Text

Application for Amend to License NPF-43,revising SRs & Bases for Div I Battery Sys to Agree with Design of New Battery Replacement
	ML20211Q174
Person / Time
Site:	Fermi
Issue date:	09/10/1999
From:	Oconnor W; DETROIT EDISON CO.
To:	; NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20211Q180	List: ML20211Q184; NRC-99-0072, Application for Amend to License NPF-43,revising SRs & Bases for Div I Battery Sys to Agree with Design of New Battery Replacement;
References
	CON-NRC-99-0072 NUDOCS 9909150006
	Download: ML20211Q174 (13)
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Fermi 2 6400 North Dixie llwy., Newport, MI 48166 Detroit Edison 1

10CFR50.92 September 10,1999 NRC-99-0072 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington D C 20555-0001

References:

1) Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43

2) NRC Letter to Detroit Edison, " Fermi 2 -Issuance of Amendment i Re: Replacement of the Division II 130/260-Volt DC Battery", I dated July 9,1999

3) Detroit Edison Letter to NRC, NRC-99-0002, " Transmittal of Revision 2 to Fermi 2 Improved Technical Specification Submittal", dated January 26,1999

4) Detroit Edison Letter to NRC, NRC-99-0050, " Transmittal of Revision 7 to Fermi 2 Improved Technical Specification Submittal (TAC No. MA1465)", dated June 24,1999

5) ANSI /IEEE Standard 450-1972," Recommended Practice for Maintenance, Testing and Replacement of Large Stationary l Type Power Plant and Substation Lead Storage Batteries."

6) ANSI /IEEE Standard 485-1983," Recommended Practice i

for Sizing Large Lead Storage Batteries for Generating Stations and Substations." !

Subject:

Proposed Technical Specification Change (License Amendment) for the Division I 130/260 VDC Battery Replacement Pursuant to 10CFR50.90, Detroit Edison hereby proposes to amend Operating License NPF-43 for the Fermi 2 plant by incorporating the enclosed changes into the 9909150006 990910 fm PDR ADOCK 05000341 i

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NRC-99-0072 Page 2 Plant Technical Specifications (TS) Surveillance Requirements (SR) 3.8.4.1,3.8.4.6, 3.8.6.2 and Surveillance Requirement Bases Section 3.8.6.2. The proposed TS

- amendment revises surveillance requirements and the Bases for the Division I Battery System to agree with the design of the new battery replacement. Detroit Edison plans to install the new battery during the Seventh Refueling Outage (RF07),

which is presently scheduled to begin in the spring of the year 2000. Approval of this proposed license amendment is requested by March 2000, with implementation prior to startup from RF07.

Enclosure 1 provides a description and evaluation of the TS proposed changes.

Enclosure 2 provides an analysis of the significant hazards consideration assessment using the standards in 10CFR50.92.

Enclosure 3 provides marked up pages of the TSs to show the proposed changes.

Because Fermi 2 is in the process of converting to the Improved Technical Specifications (ITS) and is expected to have converted to the ITS prior to startup from RFO7, the proposed changes are provided in ITS format, based on the most recent ITS conversion package submitted to the NRC. A typed version of the affected TS pages with the proposed changes incorporated has not been provided at this time as is normally done. This is due to the significant ITS conversion activity that will have taken place concurrent with the preparation of this submittal.

The NRC issued Amendment No.121 to the Fermi 2 Facility Operating License on July 9,1998 (Reference 2). Amendment 121 revised TS Surveillance Requirements for the Division II 130/260 VDC battery system to agree with the design of the new battery replacement that occurred in the Sixth Refueling Outage (RFO6). The new battery for the Division I 130/260 VDC battery system is equivalent in battery type, manufacturer, specific gravity, and number of cells as the Division 11130/260 VDC battery.

Detroit Edison has evaluated the proposed TS changes against the criteria of 10CFR50.92 and determined that no significant hazards consideration is involved.

The Fermi 2 Onsite Review Organization (OSRO) has reviewed and recommended approval of the proposed changes. The Nuclear Safety Review Group (NSRG) has also reviewed the proposed TS changes and concurs with the enclosed determinations. In accordance with 10CFR50.91, Detroit Edison is providing a copy of this letter to the State of Michigan.

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e USNRC NRC-99-0072 Page 3 j Should you have any questions or require additional information, please contact Mr. Norman K. Peterson of my staff at (734) 586-4258.

l Sincerely, (MLQGT~

Enclosures 0

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cc: A. J. Kugler .

A. Vegel I NRC Resident Office Regional Administrator, Regien III ;

Supervisor, Electric Operators, ,

Michigan Public Service Commission !

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USNRC NRC-99-0072 Page 4 t 4 I, WILLIAM T. O'CONNOR, JR., do hereby affirm that the foregoing statements are based on facts and circumstances which are true and accurate to the best of my knowledge and belief.

{A) h 0b N WILLIAM T. O'CONNOR, J Assistant Vice President, Nuclear Assessment On this / day of de274/1/d241999 before me personally appeared William T. O'Connor, Jr., being'first duly sworn and says that he executed the foregoing as his free act and deed.

l Ut LWu N'otary Public

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ROSALIE A. ARMBTA unggh!$MppgC0g4Ty MYc ei l^ 'J; i ,

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l ENCLOSUREITO NRC-99-0072 FERMI 2 NRC DOCKET NO 50 341 OPERATING LICENSE NPF-43 REQUEST TO REVISE TECHNICAL SPECIFICATIONS FOR THE DIVISION I 130/260 VDC BATTERY REPLACFMENT DESCRIPTION AND EVALUATION OF THE PROPOSED CHANGES i

Enclosure I to -

NRC-99-0072

. Page 2 DESCRIPTION:

The proposed changes involve revising Technical Specification (TS) Surveillance Requirements -(SR) 3.8.4.1,3.8.4.6,3.8.6.2 and SR Bases Section 3.8.6.2 to agree with the replacement of the Division I 130/260 VDC station batteries. As part of the ongoing Fermi 2 conversion to the Improved Technical Specification (ITS) format, the Electrical Power Systems TS and associated Bases have been submitted to the NRC and are undergoing review (References 3 and 4).

The direct current (de) electrical power system provides de emergency power via the 130/260 VDC (Class 1E and Balance of Plant) systems and the 24/48 VDC system. The function of the Class' IE 130/260 VDC system is to provide de power to Class IE de loads and for the control and switching of Class IE systems. This power is provided through two sets (Divisions I and II) of 130/260 VDC Category 1 station batteries with full capacity battery chargers. The Division 1

' 260 volt battery (2PA) consists of two 130 volt battery banks (2A-1 and 2A-2) connected in series.

The existing Division I batteries have sufficient capacity to support the Fermi Design Basis Accident load profile; however, a trend in decreasing battery capacity has been seen during battery performance discharge testing. Recent battery performance testing indicated increased signs of degradation in battery capacity for both the 130 VDC 2A-1 and 2A-2 batteries. It should be noted that even with this degradation, the existing batteries meet the present design requirements for assuring the batteries are capable of performing their functions and will be maintained above the criteria for battery replacement (as described in Reference 5, Section 6) until they are replaced. ,

The existing Division 1260 VDC battery was supplied by C&D Power Systems Inc. This battery is a KC-17 type, lead calcium,1.215 specific gravity and contains 120 cells (includes two 130 ;

VDC battery banks containing 60 cells each). The existing Division I battery will be replaced j with a higher capacity battery furnished by C&D Technologies Inc. The new battery will be a i LCR-21 type, lead calcium,1.215 specific gravity and contain 116 cells (includes two 130 VDC battery banks containing 58 cells each). The batteries are scheduled to be replaced during the j

.3eventh Refueling Outage (RF07)..

]

The battery replacement will not change the existing battery system configuration. The new Division I 260 VDC battery will remain located in the Auxiliary Building Division I Battery Room and will continue to supply de power through a set of 130 VDC station batteries. The battery replacement will increase the battery capacity and decrease the number of cells per battery

. system. ;

The replacement of the Division I 130/260 VDC battery provides benefits for the de power system. The benefits include providing more capacity than the present batteries and increasing the battery charger voltage margin during equalize charge. l l

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p Enclosure I to NRC-99-0072 Page 3 EVALUATION:

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' DeAroit Edison planst' o replace the Division I 130/260 VDC station batteries. As stated above, the primary differences between the old and new batteries are the battery capacity and number of cells per battery system. The existing Division I battery system (120 cells) is being replaced with a physically larger and higher capacity battery consisting of 116 cells.

The 116 cell battery replacement meets all the requirements of the existing 120 cell battery since

' the end of system discharge voltage of the new battery is the same as the original design for maintaining a minimum allowable battery system voltage of 210 VDC (includes two 130 VDC batteries each maintaining a minimum battery system voltage of 105 VDC). The 116 cell battery is physically larger as it requires larger size capacity cells to maintain the same minimum allowable battery system voltage.

The new battery meets the 210 VDC minimum battery system voltage because the new battery end of discharge volts per cell (V/ cell) is greater than the present system. The present 120 cell battery is designed for an end of discharge battery voltage (minimum cell voltage) of 1.75 V/ cell.

1.75 V/ cell x 120 cell = 210 VDC (i.e.,105 VDC + 105 VDC)

Since the new 116 cell battery contains fewer cells, the minimum cell voltage rnust be held at a higher value to maintain the same minimum allowable battery system voltage of 210 VDC. The new 116 cell battery is designed for a minimum cell voltage of 1.81 V/ cell.

1.81 V/ cell x 116 cell = 210 VDC (i.e.,105 VDC + 105 VDC)

The new battery cell rating will have an increased capacity of over two times the existing battery cell rating. Battery capacity is rated in ampere-hours, which determines how long it will operate at a given discharge rate. The existing battery is designed to supply de power to all required loads for 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months (with a loss of ac power), without the minimum cell voltage dropping below 1.75 volts. The 4 hour4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months rated capacity of the existing battery to 1.75 V/ cell is 560 ampere-hours.

The new battery is designed to supply de power under the same conditions as described, but without the minimum cell voltage dropping below 1.81 volts. The 4 hour4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months rated capacity of the new battery to 1.81 V/ cell is 1200 ampere-hours.

Since the end of system discharge voltage is the same, the new batteries will continue to have sufficient capacity to provide power to essential loads, in the event power to the chargers should be lost. The charge on the new batteries will be maintained by the existing battery chargers. The only change to the chargers will be a change to the setpoints to account for the difference in the number of cells per battery system. The setpoint changes are consistent with manufacturer's recommendations. ' Additionally, changing the battery system from 120 to 116 cells reduces the concem of the Division I battery chargers tripping on high voltage during equalize charging.

. Using fewer battery cells allows the setpoint band between the high voltage shutdown and

l Enclosure I to NRC-99-0072 Page 4 equalizing voltage to be widened from approximately one volt to approximately three volts as shown in the table below:

Division I Battery Charcer Setnoint Chances i

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Description Existing Setpoint New Setpoint j High Voltage Shutdown 138.5 VDC (2.31 V/ cell) 138.5 VDC (2.39 V/ cell) i Equalize Voltage 137.5 VDC (2.29 V/ cell) 135.5 VDC (2.34 V/ cell)

High Voltage Alarm 136.0 VDC (2.27 V/ cell) 134.0 VDC (2.31 V/ cell)

Float Voltage 133.0 VDC (2.22 V/ cell) 129.0 VDC (2.22 V/ cell) 1 Low Voltage Alarm 128.5 VDC (2.14 V/ cell) 124.2 VDC (2.14 V/ cell)

' Discharged Battery is 105 VDC (1.81 V/ cell for Divisions I and Division II) l The existing and the new Division I battery system was sized in accordance with Reference 6. ,

i Reference 6 recommends a design margin of 10 - 15 percent and an aging factor of 1.25 (20 years) to be used in the design of a de system. A design margin of 10 percent and an aging factor ,

of 1.25 (20 years) were used to determine the size of the new battery system. !

This TS amendment is proposing to change: the 7 day and 18 month surveillance requirements

-(TS Sections SR 3.8.4.1 and SR 3.8.4.6) for the battery system terminal voltage on float charge I and the minimum battery charger voltage; and the 92 day surveillance requirement and Bases (TS Section SR 3.8.6.'2 and Bases SR Section 3.8.6.2) for overcharge battery voltage to correspond to the requirements of the replacement batteries. Each requested TS change is defined and described below, corresponding to the changes provided in markup format in Enclosure 3.

1. Channe to Surveillance Requirement 3.8.4.1:

TS Surveillance Requirement 3.8.4.1 states that once per 7 days," Verify battery terminal voltage is 2130 V for Division I and 2125.7 V for Division II on float charge." This surveillance ;

requirement will be changed to state, " Verify battery terminal voltage is 2125.7 V on float I charge." Under normal operating conditions, the battery chargers produce a de output, which

" float" derges the batteries. This new terminal (charging) voltage is acceptable because it is based on the same individual cell voltage as the existing 130 volt,1.215 specific gravity, lead l calcium,60 cell system covered in the present T.S.

Existing: (130 volts) / (60 cells) = 2.167 volts / cell

'New; (2.167 volts / cell) x (58 cell) = 125.7 volts The basis for the battery terminal float voltage ensures the effectiveness of the charging system and the ability of the batteries to perform their intended function. Float charge is the condition in

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Enclosure 1 to NRC-99-0072 Page 5 which the charger is supplying a continuous charge required to overcome internal losses of a battery (or battery cell) and maintain the battery (or a battery cell) in a fully charged state.

2. Channe to Surveillance Reauirement 3.8.4.6:

TS Surveillance Requirement 3.8.4.6 states that once per 18 months, " Verify each required battery charger supplies for Division I: 2100 amps at 2129 V for 2 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months ; and Division II: 2 100 anies at 2124.7 V for 2 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months ." This surveillance requirement will be changed to state,

" Verify each required battery charger supplies 2100 amps at 2124.7 V for 2 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months ." This new battery charger terminal voltage for Division I is acceptable because it is based on the same individual cell voltage as the existing 130 volt,1.215 specific gravity, lead calcium,60 cell system covered in the T.S.

Existing: (129 volts) / (60 cell) = 2.15 volts / cell New: (2.15 volts / cell) x (58 cell) = 124.7 volts 1

The minimum voltage of 124.7 volts (or 2.15 volts / cell), ensures that the battery can be i maintained charged. The minimum voltage of 2.15 volts / cell is greater than the required l continuous minimum cell float voltage of 2.13 volts / cell required by T.S. Table 3.8.6-1.

Therefore, the surveillance requirement of the battery charger supplying this minimum voltage of 124.7 volts (or 2.15 volts / cell) at the chargers rated ampacity is acceptable.

3. Channe to Surveillance Reauirement 3.8.6.2 and Bases:

TS Surveillance Requirement 3.8.6.2 states, " Verify battery cell parameters meet Table 3.8.6-1 Category B limits," once every 92 days "AND once within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after battery overcharge >

150 V for Division I and > 145 V for Division II." This surveillance requirement of verifying individual cells after an overvoltage condition will be changed to state. "AND once within 24 ,

hours after battery overcharge > 145 V." The Bases SR Section 3.8.6.2 also states,"In addition, !

within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of a battery discharge < 105 V or a battery overcharge > 150 V for Division I and l

> 145 V for Division II, the batterj must be demonstrated to meet Category B limits." This section of the Bases will be change.' to state, "In addition, within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of a battery discharge

< 105 V or a battery overcharge > 145 V, the battery must be demonstrated to meet Category B I limits." This new battery terminal overvoltage for Division I is acceptable as it is based on the same individual cell voltage as the existing 130 volt,1.215 specific gravity, lead calcium,60 cell l system covered in the T.S.

Existing: (150 volts) / (60 cell) = 2.5 valts/ cell New: (2.5 volts / cell) x (58 cell) = 145 volts i

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Enclosure 1 to NRC-99-0072 Page 6 i- 4 4 i

l This new overvoltage (or overcharge) value is acceptable as no immediate damage would be seen i by the battery at this level. Overvoltage,if extreme and uncorrected for extended periods, will l cause corrosion on the batteries' positive plates, increase cell temperatures and increase water i consumption. This voltage of 145 volts (or 2.5 volts / cell) is acceptable, as it is slightly greater I then the maximum continuous recommended equalize charge voltage for the new and existing battery of 2.38 volts / cell.

SIGNIFICANT H AZARDS CONSIDERATION:

In accordance with 10CFR50.92, Detroit Edison has made a determination that the proposed !

amendment involves no significant hazards considerations. To make this determination, Detroit l Edison must establish that operation in accordance with the proposed amendment would not: (1) l involve a significant increase in the probability or consequences of an accident previously j evaluated; or (2) create the possibility of a new or different kind of accident from any accident i l previously evaluated; or (3) involve a significant reduction in a margin of safety. The significant hazards consideration assessmeat is presented in Enclosure 2.

ENVIRONMENTAI, IMPACT:

Detroit Edison has reviewed the proposed Technical Specification change against the criteria of l 10CFR51.22 for environmental considerations. The proposed changes do not involve a significant hazards consideration, nor significantly change the types or significantly increase the amounts of effluents that may be released offsite, nor significantly increase individual or cumulative occupational radiation exposures. Based on the foregoing, Detroit Edison concludes that the proposed Technical Specifications do meet the criteria given in 10CFR51.22(c)(9) for a categorical exclusion from an environmental review.

CONCI USION:

Based on the evaluation above: 1) There is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and 2) such activities will be j conducted in compliance with the Commission's regulations and proposed amendments will not i be inimical to the common defense and security or to the health and safety of the public.

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J ENCLOSURE 2 TO I NRC-9S-0072 l FERMI 2 l NRC DOCKET NO 50 341 l OPERATING LICENSE NPF-43 i REQUEST TO REVISE TECHNICAL SPECIFICATIONS FOR THE DIVISION I 130/260 VDC BATTERY REPLACEMENT 10CFR50.92 EVALUATION

l Enclosure 2 to NRC-99-0072 Page 2 HASIS;FOR SIGNIFICANT IIAZARDS DETERMINATION:

The proposed Technical Specification changes described in Enclosure 1 do not involve a significant hazards consideration for the following reasons:

1. The changes do not involve a significant increase in the probability or consequences of an accident previously evaluated.

The proposed changes do not involve a change in the manner in which the plant is operated.

TS Sections 3.8.4.1,3.8.4.6,3.8.6.2 and Bases Surveillance Requirement Section 3.8.6.2 are being revised to reflect the new Division I battery cell / system characteristics and associated requirements. The new battery will have an increased capacity over the present battery, while maintaining the existing battery system voltage requirements. This is possible because the present and new battery specific gravity (1.215) and type (lead calcium) are the same. Also, the end of battery system discharge volage remains the same as 210 VDC. The Division I batteries will continue to furnish power to redundant essential i loads as required and as designed. The new surveillance requirement voltages are based on the same volts / cell criteria used for the existing batteries. Furthermore, failure or malfunction of the station batteries does not initiate any of the analyzed accidents previously evaluated in the UFSAR. The changes described will therefore not involve an i increase in the probability or consequences of an accident previously evaluated. I

2. The changes do not create the possibility of a new or different kind of accident from any accident previously evaluated.

The new battery is Class IE qualified equipment and is being maintained within the same overall design parameters as tre existing battery. That is, the battery terminal voltage on float voltage conditions (2.16~! volt / cell), overvoltage conditions (2.5 volts / cell) and charger ,

capability (2.15 volts / cell) are the same as the original design. Furthermore, the end of j system discharge voltage of the battery system is maintained the same; therefore, there is no l negative impact to plant loads supplied by the batteries. Failures of the batteries and j chargers have been considered in both the existing and modified configurations. The !

proposed changes will not change performance or reliability nor introduce any new or different failure modes or common mode failure and will therefore not create the possibility of a new or different kind of accident from any accident previously evaluated. l

3. The changes do not involve a significant reduction in the margin of safety.

The changes act to increase overall battery capacity from 560 ampere-hours to 1200 ampere-hours with the minimum battery discharge voltage remaining at 210 VDC (or 105 VDC per battery). The battery terminal voltage on float voltage conditions (2.167 volt / cell), overvoltage conditions (2.5 volts / cell) and charger capability (2.15 volts / cell) are the same as the original design. The new surveillance requirement voltages are based on

Enclosure 2 to NRC-99-0072 Page 3 the same volts / cell criteria used for the existing batteries. The batteries' ability to satisfy the design requirements (battery duty cycle) of the de system will not be reduced from original plant design and will therefore not have any negative impact to plant loads the battery supplies. The proposed changes therefore do not involve a teduction in the margin of safety.

NRC-99-0072, Application for Amend to License NPF-43,revising SRs & Bases for Div I Battery Sys to Agree with Design of New Battery Replacement

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