Partial trip or partial close failure modes would result In a breaker not being In its desired state of fully open or fully closed. All breaker operation is by Operator commands and failure of breakers to obtain the desired state will be noticed by the operator. Breaker Status Is available in the Keowee MOR and Oconee MCR as discussed in note 2 above and current flow or lack of current flow can also be confirmed by Keowee ammeters. A breaker that fails to trip completely (Partial trip) Is bounded by the analysis already presented for a breaker that falls to trip (Fall Closed). In a similar manner, a breaker that falls to completely close (Partial Close) Is bounded by the analysis already presented for a breaker that fails to close [Falls open (tripped)].

9. Breakers KPF-11 and KPF-12 have Identical but independent trip circuits and the following discussion can be applied to either set of protective relays. The 86 lockout relay provides breaker trip commands for its associated breaker upon Initiation of protective relays ZIG (ground overcurrent) or 50/51 (overcurrent) relays for faults detected on the circuit from its associated breaker. This lockout relay must be reset before the associated breaker can be re-closed. The 51G ground overcurrent relays are also supervised by a 69GNPX (generator neutral ground overvoltage) relay to prevent nuisance tripping during downstream transformer (CT6 or CTT) Initial current Inrush or fault in the feeder cables. Failure of contacts to close (falls open) for any of these relays during phase fault conditions would result in the upstream breaker (either KPF-9 or KPF-10) clearing the fault with either the breaker failure (50B KPFI I or SOB KPFI2) relays or overcurrent (51 KPF9 or 51 KPFIO) relays on the upstream breaker. The failure of breaker trip will Initiate the respective Generator trip by 59GNI or 59GN2. The loss of one feed is acceptable as discussed in note I above due to diverse and redundant dual power feed options.

10. Breakers KPF-9 (Keowee Unit 1) and KPF-10 (Keowee Unit 2) equipped with identical sets of protective relays per Dwg KC-700 that will operate lockout relay 86 KPF to trip whichever unit breaker (KPF-9 or KPF-10) is closed as well as downstream breakers KPF-11 and/or KPF-

12. Once operated, this lockout relay must be reset before any of these breakers can be re-closed. Breakers KPF-9 and KPF-10 are electrically interlocked so only one breaker can be closed at any given time. Breakers KPF-9 and KPF-10 have fault phase overcurrent relays (51 KPF9 and 51 KPFIO) that provide coordinated upstream overcurrent fault protection should feeder breakers KPF-11 or KPF-12 fall to clear a downstream fault. A breaker failure scheme is also provided to trip Keowee Generator I or 2 If KPF-9 or KPF-10 will not clear after an appropriate time delay (relays 62B KPFII or 62B KPF12). The ground fault relays (51G KPF1i or 51G KPF12) will trip Keowee Generator I or 2 if breaker KPF-11 and/or KPF12 falls to trip on the feeder ground fault.

APPENDIX- A PAGE A26 Station: Keowee Hydro Units 1&2 Calculation: KC-2190 System: PSW-Keowee Emergencv Backup Power Revision No: 0 Subsystem: N/AL.. Prepared by: 0Dinesh R. Pate Equipment. Keowee 13.8 kV KPF-Switchgear Breaker for PSW Emergency Feed Date: 2/s1/12 Date :. 2/21/12 Drawings: K-700 & K-704 Method of Case Component Funcon Failure Failure Effects on Train Failure RO No. Identification (3) Mode Mechanism and/or System o Remarks and Other Effects (1) (2) (3) (4) (5) (6) (7) (8)

11. Failure of protective relays In this trip circuit to operate for fault conditions downstream of breakers 11 and 12 would be Identified during operator post jvent review of upstream breaker (9 or 10) operation for fault clearance. Operator tools available would Include sequence of events recorder Inputs from various protective relays, observation of protective relay trip targets, and visual observation of equipment and cables. Prior to faults, failure of these normally de-energized relays and normally open contacts would only be detectable by periodic trip circuit testing.

12. These events could be mitigated by the following corrective actions:

Add Reverse Power Protection.

Add a cable tie with a breaker and protective relaying between load side of breaker KPF-9 and 10.

" Remove the cable tie between KPF-1 and 2 switchgear buses. In the event If power to PSW is available only from one path then close the bus-tie breaker at PSW B6TIB7T switchgear (PSW building).

" Ifone breaker KPF-9 (10) Is closed then keep, administratively or procedurally, the other breaker KPF-10 (9) in disconnected position.

Consider providing a mechanical Kirkkey Interlock between breakers KPF-9 and 10.

Failure Modes and Effects Analysis For Protected Service Water System

ML12080A199

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