CP-201201518, License Amendment Request (LAR) 12-007, Revision to Technical Specification 3.8.1, AC Sources - Operating, for Two 14-Day Completion Times for Offsite Circuits

License Amendment Request (LAR)12-007, Revision to Technical Specification 3.8.1, AC Sources - Operating, for Two 14-Day Completion Times for Offsite Circuits

ML13023A237
Person / Time
Site:	Comanche Peak
Issue date:	12/19/2012
From:	Flores R Luminant Generation Co, Luminant Power
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CP-201201518, LAR 12-007, TXX-12198
Download: ML13023A237 (54)

Text

Rafael Flares Lurminant Power 0 Senior Vice President

& Chief Nuclear Officer rafael.flores@luminant.com P.O. Box 1002 6322 North FM 56 Glen Rose, TX 76043 Luminant T 254 897 5590 C 817 559 0403 F 254 897 6652 CP-201201518 Ref: 10 CFR 50.90 TXX-12198 File # 236 December 19, 2012 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

SUBJECT:

COMANCHE PEAK NUCLEAR POWER PLANT (CPNPP) DOCKET NOS. 50-445 AND 50-446, LICENSE AMENDMENT REQUEST (LAR)12-007, REVISION TO TECHNICAL SPECIFICATION 3.8.1, "AC SOURCES - OPERATING," FOR TWO, 14-DAY COMPLETION TIMES FOR OFFSITE CIRCUITS

REFERENCES:

1. Luminant Power letter, logged TXX-12084, from Rafael Flores to the NRC titled "Comanche Peak Nuclear Power Plant (CPNPP) Docket Nos. 50-445 and 50-446, License Amendment Request (LAR)12-004, Revision to Technical Specification 3.8.1, 'AC Sources - Operating,' for Two, 14-Day Completion Times for Offsite Circuits," dated October 2, 2012.

2. Phone Conference between Luminant Power and the NRC to Discuss Acceptance Review of License Amendment Request 12-004, on December 12, 2012.

3. Luminant Power letter, logged TXX-12197, from Rafael Flores to the NRC titled "Comanche Peak Nuclear Power Plant (CPNPP) Docket Nos. 50-445 and 50-446, Withdrawal of License Amendment Request (LAR)12-004, Revision to Technical Specification 3.8.1, 'AC Sources - Operating,' for Two, 14-Day Completion Times for Offsite Circuits," dated December 13, 2012.

Dear Sir or Madam:

Reference 1 was License Amendment Request (LAR)12-004 for two, one-time, 14-day Technical Specification (TS) Completion Times (CTs) to complete a plant modification to be completed by March 31, 2014. As discussed between the NRC and Luminant Generation Company LLC (Luminant Power) in Reference 2, Luminant Power decided to withdraw LAR 12-004 and re-submit the LAR supported by a deterministic analysis for the CT extensions. In Reference 3, Luminant Power withdrew the LAR.

Pursuant to 10CFR50.90, Luminant Generation Company LLC (Luminant Power) hereby requests an amendment to the Comanche Peak Nuclear Power Plant (CPNPP), Unit 1 Operating License (NPF-87) and CPNPP Unit 2 Operating License (NPF-89) by incorporating the attached change into the CPNPP Unit 1 and 2 Technical Specifications (TS). This change request applies to both Units.

The proposed change will revise TS 3.8.1 entitled "AC Sources - Operating" to extend, on a one-time basis, two allowable Completion Times (CTs) of Required Action A.3 for one inoperable offsite circuit, from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days. This change is only applicable to startup transformer (ST) XST1 and will expire on March 31, 2014. This change is needed to allow sufficient time to 1) modify the XST1 138kV tower to add A member of the STARS Alliance Callaway - Comanche Peak

• Diablo Canyon

• Palo Verde

• San Onofre

• South Texas Project

• Wolf Creek Acc

U. S. Nuclear Regulatory Commission TXX-12198 Page 2 12/19/2012 disconnects for new alternate ST XST1A and replace existing disconnects for XST1 and 2) to make final terminations to facilitate connection of ST XST1 or alternate ST XST1A to the 1E buses. After completion of this modification, if XST1 should require maintenance or repair or if failure occurs, then the alternate ST XST1A can be aligned to the 1E buses well within the current CT of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

Three important elements provide the basis for the requested Technical Specifications (TS) change and provide a high degree of assurance of the capability to provide power to the safety related 6.9 kilo volt (kV) alternating current (AC) Engineered Safety Features (ESF) buses during the two, one-time, 14-day Completion Times (CTs) (allowed outage time (AOT) or CT as used in the Improved Standard Technical Specifications). The important elements are (1) a traditional engineering analyses, (2) avoidance of risk significant plant configurations using mitigation measures and (3) continued implementation of a Configuration Risk Management Program (CRMP) during the two, one-time 14-day extended CTs.

Attachment I provides a detailed description of the proposed change, a technical analysis of the proposed change, Luminant Power's determination that the proposed change does not involve a significant hazard consideration, a regulatory analysis of the proposed change, and an environmental evaluation. provides the affected TS page marked-up to reflect the proposed change. Attachment 3 provides the proposed changes to the TS Bases for information only. These changes will be processed per CPNPP site procedures. provides the retyped TS page which incorporates the requested change. Attachment 5 provides retyped TS Bases pages which incorporate the proposed changes for information only. provides marked-up pages of the Final Safety Analysis Report (FSAR) (for information only) which reflect the proposed changes to the FSAR. contains new commitments which will be completed or incorporated in the CPNPP Licensing Basis as noted. The commitment number is used by Luminant Power for the internal tracking of CPNPP commitments.

Luminant Power requests approval of the proposed License Amendment by September 30, 2013, to be implemented within 120 days of the issuance of the license amendment. The plant does not require this amendment to allow continued safe full power operation although approval is required to support a plant modification which will facilitate future connection of either the startup transformer XST1 or an alternate ST XST1A to the 1E buses within the current TS CT of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

In accordance with 10CFR50.91(b), Luminant Power is providing the State of Texas with a copy of this proposed amendment.

Should you have any questions, please contact Ms. Tamera J. Ervin-Walker at (254) 897-6902.

I state under penalty of perjury that the foregoing is true and correct.

U. S. Nuclear Regulatory Commission TXX-12198 Page 3 12/19/2012 Executed on December 19, 2012.

Sincerely, Luminant Generation Company, LLC Rafael Flores By : A dre d W, redt W. Madden Director, Oversight and Regulatory Affairs TJEW Attachments 1. Description and Assessment

2. Proposed Technical Specifications Change

3. Proposed Technical Specifications Bases Change (for information)

4. Retyped Technical Specifications Pages

5. Retyped Technical Specification Bases Pages (for information)

6. Proposed FSAR change (for information)

7. Summary of Regulatory Commitments c - E. E. Collins, Region IV W. Walker, Region IV B. K. Singal, NRR Resident Inspectors, CPNPP Alice Hamilton Rogers, P. E.

Inspection Unit Manager Texas Department of State Health Services Mail Code 1986 P. 0. Box 149347 Austin, Texas 78714-9347

I CORRESPONDENCE DISTRIBUTION To: Distribution File - SPARCS Document Number: TXX-12198 Document Issue Date: 12/19/2012 Title /

Subject:

Resubmittal of REVISION TO TECHNICAL SPECIFICATION 3.8.1, "AC SOURCES - OPERATING," FOR TWO, 14-DAY COMPLETION TIMES FOR OFFSITE CIRCUITS LA(P.. 2.- -7 Comments:

ReguMWtoy A'faiu Contact TJEW BY SUBJECT ON SITE DISTRIBUTION F. W. Madden (RA) e-mail ALL S. Moore (LEGAL-TXU) e-mail R. Flores (SVP/CNO) e-mail DP Rl Weeeilan (Na) g-.41' T. A. Hope (RA/NLM) e-mail BY SUBJECT

-A. "(NODIL) F--. mail TXX File (ALL TXX) e-mail T. Cilder (Pi) il I. D. Bird ("g) eM al ALL B. D. Patrick (MAINT) e-mail CCG - 006A (CPNPP) e-mail _Q R '-- 1/RP

-_R'I-Pa mil, CERTREC e-mail R. J. Kidwe e-mail R, B. Mays (VP/SE) e-mail AJ&+"i*] k*-*% 2.Q & M. Smith (OP/DOPS) e-mail S. Harvey (OP/SOM) e-mail OFF SITE DISTRIBUTION W. R. Morrison (OP/WC/OM) e-mail SELECTED DOCKETED CORRESPONDENCE (STARS) n o 1iIdz _ (GOP/PS) z-mail S Maglio (Callaway) e-mail K.J. Peters (SVP) e-mail T. Baldwin (Diablo Canyon) e-mail K. L. Pete (VP) e-mail R. Barnes (Palo Verde) e-mail S L. Smith (OP/PM) e-mail Baynes M Murray M. (Palo (STP) e e-mail D. A.

J. Goodwin Taylor (ES/DES)

(ES/TS) e-mail e-mail W. Muilenburg (Wolf Creek) e-mail L. Windham (ES/DEA) e-mail L. Conklin (SONGS) e-mail L. Wind.am..E./DE.. e-mail G. Schinzel (STARSENG) e-mail S. Sewel I (OE) e-mail (STARSNEI) e-mail S. Sewell (OE) e-mail S. Bauer D. Buschbaum (STARSSRA) e-mail K. Nickerson (SE/DSE) e-mail CPNPP IR RESPONSES BY SUBJECT D. Ambrose e-mail A. Dar*ri (GGMI) " il (aOi)

IR ONLY IONYJ. Mercer (ES/SE) e-maail

.* - ..... (XGI)a-,,ii*R. Bouldin e-mail B. Smith ...

U... .

LERs / PART 21 OTHER L.Ponce C K.A. Noa (VENDOR) e-mail D. M. Bozeman e-mail Special distribution instructions: Yes ! No (If yes, attach separate sheet with instructions)

FC - First Class Mail ORC - Part 21 submittals/ incoming notifications, LER and descriptions for LBD changes.

IR - Inspection Reports NODIL - Correspondence related to material/component acceptability IOER - NRCB, GL, IN, NUREG VENDOR - Vendor documents per STA-206 (Vendor Document Group)

PUC - Monthly Operating Reports, Notices of Civil Penalty, SALP Reports and LERs If revisions are required to distribution or distribution sheet, contact Regulatory Affairs (CPNPP).

ATTACHMENT 1 to TXX-12198 DESCRIPTION AND ASSESSMENT to TXX-12198 Page 2 of 38 12/19/2012 LICENSEE'S EVALUATION

5.0 REGULATORY ANALYSIS

5.1 No Significant Hazards Consideration 5.2 Applicable Regulatory Requirements/Criteria

6.0 ENVIRONMENTAL CONSIDERATION

7.0 PRECEDENT

8.0 REFERENCES

Attachment I to TXX-12198 Page 3 of 38 12/19/2012

1.0 DESCRIPTION

By this letter, Luminant Generation Company LLC (Luminant Power) requests an amendment to the Comanche Peak Nuclear Power Plant (CPNPP), Unit 1 Operating License (NPF-87) and Unit 2 Operating License (NPF-89) by incorporating the attached change into the Comanche Peak Unit 1 and 2 Technical Specifications (TS). Proposed change license amendment request (LAR)12-007 is a request to revise TS 3.8.1, "AC Sources - Operating" to revise the OR statement to the Completion Time (CT) of Required Action A.3. The statement is applicable only to startup transformer (ST) XST1, expires on March 31, 2014, and will allow, on a one-time basis, two extensions of the CT from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days.

Proposed Final Safety Analysis Report (FSAR) (Reference 8.1) changes, as discussed in Section 2 below, are included in Attachment 6 for information only.

2.0 PROPOSED CHANGE

The proposed change is summarized below and shown in Attachment 2.

The proposed change would revise Technical Specifications (TS) 3.8.1, "AC Sources - Operating,"

OR statement to the Completion Time (CT) of Required Action A.3 to allow two, one-time 14-day outages on XST1 to complete a plant modification to be completed by March 31, 2014. The two extended CTs will allow sufficient time to 1) modify the XST1 138kV tower to add disconnects for new alternate startup transformer (ST) XST1A and replace existing disconnects for XST1 and 2) to make final terminations to facilitate connection of ST XST1 or alternate ST XST1A to the 1E buses.

After completion of this modification, if XST1 should require maintenance or repair or if failure occurs, then the alternate ST XSTIA can be aligned to the 1E buses well within the current TS CT of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

For information only, this license amendment request includes markups in Attachment 3 indicating proposed associated changes to the Bases for TS 3.8.1, "AC Sources - Operating."

Retyped TS pages and TS Bases pages which incorporate the proposed changes are provided in Attachments 4 and 5, respectively.

The proposed changes in Chapters 8 and 9 of the Final Safety Analysis Report (FSAR) (Reference 8.1) (Attachment 6) reflect ST XST1, new alternate ST XST1A, new 138kV tower disconnect switches, firewall, and the installation of new cable buses and transfer panels. The FSAR Table and Figures not shown in the Attachment, but which will also be updated, are Table 8.3-3 and Figures 1.2-1, 8.2-1, 8.2-4, 8.2-7, 8.2-9, and 8.2-11.

3.0 BACKGROUND

3.1 Current Plant Design The 138 kilo volt (kV) switchyard and 345kV switchyard are supplied from nine transmissions lines, two lines to the 138kV switchyard and seven to the 345kV switchyard. The 138kV switchyard is physically and electrically independent of the 345kV switchyard. The 345kV and the 138kV switchyards each consist of a two bus arrangement having one breaker per transmission circuit. Transmission circuits terminate in individual positions on alternate buses in the switchyards. Power can be supplied to each switchyard from any of their respective transmission circuits. The plant switchyards and transmission line connections are shown in Final Safety Analysis Report (FSAR)

Figure 8.2-1.

Attachment i to TXX-12198 Page 4 of 38 12/19/2012 Two physically independent and redundant sources of offsite power are available on an immediate basis for the safe shutdown of either Unit. The preferred source to Unit 1 is the 345kV offsite supply from the Comanche Peak Nuclear Power Plant (CPNPP) 345kV switchyard and the startup transformer (ST), XST2 or spare ST, XST2A; the preferred source to Unit 2 is the 138kV offsite supply from the CPNPP 138kV switchyard through the ST, XST1. The preferred power sources supply power to the 6.9kV Class 1E buses during plant startup, normal operation, emergency shutdown, and upon a Unit trip. This eliminates the need for automatic transfer of safety-related loads in the event of a Unit trip. In the event one ST (e.g., XST1, a preferred source) becomes unavailable to its normally fed Class 1E buses, power is made available from the other ST (e.g., XST2, an alternate source) by an automatic transfer scheme. For the loss of a ST, the load transfer only takes place in the Unit for which the transformer was the preferred source. If it becomes necessary to safely shutdown both Units simultaneously, sharing of these offsite power sources between the two Units has no effect on the station electrical system reliability because each transformer is capable of supplying the required safety related loads of both Units although the design criteria require consideration of a Design Basis Accident (DBA) on one Unit only.

The STs (XST1 and XST2) and spare ST XST2A are physically located in the protected area near the Turbine Building (TB) and not in the switchyards. The switchyards are approximately 600 feet due west of the TB. XST1 is connected to the 138kV switchyard by an overhead line, while XST2 and the spare startup transformer XST2A are connected to the 345kV switchyard by a common overhead line.

Spare ST, XST2A, is in a dedicated location under the 345kV line to XST2 (refer to FSAR Figure 8.2-1) to serve as a replacement of XST2. Cable buses from secondary X and Y windings of XST2 and XTS2A are connected to two 6.9kV transfer panels to provide 345kV offsite power to Units I and 2 safety related buses. These transfer panels allow transfer of 345kV offsite power source for safety related buses from XST2 to XST2A and vice verse. This spare transformer, XST2A, may be physically relocated to a dedicated location near XST1, to serve as a replacement of XST1.

Currently, if XST1 requires maintenance that would exceed 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, or if XST1 fails, it would take about 18 to 21 days to replace XST1 with the spare ST XST2A. The timing is dependent on the mobilization/availability of heavy haulers, extent of transformer damage, and the availability of needed equipment and personnel to perform the work.

Since each ST provides one of the two required offsite AC sources for each CPNPP Unit, an outage of XST1 for greater than the current Completion Time (CT) of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> would require that both Units be shutdown to Mode 5.

3.2 Proposed Plant Design Modification This proposed amendment is similar to one previously approved by the Nuclear Regulatory Commission (NRC) on October 29, 2010 (ML103190632), that extended, on a one-time basis, the allowable CT of Required Action A.3 for the 345kV inoperable offsite circuit, from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days. This change was only applicable to ST XST2 and expired on March 1, 2011 and allowed sufficient time to make final terminations to facilitate connection of either XST2 or the spare ST XST2A to the Class 1E buses. The entire sequence of activities was projected to require approximately 11 days and 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> to complete which fit well within the requested 14-day extended CT. The actual time required to complete the plant modification was 7 days, 21 hours2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br />, and 16 minutes.

to TXX-12198 Page 5 of 38 12/19/2012 The main difference between the previous license amendment approved in 2010 and this license amendment request is that there was an installed spare transformer XST2A under the 345kV line that also fed XST2 but had to be relocated to serve as a replacement for XST1 as described in Section 3.1. In the present situation, there is no installed alternate transformer for XST1 thus additional provisions must be made to allow for the installation of a new transformer. Consequently, this requested amendment will require three primary scopes of work:

• 14-day CT is required to complete the 138kV work,

• Perform the necessary preparation, installing and testing of the new alternate ST, and 14-day CT is required to complete the 6.9kV work.

The proposed change will revise Technical Specifications (TS) 3.8.1 entitled "AC Sources -

Operating" to extend, on a one-time basis, two allowable CTs of Required Action A.3 for one inoperable offsite circuit, from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days. This change is only applicable to ST XST1 and will expire on March 31, 2014. The proposed change is needed to allow sufficient time to 1) modify the XST1 138kV tower to add disconnects for new alternate ST XST1A and replace existing disconnects for XST1 and 2) to make final terminations to facilitate connection of ST XST1 or the alternate ST XSTIA to the 6.9kV 1E buses within the current TS CT of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

Most of the work for this modification (e.g., XST1A 6.9kV cables pulls) will occur prior to the 14-day CTs when XST1 and XST2 are energized and while both CPNPP Units continue power operations in Mode 1.

For the first scope of work, a 14-day CT is needed to modify the 138kV tower for XST1 to support the new disconnect switches for a new alternate ST and replacement of the old existing disconnect switches for XST1. Specifically, the existing disconnect switches are obsolete, there are no spare parts, and they are difficult to adjust. Completing the 138kV tower work will require that XST1 be removed from service (i.e., open the bus tie breakers in the 138kV switchyard and disconnected from the 1E buses). Once the 138kV tower work is completed, transformer XST1 will be restored and the offsite source will again be operable. The entire sequence of activities to complete the first scope of work is projected to require approximately 11.5 days. Table 1, provides a more detailed list of planned maintenance activities and their durations.

For the second scope of work, no extended CT will be required for the new alternate ST XST1A connections, testing some of the protection scheme, installation of the bushings and coolers and oil-fill. A 72-hour TS CT may be entered to set the transformer on its pad and connect to the 138kV disconnects in order to charge the transformer unloaded for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The alternate ST will then be tested to ensure it was not damaged during delivery while isolated from the 6.9kV bus. The installation of the new alternate ST will include a three-hour fire wall that will be constructed between XST1 and the new alternate ST XST1A in addition to an automatic fire suppression water system for the new alternate ST. The times in Table 2 are approximate and some activities will occur in parallel for a total period of 52 days.

to TXX-12198 Page 6 of 38 12/19/2012 Table 1. 138kV Tower Scheduled Work Dates Maintenance Activity Approximate Time (Days)

Enter Time Critical LCO and Hang Clearances and Install 0.5 Grounds

• Disconnect XST1 and Remove Equipment on From Dead 1.5 End Structure Make Changes to Dead End Structure 0.5 Install New Steel on Dead End Structure 1.0 Install Air Switch for XST1 0.5 Install Air Switch for XST1A 0.5 Install Insulators, Lightning Arrestors, Coupling Capacitors 1.0 Voltage Transformers, Carrier Line Equipment Install Conduit, Pull Cables, Terminate Wires 1.0 Connect Bus to XST1 1.0 Check and Test the Control, Instrument and Protection 2.0 Circuits Remove Grounds and Pull Clearances 0.5 Energize 138kV and Perform Checks 0.5 Energize the 6.9kV 1E Buses from XST1 and Perform Checks 1.0 Exit LCO** 11.5

• Enter 14-day CT **Exit 14-day CT Table 2. XST1A Transformer Movement, Installation, Oil fill and Process, Test and Checks Maintenance Activity Approximate Maintenance__Activity_ Time (Days)

Perform XSTIA Preparatory Work Move XST1A onto the Permanent Pad 5.0 Assemble the XST1A Transformer 10.0 Fill Transformer with Oil and Process 5.0 Connect XSTIA to the 138kV Bus 5.0 Install Transformer Fire Suppression 5.0 Perform Checks and Tests 5.0 Energize XST1A Unloaded 2.0 Complete the 6.9V Cable Connections to XST1A 10.0 Perform XST1A Control, Instrument and Protection Circuit 5.0 Checks Complete the XST1A Installation 52.0 For the third scope of work, a second 14-day CT will require XST1 be out-of-service for greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> but less or equal to 14 days in order to install the transfer panels, terminate the XST1 and XST1A 6.9kV cables in the transfer panels, and terminate the cables on XST1A. Inside the transfer panels, there are three individual bus bars, one for the 1E bus cables, one for XST1 cables, and one for the alternate ST cables. The transfer panels have removable links that can connect to a ST and the 1E bus such that only one ST can be connected to the 1E buses at any given time. Once the 6.9kV work is completed, ST XST1 will be restored and the offsite source will again be operable.

to TXX-12198 Page 7 of 38 12/19/2012 The entire sequence of activities to complete this third scope of work is conservatively projected to require approximately 12 days. However, a similar modification has been accomplished for XST2 and XST2A and completed in 7 days, 21 hours2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br />, and 16 minutes, well within the projected time of 11 days and 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> and much less than the requested CT of 14 days. Table 3, provides a list of planned maintenance activities and their approximate durations.

Table 3. 6.9kV Connections Including Final Checks/rest for XSTIA Scheduled Work Dates Maintenance Activity Approximate Time (Days)

Enter LCO Place Clearance and Grounds* 0.25 Shutdown XST1 Open Box to De-terminate Cables 0.5 Remove Tray, Identify Cables and Cut/Pull Back Cables 1.5 Install Transfer Panels, Modify Cable Trays 3.0 Pull in Cables, Install Stress Cones and Terminate Cables 3.5 Terminate Cables at XST1 and Close Boxes 1.0 Verify Link Placement and Close Boxes 0.25 Remove Clearance and Grounds 0.25 Energize and Test XST1A 1.0 Shutdown XST1A, Change Links and Energize XST1 1.0 Exit LCO** 12.0

• Enter 14-day CT **Exit 14-day CT 3.3 Post-Modification Plant Design Once the modification to the plant is complete and XST1 needs maintenance or if XST1 fails, the alternate ST XST1A can be connected to the safety buses to restore the 138kV offsite source within the current TS CT of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. After maintenance or repair on XST1 is completed, XST1 may be put back in-service. Therefore, XST1A will be a dedicated alternate for XST1 and XST2A will be a dedicated alternate for XST2.

3.4 FSAR References Related background in the CPNPP FSAR (Reference 8.1) is found primarily in Sections 1A(B), 8, and 9.5.1.5.6.

As described above, the proposed change will revise the OR statement of the CT of TS 3.8.1, "AC Sources - Operating" Required Action A.3. The statement will allow, on a one-time basis, two extensions of Required Action A.3 CT from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days for an outage of ST XST1 to 1) modify the XST1 138kV tower to add disconnects for a new alternate ST and replace the existing disconnects for XST1 and 2) to make final terminations to facilitate connection of startup transformer (ST) XST1 or a alternate startup transformer to the 1E buses within the current TS CT of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

4.0 TECHNICAL ANAYLYSES The proposed change to TS 3.8.1 Required Action A.3 CT is based upon a deterministic/qualitative analysis and will rely on compensatory actions and configuration management measures. Conformance with Nuclear Regulatory Commission (NRC) General toTXX-12198 Page 8 of 38 12/19/2012 Design Criteria," (GDC) Section 3.1 of the Final Safety Analysis Report (FSAR) (Reference 8.1) provides the basis for concluding that the station fully satisfies and complies with the GDC in Appendix A to 10 Code of Federal Regulations (CFR) Part 50. These proposed changes do not affect the basis for this conclusion and do not affect compliance with the GDC.

Three important elements provide the basis for the requested Technical Specifications (TS) change and provide a high degree of assurance of the capability to provide power to the safety related 6.9 kilo volt (kV) alternating current (AC) Engineered Safety Features (ESF) buses during the two, one-time, 14-day Completion Times (CTs) (allowed outage time (AOT) or CT as used in the Improved Standard Technical Specifications). The important elements are (1) a traditional engineering analyses, (2) avoidance of risk significant plant configurations using mitigation measures and (3) continued implementation of a Configuration Risk Management Program (CRMP) during the two, one-time 14-day extended Completion Times.

4.1 Deterministic Evaluation Offsite Power The Oncor (Transmission Owner (TO)) transmission system serves as the main outlet and source of offsite power for CPNPP. Connection of the station outputs to the system is achieved via seven 345kV overhead lines to the 345kV switchyard as. The 345kV system forms the backbone of the TO transmission system, it provides a highly reliable source of continuous power for plant shutdown. Another reliable source is the 138kV network via two 138kV lines connecting to the 138kV switchyard. Upon loss of all offsite AC power, station standby power sources, consisting of four diesel generators (two per Unit) are provided to satisfy the loading requirements of the AC safety-related loads. System redundancy precludes loss of all onsite power as a result of any single failure, and specifically, CPNPP has never had a loss of all offsite power in the life of the plant.

Two separate and physically independent startup transformers (STs) (XST1 or XST2) provide startup, preferred and alternate shutdown power to the safety-related auxiliaries of the Units on an immediate basis. One transformer is connected to the 345kV switchyard while the second transformer is connected to the 138kV switchyard; these transformers are connected to the safety-related 6900V auxiliary bus systems and, as such, provide two independent means of supplying the safety-related equipment from the offsite power system without relying on the main generator. If one ST is out-of-service the operating ST has the capacity and capability to supply the required safety related loads of both Units.

Two station service transformers (1ST and 2ST) provide power to the non-safety-related auxiliaries. These transformers are connected to the 345kV switchyard. One transformer is connected to the non-safety-related 6900V auxiliary buses of one Unit while the second transformer is connected to the non-safety-related 6900V buses of the other Unit.

CPNPP has a robust design with the desired defense-in-depth design features (i.e., the ability to mitigate design basis accidents when a ST is out-of-service). Specifically, offsite and onsite power systems are diverse and redundant and meet regulatory requirements of GDC 17. While XST1 is out-of-service during the plant modification outages, XST2 has the capacity and capability to supply the required safety related loads of both Units.

to TXX-12198 Page 9 of 38 12/19/2012 Oncor Transmission Planning (TO) performs yearly assessments of grid reliability for CPNPP. The assessment consists of voltage and stability studies. System stability studies are in accordance with Electric Reliability Council of Texas (ERCOT) requirements whenever Oncor anticipates that a new study could be expected to produce results significantly different from prior studies. ERCOT is the Reliability Coordinator (as certified by the North American Electric Reliability Corporation (NERC)) and the Independent System Operator (as certified by the Public Utility Commission of Texas (PUCT)) for the ERCOT Region.

The 2012 voltage study consisted of the steady-state evaluation of specified contingencies that would impact the CPNPP voltage, in accordance with CPNPP Station Administration Manual STA-629, "Switchyard Control and Transmission Grid Interface,"

(Reference 8.2). STA-629 defines the CPNPP Switchyard work control process, the NERC Reliability Standard NUC-001, "Nuclear Plant Interface Requirements" (NPIRs), as mutually agreed by Luminant Generation Company LLC and Oncor Electric Delivery Company LLC (TO), and TO's obligations with respect to the NPIRs, in accordance with the requirements of the Generation Interconnection Agreement and NUC-001. The 2012 voltage study consisted of an evaluation of the risk of losing offsite power to CPNPP as a result of system instability following sudden loss of system generation.

The voltage study results showed that the 345kV voltage supply to XST2 was maintained within the target maximum and minimum voltages of 361kV and 340kV, respectively and the 138kV voltage supply to XST1 was maintained within the target maximum and minimum voltages of 144kV and 135kV, respectively.

The TO Transmission Planning Procedures list the following requirements for the maintenance of offsite power to CPNPP following sudden loss of system generation:

• The loss of both CPNPP Units shall not result in loss of offsite power to CPNPP.

• The loss of the largest power plant in the ERCOT system shall not result in loss of offsite power to CPNPP.

0 The loss of the largest power plant connected to the Transmission Service Provider shall not result in loss of offsite power to CPNPP.

• The loss of the largest capacity experienced during past disturbances on the ERCOT system shall not result in loss of offsite power to CPNPP.

It is evident from the 2012 voltage studies that loss of one or both of the nuclear Units will not cause the loss of offsite power or auxiliary power to the station. In addition, the transmission system remains stable for all disturbances near CPNPP which are cleared by primary or backup relaying. CPNPP's Operations Department will contact the Transmission Operator (Transmission Grid Controller) once per day during a 14-day Completion Time to ensure no problems exist in the transmission lines feeding CPNPP switchyards or their associated switchyards that would cause post trip switchyard voltages to exceed the voltages required by STA-629.

Onsite Power Upon loss of the preferred power source to any 6.9kV Class 1E bus, the alternate power source is automatically connected to the bus and the emergency diesel generator (EDG) starts should the alternate source not return power to the Class 1E buses. Loss of both offsite power sources to any 6.9kV Class 1E bus, although highly unlikely, results in the diesel generator providing power to the Class 1E bus.

to TXX-12198 Page 10 of 38 12/19/2012 Two independent and redundant 6900V Class 1E buses are provided for each Unit, each capable of supplying the required safety-related loads to safely shut down the Unit following a design basis accident (DBA). The standby AC Power System is an independent, onsite, automatically starting system designed to furnish reliable and adequate power for Class 1E loads to ensure safe plant shutdown and standby when preferred and alternate power sources are not available.

Redundant safety-related loads are divided between trains A and B so that loss of either train does not impair fulfillment of the minimum shutdown safety requirements. There are no manual or automatic connections between Class 1E buses and loads of redundant trains. Electrical separation of redundant trains is maintained through all voltage levels, including direct current (DC) and instrumentation.

During a loss of coolant accident (LOCA), the EDGs are required to start, whether offsite power is available or not. Additionally, failure of a single active component or train associated with one EDG does not result in the inability of the redundant EDG to provide emergency standby power.

The EDGs are required to cope with Station Blackout (SBO) to satisfy the requirements of RG 1.155 "Station Blackout" (Reference 8.3). For the SBO analysis, only one Unit at the CPNPP site is assumed to be in a station blackout condition. The other Unit is assumed to have one emergency diesel generator available.

The diesel generator sets are required to start on receipt of any of the following signals:

a. Safety Injection Actuation Signal - Emergency Start

b. Undervoltage on Respective Emergency Bus - Emergency Start

c. Normal or Emergency Manual Start Automatic starting signals shall override all other operating modes and return the EDG unit to automatic control unless the unit has been placed in a manual non-operating mode for maintenance or repair.

Station Blackout CPNPP compliance with the Station Blackout Rule, 10CFR50.63, has been performed in accordance with the guidelines contained in Regulatory Guide 1.155 (Reference 8.3) and NUMARC 87-00 (Reference 8.4). In accordance with those References, CPNPP is not required under 10 CFR50.63 to consider simultaneous loss of both offsite power (LOOP) sources and both EDGs to both Units. CPNPP compliance is based on simultaneous LOOP at both Units, the non-mechanistic unavailability of both EDGs in one Unit, (i.e.,

the blackout Unit) and the availability of one of two EDGs in the other, "non-blackout" Unit.

CPNPP does not utilize an "alternate AC source," as defined in References 8.3 and 8.4, for purposes of compliance with 10CFR50.63. The single EDG in the "non-black-out" Unit is credited for powering specified ventilation cooling systems, e.g., control room ventilation, in accordance with the plant design. The compliance analyses for the "blackout Unit" are based on the "AC-Independent" approach detailed in Reference 8.3.

The required coping time for the "blackout Unit" is four (4) hours per Section 3 of Reference 8.3.

to TXX-12198 Page 11 of 38 12/19/2012 EDG reliability was determined using the methodology of Reference 8.3 and is 0.95 for CPNPP. EDG reliability is monitored under the Maintenance Rule Program. Increasing the allowed outage time for ST XST1 has no effect on EDG reliability.

Utilizing the methodology of Reference 8.3, CPNPP has been classified as "AC power Design Characteristic Group" P1. A "Pl"site is defined in Reference 8.3 as "...Sites characterized by redundant and independent power sources that are considered less susceptible to loss as a result of plant-centered and weather-initiated events."

The portion of the SBO coping analysis related to the offsite power supply system includes the following in the characterization of CPNPP as a "P1" Offsite Power Design Characteristic Group:

• Susceptibility to LOOP due to extremely severe weather (ESW Group) - Group ESW1 (least susceptible)

• Susceptibility to LOOP due to severe weather (SW Group) - Group SW1 (least susceptible)

• Independence of the offsite power system (I Group) - 11/2 Transformer Health/ Reliability Program The offsite power source (XST2 and XST2A and switchyard equipment) health and reliability are monitored as part of the CPNPP Equipment Reliability Process. This process is defined in CPNPP's Station Administrative Manual STA-748, "Equipment Reliability Process" which implements the guidance outlined in Institute of Nuclear Power Operations' (INPO) AP-913, "Equipment Reliability Process Description." The equipment reliability process directs monitoring of equipment by:

• Daily Monitoring by Responsible Work Organizations such as, Operations, Maintenance and Plant Optimization Center, 0 Weekly/Monthly Monitoring of Switchyard Equipment, 0 Operating Experience,

• System and Component Health Programs,

• Regulatory Notices,

• Predictive Maintenance,

• Preventive Maintenance/Predictive Maintenance Results, and

• Maintenance Rule.

Individual monitored points for the associated transformers (XST2 and XST2A) are established from American National Standards Institute/Institute of Electrical and Electronics Engineers (ANSI/IEEE) transformer standards, Nuclear Electric Insurance Limited (NEIL) Loss Control Program, Industry Experience and Manufacturer recommendations. When the performance or monitoring parameters are exceeded the Corrective Action Process is utilized for resolution. Each corrective action item is reviewed by the Management Review Committee for appropriate assignments and level.

The ST XST2 had high capacitance value on the neutral bushing and low side winding bushing leaks which were corrected in August 2012. Completion of the XST2 maintenance outage will have all preventive maintenance (PM) work orders associated with XST2 current. Further, to allow XST2 maintenance to occur, CPNPP implemented reliability improvements to the spare, startup transformer XST2A. Additionally, CPNPP to TXX-12198 Page 12 of 38 12/19/2012 utilized a NRC approved 14-day CT extension which allowed sufficient time to make final terminations to facilitate connection of either XST2 or the spare ST XST2A to the Class 1E buses. These activities will support and maintain the availability of the ST XST2 to remain a reliable offsite power source to meet CPNPP requirements during the two, one-time CT extensions for XST1.

The individual monitoring points for the switchyard equipment are established from NEIL Loss Control Program, Industry Experience and Manufacturer recommendations.

The switchyard equipment associated with the offsite power source XST2 are 345kV breakers 7970 and 7980 and associated air disconnect switches 7981/7979 and 7969/7971.

If the performance or monitoring parameters are exceeded the Corrective Action Process (CAP) is utilized for resolution. Each corrective action item is reviewed by the Management Review Committee (MRC) for appropriate assignments and level. There are no outstanding corrective actions for switchyard equipment associated with the Unit 1 preferred offsite power source XST2.

Breaker 7970 was replaced on December 04, 2010, as an upgrade by the TO. Reliability improvements to the gas system for breaker 7980 have been implemented. Cabling to both 7970 and 7980 has been replaced as part of the TOs overall switchyard reliability improvement plan. The power from XST2 to the Unit 1 safeguard buses is through 6.9kV breakers 1EA1-1 and 1EA2-1. During a one-time, 14-day CT extension, the Unit 2 safeguard buses power will be manually transferred from the preferred source (XST1) to the alternate source (XST2). At this time, the Unit 2 safeguards buses will be supplied by XST2 by breakers 2EAl-2 and 2EA2-2. The monitoring of the 6.9kV breaker performance is by surveillance, Operations walkdowns, and PM work orders. If breaker deficiencies are identified, the CAP is utilized for resolution. Each corrective action item is reviewed by the MRC for appropriate assignments and level. Prior to initiation of a one-time, 14-day CT extension, PM task for breakers 1EA1-1, 1EA2-1, 2EA1-2 and 2EA2-2 will be verified as current.

In summary, the equipment associated with CPNPP offsite power has maintained a high degree of reliability and CPNPP has not experienced a loss of offsite power.

Maintenance Plans/Actions (Maintenance Rule) for the STs (XST1, XST2, and XST2A)

The CPNPP Maintenance Rule (MR) Program requires an evaluation be performed when equipment covered by the MR fails to meet the established performance criteria for reliability and availability. Failure of the offsite power sources (XST1, XST2/XST2A) to meet the performance criteria requires a review for determination of 10CFR50.65 (a)(1) actions. These actions would require increased management oversight and establishment of goals to restore the offsite power sources to an acceptable performance level. The CPNPP offsite power system MR status is (a)(2) with a 24 month rolling average unavailability of 0% through July 2012. On April 22, 2010 CPNPP lost power to XST1 due to bird nesting activities within the base opening of a 138kV tower insulator. This placed the CPNPP offsite power system in MR status (a)(1). Corrective actions following the event sealed off access to the openings at the insulator mounting base. This action removed the ability of bird nesting to impact the tower insulators. A continuing action has been established to perform additional visual inspection of the offsite source transmission lines and transformers during nesting season. This added action helps ensure that alternate bird nesting is not impacting the offsite power sources. Presently, there are no reliability issues identified for XST1, XST2 or XST2A. Maintenance has to TXX-12198 Page 13 of 38 12/19/2012 occurred on XST2 to remove a potential neutral bushing reliability issue. The CPNPP MR status for the offsite power system is not expected to be adversely impacted by application of the two, one-time 14-day CT's implementation because XST2 has proven to be a reliable component and the improvement to make XST2A available to feed the safety buses, in case of unavailability of XST2, has further enhanced the 345kV offsite source reliability.

The Need for Two, One-Time 14-Day Completion Times The preferred plan for the work would utilize the first 14-day CT to make modifications to the 138kV tower as discussed above which will take approximately 11.5 days as detailed in Table 1. Once the work is completed, transformer XST1 would be restored so both offsite sources would again be operable. The next scope of work as described in Table 2 will be preparing XST1A for installation on its pad, installing XST1A, assembling and testing. This scope of work is estimated to take approximately 52 days. The second 14-day CT will be used for the third scope of work, as depicted in Table 3, to install the transfer panels and make final 6.9kV cable terminations in the transfer panels. All three work scopes will take approximately three months to complete. These three work scopes have been logically planned out, sequenced, and separated considering the amount and kind of work performed, the number of diverse work groups performing work in parallel paths, work groups performing both work scopes, the necessary large lifting equipment and trucks, the limited work space in the area, the safety of the workers given the possibility of working under suspended loads, and the health and safety of the public; therefore, two separate 14-day CTs are being requested. However, either 14-day CT can be completed first without affecting the health and safety of the public. The window of time to invoke the two, one-time 14-day CTs is during the period from September 1st through March 31st when there is a significant reduction in weather risk. The time periods between the three scopes of work largely depend on weather and the actual delivery of the new ST XST1A. However, CPNPP would prefer to complete the three scopes of work as soon as practical considering the safety of plant workers and the health and safety of the public.

To further enhance the safety of the proposed modifications, appropriate just-in-time (JIT) training will be provided to Operations personnel on this TS change as well as the compensatory measures and risk reduction measures to be implemented during these two, one-time, 14-day proposed CTs. The JIT training will include the postulated loss of the operating ST (XST2) to heighten Operations personnel awareness of challenges to the electrical distribution during the modification outages. Additionally, Electrical Support and Meter and Relay crews will be trained on the procedures developed and issued for connection of the alternate ST, XST1A in place of XST1.

Installation of this modification will enhance the plant design by providing the capability to preclude an extended interruption of offsite power in case of failure of, or maintenance on, XST1 that would exceed the current CT of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Additionally, this change will improve the long-term reliability of the 138kV offsite circuit by providing connection to the ESF buses through XST1 or the alternate ST. As explained above, performing the work during two, 14-day CTs will provide a safe work environment for personnel safety and will not impact nuclear safety or the health and safety of the public.

to TXX-12198 Page 14 of 38 12/19/2012 Options and Risks with One Unit in a 14-Day CT and Other Unit is in a Refueling Outage If CPNPP removed one offsite circuit from service for 14 days while one Unit was in a Refueling Outage (RF), TS 3.8.2 "AC Sources - Shutdown" would be satisfied for the RF Unit since only one operable offsite circuit and one operable EDG is required. However, TS 3.8.1, "AC Sources - Operating" requires a Unit in Modes 1 to 4 to have two qualified offsite power circuits and two EDGs; consequently, the operating Unit would not meet the requirements of TS 3.8.1 and must shut down within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or have an approved NRC license amendment allowing the extended CT.

Further, management and plant employee focus would be split on both 14-day CT work and RF work instead of just one work scope. Moreover, RFs typically take three to four weeks, 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> per day to complete. Additionally, the same plant personnel working in the RF will be the same resources needed to complete the 6.9kV work and support the 138kV work as needed while a transmission contract crew will perform most of the 138kV tower work. Therefore, working during a 14-day CT concurrent with a RF would result in a significant reduction of resources and competing priorities.

Also, during RFs the TO works in the switchyards to do line and switchyard maintenance and there is a greater chance for tripping switchyard equipment/lines and thus the possibility to lose the operating ST, XST2, and challenge nuclear safety.

It is undesirable to enter the extended CT for the XST1 transformer with either Unit in a refueling outage/shutdown configuration. During a shutdown, a Unit undergoes continuous configuration changes in reactor coolant system (RCS) inventory, RCS temperature, equipment availability, etc. Also, in shutdown configurations automatic actuation of equipment is more limited and requires Operators to manually diagnose and respond to transient/accident conditions.

Although decay heat level in the reactor would be lower, as compared to operating in Mode 1, variations in reactor coolant system (RCS) inventory, pressure, and temperature result in configurations where time to boil is short (<15 minutes) thus limiting the available time to perform operator actions or other compensatory measures to prevent core boiling/damage. Limited response times are of particular concern given that majority of the prompt mitigating actions for shutdown configurations are manual and may require realignment of various systems. Additionally, as a result of the fluid nature of an outage, various systems relied on for mitigation of an event will be removed from service. This results in plant conditions that would be dependent upon single trains of front line mitigating and support systems.

Major accident/transient scenarios in shutdown configuration remain similar to those at power. While mechanistic LOCAs are less likely, given lower RCS pressure, the potential to inadvertently drain the RCS exists from maintenance or system realignments exist. The ability to remove decay heat via secondary heat removal may not exist dependent upon the RCS configuration. The time when the RCS is intact and the loops are filled is generally small compared to the entire shutdown duration. Also industry experience has shown that shutdown operations represent a time period of increased likelihood for unanticipated events, compared to at power (Mode 1) operations.

to TXX-12198 Page 15 of 38 12/19/2012 During the times that the reactor core will be offloaded to the spent fuel pool, the CPNPP plant design would isolate the operating Unit's capability to supply cooling and electrical power to the spent fuel pool cooling system following a design basis LOCA. Therefore, the spent fuel pool cooling would be dependent on the outage Unit which most likely is reliant on a single train of supporting equipment. Further the spent fuel pool has limited makeup capabilities and mitigation methods as compared to when the fuel is in the reactor vessel.

Given the complexity of shutdown operations, it is therefore undesirable to reduce the redundancy of offsite power by performing the extended XST1 CT while either Unit is shutdown. Planning the proposed 14-day CTs while both Units are at power provides the ability to control work in a manner that assures redundancy and diversity of mitigation equipment to contend with accident/transient conditions. Considering safety system unavailability during an event and the increased work scope required for a 14-day CT and the RF work scope, human error is more likely to be introduced which could negatively impact nuclear safety, personnel safety, and the health and safety of the public.

Alternate Power Diesel Generators (APDGs)

On October 29, 2010, the NRC previously approved License Amendment Request 09-003 (ML103190632) for XST2, to extend, on a one-time basis, the allowable CT of Required Action A.3 for the inoperable offsite circuit, from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days. This change was only applicable to ST XST2 and allowed sufficient time to make final terminations as part of a plant modification to facilitate connection of either XST2 or the alternate ST XST2A to the Class 1E buses. As a defense-in-depth feature concerning this modification, a set of alternate power diesel generators (APDGs) were installed for each Unit to maintain the capability to provide power for one train of ESF equipment needed for safe shutdown and long term cooling of each Unit during the XST2 extended CT to respond to a beyond design basis event (DBE) if loss of XST1 occurs and both EDGs of a Unit fail to start and load as designed. However, the APDGs actually installed in 2010 were rated higher than the ones described in License Amendment Request 09-003 (4275kVA vs. 4200kVA) and in the CPNPP response on May 4, 2012 to the NRC's request for additional information (ML101340121).

These APDGs have not been removed; they remain in the station yard and are designed to be manually connected to a 6.9kV bus. The sequencing of the required loads on the APDGs is also performed manually. The APDG set consist of three diesel generators operating in parallel at 480V, 3 phase, and 60 Hz. Each APDG in a set is rated at 1140kW with outputs connected in parallel for a total capacity of 3420kW. The APDG set is rated at 4275kVA. As part of the APDG package, a 480V/6900V transformer is provided to connect the APDGs to the 6.9kV bus. The transformer may be loaded to 3450kVA; therefore, the APDG load limit is approximately 3450kVA. Each generator of an APDG set has a useable fuel oil tank capacity of 340 gallons (340 gallons is gross 298.8 gallons is useable).

Plant procedure SOP-614A/ B "Alternative Power Generator Operations" (Reference 8.5) requires the APDG fuel be replenished every two hours. The APDG consumption rate is approximately 96.7 gallons per hour at 100% power with an approximate run time of 3.08 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

to TXX-12198 Page 16 of 38 12/19/2012 The APDGs maintain the same capability as described below during the two XST1 extended CTs to respond to a beyond design basis event if loss of XST2 occurs, both EDGs of a Unit fail to start and load as designed, and at least one EDG starts and loads on the other Unit. If this event were to occur, the APDGs will be manually connected to the affected Unit's 6.9kV safety bus in Modes 3, 4, and 5. Thus, the minimum set of components for one train required to maintain the affected Unit in a safe shutdown condition can be loaded onto the APDG and operating within approximately one hour to maintain the plant in a safe shutdown condition which meets CPNPP's Station Blackout analysis. The components required to be loaded onto a 1E bus to support maintenance of the plant in a safe shutdown condition are described functionally in a plant design basis document (see DBD-ME-026) and emergency response guidelines. The loads identified below represent the Unit-specific (i.e., non-common) loads. These components are the minimum set required to be loaded onto one APDG set to maintain the affected Unit in a safe shutdown condition and provide long term cooling.

Table 4. Load Description and Load in KW 6.9KV LOAD DESCRIPTION LOAD (KW)

Centrifugal Charging Pump (CCP) 526.03 Component Cooling Water (CCW) Pump 789.42 Station Service Water (SSW) Pump 643.10 480V LOAD DESCRIPTION LOAD (KW)

Containment Recirculating Fan 93.25 Safety Chillers 99.90 Safety Chiller Recirculation Pump 18.24 Emergency Lighting 132.69 Control Rod Drive Mechanism Ventilation (CDRM) Fan 92.44 Instrument Air 183.28 Pressurizer Heater Control Group A 141.40 Battery Chargers and Inverters 110.94 Reactor Makeup Water Pump 4.54 Miscellaneous 480V Loads (Fans, Pumps, Transformers, and Heaters) 116.03 SUBTOTAL 2951.26 Plus 2% Losses 59.03 TOTAL 3010.29 Each APDG set has adequate capacity and capability to supply power to the necessary equipment for safe shutdown and long term cooling for a Unit.

Prior to installation at CPNPP, the APDG vendor provided formal shop testing of the APDG set. The vendor used test instruments that were calibration certified to measure voltage, current, and frequency, and they reported the test results to CPNPP along with the instrument calibration certifications. At the beginning of the test, the APDG set was allowed to reach normal voltage and frequency prior to switching to the first load. The following load step tests were performed to show load acceptance and removal when all three generators are paralleled:

to TXX-12198 Page 17 of 38 12/19/2012

• 1000kW block load at .8 power factor and let stand for a minute.

• Removal of 1000kW block load at .8 power factor.

• 2000kW block load at .8 power factor and let stand for a minute.

• Removal of 2000kW block load at .8 power factor.

• 2500kW block load at .8 power factor and let stand for a minute.

• Removal of 2500kW block load at .8 power factor.

• 2400kW block load at .8 power factor and add 600kW at 1.0 power factor and let stand for a minute.

Removal of 3000kW of load.

The test results showed that:

• APDG set is capable of supplying power within 60 seconds of starting.

• The recorded APDG set voltage remains within 480V +/- 20% and frequency remains within 60 Hz +/- 5% during load sequencing, load rejection, or load restart.

• The maximum time to recover voltage to 90% and frequency to 98% of rated values is less than or equal to two seconds.

• While the load on the APDG set is at 3000kW, the APDG set is capable of rejecting a load of 1000 HP (horse power) without generating over-voltages that would damage safety related equipment or tripping on overspeed.

The APDG set is capable of restarting a 1000 HP motor while maintaining the system load of 3000kW, after the start of the 1000 HP motor.

Plant procedure SOP-614A/B "Alternative Power Generator Operations" (Reference 8.5) directs the Operator to monitor the APDG set parameters (e.g., lube oil, engine coolant, fuel levels, transformer temperature and liquid levels, etc.) on a shiftly basis to ensure the APDG set is ready to start. Once per month the APDG set are started and synced together unloaded to verify there are no problems with the diesels per SOP-614A/B. Additionally, SOP-614A/B directs the operation of the APDGs in Modes 3,4, 5, and 6. Further, current emergency operating procedures exist that direct Operators to respond to a loss of all AC power, recovery of power without a safety injection signal, and natural circulation cooldown of a Unit. Operators are routinely trained on and have experience in using these procedures. Therefore, if the event above were to occur, the Operations Shift Manager would declare the affected Unit 1E buses inoperable, direct the connection of the APDG set to a 1E bus and then sequence the appropriate loads onto that bus as directed by the emergency operating procedures. Phase rotation was complete when the APDGs were originally installed in late 2010. Since the APDGs remained connected, no further phase rotation is required unless they are disconnected. Thus, the affected Unit will be safely shutdown and long term cooling will be provided by the APDG.

In this scenario, the APDGs will be connected to the 1E bus only when that Unit has no other source of power; therefore, synchronization of the APDGs to the 1E bus is not applicable in this case.

The APDG set associated with the affected Unit will be able to energize the appropriate buses and the required components can be loaded onto the energized buses within approximately one hour. No consequences on safety limits are expected. The following Table shows the loading sequence of the loads that will be powered by the APDGs.

to TXX-12198 Page 18 of 38 12/19/2012 Table 5. Safe Shutdown Bus Loading Sequence LOAD LOAD SEQUENCING NOTES Station Service Water Pump These loads will remain aligned to the affected Unit 1E 480V Buses (Note 1) bus in order to energize/start them immediately upon Battery Chargers power restoration by the APDG set.

Instrument and Control Inverters Reactor Protection Inverters Emergency Lighting Direct Current (DC) Loads Shed During Following Power restoration to the 1E bus by the DC Load Shedding of Non-Essential APDG set, these DC loads will be restored to the DC Loads bus (e.g., loading AC Battery Chargers).

Component Cooling Water (CCP) These loads will be started following power source Pump restoration as directed by the emergency operating Instrument Air Compressor procedures (e.g., APDGs start and energize the 1E bus)

Centrifugal Charging Pump (CCP) to support the plant response and recovery actions (e.g., reduce Reactor Coolant System (RCS)

Containment Fan Coolers (Note 2) Temperature and Pressure).

Safety Chiller Safety Chiller Recirculation Pump Pressurizer (PRZR) Heaters (Note 3)

Reactor Makeup Water Pump Control Rod Drive Mechanism Vent This load will be started next to assist in Reactor Vessel Fans Head cooling.

Positive Displacement Pump (Note 4) Finally, these loads will be started to place the RCS in Residual Heat Removal (RHR) Pump Shutdown Cooling after RCS temperature has been (Note 5) reduced.

NOTES:

1. Some Unit specific load shedding (e.g., unavailable EDGs) will be performed to reduce loading assumed by the APDGs.

2. One Containment Fan Cooler will be aligned for Containment cooling.

3. Only a specified number of breakers will be closed to allow PRZR Heater capability for control of RCS pressure.

4. To support RHR Pump load, the CCP will be stopped and the Positive Displacement Pump will be started prior to starting the RHR Pump.

5. Secondary heat removal for natural circulation cool down is provided by the TDAFWP prior to placing RHR in shutdown cooling.

The largest motor to be loaded on the APDG is 1000 HP CCW Pump Motor. The vendor test results showed that the APDG set is capable of starting a 1000 HP motor while maintaining the system load of 3000kW, after the start of the 1000 HP motor.

Each Unit Class 1E 6.9kV buses may be connected to the APDG transformer though permanently installed non-Class 1E transfer switch specifically to facilitate the temporary connection of an APDGs set to the selected Class 1E bus. Each APDG set has cables that run in cable trays to the associated transfer switch via a plant owned 480V/6.9kV transformer and the cables will remain de-energized unless such an event as described above occurs.

to TXX-12198 Page 19 of 38 12/19/2012 Class 1E 6.9kV switchgear breakers connected to the transfer switch are normally locked in the disconnect position to assure isolation from non-class 1E transfer switch circuit.

These breakers can be manually closed, if required, to provide connection to the APDG.

The over-current protection on these breakers is disabled. The protection of the 6.9kV system and APDG circuits when the APDG set is feeding the bus is accomplished as defined below.

The 480V/6.9kV APDG output transformer is high resistance grounded on the 6.9kV side to assure that the safety related 6.9kV system is not exposed to transient over-voltages and the damage at the point of fault is limited by limiting ground fault current to less than 2A. The transformer grounding system has sensitive ground fault detection with a local ground fault indication and no tripping action.

• The associated cables that feed the Class 1E 6.9kV buses from the APDG transfer switch have sufficient capacity to carry the APDG set limiting load of 3500kW at 0.8 PF.

• The protection provided with the APDG set, or the inherent current limiting feature of the APDG set was reviewed to assure that the duration and magnitude of APDG fault contribution is within the continuous rating of 6.9kV bus.

• The 6.9kV cables from the transformer to the transfer switch provided by CPNPP are sized to carry greater than or equal to 383A and can carry the APDG set loads continuously without being over loaded.

• Postulated electrical faults that could occur at the 6.9kV bus while being fed from the APDG set are assumed to be cleared by protection provided with the APDG set. However, if this protection fails, the magnitude of the fault current could not damage the bus because the APDG set output breakers will trip in one-half cycle if fault current at the bus is 1200A, the continuous rating of the bus.

During outages when the plant is in Mode 5 or 6, the APDG may be used to supply power to either train of the 6.9kV safeguards system. The APDG is used as a backup to supply power in the event that one emergency diesel generator is out-of-service and the remaining operable emergency diesel generator fails to start and load automatically upon a loss of offsite power. The APDG is manually started and connected to the 6.9kV safeguards bus through the load transfer switch and respective bus feed breaker. There are plant procedures governing the use of the APDGs and plant personnel have many years of operating experience using the APDGs during outages and specifically since late 2010 to respond to a beyond design basis event as discussed above. Existing plant procedures describes the steps to operate the APDGs (e.g., startup, operating parameters, alarm responses, troubleshooting, shutdown, pre-run checklist, load testing, refueling, etc.).

Further, within two weeks before entering a 14-day CT, the APDG will be tested to ensure the reliability of the APDG. Additionally, the APDG provided for each Unit will be verified available to provide power to equipment for long term cooling once per shift during the two, 14-day CTs. Training has been provided to all Nuclear Equipment Operators (NEOs) as documented by the training department. New Operators are trained prior to the outages. Prior to the APDGs needing to be available for use, the APDGs are started and synchronized together unloaded on a monthly basis to verify there are no problems with the diesels per SOP-614A/B, "Alternative Power Generator Operations" (Reference 8.5). When the APDGs need to be available for use:

to TXX-12198 Page 20 of 38 12/19/2012 A shiftly checklist is completed to ensure the APDGs are ready for use per SOP-614, At the beginning of shift, briefs designate the three Operators and the roles of each Operator in starting and syncing the APDGs to the required safeguards bus, and Procedures are marked up and staged for Operators to start and synchronize the APDGs to the required safeguards bus.

Normal time to provide power from the APDGs to a safeguards bus is approximately one hour. During a 14-day CT, if an APDG becomes unavailable, both Units shall enter Condition C of TS 3.8.1 and start shutting down within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

In conclusion, the APDGs have the capacity and capability to provide power for one train of ESF equipment needed for safe shutdown and long term cooling of each Unit during the XST1 extended CT to respond to a beyond design basis event if loss of XST2 occurs and both EDGs of a Unit fail to start and load as designed.

Compliance with NRC Standard Review Plan (SRP) Branch Technical Position (BTP) 8-8 The compliance with BTP 8-8 requirements and CPNPP response is discussed below.

Commitment references have been broken up into two groups, one for the 138kV work and the other for the 6.9kV work, respectively. See Attachment 7 for a complete list of commitments.

a. A supplemental power source should be available as a backup to the inoperable EDG or offsite power source, to maintain the defense-in-depth design philosophy of the electrical system to meet its intended safety function.

Response

The CPNPP design and licensing basis for safe shutdown is hot shutdown.

Analyses performed to ensure conformance with BTP Reactor Systems Branch (RSB) 5-1 confirm the ability to achieve cold shutdown in a reasonable period of time following a LOOP with subsequent natural circulation cooldown assuming one Train of safety equipment available.

As detailed in the "Station Blackout" section above, CPNPP compliance with 10 CFR 50.63 is based on a postulated LOOP affecting both Units and the non-mechanistic unavailability of both safety-related EDGs on one of the two Units. A single EDG is assumed available on the non-blackout Unit during such a scenario. The available EDG on the non-blackout Unit is taken credit for fulfillment of control room and uninterruptible power supplies (UPS)/inverter room ventilation functions. Under those postulated conditions, the blackout Unit has been shown to be fully capable of compliance with 10CRFR 50.63 for the required four hour coping duration. Subsequent beyond design bases assessments performed in consideration of the Fukushima accident verify the effective coping period to be significantly longer.

Additionally, INPO issued Event Report (IER) Level 1(L1) 11-4, "Near-Term Actions to Address the Effects of an Extended Loss of All AC Power in Response to the Fukushima Daiichi Event" (Reference 8.6) to establish actions to improve the margins of safety for loss of AC power events. Specifically, recommendation to TXX-12198 Page 21 of 38 12/19/2012 1 required, "For all Units, develop methods to maintain (or restore) core cooling, containment integrity, and spent fuel pool inventory using existing installed and portable equipment during an extended loss of electrical AC power event that lasts at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />." CPNPP reported to INPO that CPNPP can withstand with a station blackout for at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, using existing plant equipment and procedures, with a best estimate analysis in accordance with the specified IER Li-11-4 assumptions and bases (Reference 8.7).

CPNPP has provided three (3) APDGs per Unit to provide additional safety margin against postulated loss-of-power events. The three APDGs per Unit operate in parallel as a set providing a combined output of approximately 3420 kW (4275kVA). The APDGs feed a 480 V/6900 V transformer which may be loaded to 3450kVA. Although originally provided and sized for shutdown mode conditions and associated loading, the APDGs provide an additional level of defense-in-depth for "higher" operating modes as well.

During the proposed period of XST1 extended CTs, the APDGs would be available to provide an additional measure of defense-in-depth, beyond that required by the plant design and 10 CFR 50.63, in the unlikely event of a LOOP with concurrent unavailability of both EDGs on either Unit. As was the case for the 10 CFR 50.63 analyses, the non-blackout Unit would be capable to power the aforementioned ventilation loads and shared components, while maintaining the Unit in a safe shutdown condition. The response of the Unit experiencing the total loss of AC power would basically follow the analyses performed for 10 CFR 50.63 compliance; that is to say steam generator water level would be maintained and decay heat removed via the TDAFWP. Manual starting and loading of the APDGs under such circumstances would allow for operation of the following equipment identified in Table 4.

APDG loading is not a time-sensitive activity in the sense the Unit experiencing the total loss of AC power would be in an analyzed condition for the first four hours. This is considered ample time to strip loads from the selected 6.9kV safety bus, start and align the APDGs, repower the selected 6.9kV safety bus, and then to selectively add the loads shown in Table 4 within approximately one hour.

Under those postulated conditions, the overall plant condition would be superior to that assumed in the analyses for purposes of 10 CFR 50.63 compliance. The availability of a CCP powered from the APDGs would represent a significant enhancement to plant safety under such conditions.

In the event of postulated failure of the TDAFWP, a MDAFP can be loaded onto the APDGs through manual manipulation of the loads shown in Table 4. For example, the previously operating CCP (-526.03kW) would be shed from the bus and replaced by the positive displacement charging pump (+200kW) to yield a load of approximately 2684.26kW on the APDGs. Stripping of the non-safety related Containment Recirculation Fan (-93.25kW), instrument air (-183.28kW),

and the CRDM Cooling Water Fan (-92.44kW) would yield an approximate APDG load of 2315.29kW and provide sufficient margin to place a MDAFP pump

(+611kW) in service. Under such conditions, the approximate load on the APDGs would be 2926kW.

In the unlikely event power were not restored to the blackout Unit and the decision was made to proceed to cold shutdown, manual manipulation of the loads listed in Table 4 would be required in order to support operation of a RHR to TXX-12198 Page 22 of 38 12/19/2012 pump. As in the above scenario, the previously operating CCP (-526.03kW) would be shed from the bus and replaced by the positive displacement charging pump (+200kW) to yield a load of approximately 2684.26kW on the APDGs.

Stripping of the non-safety related Containment Recirculation Fan (-93.25kW) and the CRDM Cooling Water Pump (-92.44kW) would yield an approximate APDG load of 2498.57kW and provide sufficient margin to place a RHR pump

(+368.2kW) in service. Under such conditions, the approximate load on the APDGs would be 2,866.7 kW. This postulated scenario assumes availability of the TDAFWP to support the cooldown (conservatively estimated at between 4-5 hours in duration at a nominal 50 OF/hour rate and neglecting the depressurization and cooldown effects of postulated RCP seal leakage). Based on the above, it is concluded:

The APDGs provide the ability to achieve and maintain safe (hot) shutdown for the beyond-design bases consideration of a LOOP coincident with unavailability of both EDGs on a single Unit.

The APDGs provide the ability to power a MDAFP in the beyond-design bases scenario of a LOOP, coincident with unavailability of both EDGs on a single Unit, and the non-mechanistic unavailability of the TDAFWP.

The ADGs provide the ability to achieve and maintain cold shutdown in the beyond-design bases scenario of a LOOP coincident with unavailability of both EDGs on a single Unit.

b. The supplemental source must have capacity to bring a unit to safe shutdown (cold shutdown) in case of a loss of offsite power (LOOP) concurrent with a single failure during plant operation (Mode 1).

Response

See response to a. above.

c. The staff has previously granted AOT extensions to those licensees who have installed an alternate alternating current (AAC) power source (i.e., additional diesels, gas or combustion turbines, hydro units, or other power sources) credited for SBO events which can be substituted for an inoperable EDG in the event of a LOOP, provided the power source has enough capacity to carry all LOOP loads to bring the unit to a cold shutdown without any load shedding.

Response

See response to a. above.

d. The permanent or temporary power source can be either a diesel generator, gas or combustion turbine, or power from nearby hydro units. This source can be credited as a supplemental source, that can be substituted for an inoperable EDG during the period of extended AOT in the event of a LOOP, provided the risk-informed and deterministic evaluation supports the proposed AOT and the power source has enough capacity to carry all LOOP loads to bring the unit to a cold shutdown.

Response

See response to a. above.

to TXX-12198 Page 23 of 38 12/19/2012

e. For the unit in extended AOT, the licensee must provide a permanent or a temporary power source as a substitute for the EDG in an extended AOT to maintain the same level of defense-in-depth for safe shutdown of the plant.

Response

See response to a. above.

f. For plants using AAC or supplemental power sources discussed above, the time to make the AAC or supplemental power source available, including accomplishing the cross-connection, should be approximately one hour to enable restoration of battery chargers and control reactor coolant system inventory.

Response

As described above, the APDG set associated with the affected Unit will be able to energize the appropriate buses and the required components can be loaded onto the energized buses within approximately one hour.

g. The availability of AAC or supplemental power source should be verified within the last 30 days before entering extended AOT by operating or bringing the power source to its rated voltage and frequency for 5 minutes and ensuring all its auxiliary support systems are available or operational.

Response

Testing of EDGs, APDGs, and turbine driven auxiliary feed water pumps (TDAFWPs) will occur within the two (2) weeks prior to the start of the XST1 CT.

(See commitments 4442007 and 4457008.)

h. To support the one-hour time for making this power source available, plants must assess their ability to cope with loss of all AC power for one hour independent of an AAC power source.

Response

CPNPP has been evaluated to assess compliance with the Station Blackout rule (10CFR50.63) following the guidance provided by RG 1.155 (Reference 8.3). This evaluation determined that both Units are capable of coping with a station blackout (SBO) for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> as AC Independent plants and that no modifications were required. Additionally, the Institute of Nuclear Power Operations (INPO) issued Event Report (IER) Level 1(L1) 11-4, "Near-Term Actions to Address the Effects of an Extended Loss of All AC Power in Response to the Fukushima Daiichi Event" (Reference 8.6) to establish actions to improve the margins of safety for loss of AC power events. Specifically, recommendation 1 required, "For all Units, develop methods to maintain (or restore) core cooling, containment integrity, and spent fuel pool inventory using existing installed and portable equipment during an extended loss of electrical AC power event that lasts at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />." CPNPP reported to INPO that CPNPP can cope with a station blackout for at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, using existing plant equipment and procedures, with a best estimate analysis in accordance with the specified IER L1-11-4 assumptions and bases (Reference 8.7).

to TXX-12198 Page 24 of 38 12/19/2012 The strategy in the station procedures includes load shedding to conserve battery life, depressurizing to reduce potential RCS leakage through RCP seals, and removing heat through the steam generators using the ARVs, with the SGs being fed by the turbine driven aux feed pump. Existing analysis, new owner's group analysis, new battery load shedding calculation revisions, and the plant simulator development model were used to make the assessment. An assessment of room environmental conditions and effects on key equipment was also performed.

Also see response to a. above.

The plant should have formal engineering calculations for equipment sizing and protection and have approved procedures for connecting the AAC or supplemental power sources to the safety buses.

Response

The loads required to be fed from the APDGs with their demand are as shown in Table 4. The Table defines total APDG load requirements. The review of the APDG data indicates that the APDG sets are rated to provide more than the required load. The transformer is sized to carry the required loads. The cables from the APDGs to transformer are adequately sized to carry the required loads and the APDG output breaker provides overload protection for these cables. The cables from transformer to 6.9kV bus are also adequately sized and protected.

Short circuit protection for equipment and cables is provided by current limiting feature of the APDGs. Formal engineering calculations are not performed for equipment sizing and protection.

j. The EDG or offsite power AOT should be limited to 14 days to perform maintenance activities. This time period is based on industry operating experience; for example, a maximum of 216 hours0.0025 days <br />0.06 hours <br />3.571429e-4 weeks <br />8.2188e-5 months <br /> (13.5 days, consisting of two shifts, each shift working 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />) is considered to be sufficient for a major EDG overhaul or offsite power major maintenance. The licensee must provide justification for the duration of the requested AOT (actual hours plus margin based on plant-specific past operating experience).

Response

Concerning the first scope of work, CPNPP has no plant-specific operating experience (OE) for working on transmission towers. CPNPP has contracted with a transmission construction company to perform the 138kV tower work. The company was founded in 1948 to help build the region's electric power lines.

Their crews are among the most experienced in the industry, including many foremen and superintendents who have been with the company for more than 30 years. Additionally, CPNPP's Transmission Operator (TO) subcontracts this company because they are a full-service provider of turn-key transmission structures, lines, and switchyards/ substations for new construction, maintenance, storm restoration, and upgrades. The company has many years of OE working in CPNPP's switchyards, including 138kV and 345kV switchyard breakers, air switches, disconnects, and assisted in replacing GSU transformers and has worked for Oncor or CPNPP. As discussed in Section 3.2, Table 1 estimates the first scope of work will take 11.5 days.

to TXX-12198 Page 25 of 38 12/19/2012 Pertaining to the second scope of work, CPNPP has gained valuable OE in the installation of large power transformers with the replacement of four main generator step-up (GSU) transformers. This task involved the coordination of transformer original equipment manufacturer (OEM,) heavy haulers, OEM field service, TO, isophase OEM, site security and site personnel. The GSU replacements occurred in October 2009 and March 2010. Each of the GSU installation milestones (manufacture, shipment, placement and dress out, installed on pad, testing, connection and energization) were completed within or before the defined schedule windows without any major issue. As discussed in Section 3.2, Table 2 estimates the second scope of work will take 52 days.

The OE for the third scope of work is similar to one previously approved by the NRC on October 29, 2010 (ML103190632) that extended, on a one-time basis, the allowable CT of Required Action A.3 for the 345kV inoperable offsite circuit, from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days. This change was only applicable to ST XST2 and expired on March 1, 2011 and allowed sufficient time to make final terminations to facilitate connection of either XST2 or the spare ST XST2A to the Class 1E buses. The entire sequence of activities was projected to require approximately 11 days and 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> to complete which fit well within the requested 14-day extended CT. The actual CT was 7 days, 21 hours2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br />, and 16 minutes. As discussed in Section 3.2, Table 3 estimates the third scope of work will take 12 days.

The main difference between the previous approved license amendment in 2010 and this license amendment request is that there was an installed spare transformer XST2A under the 345kV line that fed XST2 and the 1E buses.

Conversely, there is no installed alternate transformer for XST1 thus additional provisions must be made to allow connections and the installation of a new ST.

Consequently, this requested amendment will require three primary scopes of work.

Currently, if XST1 requires maintenance that would exceed 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, or if XST1 catastrophically fails, it would take about 18 to 21 days to replace XST1 with the spare startup transformer XST2A. The timing is dependent on the mobilization/availability of heavy haulers, extent of transformer damage, and the availability of needed equipment and personnel to perform the work. Since each ST provides one of the two required offsite AC sources for each CPNPP Unit, an outage of XST1 for greater than the current CT of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> would require that both Units be shutdown to Mode 5 simultaneously.

Once the modification to the plant is complete and XST1 needs maintenance or if XST1 fails, the alternate ST XST1A can be connected to the safety buses to restore the 138kV offsite source within the current TS CT of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. After maintenance or repair on XST1 is completed, XST1 may be put back in-service. As a result, XST1A will be a'dedicated alternate for XST1 and XST2A will be a dedicated alternate for XST2. Therefore, two one-time 14-day CTs are being requested.

k. An EDG or offsite power AOT license amendment of more than 14 days should not be considered by the staff for review.

Response

CPNPP is not requesting more than 14-days and is only requesting two, one-time 14-day CTs. Additionally, see response to f. above.

to TXX-12198 Page 26 of 38 12/19/2012 The TS must contain Required Actions and Completion Times to verify that the supplemental AC source is available before entering extended AOT.

Response

This requirement is for a permanent TS change and this amendment request is only applicable to two, one-time, 14-day CTs for XST1.

m. The availability of AAC or supplemental power source shall be checked every 8-12 hours (once per shift).

Response

During a 14-day CT, the APDG provided for each Unit will be verified available to provide power to equipment for long term cooling once per shift. (See commitments 4441997 and 4457004.)

n. If the AAC or supplemental power source becomes unavailable any time during extended AOT, the Unit shall enter the LCO and start shutting down within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. This 24-hour period will be allowed only once within any given extended EDG AOT.

Response

During a 14-day CT, if an APDG becomes unavailable, both Units shall enter Condition C of TS 3.8.1 and start shutting down within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. (This 24-hour period will only be allowed once within a 14-day CT.) (See commitments 4456419 and 4457005.)

Additionally, the staff expects that the licensee will provide the following Regulatory Commitments:

a) The extended AOT will be used no more than once in a 24-month period (or refueling interval) on a per diesel basis to perform EDG maintenance activities, or any major maintenance on offsite power transformer and bus.

Response

This requirement is for a permanent TS change for a 14-days; however, this proposed amendment request is not for a permanent TS change, but for two, one-time 14-day CTs. Further, providing the capability for connection of a alternate ST XSTIA to the 1E buses within the current TS CT of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is an improvement in plant design which eliminates the necessity to shutdown both Units if XST1 fails or requires maintenance that goes beyond the current TS CT of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This change will improve the long-term reliability of the 138kV offsite circuit by providing connection to the ESF buses through XST1 or the alternate startup transformer. Additionally, performing the work during two, 14-day CTs will provide a safe work environment for personnel safety and will not impact nuclear safety or the health and safety of the public. Therefore, two, one-time 14-day CTs are being requested.

b) The preplanned maintenance will not be scheduled if severe weather conditions are anticipated.

to TXX-12198 Page 27 of 38 12/19/2012

Response

In response to this requirement, CPNPP makes the following commitments:

A time in which severe weather is not expected will be selected for implementation of the XST1 CT. Based on historical information; this time frame is September 1 through March 31. This planned timing will reduce high wind/ tornados and weather challenges to the plant during the XST1 CT (Commitments 4442013 and 4457041).

Local weather conditions and forecasts will be monitored by Operations twice per shift to assess potential impacts on plant conditions. (See commitments 4442011 and 4457033.)

c) The system load dispatcher will be contacted once per day to ensure no significant grid perturbations (high grid loading unable to withstand a single contingency of line or generation outage) are expected during the extended AOT.

Response

CPNPP's Operations Department will contact the Transmission Operator (Transmission Grid Controller) once per day during a 14-day Completion Time to ensure no problems exist in the transmission lines feeding CPNPP or their associated switchyards that would cause post trip switchyard voltages to exceed the voltages required by STA-629. (See commitments 4442046 and 4457121.)

d) Component testing or maintenance of safety systems and important non safety equipment in the offsite power systems that can increase the likelihood of a plant transient (Unit trip) or LOOP will be avoided. In addition, no discretionary switchyard maintenance will be performed.

Response

In response to this requirement, CPNPP makes the following commitments:

The EDGs, APDGs, TDAFWPs, XST2, CCWPs, and SSWPs will have ALL testing and maintenance activities suspended for the duration of a one-time, 14-day CT for XST1. Additionally, signs will be placed on the doorways to the equipment, or in the case of XST2 around the equipment, noting the restriction of testing and maintenance during this XST1 CT. (See commitments 4442008 and 4457016.)

Access to both switchyards and relay houses will be controlled and posted, and all maintenance will be suspended for the duration of the CT on XST1. (See commitments 4442028 and 4457119.)

e) TS required systems, subsystems, trains, components, and devices that depend on the remaining power sources will be verified to be operable and positive measures will be provided to preclude subsequent testing or maintenance activities on these systems, subsystems, trains, components, and devices.

Response

In response to this requirement, CPNPP makes the following commitments:

to TXX-12198 Page 28 of 38 12/19/2012 Prior to initiation of a one time, 14-day CT extension, PM task for breakers 1EA1-1, 1EA2-1, 2EA1-2 and 2EA2-2 will be verified as current.

(See commitments 4442002 and 4457007.)

Testing of EDGs, APDGs, and TDAFWPs will occur within the two (2) weeks prior to the start of the XST1 CT. (See commitments 4442007 and 4457008.)

During a 14-day CT, the APDG provided for each Unit will be verified available to provide power to equipment for long term cooling once per shift. (See commitments 4441997 and 4457004.)

The seismic walkdown will be completed prior to the XST1 CT to identify any issues that could impact the EDGs and TDAFWPs during a seismic event. These impacts include mounting or interactions issues including loose parts and missing hardware. This walkdown is for assurance that these components will meet their seismic design criteria in the event of a seismic incident. (See commitments 4442016 and 4457044.)

f) Steam-driven emergency feed water pump(s) in case of PWR Units, and Reactor Core Isolation Cooling and High Pressure Coolant Injection systems in case of BWR Units, will be controlled as "protected equipment."

Response

The EDGs, APDGs, TDAFWPs, XST2, CCWPs, and SSWPs will have ALL testing and maintenance activities suspended for the duration of a one-time, 14-day CT for XST1. Additionally, signs will be placed on the doorways to the equipment, or in the case of XST2 around the equipment, noting the restriction of testing and maintenance during this XST1 CT. (See commitments 4442008 and 4457016.)

4.2 Other Mitigation Measures During the two XST1 extended CTs required to facilitate the modification outage, only one offsite source (XST2) will be available and the current TS would require the shutdown of both Units if XST1 is not restored within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; therefore, two CTs extension are requested only for the XST1 plant modification. If this requested change is approved, and any other onsite or offsite source or any combination thereof becomes inoperable during the XST1 extended CTs, the current TS CTs would apply and both Units shall shutdown accordingly.

Consistent with other similar NRC approved CT extension requests, Luminant Power provides a list of compensatory measures in addition to the risk reduction measures and commitments associated with the NRC SRP BTP 8-8 to assure safe shutdown and offsite power capability and availability. The summary of regulatory commitments is contained in Attachment 7 to this LAR. The commitments for the first and third scopes of work are the same; however, for commitment tracking and work control purposes, they have been split into two sets of commitments. The first commitment number(s) is applicable to the 14-day CT for the 138kV tower work and the second commitment number is applicable to the 14-day CT for the 6.9kV work, respectively.

Just-in-time training for affected work groups will be completed prior to the start of the XST1 outage (Commitments 4442047 and 4457122).

to TXX-12198 Page 29 of 38 12/19/2012 Appropriate just-in-time (JIT) training will be provided to Operations personnel on this TS change as well as the compensatory measures and mitigation measures to be implemented during these two, one-time, 14-day modification outage. The JIT training will include the loss of the operating ST (XST2) to heighten Operations personnel awareness of challenges to the electrical distribution during the modification outage.

Local weather conditions and forecasts will be monitored by Operations twice per shift to assess potential impacts on plant conditions (Commitments 4442011 and 4457033).

Operations personnel will monitor weather conditions and forecasts and take compensatory measures or mitigation measures to reduce challenges to plant safety or the electrical distribution system during the modification outage.

Restricted Access to and Suspension of Maintenance in the Switchyard:

Access to both switchyards and relay houses will be controlled and posted, and all maintenance will be suspended for the duration of the CT on XST1 (Commitments 4442028 and 4457119).

This measure is selected to deter any perturbations to the remaining ST power supply, 345kV switchyard, and any potential transmission grid or trip issues from the 138kV switchyard. Work in the switchyard is administratively controlled by the Operations Shift Manager who by plant procedure, STA-629 "Switchyard Control and Transmission Grid Interface," (Reference 8.2) has sole authority to grant access to the switchyard. By their authority; they will not allow any testing, maintenance or access to either switchyard; with the exception of normal operator visual inspection rounds. The STs, XST1 and XST2, are physically located in the protected area and not in the switchyard. Additionally, signs will be placed on both switchyards and relay houses noting the restriction of access, testing, and maintenance during this XST1 CT.

Suspension of Maintenance on the EDGs, APDGs, TDAFWPs, XST2, and SSWPs:

The EDGs, APDGs, TDAFWPs, XST2, CCWPs, and SSWPs will have ALL testing and maintenance activities suspended for the duration of a one-time 14-day CT for XST1. Additionally, signs will be placed on the doorways to the equipment, or in the case of XST2 around the equipment, noting the restriction of testing and maintenance during this XST1 CT (Commitments 4442008 and 4457016).

This is to ensure the availability of these components for the entire duration of the CT.

Testing of EDGs, APDGs, and TDAFWPs Will Occur Within the Two (2) Weeks Prior to the Start of the XST1 CT (Commitments 4442007 and 4457008).

To ensure the availability of the above selected components, they will be tested in the two weeks prior to the start of the XST1 CT.

to TXX-12198 Page 30 of 38 12/19/2012 Restriction on Transient Combustible Storage Along the XST2 Control and Power Cable Routing Both Unit 1 and 2 Transient Combustible safe zones that are associated with the cable routing for the XST2 transformer will have additional restrictions relating to combustible storage during the extended CT durations. Implementing this mitigation measure will reduce the likelihood of fires related to the XST2 transformer (Commitments 4457002 and 4457125).

• Suspension of Hot Work Activities Near XST2 Power and Control Cabling All hot work activities along the routing associated with power and control cabling for XST2, the in-service ST, will be suspended during the XST1 CT. This is to reduce the likelihood of fires that could damage and thus disable the XST2 transformer cabling (Commitments 4442049 and 4457123).

• Roving Hourly Fire Watch Along Paths of XST2 Power and Control Cabling A roving hourly fire watch will be in effect during the 14-day XST1 CT along the path of the XST2 power and control cabling. This is an additional measure to monitor the area for fires that could damage and disable the XST2 transformer cabling (Commitments 4442010 and 4457030).

• Thermography of the Fixed Fire Sources In the two weeks prior to the start of the CT, a thermographic survey will be conducted on the two fixed sources in the safeguards switchgear room to verify no abnormalities exist. This is to reduce the likelihood of a fire ignition (Commitments 4456879 and 4457124).

• Selection of Time of Year Due to Weather Considerations A time in which severe weather is not expected will be selected for implementation of the XST1 CT. Based on historical information; this time frame is September 1 through March 31. This planned timing will reduce high wind/tornados and weather challenges to the plant during the XST1 CT (Commitments 4442013 and 4457041).

• Seismic Walkdown for the EDGs and TDAFWPs The seismic walkdown will be completed prior to the XST1 CT to identify any issues that could impact the EDGs and TDAFWPs during a seismic event. These impacts include mounting or interactions issues including loose parts and missing hardware. This walkdown is for assurance that these components will meet their seismic design criteria in the event of a seismic incident (Commitments 4442016 and 4457044).

4.3 Configuration Risk Management Program Configuration Risk Management Program (CRMP) requires a proceduralized process to assess the risk associated with both planned and unplanned work activities. The objective of CRMP is to ensure that the risk impact of out-of-service equipment is evaluated prior to performing any maintenance activity. CRMP addresses the limitation of not being able to TXX-12198 Page 31 of 38 12/19/2012 to identify all possible risk significant plant configurations. Programs and procedures are in place at CPNPP which serve to address this objective.

CPNPP has a Configuration Risk Management program which has the characteristics of the Model Configuration Risk Management Program described in RG 1.177 (Reference 8.8) and which was previously approved for risk informed Technical Specifications. Its description has been incorporated into plant Technical Specifications. In addition, CPNPP has committed to NUMARC 93-01, "Industry Guideline for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants," (Reference 8.9).

To avoid or reduce the potential for risk-significant configurations from either emergent or planned work, CPNPP has put in place a set of administrative guidelines that go beyond the limitations set forth in the plant TS. These guidelines control configuration risk by assessing the risk impact of equipment out-of-service during all modes of operation to assure that the plant is always being operated within acceptable risk guidelines.

CPNPP employs a conservative approach to at-power maintenance. The weekly schedules are train/channel based and prohibit the scheduling of opposite train activities without additional review, approvals and/or risk reduction actions. The assessment process further minimizes risk by restricting the number and combination of systems/trains allowed to be simultaneously unavailable for scheduled work. Unplanned or emergent work activities are factored into the plant's actual and projected condition, and the level of risk is evaluated. Based on the result of this evaluation, decisions pertaining to what action, if any, are required to achieve an acceptable level of risk (component restoration or invoking risk reduction measures) are made. The unplanned or emergent work activities are also evaluated to determine impact on planned activities and the effect the combinations would have on risk.

Technical Specification 5.5.18, "Configuration Risk Management Program (CRMP)," will apply to this license amendment request and is quoted below for information:

The Configuration Risk Management Program (CRMP) provides a proceduralized risk-informed assessment to manage the risk associated with equipment inoperability. The program applies to technical specification structures, systems, or components for which a risk-informed Allowed Outage Time has been granted. The program shall include the following elements:

a. Provisions for the control and implementation of a Level 1, at-power, internal events PRA-informed methodology. The assessment shall be capable of evaluating the applicable plant configuration.

b. Provisions for performing an assessment prior to entering the LCO Action for preplanned activities.

c. Provisions for performing an assessment after entering the LCO Action for unplanned entry into the LCO Action.

d. Provisions for assessing the need for additional actions after the discovery of additional equipment out-of-service conditions while in the LCO Action.

e. Provisions for considering other applicable risk significant contributors such as Level 2 issues, and external events, qualitatively or quantitatively.

Attachment I to TXX-12198 Page 32 of 38 12/19/2012 At CPNPP the procedures WCI-606 "Work Control Process" (Reference 8.10), WCI-202 "Maintenance Risk Assessment" (Reference 8.11), and WCI-203 "Weekly Surveillances/Work Scheduling" (Reference 8.12) are three of the controlling procedures for maintenance process. The CRMP program at CPNPP ensures that configuration risk has been managed prior to initiating any maintenance activity consistent with the requirements of 10CFR50.65(a)(4).

Currently CPNPP uses the Equipment Out-of-service (EOOS) software to perform online risk assessment. All Probability Risk Assessment (PRA) components are represented in EOOS with the ability to take one or multiple components out-of-service. After the activities have been added (i.e. component taken out-of-service) the model is re-quantified and the core damage frequency (CDF) and large early release frequency (LERF) are calculated. The risk is then compared to preset values and colors are assigned based on these preset values. As the risk is increased the requirement for management approval is raised. External events are evaluated qualitatively to determine their impact on the configuration risk.

In summary, this process is performed for all activities that affect PRA components, initiating events or recoveries. The Work Control Group uses the weekly schedule to calculate the plant risk for the week on an activity basis. The proposed CT would be planned and added to the weekly schedule and the risk for the activity would be calculated. The weekly risk assessment will be reviewed and appropriate management approval will be obtained. The process is the same for emergent activities as above. The risk is assessed prior to the emergent activity being worked. The risk is calculated and scheduled activities may be moved to a later date or equipment put back in-service to ensure that the risk is acceptable. Again the risk will be reviewed and appropriate management approval will be received. The above process meets the requirement of RG 1.177 Section 2.3.7 (Reference 8.8).

Summary of Technical Analysis The analysis of the proposed extended CT consists of three main elements: (1) a traditional engineering analyses, (2) avoidance of risk significant plant configurations using mitigating measures, and (3) continued implementation of a Configuration Risk Management Program (CRMP) during the two, one-time 14-day extended Completion Times.

CPNPP has a robust design with the desired defense-in-depth design features (i.e., the ability to mitigate design basis accidents when a ST is out-of-service). Specifically, offsite and onsite power systems are diverse and redundant and meet regulatory requirements of GDC 17. While XST1 is out-of-service during the plant modification outages, XST2 has the capacity and capability to supply the required safety related loads of both Units. Further, XST2A availability to feed the safety buses, in case of unavailability of XST2, has further enhanced the 345kV offsite source reliability. During the two, one-time, 14-day CTs for XST1, compensatory and mitigating measures will be in place to assure safe shutdown and offsite power capability and availability.

One measure, the APDGs, will provide an alternate power source to one safety related bus in Modes 3, 4, 5, and 6 to maintain the capability for safe shutdown and long term cooling of the Unit. Further, providing the capability for connection of a alternate ST XST1A to the 1E buses within the current TS CT of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is an improvement in plant design which eliminates the necessity to shutdown both Units if XST1 fails or requires maintenance that goes beyond the current TS CT of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This change will improve the long-term reliability of the 138kV offsite circuit by providing connection to the ESF buses through XST1 or the alternate ST. Additionally, to TXX-12198 Page 33 of 38 12/19/2012 performing the work during two, 14-day CTs will provide a safe work environment for personnel safety and will not impact nuclear safety or the health and safety of the public.

5.0 REGULATORY ANALYSIS

5.1 No Significant Hazards Consideration Luminant Power is proposing a change to the Comanche Peak Nuclear Power Plant (CPNPP) Technical Specifications (TS) 3.8.1 entitled "AC Sources - Operating" to extend, on a one-time basis, two allowable Completion Times (CTs) of Required Action A.3 for one inoperable offsite circuit, from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days. This change is only applicable to startup transformer (ST) XST1 and will expire on March 31, 2014. This change is needed to 1) modify the XST1 138kV tower to add disconnects for a new alternate ST and replace the existing disconnects for XST1 and 2) to make final terminations to facilitate connection of ST XST1 or a alternate ST to the 1E buses. Installation of the cabling from XST1 and an alternate ST XST1A to two new 6.9kV transfer panels will allow alternate ST XST1A to be a fully installed alternate capable of being aligned to the 1E buses in place of XST1 within the original TS CT of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Luminant Power has evaluated whether or not a significant hazards consideration is involved with the proposed amendment(s) by focusing on the three standards set forth in 10CFR50.92, "Issuance of amendment," as discussed below:

5.1.1 Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No The proposed change will revise the CT for the loss of one offsite source from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days to allow two, one-time, 14-day CTs. The proposed two, one-time extensions of the CT for the loss of one offsite power circuit does not significantly increase the probability of an accident previously evaluated. The TS will continue to require equipment that will power safety related equipment necessary to perform any required safety function. The two, one-time extensions of the CT to 14 days does not affect the design of the STs, the interface of the STs with other plant systems, the operating characteristic of the STs, or the reliability of the STs.

The consequence of a LOOP event has been evaluated in the CPNPP Final Safety Analysis Report (Reference 8.1) and the Station Blackout evaluation. Increasing the CT for one offsite power source twice on a one-time basis from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days does not increase the consequences of a LOOP event nor change the evaluation of LOOP events.

Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

5.1.2 Do the proposed changes create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No The proposed change does not result in a change in the manner in which the electrical distribution subsystems provide plant protection. The proposed change to TXX-12198 Page 34 of 38 12/19/2012 will only affect the time allowed to restore the operability of the offsite power source through a ST. The proposed change does not affect the configuration, or operation of the plant. The proposed change to the CT will facilitate installation of a plant modification which will improve plant design and will eliminate the necessity to shut down both Units if XST1 fails or requires maintenance that goes beyond the current TS CT of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This change will improve the long-term reliability of the 138kV offsite circuit ST which is common to both CPNPP Units.

There are no changes to the STs or the supporting systems operating characteristics or conditions. The change to the CT does not change any existing accident scenarios, nor create any new or different accident scenarios. In addition, the change does not impose any new or different requirements or eliminate any existing requirements. The change does not alter any of the assumptions made in the safety analysis.

Therefore, the proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.

5.1.3 Do the proposed changes involve a significant reduction in a margin of safety?

Response: No The proposed change does not affect the acceptance criteria for any analyzed event nor is there a change to any safety limit. The proposed change does not alter the manner in which safety limits, limiting safety system settings, or limiting conditions for operation are determined. Neither the safety analyses nor the safety analysis acceptance criteria are affected by this change. The proposed change will not result in plant operation in a configuration outside the current design basis. The proposed activity only increases, for two, one-time pre-planned occurrences, the period when the plant may operate with one offsite power source. The margin of safety is maintained by maintaining the ability to safely shut down the plant and remove residual heat.

Therefore, the proposed change does not involve a reduction in a margin of safety.

Based on the above evaluations, Luminant Power concludes that the proposed amendment present no significant hazards under the standards set forth in 10CFR50.92(c) and, accordingly, a finding of "no significant hazards consideration" is justified.

5.2 Applicable Regulatory Requirements/Criteria GDC 5 - Sharing of Structures, Systems, and Components, "Structures, systems, and components important to safety shall not be shared between nuclear power Units unless it can be shown that such sharing will not significantly impair their ability to perform their safety functions including, in the event of an accident in one Unit, an orderly shutdown and cooldown of the remaining Unit."

GDC 17 - Electric Power Systems, "An onsite electric power system and an offsite electric power system shall be provided to permit functioning of structures, systems, and components important to safety. The safety function for each system (assuming the other to TXX-12198 Page 35 of 38 12/19/2012 system is not functioning) shall be to provide sufficient capacity and capability to ensure that (1) specified acceptable fuel design limits and design conditions of the reactor coolant pressure boundary are not exceeded as a result of anticipated operational occurrences, and (2) the core is cooled and containment integrity and other vital functions are maintained in the event of postulated accidents.

The onsite electric power sources, including the batteries, and the onsite electrical distribution system, shall have sufficient independence, redundancy, and testability to perform their safety functions, assuming a single failure.

Electric power from the transmission network to the onsite electric distribution system shall be supplied by two physically independent circuits (not necessarily on separate rights of way) designed and located so as to minimize to the extent practical the likelihood of their simultaneous failure under operating and postulated accident and environmental conditions. A switchyard common to both circuits is acceptable. Each of these circuits shall be designed to be available in sufficient time following a loss of all onsite alternating current power supplies and the other offsite electrical power circuit, to ensure that specified acceptable fuel design limits and design conditions of the reactor coolant pressure boundary are not exceeded. One of these circuits shall be designed to be available within a few seconds following a loss of coolant accident to ensure that core cooling, containment integrity, and other vital safety functions are maintained. Provisions shall be included to minimize the probability of losing electric power from any of the remaining supplies as a result of, or coincident with, the loss of power generated by the nuclear power Unit, the loss of power from the transmission network, or the loss of power from the onsite electrical power supplies."

GDC 18 - Inspection and Testing of Electric Power System, "Electric power systems important to safety shall be designed to permit appropriate periodic inspection and testing of important areas and features, such as wiring, insulation, connections, and switchboards, to assess the continuity of the systems and the condition of their components. The systems shall be designed with a capability to test periodically (1) the operability and functional performance of the components of the systems, such as onsite power sources, relays, switches, and buses and (2) the operability of the systems as a whole and, under conditions as close to design as practical, the full operational sequence that brings the systems into operation, including operation of applicable portions of the protection system and the transfer of power among the nuclear power Unit, the offsite power system, and the onsite power system."

NRC Regulatory Guide 1.53, dated June 1973, titled "Applicability of Single-Failure Criterion to Nuclear Power Plant Protection Systems" (Reference 8.13).

NRC Regulatory Guide 1.62, dated October 1973, titled "Manual Initiation of Protective Actions" (Reference 8.14).

NRC Regulatory Guide 1.75, Revision 1, dated January 1975, titled "Physical Independence of Electrical Systems" (Reference 8.15).

NRC Regulatory Guide 1.81, Revision 1, dated January 1975, titled "Shared Emergency and Shutdown Electric Systems for Multi-Unit Nuclear Power Plants" (Reference 8.16).

NRC Regulatory Guide 1.93, dated December 1974, titled "Availability of Electric Power Sources" (Reference 8.17). The current CT associated with inoperable AC power source(s) is intended to minimize the time an operating plant is exposed to a reduction in the to TXX-12198 Page 36 of 38 12/19/2012 number of available AC power sources. NRC Regulatory Guide (RG) 1.93 is referenced in the TS Bases for actions associated with TS 3.8.1. RG 1.93 provides operating restrictions (i.e., CT and maintenance limitations) that the NRC considers acceptable if the number of available AC power sources is one less than the LCO. RG 1.93 specifically states, "If the available a.c. power sources are one less than the LCO, power operation may continue for a period that should not exceed 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> if the system stability and reserves are such that a subsequent single failure (including a trip of the Unit's generator, but excluding an unrelated failure of the remaining offsite circuit if this degraded state was caused by the loss of an offsite source) would not cause total loss-of-offsite power." RG 1.93 additionally states, "The operating time limits delineated above are explicitly for corrective maintenance activities only."

NRC Regulatory Guide 1.155, "Station Blackout," dated August 1988 (Reference 8.3).

NRC regulatory Guide 1.177, "An Approach for Plant-Specific, Risk-Informed Decisionmaking: Technical Specifications," dated August 1998 (Reference 8.8).

Analysis Only conformance with Regulatory Guide 1.93 is affected by this proposed change.

According to RG 1.93, operation may continue with one inoperable offsite circuit for a period not to exceed 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. If the proposed change is approved, CPNPP will continue to conform to this RG with the exception that the allowed CT for restoration of an offsite circuit will be increased, twice, on a one-time basis, to 14 days.

In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

6.0 ENVIRONMENTAL CONSIDERATION

Luminant Power has determined that the proposed amendment would change requirements with respect to the installation or use of a facility component located within the restricted area, as defined in 10CFR20, or would change an inspection or surveillance requirement. Luminant Power has evaluated the proposed change and has determined that the change does not involve (1) a significant hazards consideration, (2) a significant change in the types or significant increase in the amounts of any effluent that may be released offsite, or (3) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed change meets the eligibility criterion for categorical exclusion set forth in 10CFR51.22(c)(9). Therefore, pursuant to 10CFR51.22(b), an environmental assessment of the proposed change is not required.

7.0 PRECEDENT On October 15, 2010, the NRC issued Amendment Nos. 224 and 217, Docket Nos. 50-361 and 50.362, to San Onofre Nuclear Generating Units Unit Nos. 2 and 3 respectively. The amendments revised TS 3.8.1, "AC [Alternating Current] Sources - Operating," Condition A, to allow a one-time extension, from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 10 days based on a deterministic evaluation (Reference 8.18).

to TXX-12198 Page 37 of 38 12/19/2012

8.0 REFERENCES

8.1 Comanche Peak Nuclear Power Plant Final Safety Analysis Report, Docket Nos. 50-445 and 50-446.

8.2 STA-629, "Switchyard Control and Transmission Grid Interface," Comanche Peak Nuclear Power Plant, Revision 7.

8.3 NRC Regulatory Guide 1.155, "Station Blackout," dated August 1988.

8.4 NUMARC 87-00, "Guidelines and Technical Bases for NUMARC Initiatives addressing Station Blackout at Light Water Reactors.

8.5 SOP-614A/B, "Alternate Power Generator Operation," Comanche Peak Nuclear Power Plant Procedure, Revision 12.

8.6 INPO IER Li 11-4, "Near-Term Actions to Address the Effects of an Extended Loss of All AC Power in Response to the Fukushima Daiichi Event," Dated August 1, 2011 and Revised September 29, 2011.

8.7 Letter from Rafael Flores (Comanche Peak Nuclear Power Plant) to Ms. Kim Maza (Institute of Nuclear Power Operations), "Response to IER No. Li 11-4, 'INPO IER Li 11-4, "Near-Term Actions to Address the Effects of an Extended Loss of All AC Power in Response to the Fukushima Daiichi Event,'" dated January 25, 2012.

8.8 NRC Regulatory Guide 1.177, "An Approach for Plant-Specific, Risk-Informed Decisionmaking: Technical Specifications," Revision 1, May 2011.

8.9 NUMARC 93-01, Industry Guideline For Monitoring the Effectiveness Of Maintenance At Nuclear Power Plants," Revision 4A, April 2012.

8.10 WCI-606, "Work Control Process," Comanche Peak Nuclear Power Plant Procedure, Revision 14.

8.11 WCI-202, "Maintenance Risk Assessment," Comanche Peak Nuclear Power Plant Procedure, Revision 0.

8.12 WCI-203, "Weekly Surveillances Work Scheduling," Comanche Peak Nuclear Power Plant Procedure, Revision 27.

8.13 NRC Regulatory Guide 1.53, "Applicability of Single-Failure Criterion to Nuclear Power Plant Protection Systems," June 1973.

8.14 NRC Regulatory Guide 1.62, "Manual Initiation of Protective Actions," October 1973.

8.15 NRC Regulatory Guide 1.75, Revision 1, "Physical Independence of Electrical Systems,"

January 1975.

8.16 NRC Regulatory Guide 1.81, Revision 1, "Shared Emergency and Shutdown Electric Systems for Multi-unit Nuclear Power Plants," January 1975.

to TXX-12198 Page 38 of 38 12/19/2012 8.17 NRC Regulatory Guide (RG) 1.93, "Availability of Electric Power Sources," December 1974.

8.18 Letter to Mr. James J. Shepard (Southern California Edison Company) from James R. Hall (USNRC) dated October 15, 2010, "San Onofre Nuclear Generating Station Units 2 and 3 -

Issuance of Amendments Revising Technical Specification 3.8.1, 'AC Sources -

Operating' (TAC Nos. ME4508 and ME4509)."

ATTACHMENT 2 to TXX-12198 PROPOSED TECHNICAL SPECIFICATION CHANGES (MARK-UP)

Page 3.8-2

Attachment 2 to TXX-12198 Page 2 of 2 AC Sources -- Operating 3.8.1 ACTIONS

• l f"*"lPr""

Iu I II--I------------------------------------------

LCO 3.0.4.b is not applicable to DGs.

CONDITION REQUIRED ACTION COMPLETION TIME A. One required offsite circuit A.1 Perform SR 3.8.1.1 for required 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> inoperable. OPERABLE offsite circuit.

AND Once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter AND A.2 ----------- NOTE ----------

In MODES 1, 2 and 3, the TDAFW pump is considered a required redundant feature.

Declare required feature(s) with no 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> from discovery offsite power available inoperable of no offsite power to when its redundant required one train concurrent feature(s) is inoperable, with inoperability of redundant required feature(s)

AND two, A.3 Restore required offsite circuit to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> OPERABLE status.

OR 14 days for a one-time outages on XST1o complete a plant i

modification to be completed by March 31,2014 COMANCHE PEAK - UNITS 1 AND 2 3.8-2 Amendment No. 44507 46a

ATTACHMENT 3 to TXX-12198 PROPOSED TECHNICAL SPECIFICATIONS BASES CHANGES (Markup For Information Only)

Pages B 3.8-8

AC Sources - Operating Attachment 3 to TXX-12198 B 3.8.1 Page 2 of 2 BASES ACTIONS (continued)

A.3 According to Regulatory Guide 1.93 (Ref. 6), operation may continue in Condition A for a period that should not exceed 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. With one offsite circuit inoperable, the reliability of the offsite system is degraded, and the potential for a loss of offsite power is increased, with attendant potential for a challenge to the unit safety systems. In this Condition, however, the remaining OPERABLE offsite circuit and DGs are adequate to supply electrical pow .t"e onsite Class 1 E Distribution System.

The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Comi le Time takes into account the capacity and capability of the remaining A sour , a reasonable time for repairs, and the low probability of a DBAuring this period. to aeAn OR statement for temporary Co letion Times is added to tle Completion Time abov4472 hours). The one-time, 14-day (ýompletion Times

-- applicable to XST1( only and expires on March 31, 20141 The 4-day Completion Times applyico when makin*g the final terminipiens as part of the plant modification to facilitate connection of either XST1 or XST1A6seF startup transformers to the 1 E buses. If during the conduct of the prescribed maintenance outage, should any combination of the remaining OPERABLE AC Sources be determined inoperable, current TS requirements would apply.

B.1 To ensure a highly reliable power source remains with an inoperable DG, it is necessary to verify the availability of the offsite circuits on a more frequent basis. Since the Required Action only specifies "perform," a failure of SR 3.8.1.1 acceptance criteria does not result in a Required Action being not met. However, if a circuit fails to pass SR 3.8.1.1, It is inoperable. Upon offsite circuit inoperability, additional Conditions and Required Actions must then be entered.

B.2 Required Action B.2 is intended to provide assurance that a loss of offsite power, during the period that a DG is inoperable, does not result in a complete loss of safety function of critical systems. These features are designed with redundant safety related trains. This includes the motor driven auxiliary feedwater pumps and the TDAFW pump which must be available for mitigation of a Feedwater line break. Single train systems, other than the turbine driven auxiliary feedwater pump, are not included.

Redundant required feature failures consist of inoperable features associated with a train, redundant to the train that has an inoperable DG.

(continued)

COMANCHE PEAK- UNITS 1 AND 2 B 3.8-8 Revision 464.

ATTACHMENT 4 to TXX-12198 RETYPED TECHNICAL SPECIFICATION PAGES Page 3.8-2

Attachment 4 to TXX-1 2198 Page 2 of 2 AC Sources -- Operating 3.8.1 ACTIONS

-NOTE-LCO 3.0.4.b is not applicable to DGs.

CONDITION REQUIRED ACTION COMPLETION TIME A. One required offsite circuit A.1 Perform SR 3.8.1.1 for required 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> inoperable. OPERABLE offsite circuit.

AND Once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter AND A.2 ----------- NOTE ----------

In MODES 1, 2 and 3, the TDAFW pump is considered a required redundant feature.

Declare required feature(s) with no 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> from discovery offsite power available inoperable of no offsite power to when its redundant required one train concurrent feature(s) is inoperable, with inoperability of redundant required feature(s)

AND A.3 Restore required offsite circuit to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> OPERABLE status.

OR 14 days for two one-time outages on XST1 to complete a plant modification to be completed by March 31, 2014.

COMANCHE PEAK - UNITS 1 AND 2 3.8-2 Amendment No. 4f&, 4&2-,

ATTACHMENT 5 to TXX-12198 RETYPED TECHNICAL SPECIFICATION BASES PAGES Pages B 3.8-8

AC Sources - Operating B 3.8.1 Attachment 5 to TXX-1 2198 Page 2 of 2 BASES ACTIONS (continued)

A.3 According to Regulatory Guide 1.93 (Ref. 6), operation may continue in Condition A for a period that should not exceed 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. With one offsite circuit inoperable, the reliability of the offsite system is degraded, and the potential for a loss of offsite power is increased, with attendant potential for a challenge to the unit safety systems. In this Condition, however, the remaining OPERABLE offsite circuit and DGs are adequate to supply electrical power to the onsite Class 1 E Distribution System.

The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

An OR statement for two temporary Completion Times is added to the Completion Time above (72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />). The two-time, 14-day Completion Times are applicable to XST1 only and expires on March 31, 2014. The two, 14-day Completion Times apply as part of the plant modification to facilitate connection of either XST1 or XST1 A startup transformers to the 1E buses. If during the conduct of the prescribed maintenance outage, should any combination of the remaining OPERABLE AC Sources be determined inoperable, current TS requirements would apply.

B.1 To ensure a highly reliable power source remains with an inoperable DG, it is necessary to verify the availability of the offsite circuits on a more frequent basis. Since the Required Action only specifies "perform," a failure of SR 3.8.1.1 acceptance criteria does not result in a Required Action being not met. However, if a circuit fails to pass SR 3.8.1.1, it is inoperable. Upon offsite circuit inoperability, additional Conditions and Required Actions must then be entered.

B.2 Required Action B.2 is intended to provide assurance that a loss of offsite power, during the period that a DG is inoperable, does not result in a complete loss of safety function of critical systems. These features are designed with redundant safety related trains. This includes the motor driven auxiliary feedwater pumps and the TDAFW pump which must be available for mitigation of a Feedwater line break. Single train systems, other than the turbine driven auxiliary feedwater pump, are not included.

Redundant required feature failures consist of inoperable features associated with a train, redundant to the train that has an inoperable DG.

(continued)

COMANCHE PEAK - UNITS 1 AND 2 B 3.8-8 Revision

ATTACHMENT 7 to TXX-12198

SUMMARY

OF REGULATORY COMMITMENTS to TXX-12198 Page 2 of 4 Regulatory Commitment Summary Number Commitment Due Date/Event The Following Commitments Are Associated With The 138kV Work 4441997 During a 14-day CT, the APDG provided for each Unit will be During the 14-day verified available to provide power to equipment for long term CT for the 138kV cooling once per shift. work.

4456419 During a 14-day CT, if an APDG becomes unavailable, both Units During the 14-day shall enter Condition C of TS 3.8.1 and start shutting down within 24 CT for the 138kV hours. (This 24-hour period will only be allowed once within a 14-day work.

CT.)

4442002 Prior to initiation of a one time, 14-day CT extension, PM task for Prior to the start breakers 1EA1-1, 1EA2-1, 2EA1-1 and 2EA2-2 will be verified as of the 14-day CT current, for the 138kV work.

4442007 Testing of EDGs, APDGs, and TDAFWPs will occur within the two (2) Within two weeks weeks prior to the start of the XST1 CT. prior to the start of the 14-day CT for the 138kV work 4442008 The EDGs, APDGs, TDAFWPs, XST2, CCWPs, and SSWPs will have During the 14-day ALL testing and maintenance activities suspended for the duration of CT for the 138kV a one-time, 14-day CT for XST1. Additionally, signs will be placed on work.

the doorways to the equipment, or in the case of XST2 around the equipment, noting the restriction of testing and maintenance during this XST1 CT.

4442010 A roving hourly fire watch will be in effect during the 14-day XST1 During the 14-day CT along the path of the XST2 power and control cabling. This is an CT for the 138kV additional measure to monitor the area for fires that could damage work.

and disable the XST2 transformer cabling.

4442011 Local weather conditions and forecasts will be monitored by During the 14-day Operations twice per shift to assess potential impacts on plant CT for the 138kV conditions. work.

4442013 A time in which severe weather is not expected will be selected for During the 14-day implementation of the XST1 CT. Based on historical information; this CT for the 138kV time frame is September 1 through March 31. This planned timing work.

will reduce high wind/tornados and weather challenges to the plant during the XST1 CT.

4442016 The seismic walkdown will be completed prior to the XST1 CT to Within two weeks identify any issues that could impact the EDGs and TDAFWPs during prior to the start a seismic event. These impacts include mounting or interactions of the 14-day CT issues including loose parts and missing hardware. This walkdown is for the 138kV for assurance that these components will meet their seismic design work criteria in the event of a seismic incident.

4442028 Access to both switchyards and relay houses will be controlled and Prior to the start posted, and all maintenance will be suspended for the duration of the of the 14-day CT CT on XST1. for the138 kV work 4442046 CPNPP's Operations Department will contact the Transmission During the 14-day Operator (Transmission Grid Controller) once per day during a 14- CT for the 138kV day Completion Time to ensure no problems exist in the transmission work.

lines feeding CPNPP or their associated switchyards that would cause post trip switchyard voltages to exceed the voltage required by STA-629.

to TXX-1 2198 Page 3 of 4 Number Commitment Due Date/Event 4442047 Just-in-time training for affected work groups will be completed prior Prior to the start to the start of a XST1 outage. of the 14-day CT for the 138kV work 4442049 All hot work activities along the routing associated with power and During a 14-day control cabling for XST2, the in-service ST, will be suspended during CT for the 138kV the XST1 CT. This is to reduce the likelihood of fires that could work.

damage and thus disable the XST2 transformer cabling.

4456879 In the two weeks prior to the start of the CT, a thermographic survey. Within two weeks will be conducted on the two fixed sources in the safeguards prior to the start switchgear room to verify no abnormalities exist. This is to reduce the of the 14-day CT likelihood of a fire ignition. for the 138kV work 4457002 Both Unit 1 and 2 Transient Combustible safe zones that are During a 14-day associated with the cable routing for the XST2 transformer will have CT for the 138kV additional restrictions relating to combustible storage during the work.

extended CT durations. Implementing this mitigation measure will reduce the likelihood of fires related to the XST2 transformer.

The Following Commitments Are Associated With The 6.9kV Work 4457004 During a 14-day CT, the APDG provided for each Unit will be verified During the 14-day available to provide power to equipment for long term cooling once CT for the 6.9kV per shift. work.

4457005 During a 14-day CT, if an APDG becomes unavailable, both Units During the 14-day shall enter Condition C of TS 3.8.1 and start shutting down within 24 CT for the 6.9kV hours. (This 24-hour period will only be allowed once within a 14-day work.

CT.)

4457007 Prior to initiation of the one time, two CT extensions, PM task for Prior to the start breakers 1EA1-1, 1EA2-1, 2EAI-1 and 2EA2-2 will be verified as of the 14-day CT current. for the 6.9kV work.

4457008 Testing of EDGs, APDGs, and TDAFWPs will occur within the two (2) Within two weeks weeks prior to the start of the XST1 CT. prior to the start of the 14-day CT for the 6.9kV work 4457016 The EDGs, APDGs, TDAFWPs, XST2, CCWPs, and SSWPs will have During the 14-day ALL testing and maintenance activities suspended for the duration of CT for the 6.9kV a one-time, 14-day CT for XST1. Additionally, signs will be placed on work.

the doorways to the equipment, or in the case of XST2 around the equipment, noting the restriction of testing and maintenance during this XST1 CT.

4457030 A roving hourly fire watch will be in effect during the 14-day XST1 During the 14-day CT along the path of the XST2 power and control cabling. This is an CT for the 6.9kV additional measure to monitor the area for fires that could damage work.

and disable the XST2 transformer cabling.

4457033 Local weather conditions and forecasts will be monitored by During the 14-day Operations twice per shift to assess potential impacts on plant CT for the 6.9kV conditions. work.

to TXX-12198 Page 4 of 4 Number Commitment Due Date/Event 4457041 A time in which severe weather is not expected will be selected for During the 14-day implementation of the XST1 CT. Based on historical information; this CT for the 6.9kV time frame is September 1 through March 31. This planned timing work.

will reduce high wind/tornados and weather challenges to the plant during the XST1 CT.

4457044 The seismic walkdown will be completed prior to the XST1 CT to Within two weeks identify any issues that could impact the EDGs and TDAFWPs during prior to the start a seismic event. These impacts include mounting or interactions of the 14-day CT issues including loose parts and missing hardware. This walkdown is for the 6.9kV for assurance that these components will meet their seismic design work criteria in the event of a seismic incident.

4457119 Access to both switchyards and relay houses will be controlled and Prior to the start posted, and all maintenance will be suspended for the duration of the of the 14-day CT CT on XST1. for the 6.9kV work 4457121 CPNPP's Operations Department will contact the Transmission During the 14-day Operator (Transmission Grid Controller) once per day during a 14- CT for the 6.9kV day Completion Time to ensure no problems exist in the transmission work.

lines feeding CPNPP or their associated switchyards that would cause post trip switchyard voltages to exceed the voltage required by STA-629.

4457122 Just-in-time training for affected work groups will be completed prior Prior to the start to the start of a XST1 outage. of the 14-day CT for the 6.9kV work 4457123 All hot work activities along the routing associated with power and During a 14-day control cabling for XST2, the in-service ST, will be suspended during CT for the 6.9kV the XST1 CT. This is to reduce the likelihood of fires that could work.

damage and thus disable the XST2 transformer cabling.

4457124 In the two weeks prior to the start of the CT, a thermographic survey Within two weeks will be conducted on the two fixed sources in the safeguards prior to the start switchgear room to verify no abnormalities exist. This is to reduce the of the 14-day CT likelihood of a fire ignition. for the 6.9kV work 4457125 Both Unit 1 and 2 Transient Combustible safe zones that are During a 14-day associated with the cable routing for the XST2 transformer will have CT for the 6.9kV additional restrictions relating to combustible storage during the work.

extended CT durations. Implementing this mitigation measure will reduce the likelihood of fires related to the XST2 transformer.