RS-06-126, Additional Information Supporting License Amendment Request Associated with Direct Current Electrical Power

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

ML062560525
Person / Time
Site:	LaSalle
Issue date:	09/13/2006
From:	Benyak D Exelon Generation Co, Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RS-06-126
Download: ML062560525 (16)

Text

RS-06-126 10 CFR 50-90 September 13, 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 Supporting the License Amendment Request Associated With 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 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 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 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 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.

September 13, 2006 U. S . Nuclear Regulatory Commission Page 2 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 Batteries of Vented Lead-Acid 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.

Attachments 1 through 3 provide the additional information requested including specific responses to NRC concerns 2 and 5a, (i.e., Reference 5).

NRC concern 2 identified the need for additional justification to replace battery specific gravity monitoring with float current monitoring in the TS. The NRC agreed that concurrence from the battery manufacturer endorsing the use of float current as an acceptable method to determine the battery state of charge would provide the additional justification . Attachment 1 provides this concurrence from the battery manufacturers (i .e., GNB/NLI for the Division 1 250 VDC, Division 1 125 VDC and Division 2 125 VDC and C&D Technologies for the Division 3 125 VDC) . In addition, the equipment used to monitor float current will have the necessary accuracy and capability to measure current in the expected range.

NRC concern 5a identified that the licensees seeking to create a new battery monitoring and maintenance program need to provide assurance that the relocated battery parameter values will continue to be controlled at their current level, and actions will be implemented in accordance with the licensee's corrective action program. Reference 3 Attachment 3 provided a draft copy of the new section in the LSCS owner controlled Technical Requirements Manual, TRM 3 .8.d "Battery Monitoring and Maintenance ." In addition, EGC is making a regulatory commitment to relocate the current battery parameters (i.e., specific gravity, electrolyte level, cell temperature, float voltage, connection resistance, and physical condition) to a new Battery Monitoring and Maintenance Program. This program (i.e ., LSCS TRM 3.8.d) will be controlled by 10 CFR 50.59, "Changes, tests, and experiments," and the EGC Corrective Action Program.

This regulatory commitment is documented in Attachment 4 .

EGC is also making a regulatory commitment to reserve a 5% design margin for the Division 1 and Division 2 batteries and a 10% design margin for the Division 3 batteries . This requirement will be added to the TS Bases on approval of the proposed amendment . The margin requirements were addressed in Reference 3 Attachment 2 and are documented in .

September 13, 2006 U . S . Nuclear Regulatory Commission Page 3 Additional wording to be included in the TS and TS Bases was agreed on during the NRC teleconference on August 24, 2006. These changes are provided in Attachments 2 and 3 .

Specifically TS 5,5.14 is revised to remove the reference to IEEE-450 ; change TS 5 .5 .14.b from

" . - . below the minimum established design limit" to ". . . below the top of the plates" and to add 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".

TS Bases Section B 3.8.4 is revised to include a specific statement that references the backup battery chargers associated with the Division 1 and Division 2 125 VDC system as being fully qualified chargers that are powered from a diesel generator backed safety related distribution system. In addition, these 100% capacity battery chargers are the "alternate means" for supporting the Division 1 and Division 2 125 VDC systems.

TS Bases Section B 3 .8 .6 is revised to include specific wording that the Technical Requirements Manual implements the program specified in Specification 5.5 .14 for monitoring various battery parameters including temperature, voltage, and level requirements .

Note that the associated revised TS Bases pages are provided for information only and do not require NRC approval .

EGC has reviewed the information supporting a finding of no significant 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.

Regulatory commitments for LSCS are provided in Attachment 4 of this letter. Any other statements in this submittal are provided for information purposes and are not considered to be regulatory commitments. Should you have any questions concerning this letter, please contact Ms. Alison MackeHar at (630) 657-2817 .

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 13t" day of September 2006.

Respectfully, Darin M. Benyak Manager, Licensing and Regulatory Affairs : Letters from GNB/NLI and C&D Technologies : Revised Technical Specification Page : Revised Technical Specification Bases Pages : Summary of Regulatory Commitments

ATTACHMENT 1 LaSalle County Station Facility Operating License Nos. NPF-1 1 and NPF-1 8 Letters from GNB/NLI for the Division 1 250 VDC, Division 1 125 VDC and Division 2 125 VDC Letter from C&D Technologies for the Division 3 125 VDC

INDUSTRIAL POWER 8 September 2006 GNB Industrial Power 3950 Sussex Avenue Float Curren Aurora, IL 60504-7932 USA From : Robert 630.862 .2200 tel 800.872 .0471 toll free Staff Engineer 6301622325 flax GNB Network Power www.gnb .com To: Don Davis NL 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:

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 determine 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,

j S

July 21, 210304 MEMO-1558 To: Hassan Abugholah Sargent Lundy Float Current Reference, E-mail dated July 16 . 2004

Dear i-tassan,

Per your e-mail request for float current for both NCN-I 7 and NCN-27 at 100% charge and 95% charge . Attached is a graph M*1 shows current vs . temperature. The provided graph represents the average of the entire line of lead-calcium Both the NCN- 17 and NCN-27 o0s fall than 1 amp when the cells are 1 OW1o fully charged ensures that the float current on the graph, regardless of temperature, The cells should be app manufactures recommended graph that a requirement of 2 amps 89OR At 2.33 VPC the 2-amp requirement blow MIR do not hesitate to contact myself or Archie Bell, acbell@nudeatiogishes.com .

Nuclear Logis Tel: 817-284-0077 ext 335 Email: ddavis@nuclearlogistics.com hie Bell, NLI Settings Graph 7450 Whitehall Street - Fort Worth, TX 76118 Telephone (817) 284-0077 - Fax (817) 590-0484

P o w e r Solution s 1400 Union Meeting Road P.O. Box 3053 Blue Bell, PA 19422-0858 Telephone {215)619-2700 Fax (215) 619-7840 August 25, 2006 Mn Kent C . Nelson Exelon Generation Company, LLC LaSalle County Station 2601 N. 21 s` Road Marseilles, 11, 61341-9757 Subject : Float Current Used as an Indicator of Battery Cliaxge State Reference : LaSalle CoUT-ity Station

Dear Mr. Nelson :

As requested, I wish to state C&D's position that a float current value of less than 2-Amps is a both a reliable and an accurate parameter to use to ascertain a state of full rge in lieu of specific gravity readings. That is to say, a float current value of <2.0 Amps on C&D batteries used in the subject generating plant is a reasonable indicator of a full state of charge . The accuracy and reliability of this reading will hold true over the expected life of these batteries (i.e. 20-years).

Please contact me if you have any questions at telephone 215VI90700 extension 365 or via e-mail at ihohensteinacdtecIu-io.com .

ohenstein r, Nuclear Applications Engineering

ATTACHMENT 2 LaSalle County Station Facility Operating License Nos. NPF-1 1 and NPF-1 8 Revised Technical Spec anon Page 5 .5-13

Programs and Manuals 5 .5 Programs and Manuals 13 Primary Containment Leakage Rate Testina Program (continued)

NEI 94 1995, Section 9 .2 .3 : The first Unit 2 Type A test med after December 13, 1993 Type A test shall be per than December 7, 2008 .

The peak calculated ntainment internal pressure for the design lant accident, n, is 39 .9 prig .

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

ge rate acceptance criteria are :

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

lock testing acceptance criteria are :

a) Overall air lock leakage rate is n 0 .05 L~

tested at ! Pd .

b) For each door, the seal leakage rate is <_ 5 scf per he gap between the door seals is pressurized to >_ 10 psig .

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 ovides for restoration and maintenance, which 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 . ions to verify that the remaining cells are > 2 .07 V when a I or cells have been found to be < 2 .13 V .

aSalle 1 and 2 5 .5-13 Amendment No .

ATTACHMENT 3 LaSalle County Station Facility Operating License Nos. NPF-1 1 and NPF-1 8 d Technical Specification Bases Pages E318.4-3 B 3.8.4-13 B 3.8-6-1 B 3.8.6-10

DC Sources-Operating B 3 .8 .4 BASES Based on LaSalle Station battery sizing calculations, weds Divisions 1 and 2 batteries have a margin of at least 5%

(Ref . 10) . The Division 3 batteries have a margin 10% ( io) .

The backup battery chargers associated with the Division I 2 125 UDC system are fully qualified chargers hat are powered from a these related (Class 1E) distribution system, and are capable of supporting system resign requirements . Se 100% capacity battery chargers are the "alternate means" for supporting the Division 1 and Division 2 125 VDC systems .

The batteries for a DC electrical power subsystem are to produce required capacity at 80% of nameplate rating, corresponding to warranted capacity at end of life cycles and the 100% design demand . The minimum design voltage limit is 105/210 V .

The battery cells are of flooded lead acid construction with a nominal specific gravity of 1 .215 . This specific gravity corresponds to an open circuit battery voltage of approximately 120 V for a 58 cell battery and 240 V for a 116 cell battery (i .e ., cell voltage of 2 .065 volts per cell e open circuit voltage is the voltage maintained when there is no charging or discharging . Once fully charged with its o rcuit voltage 1 2 .065 Vpc, the battery will maintain i capacity for 30 days without further charging per man tuners instructions . Optimal long term performance however, is obtained by maintaining a float voltage 2 .17 Vpc to 2 .25 Vpc for Division I and Division 2 and maintaining a float voltage of 2 .20 V 0 2 .25 Vpc for Division 3 . This provides adequate over-potential, which limits the formation of lead sulfate and self discharge . The nominal float voltage of 2 .23 Vpc corresponds to a total float voltage output of 129 .3 V for a 58 cell battery and 258 .7 V for a 116 cell battery as discussed in the UFSAR, Section 8 .3 .2 (Ref . 4) .

Each Division 1, 2, and 3 DC electrical power subsystem charger has ample power output capacity for the steady state operation of connected loads required normal operation, while at the same time maintaining battery bank fully charged . Each battery charger has sufficient capacity to restore the battery bank design Tin ~ charge to its fully charged state wit (continued)

LaSalle I and 2 B 3 .8 .4-3 Revision

DC Sources-Operating B 3 .8 .4 BASES SURVEILLANCE REQUIREMENTS I Specifications exempts perocrmance of an opposite unit SR (however, as stated in the ;=rite unit SR 3 .8 .5 .1 Note 1, while performance of an SR is exempted, the SR must still be met) .

CES 10 CFR 50, Appendix A, GDC 17 .

Regulatory Guide 1 .6, March 10, 1 IEEE Standard 308, 1971 .

AR, Section 8 .3 .

UFSAR, Chapter 6 .

UFSAR, Chapter 15 .

Regulatory Guide 1 .93, December 1974 .

IEEE Standard 450, 1995 .

9 . Regulatory Guide 1 .32, August 1972 .

10 . NRC Regulatory Commitment documented in letter from D . M . Benyak to NRC, "Additional Information Supporting the License Amendment Request Associated Direct Current Electrical Request," dated September 13, 2006 .

LaSalle 1 and 2 B 3 .8 .4-13 Revision

Battery Parameters B 3 .3 .6 B 3 .8 ELECTRICAL SYSTEMS B 3 .8 .6 a meters BASES CKG _',) This LCO delineates the limits on battery float current as well as electrolyte tem7-ra"re, love" anQ float discussion source batteries . A of these in OPE 7 = :IITY requirements is provided in ses for LCO 3 .8 .4, "DC Sources-Operatin 8 .5, "DC Sources-Shutdown ." In addition to th e the limitations Specification, Battery Monitoring and Maintenance Program described in the Technical cements Manual (Ref . 7) implements the program sped led in Specification 5 .5 .14 for monitoring various battery parameters including temperature, voltage, and level requirements that are based on the recommendations of IEEE Standard 450-1995, "IEEE Recommended Practice for Maintenance, Testing, and Replacement of Vented Lead-Acid Batteries for Stationary Applications" (Ref . 4) .

The battery cells are of flooded lead acid construction with a nominal specific gravity of 1 .215 . This specific gravity corresponds to an open circuit battery voltage of approximately 120 V for a 58 cell battery and 240 V for a 116 cell battery (i .e ., cell voltage of 2 .065 volts per cell (Vpc)) . The open circuit voltage is the voltage maintained when there is no charging or discharging . Once fully charged with its open circuit voltage 1 2 .065 Vpc, the battery will maintain its capacity for 30 days without further charging per manufacturers instructions . Optimal long term performance however, is obtained by maintaining a float voltage 2 .20 to 2 .25 Vpc . This provides adequat which limits the formation of lead sulfate and self discharge . The nominal float voltage of 2 .23 Vpc corresponds to a total float voltage output of 129 .3 V for a 58 cell battery and 258 .7 V for a 116 cell battery as discussed in the UFSAR, Section 8 .3 .2 (Ref . 2) .

APPLICABLE The initial conditions of Design Basis Accident WBA) and SAFETY ANALYSES transient analyses in UFSAR, Chapter 6 (Ref . 1) and Chapter 15 (Ref . 3), assume Engineered Safety Feature systems are OPERABLE . The DC electrical power subsystems z I - ____

al and emergency D C electrical power for the sel generators, emergency auxiliaries, and control an ing during all MODES of operation .

(continued)

LaSalle 1 and 2 B 3 .8 .6-1 Revision

Battery Parameters B 3 .8 .6 ES (continue a successful Surveillance, and offsite or cnsite system when they are tied together dently for the partial Surveillance ; as well available to cope witi se outcomes . measured risk of a and startup to termire nt safety is or enhanced when ors of the Surveillance are in MODE 1 or 2 .

Risk insights or deter be used for this assessment . Credit may for unplanned events that satisfy this SR .

The reason for the second Note is to preclude requiring the OPERABLE DC sources from being discharged below their capability to provide the required power supply or otherwis rendered inoperable during the performance of SRs . It is the intent that these SRs must still be capable of being met, but actual performance is not required .

REFERENCES UFSAR, Chapter 6 .

UFSAR, C 8.

UFSAR, Chapter 15 .

IEEE Standard 450, 1995 .

F, 485, 1983 .

Technical NRC Regulatory Commitment documented in letter from D . M . Benyak to NRC, "Additional Information Supporting the License Amendment Request Associated with Direct Current Electrical Request," dated September 13, 2006 .

LaSalle 1 and 2 8 3 .8 .6-10 Revision

ATTACHMENT 4

SUMMARY

OF REGULATORY COMMITMENTS The following table identifies commitments made in this document. (Any other actions discussed in the submittal represent intended or planned actions. They are described to the NRC for the NRC's information and are not regulatory commitments.)

COMMITTED COMMITMENT TYPE COMMITMENT DATE OR ONE-TIME ACTION Programmatic

OUTAGE

(Yes/No) (Yes/No)

EGC is making a regulatory commitment to Implemented by Yes Yes relocate the current battery parameters (i .e., TS Amendment specific gravity, electrolyte level, cell implementation temperature, float voltage, connection date .

resistance, and physical condition) to a new Battery Monitoring and Maintenance Program.

This program will be located in the LaSalle County Station (LSCS) Units 1 and 2 owner controlled Technical Requirements Manual (TRM), and controlled by 10 CFR 50.59 and the EGC Corrective Action Program.

EGC is making a regulatory commitment to Implemented by Yes Yes reserve a 5% design margin for the Division 1 TS Amendment and Division 2 batteries and a 10% design implementation margin for the Division 3 batteries. date.

The 5% design margin for the Division 1 and Division 2 batteries and the 10% design margin for the Division 3 batteries will be added to the TS Bases.