NL-09-009, Response to Request for Additional Information on License Amendment to Allowable Completion Time for Offsite AC Sources

Response to Request for Additional Information on License Amendment to Allowable Completion Time for Offsite AC Sources

ML090490835
Person / Time
Site:	Indian Point
Issue date:	02/02/2009
From:	Joseph E Pollock Entergy Nuclear Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NL-09-009, TAC MD9348
Download: ML090490835 (10)

Text

SEntergy Indian Point Energy Center 450 Broadway, GSB P.O. Box 249 Buchanan, N.Y. 10511-0249 Tel (914) 734-6700 J.E. Pollock Site Vice President Administration February 2, 2009 Indian Point Unit 2 Docket No. 50-247 NL-09-009 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Stop O-P1-17 Washington, D.C. 20555-0001

Subject:

Response to Request For Additional Information Regarding License Amendment to the Allowable Completion Time for Offsite AC Sources (TAC NO. MD9348)

References:

1.

John Boska (NRC) letter to Vice President Operations (Entergy Nuclear Operations, Inc.) "Indian Point Nuclear Generating Unit No. 2 - Request for Additional Information Regarding Amendment Application for Technical Specification for Offsite AC Sources (TAC NO. MD9348)," dated December 19, 2008.

2.

Joe Pollock (Site Vice President, Indian Point Energy Center) to U.S. Nuclear Regulatory Commission, "Exigent License Amendment Request to the Allowable Completion Time for Offsite AC Sources," dated July 30, 2008.

Dear Sir or Madam:

Entergy Nuclear Operations, Inc (Entergy) hereby responds to a request for additional information (Reference 1) regarding an exigent amendment request (Reference 2) to the Indian Point 2 (IP2) Operating License DPR-26. The proposed change to Technical Specification (TS) 3.8.1 would allow a one time extension to the completion time of Required Action A.4 to support replacement of one of the Station Auxiliary Transformer (SAT) cooling oil pumps. The change is no longer exigent but approval on an expedited basis is requested.

A copy of this letter with the attachments is being provided as required by 10 CFR 50.91 to the designated New York State official. If you have any questions, please contact Mr. Robert Walpole, Licensing Manager, at (914) 734-6710.

002

NL-09-009 Docket 50-247 Page 2 of 2 I declare under penalty of perjury that the foregoing is true and correct. Executed on February "t-2009.

Sincerely, 5J.E. Pollock Site Vice President Indian Point Energy Center Attachments: 1.

Response to Request For Additional Information Regarding Amendment to The Allowable Completion Time For Offsite AC Sources

2.

Markup of Technical Specification Page Regarding the Allowable Completion Time cc: Mr. Samuel J. Collins, Regional Administrator, NRC Region 1 Mr. John P. Boska, Senior Project Manager, NRC NRR DORL NRC Resident Inspectors Office, Indian Point 2 Mr. Paul Eddy, NYS Department of Public Service Mr. Mr. Robert Callender, Vice President, NYSERDA

ATTACHMENT 1 TO NL-09-009 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING AMENDMENT TO THE ALLOWABLE COMPLETION TIME FOR OFFSITE AC SOURCES ENTERGY NUCLEAR OPERATIONS, INC.

INDIAN POINT NUCLEAR GENERATING UNIT NO. 2 DOCKET NO. 50-247

NL-09-009 Docket 50-247 Page 1 of 5 REQUEST FOR ADDITIONAL INFORMATION (TAC NO. MD9348)

On July 30, 2008, Entergy Nuclear Operations, Inc. (Entergy), submitted an application for a proposed amendment for Indian Point Nuclear Generating Unit No. 2 (IP2) which would allow a one-time extension to the completion time for the loss of one offsite power circuit (ADAMS Accession No. ML082180351). The Nuclear Regulatory Commission staff requested additional information by letter dated December 19, 2008. The NRC staff questions and the Entergy response are as follows:

Question 1 Provide additional detail concerning the basis for the need for an additional 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> given that, according to your license amendment request (LAR) technical analysis, the maintenance can ideally be completed in 60-70 hours. Also, confirm that this work will be completed in 2009 (LAR says 2008).

Response

The scope to replace the failed cooling pump on the Unit #2 SAT transformer involves the following activities:

1.

De-energize SAT.

2.

Operations apply tag out

3.

Assemble scaffold for LV link removal

4.

Disconnect HV links

5.

Disconnect LV links

6.

Connect processor to SAT and drain oil

7.

Determinate and remove failed cooling pump

8.

Install and terminate new cooling pump (replace gaskets and power supply cord).

9.

Test #2 pump for any degradation.

10. Hold vacuum - 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> minimum

11. Vacuum fill SAT with reprocessed oil

12. Temp lift to allow bumping new cooling pump

13. Correct supply connections as necessary.

14. Run new cooling pump and test for vibration, FLA, voltage and flow.

15. Test transformer as per Engineering / PM procedure

16. Reinstall HV and LV links / close all covers

17. Run pumps

18. Engineering review transformer test data

19. Remove tag out

20. Place SAT in service The above scope was evaluated and it was determined that it would require a duration of 60 hours6.944444e-4 days <br />0.0167 hours <br />9.920635e-5 weeks <br />2.283e-5 months <br /> to complete the work. This determination was made based on all of the items above being executed without any anomalies and with good results. From past experience Items 8, 9, 10, 15 and 18 are the most likely to challenge the schedule. During past outages these item have created problems that required more that the optimal time schedules for

NL-09-009 Docket 50-247 Page 2 of 5 completion. For example, if the final testing of the existing #2 pump shows any degradation, (item 9), it will need to be replaced adding up to an additional 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of time. Past experience shows that item 10, pulling vacuum, is likely to require more than the minimum time of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> to accomplish. How much more time can not be determined currently since many factors effect this process and it is a critical process for ensuring the transformer is moisture free prior to filling with oil. The potential exists to double or triple the time estimated. There are also six (6) tests that are required to be performed that have the potential to exceed the estimated time when performing and interpreting results (items 15 and 18). For example, the series of transformer electrical tests which include the Doble power factor test. This test is complicated to perform on older transformers like the SAT. All of these tests are often performed several times to ensure accuracy. While weather conditions adverse to grid reliability are to be avoided, conditions such as rain, cold and winter conditions that could occur have the potential to affect all of the items above and therefore increase time to complete.

In conclusion, under ideal conditions and with a newer vintage transformer, there is a high level of confidence that the 60 hours6.944444e-4 days <br />0.0167 hours <br />9.920635e-5 weeks <br />2.283e-5 months <br /> would be easily achievable. With uncertainty concerning weather conditions, the existing running #2 pump condition and how the 38 year old transformer will respond to specific testing and vacuum activities, the 60 hours6.944444e-4 days <br />0.0167 hours <br />9.920635e-5 weeks <br />2.283e-5 months <br /> is a concern and the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> extension will provide a level of margin and security to ensure quality repair, testing and return to service of the transformer. The repair activities are to be performed in an expedited but safe manner and the time that the transformer is out of service will be kept to a minimum.

If approved, the planned work will be completed in 2009 and the proposed amendment will revise the Completion Time for Required Action A.4 to reflect this. The revision will be as follows:

"OR 144 hours0.00167 days <br />0.04 hours <br />2.380952e-4 weeks <br />5.4792e-5 months <br /> for a one time maintenance outage on the Station Auxiliary Transformer to be completed as conditions allow in 2009" The revised page is contained in attachment 2.

Question 2 Per Title 10 of the Code of Federal Regulations Part 50, Appendix A, General Design Criteria 17 (GDC-17), the 13.8 kV offsite circuits would normally be classified as the delayed access safe shutdown circuits. Provide assurance that these circuits are capable of supporting the safety-related electrical loads as GDC-1 7 immediate access (within a few seconds) circuits for design basis accidents on IP2 while simultaneously supplying safe shutdown loads (including all reactor coolant pumps) on Indian Point 3 (IP3). Include a detailed summary of any analyses used to make this determination.

Response

As indicated in Attachment 1 (page 2 of 8) of our letter dated July 30, 2008 (NL-08-094):

NL-09-009 Docket 50-247 Page 3 of 5 "The 13.8 kV offsite circuit is considered a delayed access circuit because operator action is normally required to supply offsite power to the plant using the 13.8 kV offsite source."

"For the 13.8 kV offsite circuit, there is a separate 13.8 kV/6.9 kV auto transformer associated with each of two feeders (13W92 and 13W93). Feeder 13W92 and its associated auto transformer is the preferred feeder for the IP2 13.8 kV circuit and the backup feeder for the IP3 13.8 kV circuit. Feeder 13W93 and its associated auto transformer is the backup feeder for the IP2 13.8 kV circuit and the preferred feeder for the IP3 13.8 kV circuit."

"The plant distribution system is configured around 6.9 kV buses 1, 2, 3, 4, 5, and 6.

All offsite power to the safeguards buses enters the plant via buses 5 and 6, normally supplied by the 138 kV offsite circuit but may be manually loaded on the 13.8 kV offsite circuit. When the plant is operating, 6.9 kV buses 1, 2, 3, and 4 receive power from the main generator via the unit auxiliary transformer (UAT). However, when the main generator or UAT is not capable of supporting this arrangement, 6.9 kV buses 1 and 2 receive offsite power via 6.9 kV bus 5 and 6.9 kV buses 3 and 4 receive offsite power via 6.9 kV bus 6. Following a unit trip, 6.9 kV buses 1, 2, 3, and 4 will auto transfer (fast bus-transfer) to 6.9 kV buses 5 and 6 in order to receive offsite 138 kV offsite power. When 138 kV power is unavailable, the fast bus transfer is taken out of service due to the inability to power all the loads (e.g., four reactor coolant pumps)."

In the configuration where 13.8 kV offsite power is feeding IP2 6.9 kV buses 5 and 6, the remaining 6.9 kV buses 1, 2, 3, and 4 will not transfer to offsite power with loss of the main generator. Immediate access to offsite power, in accordance with GDC-17, will only apply to two of the three safety-related trains (480V Buses 5A & 6A). The remaining safety-related train will be powered from an emergency diesel generator for design basis accidents. This design is consistent with the plant's design basis, and the existing Technical Specifications with the station auxiliary transformer out of service.

There are two 13.8 kV offsite power circuits, but only one is required per design. Feeder 13W92 and its associated auto-transformer will be available for IP2, and Feeder 13W93 will be available for IP& Each circuit has the capacity to feed safety-related loads at both plants if needed (20 MVA), but this configuration is not required per GDC-1 7. The 13.8 kV circuits are not capable of supplying all reactor coolant pumps, and 6.9 kV buses 1 thru 4 will only be supplied from the 13.8 kV system if sufficient loads are stripped from these buses.

The 13.8 kV circuit was analyzed in calculation IP-CALC-04-01589, "Load Flow and Short Circuit Analysis of the IP2 Electrical Distribution System supplied from the 13.8kV Distribution System". This analysis considered; (1) steady state load flow and voltages for plant normal operation and accident conditions under minimum 13.8kV system voltages; (2) short circuit studies for three phase and single line to ground faults; and (3) motor starting transients for the largest 480V motor. The study was performed using ETAP PowerStation software, and evaluated the adequacy of voltages at equipment and motor terminals to meet minimum voltage requirements. Minimum expected 13.8 kV system voltage was established as 13.47 kV, and the largest 480V motor is for the auxiliary feedwater pump. Conclusions

NL-09-009 Docket 50-247 Page 4 of 5 indicate that voltages, load flow and short circuit levels are adequate for safety-related loads powered from the 13.8 kV circuit.

Question 3 Provide assurance that IP3's license does not preclude use of its Appendix R diesel in support of IP2 as described in this license amendment and confirm how long it take to align it to IP2 busses. Discuss the impact on IP3 if its Appendix R diesel is aligned and loaded for IP2 per this amendment. Include a detailed summary of any analyses used to support these bases.

Response

A review of the IP2 and IP3 licensing basis documents did not reveal any prohibition against use of the Unit 3 Appendix R diesel in support of Unit 2. This was as expected since the NRC has approved the use of single Appendix R diesels / SBO diesels for dual unit sites.

The diesel was designed to be available for Unit 3 within one hour, and is also expected to be available for Unit 2 in one hour since similar switching alignments are involved. The IP3 Appendix R diesel would be declared inoperable for Unit 3 while it was being used to support Unit 2. The out of service Appendix R diesel is governed by the Technical Requirements Manual which limits the allowable outage time but the outage time is not shorter than the requested outage time during the repair.

Analyses that support the use of the Unit 3 Appendix R diesel generator for Unit 2 are addressed by the following calculations. Both studies were performed using the ETAP PowerStation software.

Calculation IP-CALC-08-00023, "Analysis of IP3 Appendix R DG Supplying IP2 SBO Loads". This study evaluated a station blackout event at Unit 2 and analyzed load flow, voltage drop, short circuits, motor starting, and protective device coordination.

Results were acceptable, but the study identified limitations that diesel generator voltage should be maintained at 1.05 pu to enable proper starting of large 480V motors (AFW pump).

Calculation IP-CALC-08-00079, "Evaluation of Appendix R Diesel Generator Power Supply for IP2 Alternate Safe Shutdown System (ASSS)". This study evaluated an App R safe shutdown event at Unit 2 and analyzed load flow, voltage drop, short circuits, motor starting, and protective device coordination. Results were determined to be acceptable.

Question 4 Provide assurance that safety-related Vital DC systems are included in the list of TS equipment that will be controlled and protected during this transformer outage (Second paragraph on page 4 of 8 of the LAR).

Response

Commitment NL-08-094-01 said in part "Equipment in the TS relied upon for postulated transients and accidents will be administratively controlled and protected to ensure the equipment remains operable and available for the duration of the planned SAT outage."

NL-09-009 Docket 50-247 Page 5 of 5 Since the safety related Vital DC systems are included in TS Sections 3.8.4; 3.8.7 and 3.8.9, they will be controlled and protected during the transformer outage.

ATTACHMENT 2 TO NL-09-009 MARKUP OF TECHNICAL SPECIFICATION PAGE REGARDING THE ALLOWABLE COMPLETION TIME Underline and Bold for added text Strwkeeut for deleted text ENTERGY NUCLEAR OPERATIONS, INC.

INDIAN POINT NUCLEAR GENERATING UNIT NO. 2 DOCKET NO. 50-247

AC Sources Operating 3.8.1 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

- NOTE -

Only required if 13.8 kV offsite circuit is supplying 6.9 kV bus 5 or 6 and the Unit Auxiliary Transformer is supplying 6.9 kV bus 1,2, 3 or 4.

A.2 Verify automatic transfer of 6.9 kV buses 1, 2, 3, and 4 to 6.9 kV bus 5 and 6 is disabled.

AND A.3 Declare required feature(s) with no offsite power automatically available inoperable when its redundant required feature(s) is inoperable.

AND A.4 Restore offsite circuit to OPERABLE status.

1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> AND Once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> from discovery of no automatically available offsite power to one train concurrent with inoperability of redundant required feature(s) 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Insert 1 B.

One DG inoperable.

B.1 Perform SR 3.8.1.1 for the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> offsite circuits.

AND Once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter AND Insert 1 "OR 144 hours0.00167 days <br />0.04 hours <br />2.380952e-4 weeks <br />5.4792e-5 months <br /> for a one time maintenance outage on the Station Auxiliary Transformer to be comDleted as conditions allow in 2009."

INDIAN POINT 2 3.8.1-2 Amendment No.