HL-1854, Forwards Response to Generic Ltr 91-06, Resolution of Generic Issue A-30, 'Adequacy of Safety-Related DC Power Supplies.'

Forwards Response to Generic Ltr 91-06, Resolution of Generic Issue A-30, 'Adequacy of Safety-Related DC Power Supplies.'

ML20085G147
Person / Time
Site:	Hatch
Issue date:	10/18/1991
From:	Beckham J GEORGIA POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-GTECI-030, REF-GTECI-NI, TASK-A-30, TASK-OR GL-91-06, GL-91-6, HL-1854, NUDOCS 9110240142
Download: ML20085G147 (22)

Text

.

C.eorpa iher Company

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. Mrt lngham Atattama W" haophone M6 07177/9 m

J. T, Bec kham, Jr. 30 0 OE V!ce Prescer.t-Nxier * '

Hath hv;ect HL-1854 002237 October 18, 1991 U. S. Nuclear Regulatory Commission AlTN: Document Control Desk Washington, D. C. 20555 PLANT HATCH - UNITS 1 AND 2 NRC DOCKET NOS. 50-321 AND 50-366 OPERATING LICENSE N05. DPR-57 AND NPF-5 RESPONSE TO GENERIC LETTER 91-06 Gentlemen:

The information requested by Generic letter 91-06, Resolution of Generic Issue A-30, " Adequacy of Safety-Related DC Power Supplies,"

Pursuant to 10 CFR 50.54(f), for Plant Hatch Units 1 and 2 is provided in the closures to this letter.

Mr. J. T. Beckham, Jr. states that he is Vice President of Georgia Power Company and is authorized to execute this oath on behalf of Georgia Power Company, and to the best of his knowledge and belief, the facts set forth in this letter and the enclosures are true.

GEORGIA POWER COMPANY

/1 f By: Y #/l<---/7 s

Mp

/J.T.Beckham,Jpf 3 Sworn to and subscribed before me this 18 tiday of behhtu 1991.

b) U utN flotary Public /

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mcan mama 10.1m JKB/KWW/cr

Enclosure:

Information Requested in Generic Letter 91-06 cc: (See next page.)

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Georgia Powerkh V. S. Nuclear Regulatory Commission October 18, 1991 Page Two cc: Georoia Power Company Mr. H. L. Sumner, General Manager - Plant Hatch NORMS U. S. Nuclear Reaulatory Commission. Washinatt n D. C.

Mr. K. Jabbour, Licensing Project Manager - Hatch U. S. Nuclear heaulatory Commission. Reaion Il Mr. S. D. Ebneter, Regional Administrator Mr. L. D. Wert, Senior Resident inspector - Hatch State of Georaia Mr. J. D. Tanner, Commissioner - Department of Natural Resources nwns .

4 i

ENCLOSURE 1 INFORMATION RE0 VESTED IN GENERIC LETTER 91-06 PLANT HATCH. UNIT 1 Question 1:

Unit?

Response

Unit 1.

Question 2:

A. The number of independent redundant divisions of Class IE or safety-related - DC power for this plant is (include any separate Class- IE or safety-related DC, such as any DC dedicated to the diesel generators.)

B. The number of - functional safety-related divisions of DC power necessary to attain safe shutdown for.this unit is.

Response

A. Two. Each division has one 125/250 V Station Service Battery (IA or 18) and -one 125 V Diesel. Generator Battery (lA or 10).

Additionally,_ there is an independent 125 V Diesel Generator i Battery (18) for " swing" Diesel Generator IB which is shared between Hatch Units 1 and 2. [ Note: Alarms and Indicators for Diesel. Generator Battery IB are duplicated in both control rooms.]

B. One.

Question 3:

Does the control room at this unit have the following separate, independently annunciated alarms and indications for each division of DC powor?

A. Alarms

1. Battery disconnect or circuit breaker open? ,

2. Battery charger disconnect or circuit breaker open (both input AC and output DC)?

3. DC system ground?

l 1

002237 HL-1854 El-1

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_ _N k _ _

a a ENCLOSURE lIL(CONTINUED)

' I'NFORMATION REQUESTED IN GENERICcLETTER 91-06 PLANT HATCH. UM11_1

4. LDC'busfundervoltage?

5.100 bus overvoltage?

6. Batteryfcharger_ failure?

7. Battery discharge?

18. Indications >

1. Batteryf float' charge current?

2. Battery; circuit output current?-

3.- Battery discharge?

4. Bus = voltage?

-C. .Does -the~ unit have: written procedures for_ response to the above alarms and indications?

- Response:

A; -Alarms fl. :Yes.

2. c AC -- Yes .

~DC :No. -

3a Yes.

L4. Ye s '.

~5.. No.

-6..=Yes.

7. No.

1B; LIndications:

1. Station Service Batteries - Yes.

Diesel 1 Generator Batteries - No.

002237 HL-1854- El-2 1

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4 ENCLOSURE I (CONTINVED)

INFORMATION RE0 VESTED IN GINERIC LETTER 91-06 PLANT HATCH. UNIT 1

2. Station Service Batteries - Yes.

Diesel Generator Batteries - No.

3. Yes.

4. Yes.

C. Yes.

Question 4:

Does this unit have indication of bypassed and inoperable status of circuit breakers or other devices that can be used to disconnect the battery charger from its DC bus and the battery charger from its AC power source during maintenance or testing?

Respon.se:

No.

Question 5:

If the answer to any part of question 3 or 4 is no, then provide information justifying the existing design features of the facility's safety-related DC systems.

Response

Explanation and Justification Relative to Questions 3 and 4

-A "yes" response to an alarm (3.A) indicates that there is a separate, independently-annunciated alarm for the specific function in question. It does not mean that the specific function has a dedicated annunciator window. Several alarm signals may be transmitted to a single annunciator window. As an example, an alarm could be received'on Alarm Panel 651-1 indicating that one of the battery chargers had malfunctioned due to any of the following conditions:

1. Low DC output voltage as sensed by the LVR relay internal to the affected charger.

2. Blown fuse as sensed by PLR-2 relay internal to the affected charger.

3. Loss of AC supply voltage as sensed by PLR-1 relay internal to the affected charger.

002237 HL-1854 El-3

ENCLOSURE I (CONTINUED)

INFORMATION RE0MESTED IN GENERIC LETTER 91-06 PLANT HATCH. UNIT 1 This annunciator would alert the operator to a problem associated with one of the battery chargers. The specific problem would then be ascertained and corrected in accordance with the appropriate annunciator response procedure. Since the functions are alarmed in the control room and any of the conditions that cause 'he annunciator to activate would be investigated and correctv + is believed that the functions are adequately monitored, a- "o 'd annunciator window for each alarm function is not necessar.

Question 3.A.2 - There is u - slarm that would be initiated if one. of the battery charc . J ircuit breakers should open.

However, each battery cha w a an alarm if a DC system ground was detected or low DC ; wed. The low voltage alarm

-is at a setpoint which would indi:. 4 tharger had been lost. The annunciator response procedures would idL . f y the operator actions that should be taken to locate the specific alana condition. The procedures specify various voltmeters and ammeters both in the control room and locally mounted that- may be used to assess the problem and initiate corrective action. The use of such detailed procedures along with available indications support the adequacy of the Hatch DC electrical system design.

Question 3.A.5 - There are no alarms which will. alert the operators to an overvoltage -condition on the DC systems. However, there are operator rounds procedures which. require that battery charger voltage and current readings be taken each shift. It is expected that any overvoltage condition would be detected and corrected in a timely manner. The currently installed battery chargers are scheduled to be replaced during the Fall 1991 outage. In conjunction with the charger replacement, a DC bus overvoltage alarm will be provided.

Question 3. A.7 - There are no alarms that specifically annunciate that a battery is being discharged. However, the DC undervoltage alarms would effectively perform the same function since the setpnints are at a value which would cause an alanr should the battery be the source of power for the DC system. Additionally, daily rounds procedures would also identify battery charger ficat voltage at less than optimum values. Minimal battery discharge is expected during the period betwun rounds if the DC system voltage is between the normal float voltage and the alarm setpoint.

The new battery chargers have a low DC output current alarm that provides an-_ indirect indication of battery discharge. This alarm will provide local annunciation (at the chargers) when output current falls substantially below the minimum required under normal plant loading conditions. Daily rounds will identify the status of this alarm. Minimal battery discharge is expected during the period between rounds.

002237 HL-1854 El-4

s ENCLOSURE I (CONTINUED)

INFORMATION RE0 VESTED IN GENERIC LETTER 91-06 PLANT HATCH. UNIT 1 The absence of.a' battery discharge alarm does not have an adverse affect on _ safety due to the daily _ rounds procedures, undervoltage alarm

-setpoints, and the available control room annunciation.

Question 3.B.1 - There are no ammeters in the control room that can read the diesel generator batteries float current. However, the low voltage and _ battery charger malfunction alarms would indicate a discharging battery;--the fuse trouble alarm would indicate a disconnected battery; and the daily: rounds procedures would indicate abnormal charging conditions.

Additionally, battery charging current is specifically checked once a week per battery surveillance procedures. The absence of ammeters in the control room,is not considered'to represent a significant problem adverse to safety lin~ light of the undervoltage alarm setpoints, the rounds procedures, and the available control room indication. ,

Question 3.B.2 - There are no ammeters in the control room that can read the = diesel generator: batteries output current. However, the low voltage-

and battery -charger malfunction alares would indicate a discharging battery;1the fuse trouble alarm would indicate a disconnected battery; and the . daily rounds procedures would-indicate abnormal charging conditions.

Additionally, battery charging-current-is specifically checked once a week -

per:_ battery surveillance procedures _. The. absence of ammeters in the control : room is not considered to represent _a significant problem adverse tou cafety in -light :of the undervoltage alarm setpoints, :the rounds procedures, and -the available control room . indication.

Question 4 : _No direct indications of. bypassed :or inoperable status exist in= the control? room for:the circuit breakers which disconnect the battery chargers from the associated' buses-(both AC and 00). However, an open DC breaker would be annunciated _ by the low DC voltage alarms which are set at a leveliindicitive of a loss of a charger, and an:open AC breaker would be:

annunciated by the loss of AC input / charger failure alarm. While there are no_ direct indications of bypassed or inoperable fuses which initiate disconnected circuit-breaker alarms, a blown or removed fuse would initiate an alarm in the control room.

Question 6:

-- (1) L Have you conducted a review of maintenance and testing activities to e minimize the' potential for human error causing more than one DC division L -to be unavailable?-and (2) Do plant procedures prohibit maintenance or l testing on redundant DC divisions at the same time?

n

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l.

L 002237 L HL-1854 El-5 L

L

ENCLOSURE I (CONTINUED)

INFORMATION RE0 ESTED IN GENERIC _ LETTER 91-06 PLANT HATCH. UNIT 1

Response

(1) Yes.

(2) No. -However, the Unit 1 Technical Specifications, section 3.9.8 requires both trains of DC power to be operable. If either train is made or found inoperable, an orderly shutdown is initiated with a-cold shutdown condition achieved within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Question 7:

Are maintenance, surveillance and test procedures regarding station batteries conducted routinely at this plant? Specifically:

A. At least onco per 7 days are the following verified to be within acceptable limits:

1. Pilot cell electrolyte level?

2. Specific gravity or charging current?

3.- Float voltage?

4. Total bus voltage on float charge?

5. Physical condition of all cells?

B. At least once 3er 92 days, or within 7 days after a battery discharge, overclarge, or if the pilot cell readings are outside the 7-day surveillance requirements are the following verified to be within acceptable limits:

1. Electrolyte level of each cell?

2. The average specific gravity of all cells?

3. The specific gravity of each cell?

4. The average electrolyte temperature of a representative number of cells?

5. The float voltage of each cell?

6. Visually inspect or mea are resistance of terminals and connectors (including the connectors at the DC bus)?

002237 HL-1854 El-6

t .

ENCLOSURE I (CONTINUED)

INFORMATION RE0 VESTED IN GENERIC LETTER 91-06 PLANT HATCH. UNIT 1 C. At least every la months are the following verified:

1. Low resistance o+ h connection (by test)?

2. Physical condition of the battery?

3. Battery charger capability to deliver rated ampere output to the DC bus?

4. The capability of the battery to deliver its design duty cycle to the DC bus?

5. Each individual cell voltage is within acceptable limits during the service test?

D. At least every 60 months, is capacity of each battery verified by performance of a discharge test?

E. At least annually, is battery capacity verified by performance discharge test, if the battery shows signs of degradation or has reached 85% of the expected service life?

Response

A. Seven-day frequency:

1. Yes.

2. Yes.

3. Yes.

4. Yes.

5. Yes.

B. Ninety-two day frequency:

1. Yes.

2. No.

3. Yes.

002237 HL-1854 El-7

ENCLOSURE I (CONTINUED)

INFORMATION REQUESTED IN GENERIC LETTER 91-06 ELANT HATCH. UNIT 1

4. No.

5. Yes.

6. No.

C. Eighteen-month frequency:

1. Yes.

2. Yes.

3. Yes.

4. Yes.

5. Yes.

D. Sixty-month frequency:

Yes.

E. Annual frequency upon identification of degraded condition:

Yes.

. Question 8:

Does this plant have operational features such that following loss of one safety-related DC power supply or bus:

A. Capability is maintained for ensuring continued and adequate reactor cooling?

B. Reactor coolant system integrity and isolation capability are maintained?

C. Operating procedures, instrumentation (including indicators and annunciators), and control functions are adequate to initiate systems as required to maintain adequate core cooling?

Response

A. Yes. Redundancy of batteries assures the ability to comply with this requirement. Each of the two divisions has the necessary equipment to assure adequate reactor cooling.

002237 .

HL-1854 El-8 l

L .

4 ENCLOSURE I (CONTINUED)

INFORMATION RE0 VESTED IN GENERIC LETTER 91-06 PLANT HATCH. UNIT 1 B. Yes. Redundancy of batteries assures the ability to comply with this requirement. Either of the DC divisions is capable of providing DC power for the necessary isolation functions.

C. Yes. Symptom-oriented emergency operating proceaures address the contingencies for coping with various failures including the loss of a battery. Redundancy of the batteries assures that adequate equipment will be available for the operator's use.

Question 9:

If the answer to any part of question 6, 7, or 8 is no, then provide your basis for not performing the maintenance, surveillance and test procedures described and/or the bases for not including the operational features cited.

Response

Question 6 - Plant procedures do not specifically prohibit maintenance and testing on redundant divisions. However, prior to the performance of any work on the batteries, the Shift Supervisor must be notified and would prevent any activity which would cause both divisions of batteries to be inoperable at the same time. Plant Technical Specifications do not permit both divisions of DC power to be out of service at the same time for maintenance and testing or for any other reason when operating at power.

During plant shutdown conditions only one divisioa is required to be in service.

Question 7.B.2 - The average specific gravity of the battery cells is currently calculated on an 18-month frequency. The calculation of the average specific gravity is not considered to be a significant parameter for Hatch Unit I since the comparisons are made against the minimum required values.

Question _ 7.B.4 - Currently, representative temperatures are used on an 18-month frequency for determining specific gravity corrections.

While not required for regulatory compliance, applicable procedures will be revised, based on good engineering practices, to assure that representative battery electrolyte tenperatures are taken at a frequency consistent with the Technical Specifications surveillance for measuring the specific gravity (i.e., monthly).

002237 HL-1854 El-9

h 9

4 2

ENCLOSURE I (CONTINUED)

INFORMATION REQUESTED IN GENERIC LETTER 91-06 PLANT HATCH. UNIT 1 Question 7.B.6 - The connectors at the DC bus are not currently inspected during the monthly battery surveillance. While not required for regulatory compliance, applicable procedures will be revised, based on good engineering practices, to include this inspection. Monthly visual inspections of the connectors at the battery fuses and the DC switchgear will be required. In addition, visual and resistance checks are performed for all battery cell connectors during each refueling outage. The DC switchgear is also inspected during the 5-year preventive maintenance inspection.

002237 HL-1854 El-10

~

ENCLOSURE 2 INFORMATION RE0 VESTED IN GENERIC LETTER 91-05 P_LANT HATCH. UNIT 2 Question 1:

Unit?

Response

Unit 2.

Question 2:

A. The number of independent redundant divisions of Class 1E or '

safety-related DC power for this _ plant is (include any separate Class IE or safety-related DC, such as any DC dedicated to the '

diesel generators.)

l B. The number of functional safety-related divisions of DC power i necessary to attain safe shutdown for this unit is. I

Response

A. Two. -Each division has one 125/250 V Station Service Battery (2A I or- 2B) and one 125 V Diesel Generator Battery (2A or 2C).

Additionally, there is an independent. 125 V Diesel Generator Battery (IB) for " swing" Diesel Generator IB which is shared I between Hatch Units 1 and 2. [ Note: Alarms and Indicators for Diesel Generator Battery 18 are duplicated in both control rooms.]

B. One.

Question 3:

Does the control room at this unit have the following separate,

' independently annunciated alarms and indications for each division of DC power?;

A. Alarms

1. Battery disconnect or circuit breaker open?

2. Battery charger disconnect or circuit breaker open (both input AC and output DC)?

3. DC system ground?

L 002237 HL-1854 E2-1

f:

, , -ENCLOSURE 2 (CONTINUED)-

INFORMATION RE0 VESTED IN GENERIC LETTER 91-06 PLANT HATCHi UNIT 2 L4. DC bus undervoltage?_

5. -DC' bus overvoltage?

i

6._ Battery charger failure? '

7 .- Battery discharge?

D. Indications-1._ Battery float cobrge current?

2. -Battery circuit output current?-

3.- Battery discherge?

4. Busivoltage?

C. Does the unit >have written procedures for response to_-- the_above

- alarms :and'. indications?

,+

' Response:

1A. iAlarms

' 1. Lyes . .  ;

J2. :AC - Yes.- -

m > DC - No.= -r a 3e .Yes.- -

4. Yes.

5.-

No.

6. Yes.'

- 7.- No .:

_ B. Indications:

~'

l '. Station Service Batteries 'Yes; Diesel Generator Batteries .No.

. - 002237' HL-1854- E2-2.

4

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4

ENCLOSURE 2 (CONTINUED)

INFORMATION REQUESTED _IN_GENERLC_LU IER 91-06 PLANT HATCH. UNIT 2

2. Station Service Batteries - Yes.

Diesel Generator Batteries - No.

3.- Yes.

4. Yes.

C. Yes.

Question 4:

Does this unit have indication of bypassed and inoperable status of circuit breakers or other devices that can be used to disconnect the battery charger from its DC bus and the battery charger from its AC power source during maintenance or testing?

Response

No.

Question 5:

If the answer to any part of question 3 or 4 is no, then provide information justifying the existing design features of the facility's safety-related DC systems.

Response

Explanation and Justification Relative to Questions 3 and 5 A "yes" response to -an alarm (3. A) indicates that there is a separate, independently-annunciated alarm for the specific function in question. It does not mean that the specific function has a dedicated annunciator window. Several alarm signals may be transmitted to a single annunciator window. As an example,-an alarm received on Alarm Panel 652-1 would indicate that Battery Charger 2R42-S032A or Battery Charger 2R42-S0320 had malfunctioned due to one of the following conditions:

1. AC power cource not available, 6

2. Batteries discharged.

3. Ground in battery charger or system.

002237 HL-1854 E2-3

4 ENCLOSURE 2 (CONTINUED)

INFORMATION REQUESTED IN GENERIC LETTER 91-06 PLANT HATCH. UNIT 2 This annunciator would alert the operator to a problem associated with one of the indicated battery chargers. The specific problem would then be ascertained and corrected in accordance with the appropriate annunciator response procedure. Since the functions are alarmed in the control room and any of the conditions that cause the annunciator to activate would be investigated and corrected, it is believed that the functions are adequately monitored, and a dedicated annunciator window for each alarm function is not necessary.

Question 3.A.2 - There is no control room alarm that would be initiated if one of the battery charger output DC circuit breakers should open, However, each battery charger would initiate an alarm if a DC system ground was detected or low DC voltage was sensed. The icw voltage alarm '

is at a setpoint which would indicate that the charger had been lost. The annunciator response procedures would identify tia operator actions that should- by taken to locate the specific alarm condition. The procedures specify various voltmeters and ammeters both in the control room and locally mounted that may be used to assess the problem and initiate corrective action. The use of such detailed procedures along with available indications support the adequacy of the Hatch DC electrical system design.

Question' 3.A.5 - There are no alarms which will alert the operators to an overvoltage condition on the DC systems. However, there are operator rounds procedures which require that battery charger voltage and current readings be taken each- shift. It is expected that any overvoltage condition would be detected and corrected in a timely manner. The currently installed battery chargers are scheduled to be replaced during the Fall 1992 Unit 2 refueling outage. In conjun:: tion with the charger replacement, a DC bus overvoltage alarm will be provided.

Question 3.A.'i - There are no alarms that specifically annunciate that a battery is being discharged. However, the DC undervoltage alarms would effectively perform the same function since the setpoints are at a value which would cause an alarm should the battery be the source of power for the DC system. Additionally, daily rounds procedures would also identify battery charger float voltage at less than optimum values. Minimal battery discharge is expected during the period between rounds if the DC

- system voltage is between the normal float voltage and the alarm setpoint.

The new battery chargers have a low DC output current alarm that provides an indirect indication of battery discharge. This alarm will provide local annunciation (e . the chargers) when output current falls

! substantially below the minimum required under normal plant loading 002237 HL-1854 E2-4

l .

ENCLOSURE 2 (CONTINUED)

INFORMATION EQESILD_IN.0LMERILLEITER 91-06 PLANT HATCH. UML2 conditions. Daily rounds will identify the status of this alarm. Minimal battery discharge is expected during the period between rounds. The absence of a battery discharge alarm does not have an adverse affect on safety due to the daily rounds procedures, undervoltage alarm setpoints, and the available control room annunciation.

Question 3.B.1 - There are no ammeters in the control room that can read the diesel generator batteries float current. However, the low voltage and battery charger malfunction alarms would indicate a discharging battery; the fuse trouble alarm would indicate a disconnected battery; and the daily rounds procedures would indicate abnormal charging conditions.

Additionally, battery charging current is specifically checked once a week per battery surveillance procedures. The absence of ammeters in the control room is not considered to represent a significant problem adverse to safety in light of the undervoltage alarm setpoints, the rounds procedures, and the available control room indication.

Question 3.B.2 - There are no ammeters in the control room that read the diesel generator batteries output current. However, ths low voltage and battery charger malfunction alarms would indicate a discharging battery; the fuse trouble al arm would indicate a disconnected battery; and the daily rounds procedures would indicate abnormal charging conditions.

Additionally, battery charging current is specifically checked once a week per battery surveillance procedures. The absence of ammeters in the control room is not considered to represent a significant problem adverse to safety in light of the undervoltage alarm setpoints, the rounds procedures, and the available control room indication.

Question 4 - No direct indications of bypassed or inope able status exist in the control room for the circuit breakers which disconnect the battery chargers from the associated buses (both AC and DC). However, an open DC breaker would be annunciated by the low DC voltage alarms which are set at a level indicative of a loss of a charger, and an open AC-breaker would be annunciated by the loss of AC input / charger failure alarm. While there are no direct indications of bypassed or inoperable fuses which initiate disconnected circuit breaker alarms, a blown or removed fuse would initiate an alarm in the control room.

Question 6 (1) Have you conducted a review of maintenance and testing activities to minimize the potential for human error causing more than one DC division to be unavailable? and (2) Do plant procedures prohibit maintenance or testinq on redundant DC divisions at the same time.

032237 HL '854 E2-5

1 ENCLOSURE 2 (CONTINUED)

INFORMATION RE0 VESTED IN CENERIC LETTER 91-06 PLANT HAlCH. UNIT 2

Response

(1) Yes.

(2) No. However, Unit 2 Technical Specifications, section 3.8.2.3 requires a 2-hour LC0 followed by an action to place the reactor in hot shutdown in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in cold shutdown in the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> if either of the two safety-related divisions of DC power are inoperable.

Question 7:

Are maintenance, surveillance and test procedures regarding station batteries conducted routinely at this plant? Specifically:

A. At least once per 7 days are the following verified to be within acceptable limits:

1. Pilot cell electrolyte level?

2. Specific gravity or charging current? ,

3. Float voltage?

4. Total bus v91tage on float charge?

5. Physical condition of all cells?

B. At least once 3er 92 days, or within 7 days after a battery discharge, overclarge, or if the pilot cell readings are outside the 7-day surveillance requirements _are the following verified to  !

be within acceptable limits:

1. Electrolyte level of each cell?

2. The average specific gravity of all cells?

3. The specific gravity of each cell?

4. The average electrolyte temperature of a representative number of cells?

5. The float voltage of each cell?

I 002237 HL-1854 E2-6

ENCLOSdRE 2 (CONTINUED)

INFORMATION REQUESTED IN GENERIC LETTER 91-06 PLANT HATCH. UNIT 2

6. Visually inspect or measure resistance of terminal s and connectors (including the connectors at the DC bus)?

C. At least every 18 months are the following verified:

1. Low resistance of each connection (by test)?

2. Physical condition of the battery?

3. Battery charger capability to deliver rated ampere output to the DC bus?

4. The capability of the battery to deliver its design duty cycle to the DC bus?

5. Each individual cell voltage is within acceptable limits during the service test?

D. At least every 60 months, is capacity of each battery verified by performance of a discharge test?

E. At least annually, is battery capacity verified by performance di:starge test, if the battery shows signs of degradation or has reached 85". of the expected service life?

Response

A. Seven-day frequency:

1. Yes.

2. Yes.

3. Yes.

4. Yes.

5. Yes.

B. Ninety-two day frequency:

1. Yes.

2. No.

002237 HL-1854 E2-7

i ENCLOSURE 2 (CONTINUED)

INFORMATION RE0 VESTED IN GENERIC LETTER 91-06 PLANT HATCH. UNIT 2

3. Yes.

4. No.

5. Yes.

6. No.

C. Eighteen-month frequency:

1. Yes.

2. Yes.

3. Yes.

4. Yes.

5. Yes.

D. Sixty-month frequency:

Yes.

E. Annual frequency upon identification of degraded condition:

Yes.

Question 8:

Does this plant have operational features such that following loss of one safety-related DC power supply or bus:

A. Capability is maintained for ensuring continued and adequate reactor cooling?

B. Reactor coolant system integrity and isolation capability are maintained?

C. Operating procedures, instrun.entation (including indicators and annunciators), and control functions are adequate to initiate systems as required to maintain adequate core cooling?

002237 HL-1854 E2-8

4 ENCLOSURE 2 (CONTINUED)

INFORMATION RE0VISJ10 IN GENERIC LETTER 91-03 PLANT HATCH. UNIT 2

Response

A. Yes. Redundancy of batteries assures the ability to comply with this require:.:at. Each of the two divisions has the necessary equipment to assure adequate reactor cooling.

B. Yes. Redundancy of batteries assures the ability to comply with this requirement. Either of the DC divisions is capable of providing DC power for the necessary isolation functions.

C. Yes. Symptom-oriented emergency operating procedures address the contingencies for coping with various failures including the loss of a battery. Redundancy of the batteries assures that adequate equipment will be available for the operator's use.

Question 9:

If the answer to any part of question 6, 7, or 8 is no, then provide your basis for not performing the maintenance, surveillance and test procedures described and/or the bases for not including the operational features cited.

Response

Question 6 - Plant procedures do not specifically prohibit maintenance and testing on redundant divisions. However, prior to the performance of any work on the batteries, the Shift Supervisor must be notified and would prevent any activity which would cause both divisions of batteries to be inoperable at the same time. Plant Technical Specifications do not permit both divisions of DC power to be out of service at the same time for maintenance and testing or for any other reason when operating at power.

During plant shutdown conditions, only one division is required to be in service.-

Question 7.B.2 - The average specific gravity of the battery cells is currently calculated on an 18-month frequency. The calculation of the average specific gravity is not considered to be a significant parameter for Hatch Unit 2 since: the comparisons are made against the minimum required values.

Question 7.B.4 - Currently, represantative temperatures are used on an 18-month frequency for determining specific gravity corrections.

While not required for regulatory compliance, applicable procedures will be revised, based on good engineering practices, to assure that representative battery electrolyte temperatures are taken at a frequency consistent with the Technical Specifications surveillance for measuring the specific gravity (i.e., quarterly).

002237 HL-1854 E2-9

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ENCLOSURE 2 (CONTINVED)

INFORMATION RE0 VESTED IN GENERIC LETTER 91-06 PLANT HATCH. UNIT 2 Question 7.B.6 - The con.iectors at the DC bus are not currently inspected during the monthly battery surveillance. While not required for regulatory compliance, applicable procedures will be revised, based on geod engineering practices, to include this inspection. Monthly visual inspections of the connectors at the battery fuses and the DC switchgear will be required. In addition, visual and resistance checks are performed for all bactery cell connectors during each refueling outage. The DC switchgear is also inspected during the 5-year preventive maintenance inspection. ll 002237 HL-1854 E2-10

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