ML20212J948

Application for Amend to License NPF-3,revising Tech Specs 3.8.2.3,4.8.2.3.1,4.8.2.3.2,4.8.2.4.1 & Table 4.8-1 Re Battery Surveillance Requirements.Safety Evaluation Encl

ML20212J948
Person / Time
Site:	Davis Besse
Issue date:	01/21/1987
From:	Willliams J TOLEDO EDISON CO.
To:
Shared Package
ML20212J918	List: ML20212J915 ML20212J948 ML20212J954
References
TAC-64465, NUDOCS 8701280376
Download: ML20212J948 (16)

Text

, DockIt N3. 50-346 License No. NPF-3 Serial No. 1344 Attachment APPLICATION FOR AMENDMENT TO FACILITY OPERATING LICENSE NO. NPF-3 FOR DAVIS-BESSE NUCLEAR POWER STATION UNIT NO. 1 Enclosed a e cequested changes to the Davis-Besse Nuclear Power Station, Unit No. 1, Facility Operating License No. NPF-3. Also included are the Safety Evaluation and Significant Hazards Consideration.

The proposed changes (submitted under cover letter Serial No. 1344) concern:

Section 3/4.8.2, Onsite Fower Distribution Systems, Specification 3.8.2.3; Section 3/4.8.2, Onsite Pover Distribution Systems, Specification 4.8.2.3.1; Section 3/4.8.2, Onsite Power Distribution Systems, Table 4.8-1, Battery Surveillance Requirements; Section 3/4.8.2, Onsite Power Distribution Systems, Specification 4.8.2.3.2; Section 3/4.8.2, Onsite Power Distribution Systems, Specification 4.8.2.4.1; Bases, Section 3/4.8, Electrical Power Systems.

By !jpi k &.

Snior Vice Presiden Nuclear

-Sworn to and subscribed before me this 21st day of January, 1987.

OkLLM $ 01 anfin Notary Public, State of Dhio My commission expires d/f!f/

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DR p, O DR P

, psckrt No. 50-346 License No. NPF-3 Serial No. 1344 Attachment-The following information is provided to support issuance of the requested changes to the Davis-Besse Nuclear Power Station, Unit No. 1, Operating License NPF-3, Specifications 3.8.2.3, 4'.8.2.3.1, 4.8.2.3.2, 4.8.2.4.1 and Bases Section 3/4.8:

A. Time required to implement: This caange is to be effective upon NRC approval.

B. Reason for change (Facility Change Request No.82-029, Revision E):

Revise Technical Specifications for the D.C. Distribution System using the guidance of the model Technical Specification for station batteries as attached to the NRC's letter to Toledo Edison dated July 16, 1981 (Log No. 756).

C. Safety Evaluation: See attached Safety Evaluation.

D. Significant Hazards Consideration: See attached Significant Hazards Consideration.

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., ,Dockst No. 50-346

-License No. NPF-3 Serial No. 1344 Attachment Page-1 SAFETY EVALUATION DESCRIPTION OF THE PROPOSED ACTIVITY V

The purpose of this License Amendment Request is to revise the Davis-Besse Nuclear Power Station, Unit No. 1, Technical Specifications, Appendix A to the Operating License for the D.C. Distribution System using the guidance of the model Technical Specifications for station batteries as attached to the Nuclear Regulatory Commission's (NRC) . letter to Toledo Edison dated July 16, 1981 (Log No. 756).

SYSTEM AFFECTED

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D.C. Distribution System SAFETY FUNCTION OF SYSTEM AFFECTED The safety function of Technical Specifications 3.8.2.3, 4.8.2.3.1,

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4.8.2.3.2, 3.8.2.4, 4.8.2.4.1 and 4.8.2.4.2 is to, 1) specify the minimum

,' functional capability of the D.C. power and distribution system required for. safe operation and shutdown of.the Davis-Besse Nuclear Power Station, Unit No. 1, and, 2) specify Surveillance Requirements for testing and inspecting the D.C. power and distribution system to assure that the necessary quality of the system is maintained and that the Limiting 1 Conditions for Operation are met in all modes of station operation.

The station D.C. equipment consists of four batteries, two 250/125V D.C.

motor control centers (MCC), six battery chargers, four essential -

distribution panels, four 480V A'C./125V D.C. rectifiers, and four non-essential distribution panels. Each of the two redundant 250/125V D.C. motor control centern has a positive, negative and neutral bus. Each live bus is connected to a corresponding 125 volt battery, a normal battery charger source, and a manual standby battery charger.

Four 125V D.C.1500 ampere hour, on eight hours discharge basis, lead-calcium batteries are provided and arranged to form two independent 250/

125V D.C. systems. Each battery is maintained in a fully charged condition and is normally float charged at approximately 130 volts from its associsted battery charger. Battery discharge will occur either when the D.C. requirements temporarily exceed the charger capacity or during a loss of a battery charger supply. Each battery is connected to one 125V D.C. bus _(positive / neutral; neutral / negative) of one of the two D.C.

motor control centers.

Each of the six static, solid-state battery chargers are rated at 480V A.C., 3 phase, 60 Hertz input and has a nominal output of 125V D.C. Each charger is capable of supplying all steady-state D.C. loads required under any conditions of operation while recharging the battery to a fully charged condition over a period of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> from a discharged condition of 105 volts per battery.

pockrt No. 50-346 License No. NPF-3 Serial No. 1344 Attachment Page 2 The safety function of the D.C. distribution system is to provide a continuous, reliable and redundant 250/125V D.C. power source for control, instrumentation and D.C. loads required for normal operation and orderly shutdown and control of the station. The system is arranged to form two completely independent load groups. The D.C. distribution system also supplies many non-1E loads important to the reliable operation of the station. The batteries are sized to supply the antici-pated D.C. and instrument A.C. loads for a period of one hour after the loss of the battery charger supply.

Operable A.C. and D.C. power sources and associated distribution systems during station operation under Technical Specification 3/4.8.2.3 ensure that sufficient power will be available to supply the safety-related equipment required for 1) the safe shutdown of the facility and 2) the nitigation and' control of accident conditions within the station. The minimum specified independent and redundant A.C. and D.C. power sources and distribution systems satisfy the requirements of General Design Criterion 17 of Appendix A to 10 CFR Part 50.

The action requirements specified in the Limiting Condition for Operation for the levels of degradation of the power sources provide restriction upon continued facility operation commensurate with the level of degradation. The operability of the power sources are consistent with the initial condition assumptions of the safety analyses. The assumptions are based upon maintaining at least one redundant set of onsite A.C. and D.C power sources and associated distribution systems operable during accident conditions coincident with an assumed loss of offsite power and single failure of the other onsite A.C. and D.C. source.

, The operability of the minimum specified A.C. and D.C. power sources and

associated distribution systems during shutdown and refueling under Technical Specification 3/4.8.2.4 ensures that 1) the facility can be maintained in the shutdown or refueling condition for extended time periods and 2) sufficient instrumentation and control capability is available for monitoring and maintaining the station status.

EFFECTS ON SAFETY / PROPOSED CHANGES The proposed Surveillance Requirements (as contained within the NRC's model Technical Specification o2 July 16, 1981) for demonstrating the operability of the station batteries are based on the recommendations of Regulatory Guide 1.129, " Maintenance Testing and Replacement of Large Lead Storage Batteries for Nuclear Power Plants", February 1978, and IEEE Standard 450-1980, "IEEE Recommended Practice for Maintenance, Testing, and Replacement of Large Lead Storage Batteries for Generating Stations and Substations". Present Technical Specification Surveillance Require-ments were incorporated into the station's operating license during earlier revisions of these documents.

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, Docket.No. 50-346 License No. NPF-3

' Serial No. 1344 Attachment Page 3

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Several statements of the NRC's model Technical Specification were modified or retained as. presently exists to accommodate Davis-Besse j specific equipment designations and to reflect Davis-Besse specific design. .In the Limiting Condition for Operation (LCO) and Action State-ment of Technical Specification 3.8.2.3, the differences from the model Technical Specification are as follows:

1. The words " disconnect switches" (substituted for the present nomenclature " tie breakers" by this amendment request) were added since the D.C. distribution system utilizes disconnect switches between redundant buses which must'be open to ensure bus train independence. ,

2. "D.C. MCC 1" and "D.C. MCC 2" were retained instead of model Technical Specification nomenclature, "D.C. Bus No. 1" and "D.C.

Bus No. 2" respectively, in order to reflect the Davis-Besse l design.

3. Station batteries "1P and IN" and station batteries, "2P and 2N" were retained instead of using " lead battery bank No. I and lead battery bank No. 2", respectively, to use Davis-Besse

, specific terminology.

4. "Two full capacity chargers" were retained instead of "one full

, capacity charger" since Davis-Besse utilizes two chargers per D.C. MCC.

5. The Technical Specification Action Statement was retained as j divided into two statements addressing the D.C. MCCs and power L sources separately. This provides for a clearer reading of the action requirements.

! The intent of the wording of both the LCO and Action Statement is

• consistent with the wording of the model Technical Specification. In the l Action Statement, the station modes, time constraints and required

actions are consistent with the model Technical Specification.

l In Surveillance Requirement 4.8.2.3.1, the words " disconnect switches" were substituted for " tie breakers" since this is correct terminology for the devices used. Also the words " disconnect switch" and a slash were 1 added in front of breaker alignment. Disconnect switches are utilized in the D.C. distribution system for power isolation whereas breakers are used to isolate the battery chargers from their incoming A.C. lines.

l Battery power availability is indicated via Surveillance Requirement l 4.8.2.3.2a with the appropriate electrical connections verified.

Surveillance Requirement 4.8.2.3.2a has been revised to incorporate the L NRC model Technical Specification wording. This revision transfers the minimum and maximum electrolyte levels, specific gravity and float

! voltage parameter requirements from 4.8.2.3.2a.1, 4.8.2.3.2a.2 and 4.8.2.3.2a.3 to Table 4.8-1, Battery Surveillance Requirements.

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,Dockst;No. 50-34'6 License No. NPF-3 Serial No. 1344 Attachment-Page 4 Table 4.8-1 of the proposed Technical Specification (which uses the guid-ance of the model Technical Specification) specifies the normal limits for each designated pilot cell and each connected cell for electrolyte level, float voltage and specific gravity. The Category A limits for the designated pilot cell's float voltage and specific gravity (greater than or equal to 2.13 volts, and .015 below the manufacturer's full charge specific gravity of.1.215) is characteristic of a charged cell with adequate capacity.

The Category B limits for each connected cell for float voltage and specific gravity (greater than or equal to 2.13 volts, with an average specific gravity of all the connected cells not more than .01 below the full charge specific gravity of 1.215) are the battery manufacturer's recommended limits for these parameters. The Category B limit 'of a specific gravity not more than .02 below the full charge specific gravity of 1.215 for each connected cell allows for some stratification in individual cells. Stratification is due to water addition or slow mixing of the electrolyte after recharging due to very low end charge currents liberating a small amount of gas.

Operation with a battery cell parameter outside the normal limit but within the allowable value specified in Table 4.8-1 would be permitted for up to seven days by the proposed Technical Specification which is consistent with the NRC model Technical Specification. The minimum value for electrolyte level. ensures no physical damage to the plate and an adequate electron transfer capability exists. The maximum allowable value for electrolyte level allows for an increase in level after charging and minimizes maintenance of the battery water level. The allowable value for the average specific gravity of all the cells, not more than .02 below the manufacturer's recommended full charge specific gravity, ensures that the decrease in output will be less than the aging margin provided in sizing. According to the Updated Safety Analysis Report, Section 8.3, the battery with the largest load was used in sizing the capacity and ampere rating of all four batteries. The one-minute rating of this battery included the starting current requirements of the D.C. motors, the diesel generator flashing, the current requirements for operation of 13.8 KV, 4.16 KV and 480V breakers, and all continuous loads. The one-hour duration load included an extra requirement of a two-breaker operation. The plate requirement which satisfies the above load cycle is a battery with a one-hour capacity of 600 ampere hours and a one-minute rating of 1360 amperes which is higher than the required one-minute load of 1244.2 amperes. The station batteries have a one-hour capacity of 750 ampere hours and a one-minute rating of 1600 amperes; this rating includes the approximate 20 percent overcapacity to compensate for the loss due to aging over a 20-year period. According to the battery manufacturer, GNB, a decrease in specific gravity of .010 decreases  ;

battery capacity by 3%. Therefore, a decrease in specific gravity of .020 would results in a 6% decrease in a battery capacity, much less than the originally designed 20% extra capacity.

The allowable value for an individual cell's specific gravity not more than .02 below the average of all connected cells allows for stratifi-

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, Dockst No. 50-346 License No. NPF-3 Serial No. 1344 Attachment Page 5 cation due to water addition or slow mixing of the electrolyte after recharging due to. very low end charge currents liberating a small amount of gas. The allowable value for an individual cell's float voltage greater than 2.07 volts, ensures the battery's capability to perform its design function as stated by the NRC model Technical Specification. Per Appendix C to IEEE Standard 450-1980, a cell voltage of 2.07 volts D.C. or below under float. conditions, not caused by elevated temperature of the cell, indicates internal cell problems and may require cell replacement.

A Surveillance Requirement (proposed Specification 4.8.2.3.2a.2) has been '

added to verify that the total battery terminal voltage is greater than or equal to 129 volts on float charge. This is consistent with the NRC's model Technical Specification. Verifying total battery terminal voltage on t

float charge ensures the effectiveness of the charging system, Surveillance Requirement 4.8.2.3.2b has been revised to incorporate the NRC model Technical Specification wording. This revision transfers the minimum and maximum electrolyte levels, specific gravity and float voltage parameter requirements from 4.8.2.3.2b.1, 4.8.2.3.2b.2 and 4.8.2.3.2b.3 to Table 4.8-1, Battery Surveillance Requirements. Surveil-lance Requirement 4.8.2.3.2b also ensures the operability of the battery after a discharge to 110 volts D.C. or overcharge to 150 volts D.C. A method currently exists to detect an undervoltage (discharge) condition.

A Facility Change Request (FCR) is being generated which will develop a method to detect an overcharge condition.

Surveillance Requirement 4.8.2.3.2b.2 ensures the connection resistance of the battery is sufficiently low ensuring the ability of the battery to handle high discharge rates. The value for connection resistance, less

. than 150 x 10 8 ohms, is the internal connection resistance acceptance

criteria at Davis-Besse.

! In Surveillance Requirement 4.8.2.3.2b.3 the temperature of every sixth connected cell will be taken as a representative number of cells. This battery cell sample will assure that the temperature of cells in different physical locations will be taken. The wording of this Surveillance Requirement is in accordance with IEEE Standard 450-1980 and the NRC's 4

model Technical Specification.

i Surveillance Requirements 4.8.2.3.2c, 4.8.2.3.2d and 4.8.2.3.2e have been revised to be consistent with the NRC's model Technical Specification.

The wording of proposed Surveillance Requirement 4.8.2.3.2c.4 is unchanged from the present Surveillance Requirement. Since the battery is float charged at 132.5V . 5V D.C., a minimum of 130V D.C. is a more station specific criteria for charger output voltage. Also, 475 amps output current satisfies USAR Section 8.3.2.1.3 requirements for battery chargers which states "Each charger is capable of supplying all steady state D.C. loads required under any conditions of operation while n w-y- .

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. Dockst No. 50-346 License No. NPF-3 Serial No. 1344 Attachment Page 6 recharging the battery to a fully charged condition over a period of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> from a discharged condition of 105 volts per battery". This battery charger output current -requirement is more conservative than the 400 amps required by the model Technical Specification. j A Surveillance Requirement (proposed Specification 4.8.2.3.2f) has been added, consistent with the model Technical Specification, to require a performance discharge test of battery capacity be given to any battery showing signs of degradation or having reached 85 percent of the service life. .The periodicity of the test has been changed from " Annual" to "Every 18 months, during shutdown". Performance of this test requires that the battery and battery charger be isolated from the D.C. system.

To accomplish the test at any time other than during a normal plant shutdown would place the plant in a Limiting Condition for Operation per proposed Technical Specification 3.8.2.3. This would result in an unscheduled plant shutdown.and unnecessarily restrict plant availability without a significant increase in plant safety.

Surveillance Requirement 4.8.2.4.1 for Modes 5 and 6 was reworded to be consistent with the intent of Surveillance Requirement.4.8.2.3.1.

The words " disconnect switch /" were added before " breaker alignment" to l correctly identify these D.C. devices utilized for power interruption.

Also, the words "from the charger and battery, and voltage on the bus of greater than or equal to 125 volts D.C." were added to ensure power avail-ability from either source and to ensure nominal voltage on the bus.

Technical Specification Bases Section 3/4.8, Electrical Power Systems, has been revised to reflect the changes to Technical Specification 3/4.8.2.3.

In addition, three typographical errors have been corrected.

UNREVIEWED SAFETY QUESTION EVALUATION The implementation of these proposed changes would not:

1. Increase the probability of occurrence of an accident previously evaluated in the USAR because the accident conditions and assumptions are not affected by the proposed Technical Specification changes.

The proposed Technical Specifications continue to meet the safety function of the LCO and Surveillance Requirements (10CFR50.59(2)(i)).

2. Increase the consequences of an accident previously evaluated in the USAR because the accident conditions and assumptions are not affected by the proposed Technical Specification changes. The proposed Technical Specifications continue to meet the safety function of the LCO and Surveillance Requirements (10CFR50.59(2)(i)).

3. Increase the probability of a malfunction of equipment important to safety because the accident conditions and assumptions are not affected by the proposed Technical Specification changes. The proposed Technical Specifications continue to meet the safety function of the LCO and Surveillance Requirements (10CFR50.59(2)(ii)).

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pockst No.;50-346

, License No..NPF-3

- Serial No.,1344 Attachment i Page 7

4. Increase the consequences of a malfunction of equipment important to safety because the accident conditions and assumptions are not

affected by the proposed Technical Specification changes. The 4

proposed Technical Specifications continue to meet the safety '

, function of the LCO and Surveillance Requirements (,10CFR50.59(2)(ii)).

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5. Create a possibility for an accident of.a different type than any evaluated previously in the USAR because no station equipment is modified by these changes and the station batterie and distribution L system will continue to be tested and inspected to ensure its opera-bility.(10CFR50.59(2)(ii)).

- 6. Create a possibility for a malfunction of equipmeat of a different i

type than any evaluated previously in the USAR be cause no station equipment is modified by these changes and the station batteries and i distribution system will continue to be tested aad inspected to ensure its operability (10CFR50.59(2)(ii)).

7. Reduce any margin' of safety as defined in the basis for these

Technical Specifications because the operability of the A.C. and

D.C. power sources and associated distribution systems will continue to be demonstrated to ensure sufficient power 1s available to supply the safety-related equipment required for 1) the safe shutdown of

. the station, 2) the mitigation and control of accident conditions 4 within the station, 3) the maintaining of the station in the i shutdown or refueling condition for extended periods of time and

4) instrumentation and control capability for monitoring and ,

maintaining the station's status (10CFR50.59(2)(iii)).

CONCLUSION i

p Based on the above evaluation, it is determined that this revision does 3

not involve an unreviewed safety question.

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. 'Dockst Ns. 50-346 License No. NPF-3

-Serial No. 1344 Attachment Page.8 SIGNIFICANT HAZARDS CONSIDERATION '

l DESCRIPTION OF THE PROPOSED ACTIVITY The purpose of this License Amendment Request is to revise the Davis-Besse Nuclear Power Station, Unit No. 1, Technical Specifications, Appendix A to the Operating License for the D.C. Distribution System using the guidance of the model Technical Specifications for station batteries as attached to the Nuclear Regulatory Commission's (NRC) letter to Toledo Edison dated July 16, 1981 (Log No. 756).

SYSTEM AFFECTED D.C. Distribution System SAFETY FUNCTION OF SYSTEM AFFECTED ,

The safety function of Technical Specifications 3.8.2.3, 4.8.2.3.1, 4.8.2.3.2, 3.8.2.4, 4.8.2.4.1 and 4.8.2.4.2 is to, 1) specify the minimum functional capability of.the D.C. power and distribution system required for safe operation and shutdown of the Davis-Besse Nuclear Power Station, Unit No. 1, and, 2) specify Surveillance Requirements for testing and inspecting the D.C. power and distribution system to assure that the necessary quality of the system is maintained and that the Limiting Conditions for Operation are met in all modes of ctation operation.

The station D.C. equipment consists of four batteries, two 250/125V D.C.

motor. control centers (MCC), six battery chargers, four essential distribution panels, four 480V A.C./125V D.C. rectifiers, and four non-essential distribution panels. Each of the two redundant 250/125V D.C. motor control centers has a positive, negative and neutral bus. Each live bus is connected to a corresponding 125 volt battery, a normal battery charger source, and a manual standby battery charger.

Four 125V D.C. 1500 ampere hour, on eight hours discharge basis, lead calcium batteries are provided and arranged to form two independent 250/

125V D.C. systems. Each battery is maintained in a fully charged condition and is normally float charged at approximately 130 volts from its associated battery charger. Battery discharge will occur either when the D.C. requirements temporarily exceed the charger capacity or during a ,

loss of a battery charger supply. Each battery is connected to one 125V D.C. bus (positive / neutral; neutral / negative) of one of the two D.C.

motor control centers.

Each of the six static, solid-state battery chargers are rated at 480V A.C., 3 phase, 60 Hertz input and has a nominal output of 125V D.C. Each charger is capable of supplying all steady-state D.C. loads required under any condition of operation while recharging the battery to a fully charged condition over a period of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> from a discharged condition of 105 volts per battery.

pockat_No. 50-346 License No. NPF-3 Serial No. 1344 Attachment Page 9 The safety function of the D.C. distribution system is to provide a continuous,_ reliable and redundant 250/125V D.C. power source for control, instrumentation and D.C. loads required for normal operation and orderly shutdown and cuntrol of the station. The system is arranged to

- form two completely independent load groups. The D.C. distribution system also supplies many non-1E loads important to the reliable operation of the station. The batteries are sized to supply the antici-pated D.C. and instrument A.C. loads for a period of one hour after the loss of the battery charger supply.

Operable A.C. and D.C. power sources and associated distribution systems during station operation under Technical Specification 3/4.8.2.3 ensure that sufficient power will be available to supply the safety-related equipment required for 1) the safe shutdown of the facility and 2) the mitigation and control of accident conditions within the station. The minimum specified independent and redundant A.C. and D.C. power sources and distribution systems satisfy the requirements of General Design Criterion 17 of Appendix A to 10 CFR Part 50.

The action requirements specified in the Limiting Condition for Operation for the levels of degradation of the power sources provide restriction upon continued facility operation commensurate with the level of degradation. The operability of the power sources are consistent with the initial condition assumptions of the safety analyses. The ,

assumptions are based upon maintaining at least one redundant set of onsite A.C. and D.C pcwer sources and associated distribution systems operable during accident conditions coincident with an assumed loss of offsite power and single failure of the other onsite A.C. and D.C. source.

The operability of the minimum specified A.C. and D.C. power sources and associated distribution systems during shutdown and refueling under Technical Specification 3/4.8.2.4 ensures that 1) the facility can be i maintained in the shutdown or refueling condition for extended time periods and 2) sufficient instrumentation and control capability is available for monitoring and maintaining the station status.

EFFECTS ON SAFETY / PROPOSED CHANGES l The proposed Surveillance Requirements (as contained within the NRC's model Technical Specification of July 16, 1981) for demonstrating the operability of the station batteries are based on the recommendations of Regulatory Guide 1.129, " Maintenance Testiag and Replacement of Large Lead Storage Batteries for Nuclear Power Plants", February 1978, and IEEE

-Standard 450-1980, "IEEE Recommended Practice for Maintenance, Testing, L and Replacement of Large Lead Storage Batteries for Generating Stations

! and Substations". Present Technical Specification Surveillance Require-l ments were incorporated into the station's operating license during earlier revisions of these documents.

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. Docket.No. 50-346 License No. NPF-3

' Serial No. 1344-Attachment-Page 10 Several statements of the NRC's model Technical Specification were modified or retained as presently exists to accommodate Davis-Besse specific equipment designations and to reflect Davis-Besse specific design.- In the Limiting Condition for Operation (LCO) and Action State-ment of Technical Specification 3.8.2.3, the differences from the model Technical Specification are as follows: ,

1. Thewords"disconnectswitches"(sub[titutedforthepresent nomenclature." tie breakers" by this amendment request) were added since the D.C. distribution system' utilizes disconnect switches between redundant buses which must be open to ensure bus train independence. jij

2. "D.C. MCC 1" and "D.C. MCC 2" ware retained instead of model Technical Specification nomenclature, "D.C. Bus No. I'_' and "D.C .

Bus No. 2" respectively, in order to reflect the Davis-Besse design.

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3. Station batteries "1P and IN" and station batteries, "2P and 2N" were retained instead of using " lead battery bank No. I and lead-battery bank No. 2", respectively, to use Davis-Besse specific terminology.

. 4. "Two full capacity chargers" were' retained instead of "one full capacity charger" since Davis-Besse utilizes two chargers per '

D.C. MCC.

5. The Technical Specification Action Statement was retained as

-divided into two statements addressing the D.C. MCCs and power sources separately. This provides for a clearer reading of the action requirements.

The intent of the wording of both the LCO and Action Statement is consistent with the wording of the model Technical Specificatisn. In the Action Statement, the station modes, time constraints and required actions are consistent with the model Technical Specification.

In Surveillance Requirement 4.8.2.3.1, the words " disconnect switches" were substituted for " tie breakers" since this is correct terminology for I- the devices used. Also the words " disconnect switch" and a slash were added in' front of breaker alignment. Disconnect switches are utilized in the D.C. distribution system for power isolation whereas breakers are used to isolate the battery chargers from their incoming A.C. lines.

Battery power availability is indicated via Surveillance Requirement 4.8.2.3.2a with the appropriate electrical connections verified.

Surveillance Requirement 4.8.2.3.2a has been revised to incorporate the NRC model Technical Specification wording. This revision transfers the minimum and maximum electrolyte levels, specific gravity and float voltage parameter requirements from 4.8.2.3.2a.1, 4.8.2.3.2a.2 and 4.8.2.3.2a.3 to Table 4.8-1, Battery Surveillance Requirements.

pockat No. 50-346 License No. NPF-3 Serial No. 1344 Attachment Page 11 Table 4.8-1 of the proposed Technical Specification (which uses the guid-ance of the model Technical Specification) specifies the normal limits for each designated pilot cell and each connected cell for electrolyte level, float voltage and specific gravity. The Category A limits for the designated pilot cell's float voltage and specific gravity (greater than orl equal to 2.13. volts, and .015 below the manufacturer's full charge specific' gravity of 1.215) is charactaristic of a charged cell with ade-quate capacity. The Category B limits for each connected cell for float voltage and specific gravity- (greater than or equal to 2.13 volts, with an average specific gravity of all the connected cells not more than .01 below the full charge specific-gravity of 1.215) are the battery manufac-turer's recommended _ limits-for these parameters. The. Category B limit of

-a specific gravity not more than .02 below the full charge specific gravity of 1.215 for each connected cell allows for some stratification in individual cells. Stratification is due to water addition or slow mixing of the electrolyte after recharging.due to very low end charge currents liberating a-small amount of gas.

Operation with a battery cell parameter outside the normal limit but within the allowable value specified in Table 4.8-1 would be permitted for up_to seven days by the proposed Technical Specification which is consistent with the NRC model Technical Specification. The minimum value for electrolyte level. ensures no physical damage to the plate and an adequate electron transfer capability exists. The maximum allowable value _ for electrolyte level allows for an increase in level after charging and minimizes maintenance of the battery water level. The allowable value for the average specific gravity of all the cells, not more than .02 below the manufacturer's recommended full charge specific gravity, ensures that the decrease in output will be less than the aging margin provided in sizing. According to the Updated Safety Analysis Report, Section 8.3, the battery with the largest load was used in sizing the capacity and ampere rating of all four batteries. The one-minute rating of this battery included the starting current requirements of the D.C.' motors, the diesel generator flashing, the current requirements for operation of 13.8 KV, 4.16 KV and 480V breakers, and all continuous loads. The one-hour duration load included an extra requirement of a two-breaker operation. The plate requirement which satisfies the above load cycle is a battery with a one-hour capacity of 600 ampere hours and a one-minute rating of 1360 amperes which is higher than the required one-minute load of 1244.2 amperes. The station batteries have a one-hour capacity of 750 ampere hours and a one-minute rating of 1600 amperes; this rating includes the approximate 20 percent ovarcapacity to compensate for the loss due to aging over a 20 year period. According to the battery manufacturer, GNB, a decrease in specific gravity of .010 decreases battery capacity by 3%. Therefore, a decrease in specific gravity of .020 would results in a 6% decrease in a battery capacity, much less than the originally designed 20% extra capacity.

pock;t Na. 50-346 License No. NPF-3 Serial No. 1344 Attachment Page 12 The allowable value for an individual cell's specific gravity not more than .02 below the average of all connected cells allows for stratifi-cation due to water addition or slow mixing of the electrolyte after recharging due to very low end charge currents liberating a small amount of gas. The allawable value for an individual cell's float voltage greater than 2.07 volts, ensures the battery's capability to perform its design function as stated by the NRC model Technical Specification. Per Appendix C to IEEE Standard 450-1980, a cell voltage of 2.07 volts D.C. or below under float conditions, not caused by elevated temperature of the cell, indicates internal cell problems and may require cell replacement.

A Surveillance Requirement (proposed Specification 4.8.2.3.2a.2) has been added to verify that the total battery terminal voltage is greater than or equal to 129 volts on float charge. This is consistent with the NRC's model Technical Specification. Verifying total battery terminal voltage on float charge ensures the effectiveness of the charging system.

Surveillance Requirement 4.8.2.3.2b has been revised to incorporate the NRC model Technical Specification wording. This revision transfers the minimum and maximum electrolyte levels, specific gravity and float voltage parameter requirements from 4.8.2.3.2b.1, 4.8.2.3.2b.2 and 4.8.2.3.2b.3 to Table 4.8-1, Battery Surveillance Requirements. Surveil-lance Requirement 4.8.2.3.2b also ensures the operability of the battery after a discharge to 110 volts D.C. or overcharge to 150 volts D.C. A

.nethod currently exists to detect an undervoltage (discharge) condition.

A Facility Change Request (FCR) is being generated which will develop a n'ethod to detect an overcharge condition.

Surveillance Requirement 4.8.2.3.2b.2 ensures the connection resistance of the battery is sufficiently low ensuring the ability of the battery to handle high discharge rates. The value for connection resistance, less than 150 x 10~8 ohms, is the internal connection resistance acceptance criteria at Davis-Besse.

In Surveillance Requirement 4.8.2.3.2b.3 the temperature of every sixth connected cell will be taken as a representative number of cells. This battery cell sample will assure that the temperature of cells in different physical locations will be taken. The wording of this Surveillance Requirement is in accordance with IEEE Standard 450-1980 and the NRC's model Technical S I acification.

Surveillance Requirements 4.8.2.3.2c, 4.8.2.3.2d and 4.8.2.3.2e have been revised to be consistent with the NRC's model Technical Specification.

The wording of proposed Surveillance Requirement 4.8.2.3.2c.4 is unchanged from the present Surveillance Requirement. Since the battery is float charged at 132.5V .5V D.C., a minimum of 130V D.C. is a more station specific criteria for charger output voltage. Also, 475 amps

, :JDocket Ns. 50-346 License No. NPF-3 Serial No. 1344 Attachment Page 13 output current satisfies USAR Section 8.3.2.1.3 requirements for battery chargers which states "Each charger is capable of supplying all steady state D.C. loads required under any conditions of operation while recharging the battery to a fully charged condition over a period of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> from a discharged condition of 105 volts per. battery". This battery charger output current requirement is more conservative than the 400 amps required by the mcdel Technical Specification.

- A Surveillance Requirement -(proposed Specification 4.8.2.3.2f) has been added, consistent with the model Technical Specification,'to require a performance discharge test of battery capacity be given to any battery showing signs of degradation or having reached 85 percent of the service life. The periodicity of the test has been changed from " Annual" to "Every 18 months, during shutdoun". Performance of this test requires that the battery and battery charger be isolated from the D.C. system.

To accomplish the test at any time other than during a normal plant shutdown would place the plant in a Limiting Condition for Operation per proposed Technical Specification 3.8.2.3. This would result in an unscheduled plant shutdown and unnecessarily restrict plant availability without a significant increase in plant safety.

Surveillance Requirement 4.8.2.4.1 for Modes 5 and 6 was reworded to be consistent with the intent of Surveillance Requirement 4.8.2.3.1. The words

" disconnect switch /" were added before " breaker alignment" to correctly identify these D.C. devices utilized for power interruption. Also, the words "from the charger and battery, and voltage on the bus of 6reater than or equal to 125 volts D.C." were added to ensure power availability from either source and to ensure nominal voltage on the bus.

Technical Specification Bases Section 3/4.8, Electrical Power Systems, has been revised to reflect the changes to Technical Specification 3/4.8.2.3.

In addition, three typographical errors have been corrected.

SIGNIFICANT HAZARDS CONSIDERATION EVALUATION The proposed changes do not involve a significant hazards condideration because the operation of the Davis-Besse Nuclear Power Station, Unit No. 1, in accordance with these changes would not:

1. Involve a significant increase in the probability or consequences of an accident previously evaluated (10CFR50.92(c)(1)).

The accident conditions and assumptions are not affected by the proposed Technical Specification changes. The proposed Technical Specifications continue to meet the safety function of the Limiting Condition for Operation and Surveillance Requirements.

2. Create the possibility of a new or different kind of accident from any previously analyzed (10CFR50.92(c)(2)).

Dockst No. 50-346 License No. NPF-3 Serial No.' 1344 Attachment Page 14 No. station equipment is modified by these changes and the station batteries and distribution system will continue to be tested and inspected to ensure the operability. Thcrefore, no new or different kind of accident from any previously analyzed is created.

3. Involve a significant reduction in the margin of safety (10CFR 50.92(c)(3)).

The operability of the A.C. and D.C. power sources and associated distribution systems will continue to be demonstrated to ensure sufficient power is available to supply the safety-related equipment required for 1) the safe shutdown of the station, 2) the mitigation and control of accident conditions within the station, 3) the maintaining of the station in the shutdown or refueling condition for extended periods of time and 4) instrumentation and control capability for monitoring and maintaining the station's status.

Therefore, there is no significant reduction in the margin of safety.

On the basis of the above, Toledo Edison has determined that the amendment request does not involve a significant hazards consideration.

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