Text

License Amendment Request (LAR)14-001, Revision to TS 3.8.1, AC Sources - Operating, for a 14-Day Completion Time for Offsite Circuits
	ML14192A338
Person / Time
Site:	Comanche Peak
Issue date:	07/01/2014
From:	Flores R, Madden F; Luminant Generation Co, Luminant Power
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	CP-201400632, TXX-14063
	Download: ML14192A338 (83)
	v • d • e

Rafael Flores Lumninant Power Senior Vice President P.O. Box 1002

&Chief Nuclear Officer 6322. North, FMS rafael.flores@luminant.com Gl.en R.osO .X .04.

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CP-201400632 Ref: 10 CFR50%60.Y TXX-14063 July 1, 2014 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 . " j*,i

SUBJECT:

COMANCHE PEAK NUCLEAR POWER PLANT (CPNPP) DOCKET NOS- 50-445 AND 50-446, LICENSE AMENDMENT REQUEST (LAR)14-001, REVISION TO TECHNICAL SPECIFICATION 3.8.1, "AC SOURCES - OPERATING," FOR A 14-DAY COMPLETION TIME FOR OFFSITE CIRCUITS

REFERENCES:

1. Luminant Power letter, logged TXX-12198, from Rafael Flores to the USNRC titled "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," dated December 19, 2012. (ML13023A237)

2. Luminant Power letter, logged TXX-13082, from Rafael Flores to the USNRC dated May 16, 2013, "Response to Request for Additional Information for License Amendment Request (LAR)12-007, Revision to Teclnical Specifications 3.8.1,

'AC Sources - Operating,' for Two, 14-Day Completion Times for Offsite Circuits." (TAC Nos. MF0405 and MF0406). (ML13149A257)

3. Letter to Rafael Flores (CPNPP) from Balwant K. Singal (USNRC) dated September 18, 2013, "Comanche Peak Nuclear Power Plant, Units 1 and 2 -

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

Operating' for Two, 14-Day Completion Times for Offsite Circuits." (TAC Nos.

MF0405 and MF0406). (ML13232A143)

4. Luminant Power letter, logged TXX-13154, from Rafael Flores to the USNRC dated December 9, 2013, "Request for Enforcement Discretion Regarding Compliance with Technical Specifications 3.8.1, "AC Sources - Operating."

(ML13345A261)

5. Letter to Rafael Flores (CPNPP) from Kriss M. Kennedy (USNRC) dated December 11, 2013, "Notice of Enforcement Discretion for Luminant Generation Company LLC." (ML13345A157)

6. Luminant Power letter, logged TXX-13185, from Rafael Flores to the USNRC dated January 30, 2014, "Auto Start of Both Units' Auxiliary Feedwater Pumps and Emergency Diesel Generators Due to a Loss of Both Units' Safeguards Electrical Power" License Event Report 445/13-003-00. (ML14043A089)

A member of the STARS Alliance A-7. 0 o j Callaway - Comanche Peak

Diablo Canyon

Palo Verde

Wolf Creek 024L

U. S. Nuclear Regulatory Commission TXX-14063 Page 2 July 1, 2014

Dear Sir or Madam:

Reference 1 was License Amendment Request (LAR)12-007 for two, one-time, 14-day Technical Specification (TS) Completion Times (CTs) to complete a plant modification to be completed by March 31, 2014. Reference 2 was a request for additional information from the Nuclear Regulatory Commission (NRC) concerning Reference 1. Reference 3 was the NRC approval of LAR 12-007. T'he first 14-.ay CT for the XST1 modification began on October 14, 2013 and was successfully completed4n October 22, 2013.

The second 14-day CT for XST1 modification began on December 4, 2013 with XST2 powering the Class 1E 6.9 kilo-volt (kV) buses of both Unit 1 and Unit 2 as planned. Early into this CT, a. XST2 6,9kV-cable was incorrectly cut resulting in a loss of power to the Class 1E 6.9kV buses of both Unit 1 anrdUnit 2 When XST2 de-energized. Both Units' emergency diesel generators, (EDGs) autoinatically started apnd all 1E buses were re-energized from the EDGs. Both Units entered Condition C of TS 3.8.1 'AC Sources.-

Operating" to restore one required offsite circuit to OPERABLE status within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . Condition C required entrance into Condition G to be in MODE 3 in 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in MODE 5 in 36"hours if the CT of 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of Condition C could not be met. Reference 4 is Luminant Power's request for enforcement discretion (ED) to provide an additional 14 hours1.62037e-4 days 0.00389 hours 2.314815e-5 weeks 5.327e-6 months to comply with Limiting Condition for Operation (LCO) 3.8.1 Condition C. The NRC granted the ED in Reference 5. Modification work was suspended and both offsite power sources including XST1 and XST2 were restored. Reference 6 is CPNPP's License Event Report (LER) 445/13-003-00 "Auto Start of Both Units' Auxiliary Feedwater Pumps and Emergency Diesel Generators Due to a Loss of Both Units' Safeguards Electrical Power," which included immediate and subsequent corrective actions.

Due to this event and the subsequent efforts to determine the causes and take corrective action, the XST1 modification was not completed by March 31, 2014 as granted in Reference 3. Correction of the design and implementing work documents are in process as are many other corrective actions. When the applicable corrective actions in Reference 6 are completed, Luminant Power intends to complete the implementation of this modification that will enhance the reliability of the offsite power system. An amendment to the Operating License for both Units, as requested herein, will be necessary. The requested amendment is similar to the one approved in Reference 1 with applicable aspects of Reference 2 and Reference 3 incorporated.

Pursuant to 10 CFR 50.90, 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 Units 1 and 2 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, the CT of Required Action A.3 for one inoperable offsite circuit, from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 14 days to complete the remaining part of the modification described in Reference 1. This change is only applicable to startup transformer (ST) XST1 and will expire on March 31, 2017. This change is needed to allow sufficient time 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months .

Three important elements provide the basis for the requested TS change and provide a high degree of assurance of the capability to provide power to the safety related 6.9kV alternating current (AC)

Engineered Safety Features (ESF) buses during the one-time, 14-day CT (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 plant configurations that could degrade defense-in-depth (DID) using appropriate mitigation measures, and (3) continued implementation of a Configuration Risk Management Program (CRMP) to aid in identification of configurations that could degrade DID during the one-time 14-day extended CT.

U, S. Nuclear Regulatory Commission TXX-14063 Page 3 July 1, 2014 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 informatiop, only. provides marked-up pages of the Final Safety Analysis Report (FSAR) for information only which reflect the proposed changes to the FSAR. contains single line diagrams of the APDG sets. Attachment 8 contains Attachment 8.H of STA-629, "Switchyard Control and Transmission Grid Interface." Attachment 9 contains Attachment 5 to STA-726, "Non-Radioactive Spill Response." 0 contains new commitments (e.g., appropriate mitigating measures that avoidplant configurations that could degrade defense-in-depth) 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 January 15, 2015 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; however, approval is required to support a plant modification which will facilitate future connection of either the ST XST1 or an alternate ST XST1A to the 1E buses within the current TS CT of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months .

In accordance with 10 CFR 50.91(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.

Executed on July 1, 2014.

Sincerely, Luminant Generation Company, LLC Rafael Flores By: 4* *I Fred W. Madden Direct, External Affairs

U. S. Nuclear Regulatory Commission TXX-14063 Page 4 July 1, 2014 TJEW Attachments 1. Description and Assessment

2. Proposed Technical Specifications Changes (Mark-Up)

3. Proposed Technical Specifications Bases Changes (Mark-Up For Information Only)

4. Retyped Technical Specifications Pages

5. Retyped Technical Specifications Bases Pages (For Information Only)

6. Proposed FSAR Changes (For Information Only)

7. Single Line Diagrams of the APDG Sets

8. Attachment 8.H of STA-629, "Switchyard Control and Transmission Grid Interface"

9. Attachment 5 of STA-726, "Non-Radioactive Spill Response"

10. Summary of Regulatory Commitments c - M. L. Dapas, 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

ATTACHMENT 1 TO TXX-14063 DESCRIPTION AND ASSESSMENT to TXX-14063 Page 2 of 39 LICENSEE'S EVALUATION

1.0 DESCRIPTION

2.0 PROPOSED CHANGE

3.0 BACKGROUND

4.0 TECHNICAL ANALYSIS

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-14063 Page 3 of 39

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 Units 1 and 2 Technical Specifications (TS). Proposed change license amendment request (LAR)14-001 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, 2017, and will allow, on a one-time basis, an extension of the CT from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months 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 a one-time, 14-day outage on XST1 to complete a plant modification to be completed by March 31, 2017. The extended CT will allow sufficient time to make final terminations to facilitate connection of startup transformer (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 TS CT of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . The markup to the proposed change to TS 3.8.1 is provided in Attachment 2 of this letter.

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.

Markups of FSAR 8.2-2 and Figures 8.2-4, 8.2-11, 8.2-11A, 8.3-1, and Table 8.3-3 are shown in Attachment 6 to this letter. Attachment 6 provides markups of the affected FSAR pages showing the changes to be incorporated in the CPNPP FSAR as a result of the license amendment request, including changes that have been approved to date but which had not yet been incorporated as of the date of submission of this license amendment request.

Attachment 7 contains single line diagrams of the APDG sets. Attachment 8 contains Attachment 8.H of STA-629, "Switchyard Control and Transmission Grid Interface." Attachment 9 contains Attachment 5 to STA-726, "Non-Radioactive Spill Response."

Attachment 10 contains new commitments (e.g., appropriate mitigating measures that avoid plant configurations that could degrade defense-in-depth) 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.

to TXX-14063 Page 4 of 39

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.

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 alternate 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.

The STs (XST1 and XST2) and alternate STs (XST2A and XSTIA) 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 alternate startup transformer XST2A are connected to the 345kV switchyard by a common overhead line.

ST XST1 and alternate ST XST1A are connected to a common overhead line from the 138kV switchyard. Each ST is provided with a 138kV motor-operated air switch such that each ST can be energized independent of the other ST. Presently the 138kV motor-operated air switch to ST XST1 is closed and 138kV motor-operated air switch to ST XST1A is open; however, both the 138kV disconnects will remain open during the completion of the 6.9kV modification to connect XST1A to the 1E buses via the transfer panels.

Alternate ST, XST2A, is in a location under the 345kV line to XST2 (refer to FSAR Figure 8.2-1) to serve as an alternate for 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 1 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 versa.

to TXX-14063 Page 5 of 39 Currently, if XST1 requires maintenance that would exceed 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , or if XST1 fails, it would take about 14 days to complete the 6.9kV modification to connect XST1A to the 1E buses via the transfer panels. The timing is dependent on the 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months would require that both Units be shutdown to Mode 5.

3.2 Proposed Plant Design Modification This proposed amendment is similar to one approved by the Nuclear Regulatory Commission (NRC) on October 29, 2010 (ML102810130), that extended, on a one-time basis, the allowable CT of Required Action A.3 of TS 3.8.1 for a 345kV inoperable offsite circuit, from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 14 days. (Reference 8.2) 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 0.00361 hours 2.149471e-5 weeks 4.9465e-6 months 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 0.00583 hours 3.472222e-5 weeks 7.9905e-6 months , and 16 minutes. After installation of XSTIA for use as an alternate for XST1, ST XST2A will be used only as an alternate for XST2; therefore, "spare" will be replaced with "alternate."

This proposed amendment is also similar to one approved by the Nuclear Regulatory Commission (NRC) on September 18, 2013 (ML13232A143), that extended, on a one-time basis, two allowable CTs of Required Action A.3 for the 138kV inoperable offsite circuit, from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 14 days. (Reference 8.3) This change was only applicable to ST XST1 and expired on March 31, 2014. The two extended CTs allowed 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 XSTI should require maintenance or repair or if failure occurs, then the alternate ST XST1A would be aligned to the 1E buses well within the current TS CT of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months .

The first 14-day CT for XST1 was completed on October 22, 2013 for the 138kV modification. On October 30, 2013, during at power XST1 modification activities an electrician incorrectly identified and cut a wire in the ground protection circuit for XST1.

This event did not result in any protective relaying circuit actuations. The second 14-day CT for the XST1 modification began at 0100 hours0.00116 days 0.0278 hours 1.653439e-4 weeks 3.805e-5 months Central Standard Time (CST) on December 4, 2013, with XST2 powering the Class 1E 6.9kV buses of both Unit 1 and Unit

2. Early into this CT, an XST2 6.9kV cable was cut (at 1341 hours0.0155 days 0.373 hours 0.00222 weeks 5.102505e-4 months CST), 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and 41 minutes into the modification. CPNPP experienced a loss of power to the Class 1E 6.9kV buses of both Unit 1 and Unit 2 when 345kV startup transformer XST2 was de-energized.

Both Units' 1E buses were re-energized from the emergency diesel generators (EDGs),

two per Unit. Both Units remained at-power in MODE 1. At the time the cable was cut, Condition C, Required Action C.2 of TS 3.8.1 was entered which require an offsite source to be restored to OPERABLE in 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . If TS 3.8.1 Condition C was not met, both Units would have to enter TS 3.8.1 Condition G Required Actions G.1 (be in MODE 3 in 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months ) and G.2 (be in MODE 5 in 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months ). On December 4, 2013 at 1341 CST an Unusual Event (UE) was declared. Enforcement Discretion (ED) was requested from the NRC and granted for an additional 14 hours1.62037e-4 days 0.00389 hours 2.314815e-5 weeks 5.327e-6 months to go beyond the 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months allowed by Condition C of TS 3.8.1. XST2 was declared OPERABLE on December 5, 2013 at 1717 CST and the ED was terminated. The total time CPNPP Units 1 and 2 remained in the ED was 3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months and 36 minutes. Transformer XST1 was declared OPERABLE on December 6, 2013 at 0019 CST.

to TXX-14063 Page 6 of 39 The immediate corrective actions were to discontinue any field cable cut and termination activities including activities that include lifting/landing leads, repair the cut cable, restore offsite power, exit the UE and ED, and terminate the second 14-day CT.

The Root Cause Analysis team determined that during the initial conceptual design, the wrong cable tray was identified for the XST1 secondary (6.9kV) circuits and subsequent detailed design and installation documents incorrectly reflected modifications to XST2 cable trays and cable instead of XST1 cable trays and cable.

Since the second 14-day CT was terminated by the cut 6.9kV cable, this proposed amendment will facilitate the final terminations to connect alternate ST XSTIA to the 1E buses. This proposed amendment will revise TS 3.8.1, Required Action A.3 CT OR statement to extend, on a one-time basis, from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 14 days to complete a plant modification to be completed by March 31, 2017.

The 14-day CT will require XST1 to be out-of-service for greater than 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months but less than or equal to 14 days in order to install two transfer panels and one tap box, and terminate the XST1 and XST1A 6.9kV cables. See Table 1 below. The transfer panels have three sets of 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 the 1E bus to XST1 or XST1A such that only one ST can be connected to the 1E buses at any given time. Thus, the transfer panels will provide the capability to align either XST1 or XST1A to the 1E buses. Once the 6.9kV work is completed, ST XST1 will be restored and the offsite source will again be operable.

The entire sequence of activities to complete the work is conservatively projected to require approximately 10 days. However, a similar modification has been accomplished for XST2 and XST2A and completed in 7 days, 21 hours2.430556e-4 days 0.00583 hours 3.472222e-5 weeks 7.9905e-6 months , and 16 minutes, well within the projected time of 11 days and 13 hours1.50463e-4 days 0.00361 hours 2.149471e-5 weeks 4.9465e-6 months and much less thari the requested CT of 14 days.

Table 1, provides a list of planned maintenance activities and their approximate durations.

Table 1. 6.9kV Connections Including Final Checks/rest for XST1A Scheduled Work Dates Maintenance Activity Approximate Time (Days)

Enter LCO Place Clearance and Grounds* 0.5 Shutdown XST1 Open Box to De-terminate Cables 0.5 Remove Tray, Identify Cables and Cut/Pull Back Cables 1.0 Install Transfer Panels and Tap Box, Modify Cable Trays 2.0 Pull in Cables, Install Stress Cones and Terminate Cables 2.5 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** 10.0

Enter 14-day CT **Exit 14-day CT to TXX-14063 Page 7 of 39 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . 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, an extension of Required Action A.3 CT from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 14 days to make final terminations to facilitate connection of ST XST1 or the alternate ST XST1A to the 1E buses within the current TS CT of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months .

4.0 TECHNICAL ANALYSIS

The proposed change to TS 3.8.1 Required Action A.3 CT is based upon a deterministic/qualitative analysis and will rely on defense-in-depth measures and configuration management measures. Conformance with Nuclear Regulatory Commission (NRC) General 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 one-time, 14-day Completion Time (CT) (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 plant configurations that could degrade defense-in-depth (DID) using appropriate mitigating measures, and (3) continued implementation of a Configuration Risk Management Program (CRMP) to aid in identification of configurations that could degrade DID during the one-time 14-day extended CT.

4.1 Deterministic Evaluation Offsite Power The Oncor (Transmission Owner (TO)) transmission system serves as the main outlet and source of offsite power for Comanche Peak Nuclear Power Plant (CPNPP). Connection of the station outputs to the system is achieved via seven 345kV overhead lines to the 345kV switchyard. 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 emergency diesel generators (EDGs) (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.

Attachment I to TXX-14063 Page 8 of 39 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 (DBAs) 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.

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 independent system operator and works with Texas Reliability Entity, one of the eight regional entities within the North American Electric Reliability Corporation (NERC) that coordinate to improve reliability of the bulk power grid.

The 2013 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 8.4). 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 2013 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.

to TXX-14063 Page 9 of 39

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

0 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 2013 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 the 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. STA-629 Attachment 8.H, Table 1 of Section 1.0 and Section 1.3 contains the requirement of system studies and contingencies to be considered. Post contingency voltages are required to meet the voltage limits defined in Table 1 of STA-629. The relevant pages of STA-629 are provided in Attachment 8 to this letter.

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 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 results in the EDG providing power to the Class 1E bus.

Two independent and redundant 6.9kV 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 DBA. The standby alternating current (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 Regulatory Guide (RG) 1.155, "Station Blackout" (Reference 8.5). 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 EDGs 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 to TXX-14063 Page 10 of 39 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, 10 CFR 50.63, has been performed in accordance with the guidelines contained in Regulatory Guide 1.155 (Reference 8.5) and NUMARC 87-00 (Reference 8.6). In accordance with those References, CPNPP is not required under 10 CFR 50.63 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 8.5 and 8.6, for purposes of compliance with 10 CFR 50.63. 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 8.5.

The required coping time for the "blackout Unit" is four (4) hours per Section 3 of Reference 8.5.

EDG reliability was determined using the methodology of Reference 8.5 and is 0.95 for CPNPP. EDG reliability is monitored under the Maintenance Rule (MR) Program.

Increasing the allowed outage time for ST XST1 has no effect on EDG reliability.

Utilizing the methodology of Reference 8.5, CPNPP has been classified as "AC power Design Characteristic Group" P1. A "Pl"site is defined in Reference 8.5 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, to TXX-14063 Page 11 of 39

Weekly/Monthly Monitoring of Switchyard Equipment,

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 (MRC) 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 had all preventive maintenance (PM) work orders associated with XST2 current. Further, to allow XST2 maintenance to occur, CPNPP implemented reliability improvements to the alternate startup transformer XST2A. Additionally, CPNPP utilized a NRC approved 14-day CT extension which allowed sufficient time to make final terminations to facilitate connection of either XST2 or the alternate ST XST2A to the Class 1E buses within the current CT of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . These activities supported and maintained the availability of the ST XST2 to remain a reliable offsite power source to meet CPNPP requirements during the one-time CT extension 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, respectively. 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 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 and breaker protection relaying to both 7970 and 7980 have been replaced as part of the TO's 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 the 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 the one-time, 14-day CT extension, PM task for breakers 1EA1-1, 1EA2-1, 2EA1-2 and 2EA2-2 will be verified as current.

to TXX-14063 Page 12 of 39 In summary, the equipment associated with CPNPP offsite power provides a high degree of reliability.

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 10 CFR 50.65 (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 May 2014. 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. To address extent of conditions the access to the openings at the tower insulators to XST2 were also sealed. These actions 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 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 one-time 14-day CT 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 A One-Time 14-Day Completion Time The 14-day CT will be used to install two transfer panels and a tap box to make final 6.9kV cable terminations. The window of time to invoke the one-time, 14-day CT is during the period from September 1st through March 31st when there is a significant reduction in weather risk.

To further enhance the safety of the proposed modifications, appropriate just-in-time (JIT) training will be provided to Operations personnel prior to the 14-day CT as well as the avoidance of plant configurations that could degrade defense-in-depth using appropriate mitigating measures and CRMP during the one-time, 14-day proposed CT.

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. Further, all applicable corrective actions from the "cable cut" event root cause will be completed and in place prior to entry into the 14-day CT.

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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . 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.

to TXX-14063 Page 13 of 39 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months 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 0.00667 hours 3.968254e-5 weeks 9.132e-6 months 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. Therefore, working the 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. Furthermore, while 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 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.

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.

to TXX-14063 Page 14 of 39 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 CT 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 the 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 approved License Amendment Request 09-003 (ML102810130) 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months 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, 2010 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 sets consist of three diesel generators operating in parallel at 480V, 3 phase, and 60 Hertz (Hz). Each APDG in a set is rated at 1140 kilo-Watt (kW) with outputs connected in parallel for a total capacity of 3420kW.

The APDG set is rated at 4275 kilo-Volt-Amps (kVA). As part of the APDG package, a 480V/6900V transformer is provided to connect the APDGs to the 6.9kV bus. The transformer rating is 3000kVA; however to feed the loads defined in Table 2 the transformer will be loaded to 3450 kVA (i.e., 115% of the transformer rating). 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 8.7) 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 0.00222 hours 1.322751e-5 weeks 3.044e-6 months . Additionally, SOP-614A/B directs Operators to contact the appropriate APDG Refueling Contact (RC) to utilize "Engineering Work Book - Loss of Off-Site Power Supplement" for replenishing diesel fuel to the APDGs every two hours.

The Engineering Work Book contains instructions for filling the APDG during loss of offsite power conditions where the normal method of refueling truck replenishment is not available. Operations will contact the appropriate APDG RC to gather the pre-staged materials and equipment.

to TXX-14063 Page 15 of 39 If power exists to the fuel island, the normal method of refueling truck (RT) filling is used. The electric powered refueling transfer pump can fill the 2000 gallon RT (normal capacity is 1,800 gallons or less), and the 500 gallon RT if needed, such that the fuel to the affected APDGs will be replenished every two hours inside the protected area. The fuel island storage tank has an 8,000 gallon capacity tank normally filled to 5,000 to 8,000 gallons.

However, if power does not exist to the fuel island, the Engineering Work Book contains instructions on replenishing the APDGs every two hours. Inside the protected area is the 2000 gallon RT, a 5.5 horse-powered (HP) gasoline powered pump that can pump approximately 200 gallons per minute, and four emergency diesel generator (EDG) fuel oil storage tanks (FOSTs) each typically filled to greater than 86,000 gallons. The APDG RC will retrieve the materials identified in the Material List and contact the Control Room (CR). The CR will designate a FOST to use to fill the RT. The 2000 gallon RT will be positioned next to the FOST and grounded to the metal cover of the FOST. Two hoses will be connected to the gas powered pump. The gas powered pump suction hose will be connected to a rigid suction pipe then inserted into the sampling opening on the cover of the FOST. The pump will be started for a short duration such that the initial flushing of fuel oil will remove any pump or pipe debris to a 55-gallon drum or suitable container.

The pump discharge will then be directed to the top of the RT and started. Once the RT is at the desired level, the pump will be stopped and grounding device removed. The RT can then be repositioned to fill the APDGs. This process will be repeated except for the flushing and connection steps and thus the APDGs can be refueled every two hours.

If the gas powered pump becomes unavailable, an alternate method is described in the Engineering Work Book to fill the APDGs RT using an air pressure powered pump and an air compressor. Normally, two air compressors are available for use and are rated at 185 cubic-foot-per-minute (cfm) and 130 cfm respectively, and both operate at 100 pounds-per-square-inch (psi). Also available is a 100 gallon per minute (gpm) rated air pump that can be powered by an air compressor such that the air powered pump can refuel the RT in approximately 20 minutes.

The following design features and administrative controls are established to ensure that any diesel fuel leak or spill does not become a fire hazard:

The APDG sets are designed with built-in leak detection and spill containment.

The APDG user's manual states the base frame has 120% capacity of the fuel tank to prevent fuel leaking out of the generator set in the event of a fuel leakage inside the generator. A level switch is fitted inside the bund for spillage indication. This will shut down the engine when activated.

0 The APDG fuel tank fill point is external, which prevents diesel fuel from refueling activities from potentially coming in contact with running and hot diesel generator (DG) components. Additionally, the exhaust system consists of the exhaust ducting, exhaust silencer complete with spark arrestor and rain cap assembly. CPNPP procedure SOP-614A/B, "Alternate Power Generator Operation," (Reference 8.7) is established for the operation of the APDGs and requires the APDG fuel be replenished every two hours. SOP-614A/B references "Engineering Work Book - Loss of Offsite Power" for APDG refueling. This work book contains steps to ensure that the refueling truck is grounded during refueling operations.

In the event that a diesel fuel spill would occur outside of the APDG sets, CPNPP procedure STA-726, "Nonradioactive Spill Response," would be invoked as a mechanism for initial response to the spill. Attachment 9 to this letter is a spill response flow diagram which is included as Attachment 5 of STA-726.

to TXX-14063 Page 16 of 39 The APDGs maintain the same capability as described below during the XST1 extended CT 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, 5 and 6. 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, "Station Blackout") and emergency response guidelines. The loads in kW identified in Table 2 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 2 also lists the power factor (PF) and kVA demand for each load. Total kVA load, including a 2% margin for losses, is 3416kVA, thus the loading will remain within the transformer rating of 3450kVA.

Table 2. Load Description and Load in kW, PF, and kVA LOAD LOAD LOAD 6.9KV LOAD DESCRIPTION (kW) PF (kVA)

Centrifugal Charging Pump (CCP) 526.03 0.914 575.53 Component Cooling Water (CCW) Pump 789.42 0.910 867.49 Station Service Water (SSW) Pump 643.1 0.873 736.66 LOAD LOAD LOAD 480V LOAD DESCRIPTION (kW) PF (kVA)

Containment Recirculating Fan 93.25 0.85 109.71 Safety Chillers 99.9 0.85 117.53 Safety Chiller Recirculation Pump 18.24 0.85 21.46 Emergency Lighting (CR and Plant) 132.69 0.85 156.11 Control Rod Drive Mechanism Ventilation (CDRM) Fan 92.44 0.85 108.75 Instrument Air 183.28 0.85 215.62 Pressurizer Backup Heater Group A 141.4 0.85 166.35 Battery Chargers and Inverters 110.94 0.84 132.07 Reactor Makeup Water Pump 4.54 0.85 5.34 Miscellaneous 480V Loads (Fans, Pumps, Transformers, and Heaters) 116.03 0.85 136.51 SUBTOTAL 2951.26 3349.12 Plus 2% Losses 59.03 66.98 TOTAL 3010.29 3416.11 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.

to TXX-14063 Page 17 of 39 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:

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.

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

0 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 (Reference 8.7) 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 sets are started per SOP-614A/B and synchronized together unloaded to verify there are no problems with the diesels. 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 verified 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.

to TXX-14063 Page 18 of 39 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.

Table 3. Safe Shutdown Bus Loading Sequence LOAD LOAD SEQUENCING NOTES 480V Buses (Note 1) These loads will remain aligned to the affected Unit 1E Battery Chargers bus in order to energize/start them immediately upon Instrument and Control Inverters power restoration by the APDG set.

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 Pump These loads will be started following power source (CCWP) restoration as directed by the emergency operating Station Service Water Pump (SSWP) procedures (e.g., APDGs start and energize the 1E bus)

Instrument Air Compressor to support the plant response and recovery actions (e.g., reduce Reactor Coolant System (RCS)

Centrifugal Charging Pump (CCP) Temperature and Pressure).

Containment Fan Coolers (Note 2)

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. I 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 turbine driven auxiliary feedwater pump (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-14063 Page 19 of 39 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.

Each generator set contains a multi-function protec'fion and control device "GEMPAC" with the capability to actively share real (kW) and reactive kilo-volt-amp-reactive (kVAR) power with other generators. There is an instrumentation cable with three individual insulated conductors "triad" that is daisy-chained between each GEMPAC. The three conductors of the triad cable are a real power wire, a reactive power wire, and a common wire. There is a +/-5VDC (volts-direct-current) analog signal transmitted between the real wire and the common wire, and another +/-5 VDC analog signal transmitted between the reactive wire and the common wire. Real power and kVAR load share signals are generated by each GEMPAC based on the rating of the generator controlled by the GEMPAC. Zero percent of the rated load provides a 0-Volt signal and one-hundred percent of the rated load provides a 5-Volt signal. Each GEMPAC is working to equalize the load share signal voltages between all three generator sets thus assuring equal sharing, proportional to the rating of the generator, of real and reactive power. As needed, each GEMPAC will send a fuel bias "increase/decrease" signal to the engine governor, and an excitation bias "increase/decrease" signal to the voltage regulator in order to increase or decrease real power or reactive power, respectively. GEMPAC monitors real and reactive power output from the generator sets, compares it to what it "should" be for equal load sharing by looking at load share signal voltages, and compensates if necessary by sending bias signals to the engine governor and voltage regulator. The three generators of each APDG set have the same kW and kVAR ratings; therefore, they will equally share the real and reactive power load.

See Attachment 7 for the drawing(s) showing layout of major enclosures/components of the APDG sets and single-line diagrams showing connections of the APDG sets to the plant 6.9kV Class 1E buses. The description of the cable routing is described below.

to "XX-14063 Page 20 of 39 The connection from each generator to transformer is provided by five conductors per-phase (5 - 1/c) #4/0 American Wire Gauge (AWG), 600-volt cables per-phase. These cables are laid in a 24-inch cable tray. Thus, a total of 15 - 1/c #4/0 AWG cables per-phase provide connection from the APDGs to the transformer.

The secondary of the transformer is connected to the transfer switch by 1 - 1/c 500 thousand circular mills (MCM) 8kV cable per-phase. For Unit 1, the cable is installed in a tray. For Unit 2, the cable is installed in a conduit.

The transfer switch allows APDG power to be connected to either train A or train B Class 1E safety related bus at a time. A 1/C 500 MCM cable per-phase, routed in conduit and tray, connect transfer switch to breaker in the safety related 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 operators have had JIT to start the APDGs in the event of a loss of offsite power during a 14-day CT extension. Existing plant procedures describe 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 the 14-day CT, the APDG sets will be tested to ensure the reliability of the APDG. Additionally, the APDG set provided for each Unit will be verified available to provide power to equipment for long term cooling once per shift during the 14-day CT. A Nuclear Equipment Operator (NEO) will be assigned to ensure proper operation of the APDGs, during the proposed 14-day CT.

Training has been provided to all 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 8.7). When the APDGs need to be available for use:

A shiftly checklist is completed to ensure the APDGs are ready for use per SOP-614A/B,

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 APDG set to a safeguards bus is approximately one hour. During the 14-day CT, if an APDG of a set becomes unavailable, the affected Unit shall enter Condition C of TS 3.8.1 and comply with the Required Actions. If the CT for the Condition C Required Actions is not met, then Condition G of TS 3.8.1 shall be entered. This allowance will only be exercised during the 14-day CT for a given Unit. For any second, or subsequent, unavailability of an APDG of a set for a given Unit, the to TXX-14063 Page 21 of 39 affected Unit shall immediately enter TS 3.0.3. In all cases, the normal rules governing application of TS in section 1.0 of the CPNPP TS shall apply.

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. See Attachment 10 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 10 CRFR 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, Institute of Nuclear Power Operation (INPO) issued Event Report (JER) 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 8.8) 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 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ." CPNPP reported to INPO that CPNPP can withstand with a station blackout for at least 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , using existing plant equipment and procedures, with a best estimate analysis in accordance with the specified IER Li 11-4 assumptions and bases (Reference 8.9).

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 to TXX-14063 Page 22 of 39 kW (4275kVA). The APDGs feed a 480V/6.9kV transformer which is rated 3000kVA; however to feed the loads defined in Table 2 the transformer will be loaded to 3450 kVA (i.e., 115% of the transformer rating). 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 CT, 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 2.

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 2 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 motor driven auxiliary feedwater pump (MDAWFP) can be loaded onto the APDGs through manual manipulation of the loads shown in Table 2. 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 2 would be required in order to support operation of a RHR 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 to TXX-14063 Page 23 of 39 APDGs would be 2,866.7kW. 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 MDAFWP 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 APDGs 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.

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

to TXX-14063 Page 24 of 39 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 TDAFWPs will occur within the two (2) weeks prior to the start of the XST1 CT.

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 (10 CFR 50.63) following the guidance provided by RG 1.155 (Reference 8.5). This evaluation determined that both Units are capable of coping with a SBO for 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months as AC Independent plants and that no modifications were required.

Additionally, INPO issued IERL1 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 8.8) 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 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ." CPNPP reported to INPO that CPNPP can cope with a station blackout for at least 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , using existing plant equipment and procedures, with a best estimate analysis in accordance with the specified IER Li 11-4 assumptions and bases (Reference 8.9).

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 automatic relief valves (ARVs), with the steam generators (SGs) being fed by the turbine driven auxillary 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.

to TXX-14063 Page 25 of 39 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 2. 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 0.06 hours 3.571429e-4 weeks 8.2188e-5 months (13.5 days, consisting of two shifts, each shift working 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months ) 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

The operating experience (OE) for the scope of work is similar to one approved by the NRC on October 29, 2010 (ML102810130) 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months 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 0.00361 hours 2.149471e-5 weeks 4.9465e-6 months to complete which fit well within the requested 14-day extended CT. The actual CT was 7 days, 21 hours2.430556e-4 days 0.00583 hours 3.472222e-5 weeks 7.9905e-6 months , and 16 minutes. As discussed in Section 3.2, Table 1 estimates the scope of work will take 10 days.

Currently, if XST1 requires maintenance that would exceed 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , or if XST1 catastrophically fails, it would take about 14 days to complete the 6.9kV modification to connect XST1A to the 1E buses via the transfer panels and the tap box. The timing is dependent on the 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . After maintenance or repair on XST1 is completed, XST1 may be put back in-service. As a result, to TXX-14063 Page 26 of 39 XST1A will be a dedicated alternate for XST1 and XST2A is a dedicated alternate for XST2. Therefore, a one-time 14-day CT is 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 a one-time 14-day CT. Additionally, see response to f. above.

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 a one-time, 14-day CT for XST1.

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

Response

During the 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.

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 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . This 24-hour period will be allowed only once within any given extended EDG AOT.

Response

During the 14-day CT, if an APDG becomes unavailable, the affected Unit shall enter Condition C of TS 3.8.1 and comply with the Required Actions. If the CT for the Condition C Required Actions is not met, then Condition G of TS 3.8.1 shall be entered. This allowance will only be exercised during the 14-day CT for a given Unit. For any second, or subsequent, unavailability of an APDG for a given Unit, the affected Unit shall immediately enter TS 3.0.3. In all cases, the normal rules governing application of TSs in section 1.0 of the CPNPP TSs shall apply.

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

to TXX-14063 Page 27 of 39 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 a one-time 14-day CT. Further, providing the capability for connection of an alternate ST XST1A to the 1E buses within the current TS CT of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . 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 a 14-day CT will provide a safe work environment for personnel safety and will not impact nuclear safety or the health and safety of the public.

Therefore, a one-time 14-day CT is being requested.

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

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 1st through March 31st.

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

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

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 the 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.

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

to TXX-14063 Page 28 of 39 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 the 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.

Access to the 345kV switchyard and relay houses will be controlled and posted, and all maintenance will be suspended for the duration of the CT on XST1. Due to XST1 being deenergized the 138kV switchyard is not impacted and therefore, is not required to be protected.

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:

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

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

0 During the 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.

a 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.

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 the 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.

Attachment I to TXX-14063 Page 29 of 39 4.2 Other Defense-in-Depth Mitigation Measures During the XST1 extended CT 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months ; therefore, a CT extension is 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 CT, the current TS CT would apply and both Units shall shutdown accordingly.

Consistent with other similar NRC approved CT extension requests, Luminant Power provides a list of mitigation measures used to avoid plant configurations that could degrade defense-in-depth (e.g., 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 10 to this letter.

Just-in-time training for affected work groups will be completed prior to the start of the XST1 outage.

Appropriate just-in-time UIT) training will be provided to Operations personnel prior to the 14-day CT as well as the compensatory measures and mitigation measures to be implemented during the 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.

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 the 345kV switchyard and relay houses will be controlled and posted, and all maintenance will be suspended for the duration of the CT on XST1. Due to XST1 being deenergized the 138kV switchyard is not impacted. Additionally, signs will be placed on the 345kV switchyard and relay houses noting the restriction of access, testing, and maintenance during this XST1 CT.

This measure is selected to deter any perturbations to the remaining ST power supply, 345kV switchyard. Due to XST1 being deenergized the 138kV switchyard, is not impacted. Work in the switchyard is administratively controlled by the Operations Shift Manager who by plant procedure, STA-629 (Reference 8.4) has sole authority to grant access to the switchyards. By their authority; they will not allow any testing, maintenance or access to the 345kV switchyard; with the exception of normal operator visual inspection rounds. The STs, XST1/XSTIA and XST2/XST2A, are physically located in the protected area and not in the switchyards.

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 the one-time, 14-day to TXX-14063 Page 30 of 39 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.

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

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

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.

Restriction on Transient Combustible Storage Along the XST2 Control and Power Cable Routing Both Unit 1 and 2 Transient Combustible 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 defense-in-depth measure will reduce the likelihood of fires related to the XST2 transformer.

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.

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.

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.

The two fixed sources in the Unit 1 safeguards switchgear room that were identified for thermographic surveys and were identified as the motor control center (MCC) CP1-EPMCEB-01 (1EB1-1) and 6.9kV to 480V transformer CP1-EPTRET-02. The two fixed sources were identified as potential impacts to XST2 during the 14-day CT by plant walkdowns and information contained in the Individual Plant Examination of External Events (IPEEE) fire assessment. The walkdowns were performed to verify the cable routings for both XST2 and XST1, and to confirm that the information contained in the IPEEE remained valid. As only XST2 would be in-service during the extended CTs, a fire in either of these two sources could result in a loss of power from the in-service transformer and thus warranted additional preventative actions prior to entering the extended CT.

to TXX-14063 Page 31 of 39 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 1st through March 31 st. This planned timing will reduce high wind/tornados and weather challenges to the plant during the XST1 CT.

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.

Luminant Power will ensure all applicable corrective actions from the "cut cable" event root cause are complete and in place per License Event Report 445/13-003-

00. (ML14043A089)

See Reference 8.10.

A Nuclear Equipment Operator (NEO) will be assigned to ensure proper operation of the APDGs, during the proposed 14-day CT.

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 identify all possible risk significant plant configurations. Programs and procedures are in place at CPNPP which serve to address this objective. The CRMP will be used for planning and implementation purposes during the extended 14-day CT to identify configurations that would degrade defense-in-depth or identify any potential additional defense-in-depth actions that may be necessary.

CPNPP has a Configuration Risk Management program which has the characteristics of the Model Configuration Risk Management Program described in RG 1.177 (Reference 8.11) 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 8.12).

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 to TXX-14063 Page 32 of 39 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.

At CPNPP the procedures STI-606.01 "Work Control Process" (Reference 8.13), STI-604.02 "Maintenance Risk Assessment" (Reference 8.14), and STI-604.03 "Weekly Surveillances/Work Scheduling" (Reference 8.15) 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 10 CFR 50.65(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 to TXX-14063 Page 33 of 39 calculated. The weekly risk assessment will be reviewed with respect to DID and appropriate management approval will be obtained. The process is the same for emergent activities as above. The risk is assessed with respect to DID 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 with respect to DID 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 8.11).

Summary of Technical Analysis The analysis of the proposed extended CT consists of three main elements: (1) a traditional engineering analyses, (2) avoidance of plant configurations that could degrade defense-in-depth using appropriate mitigation measures, and (3) continued implementation of a CRMP during the one-time 14-day extended Completion Time.

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 outage, 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 one-time, 14-day CT for XST1, defense-in-depth 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 alternate ST XST1A to the 1E buses within the current TS CT of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . 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, performing the work during the 14-day CT 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, the allowable Completion Time (CT) of Required Action A.3 for one inoperable offsite circuit, from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 14 days. This change is only applicable to startup transformer (ST) XST1 and will expire on March 31, 2017. This change is needed to make final terminations to facilitate connection of ST XST1 or the alternate ST to the 1E buses. Installation of the cabling from XST1 and the alternate ST XST1A to two new 6.9kV transfer panels and a tap box 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 current TS CT of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . 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 10 CFR 50.92, "Issuance of amendment," as discussed below:

to TXX-14063 Page 34 of 39 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 14 days to allow a one-time, 14-day CT. The proposed one-time extension 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 one-time extension 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 on a one-time basis from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months 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 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . 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 to TXX-14063 Page 35 of 39 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 a one-time pre-planned occurrence, 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 10 CFR 50.92(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 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 to TXX-14063 Page 36 of 39 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 8.16).

NRC Regulatory Guide 1.62, dated October 1973, titled "Manual Initiation of Protective Actions" (Reference 8.17).

NRC Regulatory Guide 1.75, Revision 1, dated January 1975, titled "Physical Independence of Electrical Systems" (Reference 8.18).

NRC Regulatory Guide 1.81, Revision 1, dated January 1975, titled "Shared Emergency and Shutdown Electric Systems for Multi-Unit Nuclear Power Plants" (Reference 8.19).

NRC Regulatory Guide 1.93, dated December 1974, titled "Availability of Electric Power Sources" (Reference 8.20). 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 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months 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 8.5).

NRC regulatory Guide 1.177, "An Approach for Plant-Specific, Risk-Informed Decisionmaking: Technical Specifications," dated August 1998 (Reference 8.11).

to TXX-14063 Page 37 of 39 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . 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 on a one-time basis, from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months 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 10 CFR 20, 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 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), an environmental assessment of the proposed change is not required.

7.0 PRECEDENT 7.1 On 10/15/2010, 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 10 days based on a deterministic evaluation. (ML102790280) (Reference 8.21) 7.2 On 10/29/2010 the NRC approved (LAR 09-003) to extend, on a one-time basis, the allowable Completion Time of Required Action A.3 for the inoperable offsite circuit, from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 14 days. This change was only applicable to ST XST2 and expired on 3/1/2011 and allowed sufficient time to make final terminations as part of a plant modification to facilitate connection of either XST2 or the spare ST XST2A to the Class 1E buses. (ML102810130) (Reference 8.2) 7.3 On 9/18/2013 the NRC approved (LAR 12-007) 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 14 days. This change was only applicable to startup transformer (ST) XST1 and expired on March 31, 2014. This change was 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 alternate ST XST1A to the 1E buses. The first 14-day CT to complete the 138kV work was completed on October 31, 2013. The second 14-day CT to complete the 6.9kV work was interrupted. This LAR proposes to complete the 6.9kV work and will improve the long-term reliability of the 138kV offsite circuit by providing connection to the ESF buses through XST1 or the alternate ST. (ML13232A143) (Reference 8.3) to TXX-14063 Page 38 of 39

8.0 REFERENCES

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

8.2 Letter to Mr. Rafael Flores (Comanche Peak Nuclear Power Plant) from Balwant K. Singal (USNRC) dated October 29, 2010, "Comanche Peak Nuclear Power Plant, Units 1 and 2 -

Issuance of Amendments Re: Revision to Technical Specification 3.8.1 'AC Sources -

Operating,' for Extension of the Completion Time for the Offsite Circuits on a One-Time Basis from 72 Hours to 14 Days (TAC Nos. ME2546 and ME2547). (ML102810130) 8.3 Letter to Mr. Rafael Flores (Comanche Peak Nuclear Power Plant) from Balwant K. Singal (USNRC) dated September 18, 2013, "Comanche Peak Nuclear Power Plant, Units 1 and 2

- Issuance of Amendments Re: Revision to Technical Specification 3.8.1 'AC Sources -

Operating,' for Two 14-Day Completion Times for the Offsite Circuits (TAC Nos. MF0405 and MF0406). (ML13232A143) 8.4 STA-629, "Switchyard Control and Transmission Grid Interface," Comanche Peak Nuclear Power Plant, Revision 7.

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

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

8.7 SOP-614A/B, "Alternate Power Generator Operation," Comanche Peak Nuclear Power Plant Procedure, Revisions 12/6, respectively.

8.8 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.

8.9 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.

8.10 Luminant Power letter, logged TXX-13185, from Rafael Flores to the USNRC dated January 30, 2014, "Auto Start of Both Units' Auxiliary Feedwater Pumps and Emergency Diesel Generators Due to a Loss of Both Units' Safeguards Electrical Power" License Event Report 445/13-003-00. (ML14043A089) 8.11 NRC Regulatory Guide 1.177, "An Approach for Plant-Specific, Risk-Informed Decisionmaking: Technical Specifications," Revision 1, May 2011.

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

8.13 STI-606.01, "Work Control Process," Comanche Peak Nuclear Power Plant Procedure, Revision 0.

8.14 STI-604.02, "Maintenance Risk Assessment," Comanche Peak Nuclear Power Plant Procedure, Revision 0.

to TXX-14063 Page 39 of 39 8.15 STI-604.03, "Weekly Surveillances Work Scheduling," Comanche Peak Nuclear Power Plant Procedure, Revision 1.

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

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

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

January 1975.

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

8.20 NRC Regulatory Guide (RG) 1.93, "Availability of Electric Power Sources," December 1974.

8.21 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)." (ML102790280)

ATTACHMENT 2 TO TXX-14063 PROPOSED TECHNICAL SPECIFICATIONS CHANGES (MARK-UP)

Page 3.8-2

Attachment 2 to TXX-14063 Page 1 of 1 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 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months inoperable. OPERABLE offsite circuit.

AND Once per 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months 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 0.00667 hours 3.968254e-5 weeks 9.132e-6 months 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months OPERABLE status.

14 day t time outage$ on XST to complete a plant/

one-I modification to be completed by I March 31, 201k.

COMANCHE PEAK - UNITS 1 AND 2 3.8-2 Amendment No. 46&,-V).2-,

ATTACHMENT 3 TO TXX-14063 PROPOSED TECHNICAL SPECIFICATIONS BASES CHANGES (Mark-Up For Information Only)

Pages B 3.8-8

Attachment 3 to TXX-14063 AC Sources - Operating Page 1 of 1 B 3.8.1 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months 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 durin this period.

[s-L An OR statement [o-r for temporary mpletion TimeV is added toIt¶ pletion Time above (72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months ) he Uwe one-time, 14-day Co metion Time applicable to XST1 o and expires on March 31, 2011. The twQ 14-day Completion TimeX appl as part of the plant modification to facilitate connection of either XST1 or XST1A 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 680

ATTACHMENT 4 TO TXX-14063 RETYPED TECHNICAL SPECIFICATIONS PAGES Page 3.8-2

Attachment 4 to TXX-14063 Page 1 of 1 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 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months inoperable. OPERABLE offsite circuit.

AND Once per 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months 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 0.00667 hours 3.968254e-5 weeks 9.132e-6 months 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months OPERABLE status.

OR 14 days for a one-time outage on XST1 to complete a plant modification to be completed by March 31, 2017.

COMANCHE PEAK - UNITS 1 AND 2 3.8-2 Amendment No. 160, 162,160

ATTACHMENT 5 TO TXX-14063 RETYPED TECHNICAL SPECIFICATIONS BASES PAGES (FOR INFORMATION ONLY)

Pages B 3.8-8

Attachment 5 to TXX-14063 AC Sources - Operating Page 1 of 1 B 3.8.1 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . 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 0.02 hours 1.190476e-4 weeks 2.7396e-5 months 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 a temporary Completion Time is added to the Completion Time above (72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months ). The one-time, 14-day Completion Time is applicable to XST1 only and expires on March 31, 2017. The 14-day Completion Time applies as part of the plant modification to facilitate connection of either XST1 or XST1A 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 68

ATTACHMENT 6 TO TXX-14063 PROPOSED FSAR CHANGES (FOR INFORMATION ONLY)

Pages 8.2-2 F 8.2-4 F 8.2-11 F 8.2-11A F 8.3-1 T 8.3-3 to TXX-14063 Page 1 of 16 JAlternate I CPNPP/FSAR provided wit 345-kV motor-operated air switch such that each transformer can be energized independ t of the other transformer.

-startup transformer, XST2A with dual primary windings (345-kV and 138-kV),

to serve as ais in a

-q* *tlocation under the 345-kyline to XST2 (refer to Figure 8.2-1) re ac ent of XST2. Cable buses from secondary X and Y windings of XST2 and XTS2A are con ct to two 6.9kV transfer panels to provide 345kV offsite power to Units 1 and 2 safety relate bu es. These transfer panels allow transfer of 345kV offsite power source for safety aspacrFep',ee*,T ve a.s nt fo~ GTI.

X may related s .*from d XST2 i^..t eel',toeeat ee. r, and XST2A f XGTI to. s erThis vice verse. tranoformor be physically rcl eceted"^- ^'e.

Station servic tr nsformer 2ST is connected to the 345-kV switc ard west bus via a dedicated circuit breaker verhead line.ne The 138-kV and 34 V circuit breakers providedwithout arebreaker with an nergy ving anstorage source of power.

externalmechanism that e individual circuit allows the operation avenues of relay pr tection termed primary and The circuit breakers ha wo separate or backup to pie a high degree of operratio al reliability.

secondary into two completely I the switchyard relaysisegregated The 125-VDC supply, for eac kkf eas hs independent systems, one for primary relays and eohrfrtebcu s and the DC system s of the other areind pen entof l th t estation DC/system two sysems switchyard. ILDC SA-2012-013 Switchyard TO circuit breaker, may be operated from either the 345-ky The 345-kV switchyard of CPNPP 345-ky Oncor's

ystem Operations Center. Control Control Building or remotely from from the plant and motor-opel ated air switches is administered switchyard circuit breakers for transformer XST2A, which has local Control Room except for the motor-operatl d air switch from either the 138-ky The 1 38-ky switchyard circ it breakers may be operated 138-kymotor-motor control. System Operations Center. The 0O's Relay House or remotely from Switchyard kted from the Control Room. The 125-VDC control air switch (DXST1) may be oper' is independent operated breakers and motor-oper *ted air switches in the 345-kysystem in the 138-ky power for circuit air switches circuit bl akers and motor-operated of the 125-VDC control power for system.

Physical layouts of the switchyards are :wn in Figures 8.2-5 and 8.2-7.

The substations that are connected to t-h' s.el kPNPP switchyards (as shown on Figure 8.2-4) are as follows: Alternate startup transformer XSTIA is located under the 138-kV line to XST1 (refer to Figure DeCordova (138-kV) 8.2-1) to serve as a replacement of XST1 after-a futurc plant moldificatien to connect eable buses Stephenville (138-kV) from seconder; X and Y windings of XST-1 and DeCordova (345-kV) X-T-IA-te transfer panels t. provide 138 ,V effaitPepo rt UiS 1 and 2 safety related Wolf Hollow (345-kV) buses.

Everman (345-kV) -I \tr that allow transfer of 138kV offsite 8.2-2 Amendment No. +04-power source for safety related buses from XST1 to XST1A and <LAR 14-001 LDCR SA-2014-010 vice verse.

I ILDCR 2013-013 1 to TXX-14063 Page 2 of 16 flERAN JOHNONSso 2W& .aIaII SY Be IV 34 LV 343 LV COWvCc SIT- 345 KV PARKEL SWFTCNG - 34545V STATION a

M -,..i to TXX-14063 Page 3 of 16 I I I c I F I I IT 99 -AL A. AT 8 SA E&A ?SE CD-E 99 END 4

-c 00 ~2k"' L9*~S_ =l

-4 - -1~rSAS~~ o *-S-2 Iý CCD 44-I I I-s r- - ----- - ----------- -----

(t I

.) COMANCHEPEAK NI,.P.P.

FINAL SAFETY ANALYSIS REPORT UNITS lI d 2 START-LIP/STATION SERVICE/UWET AUX TRANSFORMERCABLE BUS CONNECTIONTO 6.9 KV SWITCHGEAR I FIGURE8.2-11 I

-rOL~dý . 0%-2-01 I Ai-i-o I A I o, I I to TXX-14063 Page 4 of 16 PARTIAL KtANVIEW SECTIN A-ASECTION B-8 COMANCE PEAXILP.P.

FINA.SAhETY ANALYSISREPORT

- - - - - - - - - - - LIMTS IoTA SPREr SlARNTIP TRANSAFOMR 1501*CABLE BLaCOfRRECIO TO 6,9 IV SWIEITACHOU to TXX-14063 Page 5 of 16 c-lf

Attachment 6 to TXX-14063 Page 6 of 16 CPNPP/FSAR Can also realign to startup transformer TABLE 8.3-3 XST1A (XST1)

POPS to Unit 2 safety FAILURE MODE AND EFFECT ANALYSIS FOR AUXILIARY AC POWER SYSTEM buses and A0PS to Unit 1 buisafety buses transmission line (Sheet 1 of 18)

FT 17cA)" Cau s of Effects of F Failure Effects on Item Descripon F tion Failure Mode Failur Failure [ Detection System 1 138-k o ite sup ies power to startup fails to provide transmisQ line loss of electrica power protective relays; None: offsite ower source power sou e trans ormer XST1 (XSTIA) electrical power ails; opeIt-ek d to transformer STI annunciation in (Item 2) or di sel generators to XST1 (XSTIA) circuit breakers (XST1A) control room are availabl o ane.

2 45-kV offsite suppli power to startup fails to provide tra ission line loss of elec ical power protective relays; None: o te power source l** t'V oo.- @Ad

)ower source transfo er XST2 (XST2A) electrical power fails; circuit breakers to transfor er XST2 annunciation in :Item 1)o diesel generators to XST2 (XST2A) in switchyd opens. (XST2A) control room reavail ble.

3 tartup supplies ,pt 6.9 14. fails to deliver internal fault; loss of to protective relays; one: ffsite power source nsformer XST1 tuo b. 2EAt

, ;,d 2E"*-G2 power component failure; buses 2EA1 and 2EA2 annunciation in Item or diesel generators overheating; fire control room e a ilable.

supplies POPS 3A 15-kV cable power from short circuit; mechanical damag For open circuj_-ross N e- Offsite power source XXSoST to bus E and open circuit fire of allS~ajepew.to (I m 2) or diesel generators Ilue A1 aAd 4E2 e available.

Fo hort circuit: Long/

manual transfer of-peweO to buses/

panels CPX- 2EA1, 2EA2, an/oss EPTSST-04X of 'alte,,atep*wer

-seamcefor buses 1 EA1 13A 15-kV cable supplies power from XST1 (XST1A) to manual transfer panels CPX-short circuit; circuit I mechanical damage; fire and IEA2.

For open circuit: Loss of AOPS to bus 1EA2.

For short circuit: Loss of protective relays; annunciation in control room

] None: Offsite power source (Item 2) or diesel generators are available.

EPTSST-05X POPS to buses 2EA1, 2EA2, and loss of AOPS for buses lEA1 and 1EA2.

Amendment No. 1.04

Attachment 6 to TXX-14063 Page 7 of 16 CPNPP/FSAR TABLE 8.3-3 Can also realign to MODE AND EFFECT ANALYSIS FOR AUXILIARY AC POWER.

startup transformer (Sheet2of P XST1A (XST1)

Causes of Failure E ects on Item Description Failure Mode Failure Failure Detection S stem 3B 15-kV cable For oR circuit. Loss protective relays; of *to bu es annunciatior in tem 2) or diesel generators I(Note 5) .EjA a 2 * *d control room Ione: offsite power source e available.

For slt cuit: Loss ofl*p*"ef buses 2EA1, ,and loss of aMtemate-Pwe8

-eeFee for buses 1 EA POPS and IEA2. I 4 startup supplies-pgw.iat.&g-lkV fails to deliver internal fault; loss of pewer o protective re lays; None: offsite power source transformer XST2 to bu 1EA 1 2,, d 1EA2 power component failure; buses 1EA1,and 1EA2 annunciatior in (Item 1) or diesel generators

/rf Unit 1 t ugh GPX overheating; fire and loss of ttems control room are available.

-E;* and-is-an for Can also realign to sepe-bu s 2EA1 and 2EA2 startup transformer XTS2A (ftew~-4).

I Amendment No. -+-94

Attachment 6 to TXX-14063 Page 8 of 16 CPNPP/FSAR TABLE 8.3-3 FAILURE MODE AND EFFECT ANALYSIS FOR AUXILIARY AC POWER SYSTEM (Sheet 3 of 18)

Causes of Effects of Failure Effects on Item Description Failure Mode Failure Failure Detection System 4A power to short circuit; Protective relays; None: offsite power source a CPX- open circuit annunciation in (Item 1) or diesel generators Y fro. X-*PTSS-T control room are available.

Can also realign to spaw startup transformer XTS2A switch consisting of removable XST2 link boxes 4B 15-KV cable T-ranmits 4gwer from short circuit; m*echanical For open ir it: Loss protection relays; None: offsit powersource transfer 0i CPX- open circuit fir e of to annunciation in (Item 1) or -iesel generators EPTSST-02X 'i,, ST2 buses2te AlIA and 2EA2 control room are availl le.

Can als realign to spe x T (XSST2A)to I For circuit: Loss startu ansformer XTS2A EE Iand CPX-EPTSST-03X of to buses 44w4) 1 EA IEA2i and loss of source for buses 2EA1 and 2EA2.

4C Spare Startup Supplies power to 6.9kV Fails to deliver Intemal fault; Loss of power to buses Protective relays; None; offiste power source transformer XST2A to buses 1EA1 and 1EA2 power co mponent failure; IEA1 and 1EA2 and annunciation in the (Item 1) or diesel generator of Unit 1 through CPX- oveheating; fire loss of alternate power control room available.

EPTSST-032Y; and is an source for buses 2EA1 Can also realign to startup alternate power source and 2EA2. transformer XST2 (Item 4).

for buses 2EA1 and 2EA2 of Unit 2 through CPX-EPTSST-032X Amendment No. +04-

Attachment 6 to TXX-14063 Page 9 of 16 CPNPP/FSAR TABLE 8.3-3 FAILURE MODE AND EFFECT ANALYSIS FOR AUXILIARY AC POWER SYSTEM (Sheet 4 of 18)

Causes of Effects of Failure Effects on Item Description Function Failure Mode Failure Failure Detection System I1 I 4D 15-KV Cable Transmits power to Short circuit; Mechanical damage; For open circuit: Loss Protective relays; None; offsite power source transfer panel CPX- open circuit fire of power to buses annunciation inthe (Item 1) or diesel generators EPTSST-03Y from lEA1 and 1EA2 from control room are available.

XST2A XST2A. For short Can also realign to startup circuit: Loss of power transformer XST2 (Item 4).

to buses 1EA1, 1EA2 and loss of alternate power source for buses 2EA1 and 2EA2.

4E 15-KV Cable Transmits power to Short circuit; Mechanical damage; For open circuit: Loss Protective relays; None; offiste power source transfer panel CPX- open circuit fire of power to alternate annunciation in teh (Item 1) or diesel generators EPTSST-032X from buses 2EA1 and 2EA2 control room are available.

XST2A from XST2A. For short Can also realign to startup circuit: Loss of power transformer XST2 (Item 4).

to buses lEA1, 1EA2 and loss of alternate power source for hu*QP 9;=AI =nri 9::A9 40F 154-1-Transfer Trc,=, F.*;;a ple~ve-to buses Short circuit; Mechanical damage; For open circuit: Loss Protective relays; None; offsite power sources

-switlhýCPX- 21q1 and 2EA2-e.-t WJt open circuit fire of 2'tQWQtQ-lOWeI annunciation in the (Item 1) or diesel generators switch EPTSST-02X#'3"X eeuree-to buses 2EA1 control room are available.

consisting of and 2EA2. For short removable circuit: Loss of fewe*

link boxes FAPS to buses lEA1, lEA2, and loss of altrnte land CPX-EPTSST-03X pewersemee for Note 6 buses 2EA1 and 2EA2.

Amendment No. 404-

Attachment 6 to TXX-14063 Page 10 of 16 CPNPP/FSAR -1ý1 TABLE 8.3-3 FAILURE MODE AND EFFECT ANALYSIS FOR AUXILIARY AC POWER SYSTEM (Sheet 5 of 18)

Supplies POPS from XST2 (XST2A)

Causes of Effects of Failure Effects on Item Description Functi/ Fai lure Mode Failure Failure Detection System T*en. pewe..to buses Short circuit; Mechanical damage; For open circuit: Loss Protective relays; None; offsite power source 1EA1 and 1EA2 e-i*-t open circuit fire of pewe to buses annunciation in the (Item 1) or diesel generators frm XCT2 o,, .. T.2A 1* and 1EA2. For contol room are available.

,hort circuit; Loss of

,vpowe to buses lEA1, 1EA2 and loss of for buses 2EA1 and 2EA2.

Short circuit; open circuit: Loss rotective relays; None; offsite power source open circuit fire ofewef to buses annunciation in the (Item 1) or diesel generators lEA1 and IEA2. For control room are available

= hort circuit: Loss of to buses lEA1 lEA2 and loss of for buses 2EA1 and 2EA2.

4F1-7' 15-KV Cable transfer pIeýCP-EPTSST-02X and)3Xý Short circuit; open circuit Mechanical damage; fire For open circuit: Loss of aft&rIate power sewFee to buses 2EA1 Protective rela ys; annunciation ir the control room None; offsite power source (Item 1) or diesel generators are available.

buses 2EA1 and 2EA2 Aand 2EA2. For short APcircuit: Loss of-xewef to buses 1EA1, 1EA2 and loss of-aternate pw-;*-:~ee9e for buses 2EA1 and 2EA2.

Amendment No. 4-4

Attachment 6 to TXX-14063 Page 11 of 16 CPNPPIFSAR TABLE 8.3-3 FAILURE MODE AND EFFECT ANALYSIS FOR AUXILIARY AC POWER SYSTEM (Sheet 6 of 18)

Causes of Effects of Failure Effects on Item Description Function Failure Mode Failure Failure System 5 6.9-kV circuit protects bus 1 EA1 fails to open; mechanical failure; 1. Failure to open . An nciation None:

breaker 1EA1 -2 fails to close stuck contacts; relay could cause loss of bit 2. riodic testing 1. Redundant equipment is failure; control power lEA1 &X,-MRXfT- f operational provided on bus 1EA2.

fails; fire; loss of 2. Fails to close: : eadiness 2. Power can be supplied from ventilation power cannot be offsite power source (Item 2) supplied from XG-T- or diesel generator 1 EGI.

6 6.9-kV circuit protects bus 1EA1 fails to open; mechanical failure; 1. Failure to open 1. Annunciation None:

breaker 1EA1-1 fails to close stuck contacts; relay could cause loss of 2. Periodic testing 1. Redundant equipment is failure; control power 1EA1 "- T erational provided on bus I EA2.

fails; fire; loss of --- T readines b 2. Power can be supplied from ventilation / 2. Fails to close: offsite power source (Item 1) power cannot be loss of bus or diesel generator 1 EGI.

IPOP transformer supplied from Vewe sIew*ee-X6SF2-7 6.9-kV circuit protects bus 1EA2 fails to open; mechanical failure; 1. Failure to n 1. Annunciation None:

breaker 1 EA2-2 fails to close stuck contacts; relay could cause A2 & 2. Periodic testing 1. Redundant equipment is failure; control power -XftSR i N' for operational provided on bus 1EA1.

fails; fire; loss of 2. Fails to close: readiness 2. Power can be supplie(: .

ventilation power cannot be from offsite power source supplied from + (Item 2) or diesel generator 1EG2.

Amendment No. 1.94

Attachment 6 to TXX-14063 Page 12 of 16 CPNPP/FSAR TABLE 8.3-3 FAILURE MODE AND EFFECT ANALYSIS FOR AUXILIARY AC POWER SYSTEM (Sheet 7 of 18)

Causes of Effects of Failure Effects on Item Description Function Failure Mode Failure Failure Detection System 8 6.9-kV circuit protects bus 1EA2 fails to open; mechanical failure; 1. Failure to open 1. Annunciation None:

breaker 1 EA2-1 fails to close stuck contacts; relay could cause loss of bus 2. Periodic testing 1. Redundant equipment is failure; control power 1EA2 - XFMR4 XCT2 for operational provided on bus 1EA1.

fails; fire; loss of .ST.

readiness 2. Power can be supplied from ventilation 2. Fails to close: offsite power source (Item 1) power cannot be oP transformer or diesel generator 1EG2.

supplied from pewer 601F8 SF-9 Bus lEA1 distributes electrical fails to deliver short circuit; loss of Train A safety 1. protective relays None: Redundant Train B power to Train A loads power overload; fire; loss of load group 2. Annunciation in from bus I EA2 available ventilation Control Room 10 Bus 1EA2 distributes electrical fails to deliver short circuit overload; loss of Train B safety 1. protective relays None: redundant Train A from power to Train B loads power fire; loss of load group 2. Annunciation in from bus 1EA1 available ventilation Control Room 11 6.9-kV circuit protects Unit Substation fails to open; mechanical failure; 1. Fails to open: back 1. protective relays None: Load supplied by breaker transformer T1 EBI fails to close stuck contacts; relay up breaker opens and 2. Annunciation redundant load group provided failure; control power loss of 1EA1 Bus redundant load from bus 1EA2 fails; fire; loss of 2. Fails to close: loss group in Control ventilation of power to 1EB1 Room 11A 8-kV cable connects circuit breaker short circuit; Mechanical damage; loss of power to 1. protective relays None: load supplied by and transformer T1 EB1 open circuit fire bus 1EB1 2. Annunication in redundant load group provided Control Room from bus 1EA2 Amendment No. 404

Attachment 6 to TXX-14063 Page 13 of 16 CPNPPIFSAR TABLE 8.3-3 FAILURE MODE AND EFFECT ANALYSIS FOR AUXILIARY AC POWER SYSTEM (Sheet 11 of 18)

Causes of Effects of Failure Effects on Item Description Function Failure Mode Failure Failure Detection System 17 tap Dox NO. I supplies orrsite power to snort circuit; mecnanicai damage loss ot aiternate source protective relays; None: bus 2tA1 and ZLA2 6.9-kV buses 2EA1 and open circuit to 2EA1 and 2EA2 annunciation in can be supplied by offsite 2EA2 control room power source (Item 1) or by diesel generator 2EG1, 2EG2.

tap box No. 3 supplies offsite power to short circuit; mechanical damage loss of preferred protective relays; None: bus 2EA1 and 2EA2 6.9-kV buses 2EA1 and open circuit source to 2EA1 and annunciation in can be supplied by offsite 2EA2 2EA2 control room power source (Item 2) or by diesel generator 2EG1, 2EG2.

tap box No. 6 supplies offsite power to short circuit; mechanical damage loss of preferred protective relays; None: buses 2EA1 and 2EA2 6.9-KV buses 2EA1 and open circuit source to 2EA1 and annunciation in can be supplied by offsite 2EA2 2EA2 control room power source (Item 2) or diesel generators 2EG1, 2EG2.

tap box No. 2 supplies offsite power to short circuit; mechanical damage loss of preferred protective relays; None: buses 1EA1 and 1EA2 6.9-kV buses 1EA1 and open circuit source to lEA1 and annunciation in can be supplied by offsite 1EA2 1EA2 control room power source (Item 1) or diesel generators 1EG1, 1EG2 17D0I tap box No. 5 supplies offsite power to short circuit; mechanical damage loss of preferred protective relays; None: buses 1EA1 and 1EA2 6.9-kV buses lEA1 and open circuit source to 1EA1 and annunciation in can be supplied by offsite 1EA2 lEA2 control room power source (Item 1) or diesel generators 1 EG1, 1EG2 Amendment No. 4-*

Attachment 6 to TXX-14063 Page 14 of 16 CPNPP/FSAR TABLE 8.3-3 FAILURE MODE AND EFFECT ANALYSIS FOR AUXILIARY AC POWER SYSTEM (Sheet 18 of 18)

Causes of Effects of Failure Effects on Item Description Function Failure Mode Failure Failure Detection System 44 Unit I Train A distributes 480-V power fails to deliver mechanical failure; loss of MCC Annunciation in None: Item redundant MCCs supplied by power short circuit; over- control room equipment on unit 1 MCCs Train A switchgears load; fire; loss of supplied by Train B ventilation switchgears 45 Common Train A distributes 480-V power fails to deliver mechanical failure; loss of MCC Annunciation in None: redundant equipment MCCs supplied by power short circuit; over- control room on common MCCs supplied by Train A unit I or 2 load; fire; loss of Train B switchgears switchgears ventilation 46 Unit I Train B distributes 480-V power fails to deliver mechanical failure; loss of MCC Annunciation in None: redundant equipment MCCs supplied by power short circuit; over- control room on unit 1 MCCs supplied by Train B switchgears load; fire; loss of Train A switchgears.

ventilation 47 Common Train B distributes 480-V power fails to deliver mechanical failure; loss of MCC Annunciation in None: redundant equipment MCCs supplied by power short circuit; over- Control Room on common MCCs supplied by Train B unit I or 2 load; fire; loss of Train A switchgears.

switchgears ventilation

5. The cables from XST1 Y-winding to manual transfer switch CPX-EPTSST-04Y are routed through tap box #3 and cables from XST1A Y-winding to manual transfer switch CPX-EPTSST-04Y are routed thru tap box #8.

6. The removable link boxes CPX-EPTSST-02X and CPX-EPTSST-03X and Eaton bus Notes: bar connection of these boxes constitute the manual transfer switch for the X-winding of XST2 and XST2A.

1. The items listed in this Table are shown on the plant one-line diagram, Figure 8.3-1. 7. The removable link boxes CPX-EPTSST-02Y and CPX-EPTSST-03Y and Eaton bus bar connection of these boxes constitute the manual transfer switch for the Y-

2. The analysis listed is for Unit 1; Unit 2 is similar, except for equipment identification numbers.

winding of XST2 and XST2A.

8. The cables from the Y-winding manual transfer switch to Unit 1 safety buses

3. Analysis of the dc system is given in Table 8.3-7.

are routed through tap box #2 and tap box #5.

4. Flooding considerations for the previously mentioned equipment are discussed in Section 8.3.1.1.14. 9. The cables from the X-winding manual transfer switch to Unit 2 safety buses are routed through tap box #1 and tap box #7.

Abbreviations: Portia' d*isher;z (PD).

1. POPS - Preferred Offsite Power Source Amendment No. 1.4

2. AOPS - Alternate Offsite Power Source

3. PD - Partial Discharge to TXX-14063 Page 15 of 16 INSERTS INSERT A 1

'C manual transfer I supplies AOPS from Ishort circuit; mechanical damage; For open circuit: Loss protective relays; None:o-ffs-ite po'wer source panel XST1 (XSTIA) to bus open circuit fire of AOPS to bus lEA1, annunciation in (Item 2) or diesel generators CPX-EPTSST-04X. lEA1 For short circuit: Loss control room are available.

I of POPS to buses 2EA1, 2EA2, and loss 1 of AOPS for buses

_! lEA1 and 1EA2.

3D manual transfer supplies AOPS from short circuit; mechanical damage; For open circuit: Loss protective relays; None: offsite power source panel XST1 (XST1A) to bus open circuit fire of AOPS to bus 1EA2, annunciation in (Item 2) or diesel generators CPX-EPTSST-05X. 1EA2 I For short circuit: Loss control room are available.

of POPS to buses 2EA1, 2EA2, and loss of AOPS for buses

_ _-1EAl and 1EA2.

3E manual transfer supplies POPS from short ciruit; mechanical damage; For open circuit: Loss protective relays; None: offsite power source panel XST1 (XSTIA) to buses open circuit fire of POPS to buses 2EA1 annunciation in (Item 2) or diesel generators CPX-EPTSST-04Y. 2EA1 and 2EA2 and 2EA2. control room are available.

For short circuit: Loss 1 of POPS to buses 2EA1, 2EA2, and loss of AOPS for buses lEA1 and 1EA2.

- lcable . .supplies-APS-from . -sho- circui-t .mech-anical damage; . For open circuit: Loss I protective relays; None: oifsite power source manual transfer panel open circuit fire of AOPS to bus 1EA I annunciation in (Item 2) or diesel generators CPX-EPTSST-04X (CPX- (lEA2). control room are available.

SEPTSST-05X) to bus For short circuit: Loss lEA1 (1EA2) of POPS to buses I 2EA1, 2EA2, and loss 1 of AOPS for buses

_ _ lEA1 and 1EA2.

to TXX-14063 Page 16 of 16 3G 15-kV cable supplies POPS from short circuit; mechanical damage; For open circuit: Loss protective relays; None: offsite power source manual transfer panel open circuit fire of POPS to bus 2EA1 annunciation in (item 2) or diesel generators CPX-EPTSST-04Y to bus (2EA2). control room are available.

2EA 1(2EA2) For short circuit: Loss I of POPS to buses 2EA1, 2EA2, and loss of AOPS for buses

___ lEA1 and 1EA2.

ATTACHMENT 7 TO TXX-14063 SINGLE LINE DIAGRAMS OF THE APDG SETS to TXX-14063 Page 1 of 4 NORTH CONTAINMENT UNIT 1 Is MCM PER PHASE

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ATTACHMENT 8 TO TXX-10463 ATTACHMENT 8.H OF STA-629, "SWITCHYARD CONTROL AND TRANSMISSION GRID INTERFACE"

Attachment 8 to TXX-14063 Page 1 of 4 CPNPP PROCEDURE NO.

STATION ADMINISTRATION MANUAL STA-629 SWITCHYARD CONTROL AND REVISION NO. 7 TRANSMISSION GRID INTERFACE INFORMATION USE PAGE 56 OF 65 ATTACHMENT 8.H PAGE 1 OF 7 CPNPP OFFSITE POWER SYSTEM PERFORMANCE CHARACTERISTICS

[C]

1.0 System Voltage CPNPP offsite power system required voltages at the Switchyards are listed in Table 1 below.

TABLE 1 CPNPP Switchyards Voltage Limits System Maximum kV Minimum kV 138kV System 144 135 345kV System 361 340 1.1 The preferred source of power, for CPNPP safety related buses, is offsite power supplied from the TO transmission system. Therefore, the availability of Switchyard voltages within the limits defined in Table 1 should be assured with high reliability considering the transmission grid network contingencies discussed below. For purposes of this provision, voltages will be measured at the Points of Interconnection, as defined-in the Generation Interconnection Agreement. The actions of both TO and ERCOT may be required to assure that the Switchyard voltages will remain within the limits of Table 1.

This Procedure does not address actions required by ERCOT.

The offsite sources of power for CPNPP are as follows:

A. Unit 1

a. Preferred - Start Up Transformer XST2 345kV interconnection with TO 345kV Switchyard

b. Alternate - Start Up Transformer XST1 138kV interconnection with TO 138kV Switchyard B. Unit 2

a. Preferred - Start Up Transformer XST1 138kV interconnection with TO 138kV Switchyard

b. Alternate - Start Up Transformer XST2 345kV interconnection with TO 345kV Switchyard 1.2 Voltage Reliability Transmission Planning shall, on an annual basis, assess the probability of an event, involving multiple individual transmission facility outages that could result in Switchyard voltages being outside the limits defined in Table 1. Transmission Planning shall notify the Generator if the probability of such event exceeds 1.0E-5.

Attachment 8 to TXX-14063 Page 2 of 4 CPNPP PROCEDURE NO.

STATION ADMINISTRATION MANUAL STA-629 SWITCHYARD CONTROL AND REVISION NO. 7 TRANSMISSION GRID INTERFACE INFORMATION USE PAGE 57 OF 65 ATTACHMENT 8.H PAGE 2 OF 7 CPNPP OFFSITE POWER SYSTEM PERFORMANCE CHARACTERISTICS System Voltage (continued) 1.3 System Studies 1.3.1 Transmission Planning shall perform annual steady state studies in accordance with ERCOT Requirements to evaluate Switchyard voltages and shall take actions as described below to address the voltage requirements of CPNPP shown in Table 1.

1.3.2 The following system conditions will be considered in evaluating the system voltages at the Switchyards:

A. Maximum expected system demand and minimum expected system demand.

B. CPNPP load modeled as described in Section 1.3.4 below.

1.3.3 The following contingencies shall be evaluated:

1.3.3.1 Transmission Planning shall perform annual studies to evaluate the CPNPP Switchyard voltages for the CPNPP defined contingencies below:

A. The trip of a CPNPP unit. The tripping of a CPNPP unit shall be considered even when the other CPNPP unit is in outage or otherwise off line.

B. Simultaneous loss of a CPNPP unit and a most critical transmission line to CPNPP.

The tripping of a CPNPP unit shall be considered even when the other CPNPP unit is in outage or otherwise off line.

C. Simultaneous loss of a CPNPP unit and a most critical generator to CPNPP. The tripping of a CPNPP unit shall be considered even when the other CPNPP unit is in outage or otherwise off line.

1.3.3.2 Transmission Planning shall also perform annual studies to evaluate the CPNPP Switchyard voltages for normal required contingencies defined by the ERCOT Requirements.

Attachment 8 to TXX-14063 Page 3 of 4 CPNPP PROCEDURE NO.

STATION ADMINISTRATION MANUAL STA-629 SWITCHYARD CONTROL AND REVISION NO. 7 PAGE 58 OF 65 TRANSMISSION GRID INTERFACE INFORMATION USE ATTACHMENT 8.H PAGE 3 OF 7 CPNPP OFFSITE POWER SYSTEM PERFORMANCE CHARACTERISTICS System Voltage (continued) 1.3.4 The studies, addressed in this Section 1.3, to determine the minimum voltages at the Switchyards shall model CPNPP loads, at 0.85 PF, as follows:

138 kV 345 kV 345 kV 345 kV 138 kV Total 138 Total 345 MVA MVA MVA MVA MVA kV kV MVA

__ MVA XST1 XST2 1ST 2ST 25 kV Transformer Transformer Transformer Transformer Transformers A 14 14 45 45 10 24 104 B 0 28 45 45 10 10 118 C 28 0 45 45 10 38 90 Scenario A - 138 kV and 345 kV normal loading scenario.

Scenario B - 345 kV maximum loading scenario.

Scenario C - 138 kV maximum loading scenario.

Generator will provide loads 'for conditions not addressed above, when requested.

1.3.5 The results of all system voltage studies including the assumptions made to perform these studies performed pursuant to Section 1.3 shall be communicated to Generator in accordance with attachment 8.F and ERCOT in accordance with ERCOT Requirements.

1.3.5.1 Under each of the contingencies identified in section 1.3.3.1, both of the offsite sources should remain immediately available within the voltage ranges of Table 1 ("Voltage Performance A"). If the studies required by 1.3.3.1 reveal that Voltage Performance A is not expected to be met, then the TO shall:

A. Identify actions it believes are appropriate to implement such that, after such implementation, the Voltage Performance Ais expected to be met.

B. Inform Generator about the condition, minimum expected voltage, and the identified actions in accordance with Attachment 8.F, and C Initiate implementation of such actions, to the extent it has the responsibility and authority to do so, in accordance with applicable laws, regulations, tariffs, and ERCOT Requirements. Such actions may include short-term (temporary or permanent) actions, as well as long-term (permanent) actions.

Attachment 8 to TXX-14063 Page 4 of 4 CPNPP PROCEDURE NO.

STATION ADMINISTRATION MANUAL STA-629 SWITCHYARD CONTROL AND REVISION NO. 7 PAGE 59 OF 65 TRANSMISSION GRID INTERFACE INFORMATION USE ATTACHMENT 8.H PAGE 4 OF 7 CPNPP OFFSITE POWER SYSTEM PERFORMANCE CHARACTERISTICS System Voltage (continued) 1.3.5.2 Under each of the contingencies referenced in section 1.3.3.2, one of the offsite sources should remain immediately available within the voltage ranges of Table 1

("Voltage Performance B"). If the studies required by 1.3.3.2 reveal that Voltage Performance B is not expected to be met, then the TO shall:

A. Identify actions it believes are appropriate to implement such that, after such implementation, the Voltage Performance B is expected to be met.

B. Inform Generator about the condition, minimum expected voltage, and the identified actions in accordance with Attachment 8.F, and C. Initiate implementation of such actions, to the extent it has the responsibility and authority to do so, in accordance with applicable laws, regulations, tariffs, and ERCOT Requirements. Such actions may include short-term (temporary or permanent) actions, as well as long-term (permanent) actions.

1.4 Normal Operating Voltage Ranges TO will take operating actions on its system, which it has the responsibility and authority to implement in accordance with applicable laws, regulations, tariffs, and ERCOT Requirements, to maintain the Switchyard voltages within the ranges shown below under normal system conditions (no maintenance outages or contingencies). For purposes of this provision, voltages will be measured at the Points of Interconnection, as defined in the Generation Interconnection Agreement. TO may change the Normal Operating Voltage Ranges depending upon various operating conditions. This Procedure will be amended to reflect such change.

138 kV Switchyard 138 to 143 kV 345 kV Switchyard 342 to 358 kV 1.5 State Estimator/Real Time Contingency Analyzer TGO state estimator/real time contingency analyzer based analyses and studies shall provide warning when the voltage at either Switchyard is projected to be outside the limits defined in Table 1 under any of the contingencies defined in Section 1.3.3. Such analyses are normally run every fifteen (15) minutes. Upon confirmation of the results of a scenario referenced in this Section 1.5, TO shall immediately notify the CPNPP Shift Manager, in accordance with Attachment 8.F.

ATTACHMENT 9 TO TXX-14063 ATTACHMENT 5 OF STA-726, "NON-RADIOACTIVE SPILL RESPONSE"

Attaachment 9 to TXX-14063 Page 1 of 1 NOTE 6.1.2 +

NOTIFY RP & MAKE IMMEDATE SM PLANT ANNOUNCEMENT ACTION REQUIRED IFTOXIC SPILL COULD AFFECT BREATHING AIR

%CTSFETY ~ 6..

6.1.96.8 NOTIFY RP/RW FOR RAD NOTIFY ASSESSMENT IF SPILL IS ENVIRONMENTAL IN RCA OR MAY CONTAIN SPILL ANY RADIOISOTOPE (e.g.. WMS Piping)

COORDINATOR ATT 4 t

CONDUCT LVW DETERMINE REPORTABILITY IMPACT ON IF ATTI REVIEW PERMITTED HAZARDOUS ASSESS OTHERS OUTFALLS MIXED WASTE REPORT RESULTS TO SM A-i 2

ATTACHMENT 10 TO TXX-14063

SUMMARY

OF REGULATORY COMMITMENTS

Attachment 10 to TXX-14063 Page 1 of 2 Summary of Regulatory Commitment Commitments 4856645 During the 14-day CT, the APDG provided for each Unit will During the 14-day CT be verified available to provide power to equipment for long term cooling once per shift.

4856652 During the 14-day CT, if an APDG becomes unavailable, the During the 14-day CT affected Unit shall enter Condition C of TS 3.8.1 and comply with the Required Actions. If the CT for the Condition C Required Actions is not met, then Condition G of TS 3.8.1 shall be entered. This allowance will only be exercised during the 14-day CT for a given Unit. For any second, or subsequent, unavailability of an APDG for a given Unit, the affected Unit shall immediately enter TS 3.0.3. In all cases, the normal rules governing application of TSs in section 1.0 of the CPNPP TSs shall apply.

4856680 Prior to initiation of the 14-day CT, PM task for breakers lEA1- Prior to the start of the 14-1, 1EA2-1, 2EA1-2 and 2EA2-2 will be verified as current. day CT 4856681 Testing of EDGs, APDGs, and TDAFWPs will occur within the Within two weeks prior to two (2) weeks prior to the start of the 14-day CT. the start of the 14-day CT 4856682 The EDGs, APDGs, TDAFWPs, XST2, CCWPs, and SSWPs will During the 14-day CT have ALL testing and maintenance activities suspended for the duration of the 14-day CT for XST1.

Additionally, sign's 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.

4856683 A roving hourly fire watch will be in effect during the 14-day During the 14-day CT 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.

4856684 Local weather conditions and forecasts will be monitored by During the 14-day CT Operations twice per shift to assess potential impacts on plant conditions.

4856688 A time in which severe weather is not expected will be During the 14-day CT 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.

4856689 The seismic walkdown will be completed prior to the XST1 CT Within two weeks prior to to identify any issues that could impact the EDGs and the start of the 14-day CT 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.

4856690 Access to the 345kV switchyard and relay houses will be Prior to the start of the 14-controlled and posted, and all maintenance will be suspended day CT for the duration of the CT on XST1. Due to XST1 being deenergized the 138kV switchyard is not impacted.

Attachment 10 to TXX-14063 Page 2 o& 2 4856691 CPNPP's Operations Department will contact the During the 14-day CT Transmission Operator (Transmission Grid Controller) once per day during the 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 voltage required by STA-629.

4856692 Just-in-time training for affected work groups will be Prior to the start of the 14-completed prior to the start of a XST1 outage. day CT 4856693 All hot work activities along the routing associated with During a 14-day CT power and control cabling for XST2, the in-service ST, will be suspended during the 14-day CT. This is to reduce the likelihood of fires that could damage and thus disable the XST2 transformer cabling.

4856694 In the two weeks prior to the start of the CT, a thermographic Within two weeks prior to survey will be conducted on the two fixed sources in the the start of the 14-day CT safeguards switchgear room to verify no abnormalities exist.

This is to reduce the likelihood of a fire ignition.

4856720 Both Unit I and 2 Transient Combustible zones that are During the 14-day CT 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.

4856724 A Nuclear Equipment Operator will be assigned to ensure During a 14-day CT CT.

proper operation of the APDGs, during the 14-day 4859995 Luminant Power will ensure all applicable corrective actions Prior to the start of the 14-from the "cut cable" event root cause are complete and in day CT place per License Event Report 445/13-003-00. (ML14043A089)

v t e Letter Sequence Request
TAC:MF3370, (Open)
Initiation Request, Request Acceptance Administration Questions Answers Results Approval... Other:
MONTHYEAR2014-07-01 [Table View]

CP-201400632, License Amendment Request (LAR) 14-001, Revision to TS 3.8.1, AC Sources - Operating, for a 14-Day Completion Time for Offsite Circuits

Text

SUBJECT:

REFERENCES:

Dear Sir or Madam:

1.0 DESCRIPTION

2.0 PROPOSED CHANGE

3.0 BACKGROUND

4.0 TECHNICAL ANALYSIS

5.0 REGULATORY ANALYSIS

6.0 ENVIRONMENTAL CONSIDERATION

8.0 REFERENCES

1.0 DESCRIPTION

2.0 PROPOSED CHANGE

3.0 BACKGROUND

4.0 TECHNICAL ANALYSIS

Response

Response

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5.0 REGULATORY ANALYSIS

6.0 ENVIRONMENTAL CONSIDERATION

8.0 REFERENCES

SUMMARY

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