RS-06-149, Additional Information Supporting the License Amendment Request Associated with Direct Current Electrical Power

Additional Information Supporting the License Amendment Request Associated with Direct Current Electrical Power

ML062860330
Person / Time
Site:	LaSalle
Issue date:	10/12/2006
From:	Benyak D Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RS-06-149
Download: ML062860330 (10)

Text

RS-06-149 10 CFR 50.90 October 12, 2006 U . S. Nuclear Regulatory Commission ATTN : Document Control Desk Washington, D. C. 20555 LaSalle County Station, Units 1 and 2 Facility Operating License Nos. NPF-1 1 and NPF-1 8 NRC Docket Nos . 50-373 and 50-374

Subject:

Additional Information With Supporting the License Amendment Request Associated Direct Current Electrical Power References : 1 . Letter from K. R. Jury (Exelon Generation Company, LLC) to U.S . NRC, "Request for an Amendment to Technical Specifications Associated With Direct Current Electrical Power," dated December 9, 2004 U .S . NRC to C . M . Crane (Exelon Generation Company, LLC), "LaSalle County Power Station, Units 1 and 2 -- Request for Additional Information Related to Request for Amendment to Technical Specifications Associated With Direct Current Electrical Power," dated June 2, 2006

3. Letter from D. M. Benyak (Exelon Generation Company, LLC) to U.S . NRC, "Additional Information With Supporting the License Amendment Request Associated Direct Current Electrical Power," dated August 16, 2006

4. Letter from D . M. Benyak (Exelon Generation Company, LLC) to U .S . NRC, "Additional Information Supporting the License Amendment Request Associated With Direct Current Electrical Power," dated August 24, 2006

5. Summary of July 12, 2006, NRC Public Meeting, "Meeting with the Technical Specifications Task Force (TSTF) to discuss TSTF-360, Revision 1, `DC Electrical Rewrite'," dated August 15, 2006 Letter from D. M . Benyak (Exelon Generation Company, LLC) to U .S . NRC, "Additional Information Supporting the License Amendment Request Associated With Direct Current Electrical Power," dated September 13, 2006

October 1 2, 2006 U . S. Nuclear Regulatory Commission Page 2 In Reference 1, Exelon Generation Company, LLC, (EGC), requested an amendment to Appendix A, Technical Specifications (TS), of Facility Operating License Nos. NPF-1 1 and NPF-18 for LaSalle County Station (LSCS) Units 1 and 2 respectively . Specifically, the proposed changes were to modify TS Sections 3 .8.4, "DC Sources - Operating," 3.8.5, "DC Sources - Shutdown," 3.8.6, "Battery Cell Parameters," and 5 .5, "Programs and Manuals." The proposed changes also requested new actions for an inoperable battery charger and alternate battery charger testing criteria for Limiting Condition for Operation (LCO) 3.8.4 and 3 .8 .5.

The proposed changes also included the relocation of a number of Surveillance Requirements (SRs) in TS Section 3.8.4 that perform preventive maintenance on the safety related batteries to a licensee-controlled program. It was proposed that TS Table 3 .8.6-1, "Battery Cell Parameter Requirements," be relocated to a licensee-controlled program, and specific actions with associated completion times for out-of-limits; conditions for battery cell voltage, electrolyte level, and electrolyte temperature be added to TS Section 3 .8.6. In addition, specific SRs were proposed for verification of these parameters.

A new program was also proposed for the maintenance and monitoring of station batteries based on the recommendations of Institute of Electrical and Electronics Engineers (IEEE)

Standard 450-1995, "IEEE Recommended Practice for Maintenance, Testing, and Replacement of Vented Lead-Acid Batteries for Stationary Applications ." The items relocated would be contained within this new program.

In Reference 2, the NRC requested additional information to complete the review of the license amendment. References 3 and 4 provided the requested information.

In a teleconference on August 24, 2006 additional information was requested by the NRC to complete the review of the proposed license amendment taking into consideration the NRC concerns with TSTF-360 that were discussed at a public meeting on July 12, 2006 (i.e.,

Reference 5). Reference 6 provided this additional information .

Following further discussions with the NRC, additional information was requested to clarify information provided in Reference 6. Attachment 1 provides an additional letter from GNB/NLI, (i .e., the battery manufacturer for the Division 1 250 VDC, Division 1 125 VDC and Division 2 125 VDC) which clarifies assurance of float current voltage. Attachment 2 provides a revision to TS 5 .5.14 that revises TS 5 .5 .14 .c to "verify that the remaining cells are ? 2.07 V when a cell or cells have been found to be < 2.13V."

significant EGC has reviewed the information supporting a finding of no hazards consideration that was previously provided to the NRC in Attachment 1 of Reference 1 . The supplemental information provided in this submittal does not affect the bases for concluding that the proposed license amendment does not involve a significant hazards consideration .

There are no regulatory commitments contained in this letter . Should you have any questions concerning this letter, please contact Ms. Alison Mackellar at (630) 657-2817 .

October 1 2, 2006 U . S. Nuclear Regulatory Commission Page 3 I declare under penalty of perjury that the foregoing is true and correct. Executed on the 12th day of October 2006.

Respectfully, Darin M . Benyak I Manager, Licensing and Regulatory Affairs  : Letter from GNB/NLI : Revised Technical Specification Page

ATTACHMENT 1 LaSalle County Station Facility Operating License Nos. NPF-1 1 and NPF-1 8 Letter from GNB/NLI for the Division 1 250 VDC, Division 1 125 VDC and Division 2 125 VDC

NUCLEAR LOGISTICS INC Date : October 11, 2006 To: Mr. Kent Nelson

Subject:

Float Current Mr. Nelson, This letter is to address the question presented by LaSalle Station via e-mail on October 9", 2006.

"The 09/08/2006 letter from GNB to NLI titled "Float Current Monitoring" included the following bullets:

" The concept of utilizing float current levels of a flooded, stationary string battery to determine a state of charge throughout the life of the battery is reasonable .

" The charge current of each battery can be affected by impurity levels, age, operating environment and maintenance history.

The NRC has asked LaSalle to provide clarification regarding these statements . Specifically, the NRC questioned if the statement that "the concept of utilizing float current . . . to determine a state of charge throughout the life of the battery is reasonable," conflicts with the statement that "the charge current of each battery can be affected by . . . age." Stated more succinctly, as a battery ages (no other factors present) will the float current of the battery at full charge change notably (i.e., so as to affect the current level used to determine state of charge)?"

Float current is expected to change over the life of a battery cell and/or string due to plate deterioration, grid corrosion, reduced capacity and contaminates. Neither GNB nor NLI has test data which documents the expected float current increase over the life of a naturally aged battery cell and/or string. However, GNB did document the float current during accelerated age testing performed on NCX battery cells. The cells were aged for an equivalent time period of 15 years at 60°C. Test data showed an increase in float current of =16% over the simulated 15 year period . ..

Based on the Tafel Curve (TC-107887) an NCN-27 (1944 Amp-Hour Rating) cell would have an initial float current of approximately 0.097 amps when on a float charge of 2.20 Volts Per Cell (VPC). An expected 16%

increase (based on accelerated age testing) would result in a float current of approximately 0.113 amps.

Don Davis Nuclear Logistics Inc.

Battery Project Engineer Attachments (3) 1 . E-mail from Kent Nelson, dated October 9a', 2006

2. GNB letter labeled "Float Current Monitoring", dated September 8"', 2006 3 . Tafel Lines of Gould Calcium Stationary Cells, Document No. TC-107887 7450 Whitehall Street " Fort Worth, Texas 76118 " 817.284.0077 " Fax 817.590.0484 " 800.448.4124 " generalinfo nuclearlogisdcs .com www.nuclearlogistics.com

Message Page I of 1 Don Davis From : kent.nelson@exeloncorp .com Sent: Monday, October 09, 2006 11 :50 AM To: ddavis@nuclearlogistics .com Cc: abell@nuclearlogistics .com; mark .murskyj@exeloncorp .co m; Alison .MacKellar@exeloncorp .co m Subject : Request for Clarification

Don, The 09/08/2006 letter from GNB to NU titled "Float Current Monitoring" includes the following bullets :

o The concept of utilizing float current levels of a flooded, stationary string battery to determine a state of charge throughout the life of the battery is reasonable .

o The charge current of each battery can be affected by impurity levels, age, operating environment and maintenance history.

The NRC has asked LaSalle to provide clarification regarding these statements. Specifically, the NRC questioned I We statement that "the concept of utilizing float current . . . to determine a state of charge throughout the life of the battery is reasonable," conflicts with the statement that "the charge current of each battery can be affected by . . . age! Stated more succinctly, as a battery ages (no other factors present) will the float current of the battery at full charge change notably (i.e., so as to affect the current level used to determine state of charge)?

A response to the NRC questions on this issue would be most appreciated .

Sincerely, Kent C. Nelson LaSalle System Engineering "15) 4113879 This e-mail and any of its attachments may contain Exelon Corporation proprietary information, which is privileged, confidential, or subject to copyright belonging to the Exelon Corporation family of Companies .

This e-mail is intended solely for the use of the individual or entity to which it is addressed. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution, copying, or action taken in relation to the contents of and attachments to this e-mail is strictly prohibited and may be unlawful . If you have received this e-mail in error, please notify the sender immediately and permanently delete the original and any copy of this e-mail and any printout.

Thank You.

10/11/2006

INDUSTRIAL POWFR A MY of 1WHAII 551W01049"as 8 September 2006 GNB Industrial Power 3950 Sussex Avenue Aurora, IL 60504-7932 Float Current Monitoring USA 630.862 .2200 tel From: Robert J. Schmitt 800.872 .0471 NO tee Staff Engineer 6318622325 fax www.gnb.com GNB Network Power To: Mr. Don Davis owl GNB's position on the use of float current measurements by Exelon's LaSalle Station to determine the state of charge of flooded stationary lead-calcium batteries is as follows :

0 The concept of utilizing float current levels of a flooded, stationary string battery to determine a state of charge throughout the life of the battery is reasonable .

There is a relationship between percentage of ampere-hours returned following a successful discharge capacity test and battery state of charge.

Proper follow-up and verification of satisfactory float charge voltage, current and specific gravities is necessary to deetrerroine whether the battery is operating properly per GNB's Installation and Operating Manual, section 93.10.

The charge current of each battery and can be affected by impurity levels, age, operating environment and maintenance history .

I hope this addresses your concerns on this matter and that you will contact me with any further questions .

Best regards, Rj S

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ATTACHMENT 2 LaSalle County Station Facility Operating License Nos. NPF-1 1 and NPF-1 8 Revised Technical Specification Page 5.5-13

Programs and Manuals 5 .5 5 .5 Programs and Manuals 5 .5 .13 Primary Containment Leaka ge_Rate Test ing Program (continued)

NEI 94 1995, Section 9 .2 .3 : The first Unit 2 Type A test performed after December 8, 1993 Type A test shall be performed no later than December 7, 2008 .

The peak calculated primary containment internal pressure for the design basis loss of coolant accident, n, is 39 .9 pSig .

C. The maximum allowable primary containment leakage rate, L, at P, is 0 .635% of primary containment air weight per day .

Leakage rate acceptance criteria are :

1 . Primary containment overall leakage rate acceptance criterion is n 1 .0 Q . During the first unit startup following testing in accordance with this program, the leakage rate acceptance criteria are n 0 .60 Q for the combined Type B and Type C tests, and <_ 0 .75 L, for Type A tests .

2. Air lock testing acceptance criteria are :

a Overall air lock leakage rate is i 0 .05 L, when tested at n P, .

b) For each door, the seal leakage rate is n 5 scf per hour when the gap between the door seals is pressurized to ! 10 psig .

e. The provisions of SR 3 .0 .3 are applicable to the Primary Containment Leakage Rate Testing Program .

5 .5 .14 Battery Monitoring and Maintenance Program This Program provides for restoration and maintenance, which includes the following :

a . Actions to restore battery cells with float voltage < 2 .13 V ;

and Actions to equalize and test battery cells that had been discovered with electrolyte level below the top of the plates ;

and C . Actions to verify that the remaining cells are ~! 2 .07 V when a cell or cells have been found to be < 2 .13 V .

LaSalle 1 and 2 5 .5-13 Amendment No . /