ML17223B295

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

ML17223B295
Person / Time
Site:	Saint Lucie
Issue date:	10/28/1991
From:	Bohlke W FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-GTECI-A-30, REF-GTECI-EL, TASK-A-30, TASK-OR GL-91-06, GL-91-6, L-91-291, NUDOCS 9111060225
Download: ML17223B295 (27)

Text

ACCELERATED DISTRIBUTION DEMONST TION SYSTEM 4

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9111060225 DOC.DATE: 91/10/28 NOTARIZED: YES DOCKET FACIL:50-335 St. Lucie Plant, Unit 1, Florida Power & Light Co. 05000335 50-389 St. Lucie Plant, Unit 2, Florida Power & Light Co. 05000389 AUTH. NAME AUTHOR AFFILIATION BOHLKE,W.H. Florida Power & Light Co.

RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Responds to Generic Ltr 91-06, "Resolution of Generic Issue A-30 Adequacy of Safety-Related DC Power Supplies." NRC requested licensees to provide written responses to D questions in Encl 1 of generic ltr within 180 days of ltr.

DISTRIBUTION CODE: AOOID TITLE: OR COPIES RECEIVED:LTR i Submittal: General Distribution ENCL Q SIZE:

NOTES RECIPIENT COPIES RECIPIENT COPIES D ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-2 LA 1 1 PD2-2 PD 1 1 NORRIS,J 2 2 D

INTERNAL: ACRS 6 6 NRR/DET/ECMB 7D 1 1 NRR/DET/ESGB 1 1 NRR/DOEA/OTSBll 1 1 NRR/DST 8E2 1 1 NRR/DST/SELB 7E 1 1 NRR/DST/SICB8H7 1 1 NRR/DS~TSRXB 8E 1 1 NUDOCS-ABSTRACT 1 1 O,C/'~LB 1 0 OGC/HDS3 1 0 FILEEO1.

'G 1 1 RES/DS IR/EIB 1 1 EXTERNAL: NRC PDR 1 1 NSIC 1 1 D

A D

D NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 24 ENCL 22

P.O. Box14000, Juno Beach, FL 33408-0420 October 28, 1991 L-91-291 10 CFR 50.54(f)

U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 Gentlemen:

RE: St. Lucie Unit Nos. 1 and 2 Docket Nos. 50-335 and 50-389 Generic Letter 91-06 Res onse Attachments 1 and 2 are the Florida Power and Light Company response to Generic Letter 91-06 "Resolution of Generic Issue A-30 Adequacy of Safety-Related DC Power Supplies" for St. Lucie Units 1 and 2 respectively.

On April 29, 1991, the NRC issued Generic Letter 91-06 which

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provided the results of its evaluation of Generic Issue A-30. The evaluation determined that certain maintenance, surveillance, and monitoring provisions are appropriate for safety-related dc systems. In order to determine whether any site specific staff action would be required, the NRC requested licensees to provide written responses to the questions in Enclosure 1 of the Generic Letter within 180 days of the date of the letter.

The attached responses for St. Lucie Unit 1 and 2 are provided pursuant to Section 182 of the Atomic Energy Act of 1954, as amended, and 10 CFR 50.54(f).

Please contact us if there are any questions about this submittal.

Very truly yours, W. H. Bohlke Vice President Nuclear Engineering and Licensing WHB/GRM/kw cc: Stewart D. Ebneter, Regional Administrator, Region II, USNRC Senior Resident Inspector, USNRC, St. Lucie Plant DAS/PSL 0547-91 9iii060225 9ii02S PDR ADOCK 05000335

! P PDR cp :9 an FPL Group company

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St. Lucie Unit Nos. 1 and 2 Docket Nos. 50-335 and 50-389.

Generic Letter 91-06 Res onse STATE OF FLORIDA )

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COUNTY OF PALM BEACH )

W. H. Bohlke being first duly sworn, deposes and says:

That he is Vice President, Nuclear Engineering and Licensing for the Nuclear Division of Florida Power 6 Light Company, the Licensee herein; That he has executed the foregoing document; that the statements made in this document are true and correct to the best of his knowledge, information and belief, and that he is authorized to execute the document on behalf of said Licensee.

W. H. Bohlke Subscribed and sworn to before me this

~cP > aay or 19 'P/

NOTARY PUBLIC, in d for the County of Palm Beach, State of Florida ffotary Public, State of Florfda My Comm. Exp. Feb. 18, 1995 My Commission expires Bonded thruPLGHARD Ins. Aaen

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ATTACHMENT1 ST. LUCIE UNIT 1 QUESTION NO. GENERIC LETTER REQUEST FPL RESPONSE Unit R-1. St. Lucie Unit 1 Docket No. 50-335 Q-2.a The number of independent redundant divisions of class R-2.a. St. Lucie Unit 1 has two (2) independent redundant 1E or safety-related DC power for this plant. (Include divisions of class 1E or safety-related DC Power designated any separate Class 1E or Safety-related DC, such as 1A and 1B. Each subsystem consists of a 125 volt DC Bus any DC dedicated to the diesel generators.) dcsignatcd 1A (1B), a 125 volt safety-related battery dcsignatcd 1A (1B), and 2 safety-related 125 volt battery chargers designated 1A and 1AA (1B and 1BB). In addition, a swing bus dcsignatcd 1AB with a single 125 volt DC battery charger dcsignatcd 1AB can bc aligned to either thc 1A bus or the 1B bus.

Q 2.b Thc number of functional safety-rclatcd divisions of R-2.b. St. Lucie Unit 1 requires onc (1) of the functional DC power necessary to attain safe shutdown for this safety-rclatcd divisions of DC power, either A or B, to attain unit. safe shutdown.

Q-3.a Does the control room at this unit have thc following R-3.a. St. Lucie Unit 1 has thc following annunciated separate, indepcndcntly annunciated alarms for each alarms in the control room:

division of DC power?

1. Battery disconnect or circuit breaker 1. Ycs, an open battery disconnect or circuit breaker is open? alarmed by ANNUNCIATORS A-30 or B30.

A-30 (B-30) "125V DC BUS 1B (1A)

UN DERVOLTAGE/MAINBATTERY BREAKER."

2. Battery charger disconnect or circuit 2. Ycs, an open battery charger disconnect or circuit breaker open ( both input AC & output DC)'? breaker (either input AC or output DC) is alarmed by ANNUNCIATORS A-20, B-20, Z 9, & Z 10.

A-20 (B-20) "125V DC BUS 1B (IA) BA7L CHGR./BATT. RM FAN TROUBLE" Z-9 (Z-10) BATTERY CHARGER 1AA (1BB)

TROUBLE"

3. DC system ground? 3. Ycs, a DC system ground is alarmed by ANNUNCIATORS A-10 & B-10.

A-10 (B-10) "125V DC BUS 1B (1A) GROUND"

4. DC bus under voltage? 4. Yes, a DC bus undervoltage is alarmed by ANNUNCIATORS A-30 & B-30 A-30 (B-30) Same annunciator as response R-3.a.1

5. DC bus over voltage? 5. Ycs, a DC bus ovcrvoltage is alarmed by ANNUNCIATORS A-20 & B-20.

A-20 (B-20) Same annunciator as response R-3.a.2 In addition high voltage causes the battery charger shutdown and trouble alarm.

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QUESTION NO. GENERIC LETTER REQUEST FPL RESPONSE

6. Battery charger failure? 6. Yes, a battery charger failure is alarmed by ANNUNCIATORS A-20 & B-20 A-20 (B-20) Same annunciator as response R-3.a.2

7. Battery discharge? 7. No, St. Lucie Unit 1 docs not have a bauery discharge alarm. Sce thc response to Q-5 for justification.

Q-3.b Docs thc control room at this unit have thc following R-3.b. St. Lucie Unit 1 has the following indications in the separate independent indications for each division of control room:

DC power'?

1. No, Unit 1 does not have battery float current indication

1. Battery float charge current'? in thc control room. Sce the response to Q-5 for gustiflcation.

2. Battery circuit output current? 2. No, Unit 1 does not have battery circuit output current indication in thc control room. Scc thc response to Q-5 for justification.

3. Bauery discharge? 3. No, Unit 1 does not have battery discharge indication in the control room. Scc thc response to Q-5 for justification.

4. Bus voltage? 4. Ycs, DC bus voltage indication is provided in the control room by volt mctcrs VM-1001 & VM-1002 and indcpcrfdcnt white indicating lights.

Q-3.c Does the unit have written proccdurcs for response to R-3.c. Ycs, written procedures for the response to thc the alarms (3.a 1-7) and indications (3b. 1<)? alarms (R-3.a.1-7) & Indications (R-3.b. 14) are listed below:

3.a.1-7 (Alarms)

OP 1-0960020 "125V DC SYSTEM NORMAL OPERATION" ONOP 1-0030131 "PLANT ANNUNCIATOR

SUMMARY

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ONOP 1M60030 "DC GROUND ISOLATION" 3.b. I< (indications)

OP 1-0960020 125V DC SYSTEM NORMAL OPERATION" ONOP 1~30136 "LOSS OF A SAFETY RELATED DC BUS" Does this unit have indication of bypassed and RP Ycs, bypass and/or inoperable status of DC output or inoperable status of circuit brcakcrs or other devices AC input circuit brcakcrs is provided by thc control room that can bc used to disconnect thc battery and thc annunciators identified in R-3, specifically A-20 (B-20) &, A-battery charger from its DC bus and the battery charger 30 (B-30) provide annunciation of battery charger trouble from its AC power source during maintenance or including AC power failure, and misalignment of battery testing? output breakers. Howcvcr, there is no specific alarm or indication provided to identify an inoperable circuit breaker.

Sce the response to Q-5 for justification.

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QUESTION

'O. GENERIC LETTER REQUEST FPL RESPONSE If thc answer to any part of question 3 or 4 is no, then R-5 A nccd has not been identified for an alarm in question provide information justifying the existing design 3.a.7 (battery discharge alarm) or thc control room features of the facility's safety-related DC systems. indications in questions 3.b.1 (battery Iloat current), 3.b.2 battery circuit output current), or 3.b.3 (battery discharge R-3.a.7 indicators) nor is any rccommcndcd by IEEE 308-1971 for R-3.b.1 these parameters.

R-3.b.2 R-3.b.3 For the inoperable status indication of question 4, thc control RP room annunciators A-20 (B-20) and A-30 (B-30) provide annunciation of battery charger trouble including AC power Instead of dcvcloping Ec supplying thc justification, failure and misalignment of the battery output brcakcrs.

FPL may commit to perform thc evaluations during the There is no specific alarm or indication provided to identify pcrformancc of the IPE for scvcre accident an inoperable circuit breaker and none is recommended by vulnerabilitics IEEE 308-1971. An inoperable circuit breaker'that will not close or that will trip prematurely would bc dctcctcd by onc of the alarms listed above. An inopcrablc circuit breaker that will not open is an undctcctable failure via normal annunciators since its normal operating mode is thc closed position. This situation will not interfere with battery operation.

Has FPL conducted a review of maintenance and R4.1 Ycs, St. Lucic Plant has pcrformcd a human factors testing activities to minimize the potential for human rcvicw of the clcctrical maintenance proccdurcs for DC error causing more than onc (1) DC division to be distribution cquipmcnt. The review was part of a unavailable? maintcnancc procedure upgrade program but was not pcrformcd specifically to prevent human error from causing more than one DC division to become unavailablc.

Do plant procedures prohibit maintenance or testing on R4.2. Plant Administrative Procedure (AP) AP 0010142 redundant DC divisions at thc same time? "Manipulation of Sensitive Systems" prohibits maintenance on two (2) portions of a sensitive system or on two separate scnsitivc systems at the same time. The 125v DC electrical system is a dcsignatcd sensitive system in AP 0010142.

If the facility Technical Specifications for this unit have R-7 Thc St. Lucic Unit 1 Tcchnical Specifications have provisions equivalent to those found in the Combustion provisions similar to the Combustion Engineering Standard Engineering Standard Tcchnical Specifications for Tcchnical Specifications for maintenance and survcillancc, maintenance and surveillance? howcvcr bccausc of thc differcnccs a response to question 7 is be provided.

Are maintenance, surveillance and test proccdurcs Ycs, as detailed in the response to questions 7.a Through 7.e requiring station battcrics conducted routinely at this below, proccdurcs for maintcnancc, surveillance, and testing plant? are routinely conducted on the station battcrics.

Q-7.a At least bncc pcr 7 days arc the following verified to R-7.a Maintenance Procedure MP 0960163 provides the bc within acccptablc limits: weekly tests and inspections.

1. Pilot cell electrolyte level? 1. Ycs, MP 0960163 verifies pilot cell electrolyte level at wcckly intervals.

2. Specific gravity and/or charging current? 2. Ycs, MP 0960163 vcrifics charging current at the output shunt mctcr connections of each battery charger using a DVOM and the charging current using the installed metering at wcckly intervals. In addition, MP 0960163 tests the specific gravity of each battery pilot cell at wcckly intervals to verify that they are within acceptable limits.

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QUESTION NO. GENEMC LETTER REQUEST FPL RESPONSE

3. Float voltage? 3. Ycs, MP 0960163 vcrifics the battery float voltage using installed panel mctcring at the battery chargcrs at wcckly intervals.

4. Total bus voltage on float charge? 4. Ycs, MP 0960163 verifies battery bus voltage using the installed panel metering at thc DC buses at weekly intervals.

S. Physical condition of all cells? S. Ycs, MP 0960163 visually inspects thc individual battery cells for cracks, loose material, dust, dirt, corrosion, and clcctrolytc leaks.

Q-7.b At least once pcr 92 days, or within 7 days aflcr a R-7.b. Maintenance Procedure MP 0960164 provides the battery discharge, overcharge, or if pilot cell readings monthly inspections and tests that correspond to the quarterly are outside the 7 day surveillance rcquircmcnts are the rcquircmcnts of question 7.b.

following verified to be within acccptablc limits:

Note: The parameters of question 7.b are verifie if thc pilot

1. Electrolyte Icvcl in each cell? cell readings arc outside the 74ay surveillance rcquircmcnts for thc batterics, pcr periodic Maintcnancc Proccdurc MP 0960163. Thcsc paramctcrs arc also vcrificd aRcr a discharge test of thc batterics pcr the requirements of Maintenance Proccdurcs MP 1%960062 & MP 1M60063 for thc 1A Ec IB battcrics rcspcctivcly. An overcharge of the station battcrics is not anticipated during thc lifetime of thc batteries, so recovery from an overcharge of the battcrics is not procedurally documented. If such an overcharge occurred, recommendations to verify the integrity of the batteries would be considered, and would likely include the paramctcrs vcrificd in thc monthly battery maintenance .

procedure as a minimum..

1. Ycs, MP 0960164 verifies the elcctrolytc level at monthly intervals.

2. The average specific gravity of all cells? 2. Ycs, MP 0960164 mcasurcs thc specific gravity of all cells and then calculates the average specific gravity of the cells monthly.

3. The specific gravity of each cell? 3. Ycs, MP 0960164 records the specific gravity of each cell monthly.

4. The average electrolyte tcmpcrature of a 4. Ycs, MP 0960164 Calculates thc average clcctrolytc rcprcscntative number of cells? temperature of the battery monthly.

S. The float voltage of each cell? S. Ycs, MP 0960164 records the battery float voltage monthly.

6. Visually inspect or mcasurc resistance of 6. Ycs, MP 0960164 visually inspects all battery terminals and connectors (including the connections monthly. If any visual corrosion is noted, connectors at the DC bus)? microwhm readings of the affcctcd battery connections arc pcrformcd. However, thc connections at the DC bus are not verified by this visual inspection since they are not in a corrosive environment and have not bccn noted to be corroded in any past periodic maintcnancc pcrformcd on this equipment.

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QUESTION NO. GENERIC LETTER REQUEST FPL RESPONSE Q-7.c At least cvcry 18 months arc thc following verified: R-7.c Maintcnancc Procedures MP 14960062, MP 1-0960063, MP 0960150, and MP 0960165 provide the 18

1. Low resistance of each connection (by month tests and inspections.

test)

l. Ycs, MP 0960150 verifies the resistance of all battery intcr~cll and terminal connections at 18 month intervals.

2. Physical condition of the battery' 2. Ycs, MP 0960150 includes a physical inspection of all battery cells at 18 month intervals.

3. Battery charger capability to deliver rated 3. Ycs, MP 0960165 verifie the capability of the battery ampcrc output to the DC bus? chargcrs to dclivcr rated output to thc DC bus cvcry 18 months.

4. The capability of the battery to deliver its 4. Ycs, MP 14960062 & MP 14960063, verify the design duty cycle to the DC bus? capability of the batteries 1A &, 1B respectively to deliver their design duty cycle to thc DC bus at 18 month intervals.

5. Each individual cell voltage is within 5. Ycs, MP 1-0960062 & MP 1-0960063 verify the acceptable limits during the service test? individual cell voltages of thc batterics 1A & 1B rcspcctivcly at 18 month intervals.

Q-7.d At least cvcry 60 months, is capacity of each battery R-7.d. Ycs, Maintenance Procedures MP 1-0960151 &

verified by performance of a discharge test? MP 14960152 verify the capacity of thc station batteries by performance of a discharge test at 60 month intervals for the 1A & 1B battcrics rcspcctivcly.

At least annually, is thc battery capacity verified by R-7.e. Ycs, Maintenance Proccdurcs MP 14960151 &

performance discharge test, if thc battery shows signs MP 14960152 provide for the annual test and inspections of degradation or has reached 85% of expected life? and performance of a battery discharge test if thc battery shows signs of degradation or has reached 85 percent of the expcctcd service life.

Q-8.a Docs thc unit have operational features such that R-8.a. Ycs UFSAR Section 8.3. discusses how the following loss of one safety-related DC power supply capability is maintained for ensuring continued and adequate or bus: reactor cooling following thc loss of onc safety-related DC power supply or bus. Load groups A and B are each capable a., Capability is maintained for ensuring of supplying thc minimum DC power requirements to safely continued and adequate reactor cooling' shutdown the plant and/or mitigate the consequences of a LOCA.

Q-g.b Docs thc unit have operational fcaturcs such that R-8.b. Ycs, UFSAR Section 8.3 discusses how reactor following loss of one safcty-related DC power supply coolant system integrity (RCS) and isolation capability are or bus: maintained following a loss of one safety-rclatcd DC power

b. Reactor coolant system integrity and supply isolation capability arc maintained?

Howcvcr, in Operational Modes 1 through 4 thc loss of one safety- related DC bus will initiate a reactor trip signal in thc reactor protection system and will cause the PORV in the opposite train to open. Off-Normal Operating Procedure ONOP 14030136 directs thc operator to close the associated block valve which restores RCS integrity. Sce the response to Q-9 for justification.

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QUESTION NO. GENERIC LETTER REQUEST FPL RESPONSE Q-g.c Does the unit have operational features such that R-8.c Ycs, Off Normal Operating Procedure ONOP 1-following loss of onc safety-related DC power supply 0440030, "Shutdown Cooling Off-Normal" provides guidance or bus: for realignment of thc shutdown cooling system should a loss occur. Additionally, alternate means of decay heat removal

c. Operating procedures, instrumentation are provided in accordance with Generic Letter 88-17, within (including indicators & annunciators), and this proccdurc.

control functions are adequate to initiate systems as required to maintain adcquatc core Off-Normal Operating Proccdurc ONOP 14030136 "Loss of cooling? Safety-Related DC Bus" provides guidance for loss of onc safety related DC bus.

Unit 1 control room annunciators are powered from the IAB DC bus, allowing manual realignment if required to an operablc 1A or 1B DC bus.

If the answer to any part of question 6, 7, or 8 is no The opening of one PORV at power is bounded by thc then provide the basis for not performing thc analysis in section 15.2 of thc UFSAR. The Off-Normal maintenance, surveillance, and/or test procedures Operating Procedure provides thc operator with guidance for described and/or the bases for not including the loss of onc safety-related DC bus.

operational features cited.

R-8.b Instead of dcvcloping Ec supplying the information in response to Question 9, FPL may commit to further evaluate thc nccd for such provisions during the performance of thc IPE for severe accident vulncrabilitics.

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ATTACHMENT2 ST. LUCIE UNIT 2 QUESTION NO. GENERIC LETTER REQUEST FPL RESPONSE Unit R-1. St. Lucie Unit 2 Docket No. 50-389 Q-2.a Thc number of independent redundant divisions of class R-2.a. St. Lucie Unit 2 has two (2) independent redundant 1E or safety-related DC power for this plant. (Include divisions of class 1E or safety-related DC power designated any separate Class 1E or Safety-related DC, such as 2A and 2B. Each subsystem consists of a 125 volt DC bus any DC dedicated to the diesel generators.) dcsignatcd 2A (2B), a 125 volt, safety-related battery designated 2A (2B), and two (2) safety-related 125 volt battery chargcrs designated 2A and 2AA (2B and 2BB). In addition, a swing bus designated 2AB with a single 125 volt battery charger designated 2AB can be aligned to either the 2A or the 2B bus.

Q-2.b The number of functional safety-related divisions of R-2.b. St. Lucie Unit 2 requires one (1) of the functional DC power necessary to attain safe shutdown for this safety-rclatcd divisions of DC power, either 2A or 2B, to unit. attain safe shutdown.

Q-3.a Does the control room at this unit have the following R-3.a St Lucic Unit 2 has the following annunciated alarms scparatc, indcpcndcntly annunciated alarms for each in the control room:

division of DC power'

1. Battery disconnect or circuit brcakcr 1. Yes, an open battery disconnect or circuit breaker is open? alarmed by ANNUNCIATORS A48 & B-50.

A<8 (B-50) "125V DC BATT. 2B (2A)

DISCHARGE HI/BKR OPEN"

2. Battery charger disconnect or circuit 2. Yes, an open battery charger disconnect or circuit brcakcr open ( both input AC & output DC)? breaker (cithcr input AC & output DC)is alarmed by ANNUNCIATORS A-20 & B-20.

A-20 (B-20) "125V DC 2B/2BB (2A/2AA) BATT.

CHGR. 2B/2BB (2A/2AA) TROUBLE"

3. DC system ground? 3. Yes, a DC system ground is alarmed by ANNUNCIATORS A-10 & B-10.

A-10 (B-10) "125V DC BUS 2B/2BB (2A/2AA)

GROUND" n

4. DC bus under voltage? 4. Ycs, a DC bus undervoltage alarm is provided by ANNUNCIATORS A-30 & B-30.

A-'30 (B-30) "125V DC BUS 2B (2A)

UNDERVOLTAGE"

QUESTION NO. GENERIC LETTER REQUEST FPL RESPONSE

5. DC bus over voltage'? 5. Yes, a DC bus overvoltage alarm is provided by ANNUNCIATORS A-20 & B-20.

A-20 (B-20) same annunciator as response R-3.a.2 In addition, high voltage causes battery charger shutdown

& trouble alarm.

6. Battery charger failure? 6. Yes, a battery charger failure alarm is provided by ANNUNCIATORS A-20 & B-20.

A-20 (B-20) same annunciator as response R-3.a.2

7. Battery discharge'? 7. Ycs, a battery discharge alarm is provided by ANNUNCIATORS AA8 & B-50.

A48 (B-50) same annunciator as response R-3.a.l Q-3.b Docs the control room at this unit have the following R-3.b. St. Lucie Unit 2 has the following indications for separate indcpcndcnt indications for each division of each division of DC power:

DC power?

1. No, Unit 2 does not have float current indication in the

1. Battery float charge current? control room. See the response to Q-5 for justification. ',

2. Battery circuit output current? 2. Yes, battery circuit output current indication is provided in the control room by AM-1801 & AM-1802.

3. Battery discharge? 3. Yes, battery discharge indication is provided in the control room by AM-1801 & AM-1802.

4. Bus voltage? 4. Bus voltage indication is provided in the control room by volt meters VM-1001 & VM-1002 and indcpcndcnt white indicating lights.

Does thc unit have written procedures for response to R-3.c. Ycs, written procedures for the rcsponsc to the Q-3.c thc alarms (3.a 1-7) and indications (3b. 1-4)? alarms (R-3.a.1-7) & indications (R-3.b.ld) are listed below:

R-3.a.1-7 (Alarms)

OP 2-0960020 "125V DC SYSTEM NORMAL OPERATION" ONOP 24030131 "PLANT ANNUNCIATOR

SUMMARY

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ONOP 2-0960030 "DC GROUND ISOLATION" R-3.b. 1< (indications)

OP 2-0960020 "125V DC SYSTEM NORMAL OPERATION" ONOP 2%030136 "LOSS OF A SAFETY RELATED DC BUS"

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QUESTION NO. GENERIC LETTER REQUEST FPL RESPONSE Docs this unit have indication of bypassed and RP Ycs, bypassed and/or inopcrablc status indication is inoperable status of circuit breakers or other dcviccs provided by control room annunciators A<8 (B-50) for an that can be used to disconnect the battery and the open battery discharge breaker. Common trouble alarms A-battery charger from its DC bus and the battery charger 20 (B-20) annunciate for a loss of AC power to the battery from its AC power source during maintenance or chargers. However, there is no specific alarm or indication testing? provided to identify an inoperable circuit breaker; sec thc response to Q-5 for justification.

Q-5 If the answer to any part of question 3 or 4 is no, then R-5 A need has not been identified for the indication in provide information justifying the existing design question 3.b.1 (battery float current) nor is any features of the facility's safety-related DC systems. rccommcndcd by IEEE 308-1971 as modified by R.G. 1.32, Rcv 0 for this paramctcr.

R-3.a.7 R-3.b.1 For thc inoperable status indication of question 4, thc R-3.b.2 control room annunciators A<8 (B-50) provide indication, of R-3.b.3 an open battery output breaker. Common trouble alarms A-RA 20 (B-20) provide annunciation of battery charger trouble including AC power failure. There is no specific alarm or Instead of dcvcloping & supplying the justification, indication provided to identify an inoperable circuit breaker FPL may commit to perform the evaluations during the and none is rccommcndcd by IEEE 308-1971 as modified performance of thc IPE for severe accident by R.G. 1.32, Rcv 0. An inoperable circuit breaker that vulnerabilitics will not close or trip prcmaturcly would be detected by one of thc alarms listed above. An inoperable circuit breaker that will not open is an undetectable failure via normal annunciators since its normal operating mode is the closed position. This situation will not interfere with battery operation.

Q4.1 Has FPL conducted a review of maintenance and R4.1 Yes, ST. Lucio plant has performed a review of thc testing activities to minimize the potential for human clcctrical maintenance proccdurcs regarding DC distribution error causing morc than one (1) DC division to be equipment with rcspcct to human factor concerns. The unavailablc? rcvicw was performed as part of a maintenance procedure upgrade program but was not performed specifically to prcvcnt human error from causing more than one DC division to become unavailable.

Q-6.2 Do plant procedures prohibit maintenance or testing on R-6-2 Plant Administrative Procedure (AP) AP 0010142 redundant DC divisions at the same time? "Manipulation of Scnsitivc Systems" prohibits maintenance on two (2) portions of same sensitive system or on two separate sensitive systems at the same time. The 125v DC electrical system is a designated sensitive system in AP 0010142.

If the facility Tcchnical Specifications for this unit have R-7 Thc St. Lucie Unit 2 Tcchnical Specifications have provisions equivalent to those found in the Combustion provisions similar to the Combustion Engineering Standard Engineering Standard Technical Specifications for Tcchnical Specifications for maintenance and surveillance,,

maintenance and surveillance? however because of the differences the response to question 7 is be provided.

Arc maintenance, surveillance and test proccdurcs Yes, as detailed in the response to questions 7.a through-7.e requiring station batterics conducted routinely at this below, procedures for maintenance, surveillance, and plant? testing arc routinely conducted for the station battcrics.

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QUESTION NO. GENERIC LETTER REQUEST FPL RESPONSE Q-7.a At least once pcr 7 days are the following verified to R-7.a Maintenance Procedure MP 0960163 provides the be within acceptable limits: weekly (7 day survcillanccs) tests and inspections.

1. Pilot cell electrolyte level? 1. Yes, MP 0960163 verifies pilot cell electrolyte level at weekly intervals.

2. Specific gravity and/or charging current? 2. Yes, MP 0960163 verifies charging current at the output shunt meter connections of each battery charger using a DVOM and the charging current using the installed metering at weekly intervals. In addition, thc specific gravity of each battery pilot cell is tested at weekly intervals to verify that they are within acceptable limits.

3. Float voltage? 3. Yes, MP 0960163 verifies the battery float voltage using installed panel metering at the battery chargcrs at weekly intervals.

4. Total bus voltage on float charge? 4. Ycs, MP 0960163 verifies battery bus voltage using the installed panel metering at the DC buses at wcckly intervals.

5. Physical condition of all cells? 5. Ycs, MP 0960163 visually inspects thc individual battery cells for cracks, loose material, dust, dirt,"

corrosion, and electrolyte leaks.

Q-7.b At least once pcr 92 days, or within 7 days after a R-7.b. Maintenance Procedure MP 0960164 provides thc battery discharge, ovcrchargc, or if pilot cell readings monthly inspections and tests that corrcspond to the are outside the 7 day surveillance requirements arc the quarterly requirements of question 7.b.

following verified to be within acceptable limits:

NOTE: The parameters of question 7.b are verifie if the

1. Elcctrolytc level in each cell? pilot cell readings are outside thc 74ay surveillance requirements for thc batteries, per periodic Maintenance Proccdurc MP 0960163. These paramctcrs are also vcrificd aflcr a discharge test of the batteries per the requirements of Maintenance Procedures MP 2-0960062, Ec MP 24960063 for the 2A & 2B batteries respectively. An overcharge of the station battcrics is not anticipated during thc lifctimc of the batteries, so recovery from an overcharge of the batteries is not procedurally documcntcd. If such an overcharge occurred, recommendations to verify the integrity of the battcrics would bc considered, and would likely include the parameters verified in the monthly battery maintenance procedure as a minimum.

1. Ycs, MP 0960164 verifies the electrolyte lcvcl at monthly intervals.

2. The average specific gravity of all cells? 2. Ycs, MP 0960164 measures thc specific gravity of all cells and then calculates thc average specific gravity of the cells monthly.

3. The specific gravity of each cell? 3. Yes, MP 0960164 records the spcciflc gravity of each cell monthly.

4. The average electrolyte tcmpcrature of a 4. Ycs, MP 0960164 calculates the avcragc clcctrolytc representative number of cells? tcmpcraturc of the battery monthly.

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n QUESTION NO. GENERIC LETTER REQUEST FPL RESPONSE

5. The float voltage of each cell? 5. Ycs, MP 0960164 records the battery float voltage

'onthly.

6. Visually inspect or measure resistance of 6. Ycs, MP 0960164 visually inspects all battery terminals and connectors (including the connections monthly. If any visual corrosion is noted, connectors at the DC bus)'? microwhm readings of the affcctcd battery connections are performed. However, the connections at thc DC bus are not vcrifled by this visual inspection since they are not located in a corrosive cnvironmcnt and have not been noted to bc corroded in any past periodic maintenance performed on this cquipmcnt.

Q-7.c At least every 18 months are the following verified: R-7.c Maintenance Procedures MP,2-0960062, MP 2-0960063, MP 0960150, & MP 0960165 provide the 18

1. Low resistance of each connection (by month tests and inspections.

test)

1. Ycs, MP 0960150 verifies the resistance of all battery inter-cell and terminal connections at 18 month intervals.

2. Physical condition of thc battery? 2. Ycs, MP 0960150 includes a physical inspection of all battery cells at 18 month intervals.

3. Battery charger capability to deliver rated 3. Ycs, MP 0960165 verifies the capability of the battery ampere output to thc DC bus'? chargcrs to deliver rated output to the DC bus every 18 months.

4. The capability of thc battery to deliver its 4. Ycs, MP 2-0960062 & MP 2-0960063 verify the design duty cycle to the DC bus? capability of the batteries 2A & 2B respectively to dclivcr their design duty cycle to thc DC bus at 18 month intervals.

5. Each individual cell voltage is within 5. Ycs, MP 2-0960062 & MP 2-0960063 verify the acceptable limits during the service test? individual cell voltages of the batteries 2A & 2B respectively at 18 month intervals.

Q-7.d At least every 60 months, is capacity of each battery R-7.d. Ycs, MP 2-0960151 & MP 2-0960152 verify the verified by performance of a discharge test? capacity of the station batteries by performance of a discharge test at 60 month intervals for the 2A & 2B batteries respectively.

Q-7.e At least annually, is the battery capacity verified by R-7.e. Ycs, Maintenance Procedures MP 2-0960151 & MP performance discharge test, if thc battery shows signs 2-0960152 provide the annual tests and inspections and of degradation or has rcachcd 85% of expected life? provide for thc battery discharge test if the battery shows signs of degradation or if the battery has reached 85 percent of the expcctcd service life.

Q-8.a. Does the unit have operational features such that R-g.a. Ycs, UFSAR Section 8.3. discusses how the following loss of one safety-rclatcd DC power supply capability is maintained for ensuring continued and adcquatc or bus: reactor cooling following the loss of onc safety-related DC power supply or bus. Load groups A and B are each

a. Capability is maintained for ensuring capable of supplying the minimum DC power requirements continued and adequate reactor cooling? to safely shutdown the plant.

l' QUESTION NO. GENERIC LETTER REQUEST FPL RESPONSE Q-8.b Docs the unit have operational features such that R-8.b. Yes, UFSAR Section 8.3 discusses how reactor following loss of onc safety-related DC power supply coolant system integrity (RCS) and isolation capability are or bus: maintained following a loss of one safety-related DC power

b. Reactor coolant system integrity and supply.

isolation capability are maintained?

However, in Operational Modes 1 through 4 the loss of one safety- rclatcd DC bus will initiate a reactor trip signal in the reactor protection system and will cause the PORV in the opposite train to open. Off-Normal Operating Procedure ONOP 2%030136 directs the operator to close the associated block valve which restores RCS integrity.

Scc the response to Q-9 for justification.

Q-g.c Does the unit have operational features such that R-8.c Off Normal Operating Procedure ONOP 2-0440030, following loss of onc safety-rclatcd DC power supply "Shutdown Cooling Off-Normal" provides guidance for or bus: realignment of thc shutdown cooling system should a loss of one safety-related DC bus occur. Additionally, alternate

c. Operating procedures, instrumentation means of decay heat removal are provided in accordance (including indicators & annunciators), and with Generi Letter 88-17, within this procedure.

control functions are adequate to initiate systems as rcquircd to maintain adequate core Off-Normal Operating Proccdurc ONOP 2-0030136 "Loss cooling? of Safety-Related DC Bus" provides guidance for loss of onc safety-related DC bus.

Unit 2 control room annunciators are powered from the vital AC bus.

If thc answer to any part of question 6, 7, or 8 is no The opening of one PORV at power is bounded by the then provide thc basis for not performing the analysis in section 15.6 of the UFSAR. The Off-Normal maintenance, surveillance, and/or test procedures Operating Procedure provides the operator with guidance dcscribcd and/or the bases for not including thc for loss of one safety-related DC bus.

operational features cited.

R-8.b Instead of dcvcloping & supplying thc information in response to Question 9, FPL may commit to further cvaluatc thc need for such provisions during the pcrformancc of the IPE for severe accident vulncrabilitics.