ML20024H089

Monthly Operating Repts for Apr 1991 for South Texas Project Electric Generating Station Units 1 & 2.W/910515 Ltr

ML20024H089
Person / Time
Site:	South Texas
Issue date:	04/30/1991
From:	Jump W, Kent A HOUSTON LIGHTING & POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
ST-HL-AE-3772, NUDOCS 9105210225
Download: ML20024H089 (15)

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c o mp a ny llouston Lighting & PowerJD "d' Tesa. Pn>jni I:luniy Gwyaijng gathin y>.g nosyn w ad. won ti, 'I m. 7 7 m May IS. 1991 ST-HL-AE-3772 File No. 002 10CFR50.71 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 South Texas Project Electric Generating Station Units 1 & 2 Docket Nos. STN 50-498 & 50-499 Monthly Operating Reports for April. 1991 Pursuant to 10CFR50,71(a) and South Texas Project Electric Generating Station (STPEGS) Technical Specification 6.9.1.5, attached are the Monthly Operating Reports for April, 1991, If you should have any questions on this matter, please contact Mr. C. A. Ayala at (512) 972-8628, 9 VAR- .

William J . Jump Manager Nuclear Licensing MPJ/kmd Attachments: 1) STPEGS Unit 1 Monthly Operating Report - April, 1391

2) STPEGS Unit 2 Monthly Operating Report - April, 1991 4 1 l.

RREP\91071001,112 A Subsidiary of Houston Industries incorporated ,

I 910S210225 910430 +'

l POR ADOCK 05000498 R PDR

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L L ST HL AE 3772 llou'ston Light.ing & Power Company File No. : CO2 South Texas Project Electric Generating Stat.ion p,g, cc:

Regional-Administrator, Region IV Rufus S, Scott Nuclear Regulatory-Commission. Associate Ceneral Counsel 611 Ryan Plaza Drive, Suite 1000 Houston Lighting & Power Company Arlington, TX 76011 P. O. Box 61867 Houston, TX 77208 George Dick, Project Manager U.S. Nuclear Regulatory Commission INPO Washington, DC 20555 Records Center 1100 Circle 75 Parkway J._I Tapia Atlanta, CA 30339-3064 Senior Resident Inspector c/o U. S. Nuclear Regulatory Dr. Joseph M. Hendrie Commission 50 Be11 port Lane P. O. Box 910 Bellport, NY 11713 Bay City,_TX 77414 D. K. Lacker

-J. R. Newman, Esquire- Bureau of Radiation Control Newman & Holtzinger, P.C. Texas Department of Health 1615-L Street, N.W. 1100 West 49th Street Washington, DC 20036 Austin, TX 78756-3189 D. E. Ward /T M. Puckett Central Power and Light Company P. O. Box 2121 Corpus Christi, TX 78403 J, C. Lanier/M. B. Lee City _of Austin Electric _ Utility Department P.O.EBox 1088 Austin, TX -78767 R. J. Costello/M. T. liardt City _Public Service Board P. O. Box 1771 San Antonio,_TX- 78296 Revised 01/29/91 L4/NRC/

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- 0F L SOUTH TEXAS PROJECT ELECTRIC GENERATING STATI0ll UNIT 1 MONTHLY OPERATING REPORT APRIL 1991 HOUSTON LIGHTING AND POWER CO.

.NRC DOCKET No. 50 498 LICENSE NO. NPF-76 Reviewed  : 5!7h]

Supervisor Date Reviewed By: h 'rf W l'/f/P/ .

Plant Ertgineerin Manager Date j Approved By: CU A ff/3f4t Plant Mq. nager Date

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, . s ATTACHMENT l-ST-HL AE- 5 77 A PAGE A 0F 6____

i Monthly SummgIy Following a refueling outage, STPEGS Unit I was returned to service for normal operation on 4/4/91 at 2249. On 4/9/91 at 0546 the plant was taken to l Mode 3 as per technical specification requirements due to the failure of the "D" I train Feedwater Isolation Valve to stroke during surveillance testing. The solenoids were disassembled revealing the presence of gel which prevented the valve from stroking. Root cause inspection identified the depletion of the desiccant filter on top of the valve reservoir as being the cause of the gel formation. The filters were replaced and the unit returned to service on 4/11/91 at 2117.

The unit tripped on 4/12/91 at 0416 following the failure of the Rod Drive Motor Generator sets. Investigation determined the cause to be the failure of a timer relay in one of the motor generator sets which caused instability in the voltage regulator operation of the other generator set. The relay was replaced and the unit returned to service on 4/13/91 at 2303.

The unit operated for the remainder of the reporting period with no shutdowns or significant power reductions.

Y AII ACHMENl I i ST-HL- AE- 3771 l PAGE 3 _ 0F . B . .

OPERATING DATA REPORT l

DOCRET NO. 50-498 UNIT 1 DATE May. 7. 1991 COMPLETED BY A.P. Rent TELEP110NE 512/972-7786 OPERATING STATUS 719

1. REPORTING PERIOD: 04/01 -04/30 GROSS 110URS 3800 IN REPORTING PERIOD:

2. CURRENTLY AUTHORIZED POWER LEVEL (MWt):

MAX. DEPEND. CAPACITY (MWe-Net): 1250.61250.6 DESIGN ELECTRICAL RATING (MWe-Net): None__

3. POWER LEVEL TO VilICll RESTRICTED N/A

('F ANY)(MWe Net):

4. REASONS FOR RESTRICTION (IF ANY):

Tills MONTil YR TO DATE CUMULATIVE

.. 631.4 640.5 14421.6

5. NUMBER OF HOURS REACTOR VAS CRITICAL.

0 0 0

6. REACTOR RESERVE SliUTDOWN ll0URS. .

.... 526.9 526.9 13668.3

7. Il0URS GENERATOR ON LINE. . .

0 0 0

8. UNIT RESERVE SHUTDOWN 110URS. ,

1648852 49327060

9. GROSS THERMAL ENERGY GENERATED (HWt) . . . .1648852 544880 544880 16642370 10, GROSS ELECTRICAL ENERGY GENERATED (MWil) .

506735 470842 15595325

11. NET ELECTRICAL ENERGY GENERATED (MWH)..

87.9% 22.2% 61.4%

12. REACTOR SERVICE FACTOR.

87.0% 22.2% 61.4%

13. REACTOR AVAILABILITY FACTOR.

73.3% 18.3% 58.2%

14. UNIT SERVICE FACTOR.... .

73.3% 18.3% 58.2%

15. UNIT AVAILABILITY FACTOR.

56.4% 13.11 53.1%

16. UNIT CAPACITY FACTOR (Using MDC). ..

56.4% 13.1% 53.1%

17. UNIT CAPACITY FACTOR (Using Design MWe).

16.8% 45.6% 17 ._3 %

18. UNIT FORCED OlJTAGE RATE.

19. SHUTDOWNS ScilEDULED OVER NEXT 6 MONTilS (TYPE, DATE, AND DURATION OF EACH):

N/A N/A

20. IF SHUT DOWN AT END OF REPORT PERIOD, ESTIMATED DATE OF STARTUP:

TTACHMENTI ST-ill-AE- 37 71 AVERAGE DAILY UNIT POWER LEVEL PAGE -'i 0F B DOCKET NO. 50 498 UNIT 1 DATE May. 6. 1991 COMPLETED BY A.P. Kent l

i TELEPHONE 512/972-7786 i

MONTH APRIL DAY AVERAGE DAILY POWER LEVEL DAY AVERAGE DAILY PCVER LEVEL I

(MWe-Net) (MWe-Net)

-1 0 17 945

-2 0 18 992 3 0 19 1206 4- 6 20 1243 5 241 21 1247 6 301 22 1247 7 605 23 1248 8 918 24 1253 9 66 25 1250 g 10 0 26 1250 11 0 27 1232 l

12 17 28 1250 13 0 29 1250 14 .

504 30 1252 15 937 31 N/A 16 942 i

UNIT SHUTDOVNS AND POWER REDUCTIONS '

. i DOCKET NO. 50-498 '

UNIT 1 DATE May. 6. 1991 i COMPLETED BY A.P. Kent TELEPHONE 512/972-7786 REPORT MONTH APRIL i

1 2 3 4 5 No. Date Type Duration Reason Method of Licensee System- Component Cause & Corrective Action to (Hours) Shutting Event Code Code Prevent Recurrence.

Down Report #

Reactor

91-01 910115 S 83.5 C 4 N/A N/A N/A Refueling and scheduled maintenance  ;

outage.

91-02 910404 S 2.4 B 9 N/A N/A N/A Turbine overspeed trip test.  ;

I 91-03 910409 F 63.5 D 1 1-91-011 .SJ ISV The "D" train FWIV failed to stroke i during its first weekly surveillance i l

following 1REO3. The valve eventually I stroked but the reason for the failure was i l unknown. The valve was placed on a daily stroke frequency and.again failed to  !

stroke. Technical specifications .uired  !

the plant to be taken to Mode 3. inspec- t tion revealed the presence of gel which .;

prevented the "D" train valve from.  ;

stroking. Chemistry samples had been-taken on the FWIV hydraulic fluid on 3/19/91 and sent offsite for analysis.

Analysis identified a high water contuac [

but analytical results were not ,a u) 3> l

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?EIk 1 2 3 4 5 E# I F: Forced Reason: Method: IEEE 805-1983 IEEE 903A-l ?S 36, E I S: Scheduled A-Equipment Failure (Explain) 1-Manual hA[g5E B-Maintenance or Test 2-Manual Scram cy;j-4  !

C-Refueling 3-Automatic Scram 71 p3 -  !

D-Regulatory Restriction 4-Cont. of Existing I CD E-Operator Training & License Exam Outage >

F-Administrative 5-Reduction G-Operational Error (Explain) 9-Other i H-Other (Explain)

UNIT SHUTDOW2S AND POWER REDUCTIONS -

DOCKET NO. 50-498' ,

UNIT 1 DATE May 6. 1991  ;

COMPLETED BY A.P. Kent TELEPHONE 512/972-7786 REPORT MONTH APRIL  ;

No. .Date Type Duration Reason Method of Licensee System Component Cause & Corrective Action to (Hours) Shutting Event Code Code Prevent Recurrence i Down Report # ,

Reactor transmitted to the site prior to the valve ,

failure. A root cause inspection identi-fled that the desiccant filter on top of l

the reservoir was depleted. The solenoid pilot valves on the "D" train FWIV were changed out, the hydraulic system flushed and the desiccant filter replaced. The inspection of desiccant filters on all' other FWIV's indicated various degrees of depletion; new filters were installed. i Corrective actions to prevent recurrence include improving analysis, maintenance and testing methods.

91-04 910412 F 42.7' A 3 1-91-012 AA RLY The unit tripped from 40% reactor power' on negative rate following the loss of both Rod Drive Motor Generator (RDMG)

. sets. The 2R timer had a defective output switch. Intermittent pick-up and' drop-vuc i of the 2R relay caused instability in-she?? -a>1 -

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1 2 3 4 5 $1 F: Forced Reason: Method: IEEE 805-1983 IEEE 803A-1 98313C 1-Manual S: Scheduled A-Equipment Failure (Explain)

B-Maintenance or Test 2-Manual Scram g-c3 y '

(( l C-Refueling Automatic Scram mN" D-Regulatory Restriction 4-Cont. of Existing 'gp E-Operator Training & License Exam Outage F-Administrative 5-Reduction .

G-Operational Error (Explain) 9-Other H-Other (Explain) 1

UNIT SHUTDOWNS AND POWER REDUCTIONS . ,

DOCKET NO. 50-498 .

UNIT 1 .,

DATE May 6. 1991

COMPLETED BY A.P. Kent TELEPHONE 512/972-7786 REPORT MONTH APRIL No. Date Type Duration Reason Method of Licensee System Component Cause & Corrective Action to (Hours) Shutting Event Code Code Prevent Recurrence Down Report #

Reactor i voltage regulator operation for RDMG =12.

The instability resulted in transients that caused a reverse current trip of RDMG all. As the timer switch continued to degrade the field current and output volt-age was lost on RDMG *12. The loss of both power sources to the Reactor Trip Switch-gear resulted in a reactor trip. The 2R relay timer and control relay were r, placed and a feedback. form was submitted for a more detailed check of these timer switches during outage PMs.

1 1 S om>l F: Forced Reason: Method: IEEE 805-1983 IEEE 803A-1983 b5]22df S: Scheduled A-Equipment Failure (Explain) 1-Manual "'( fh B-Maintenance or Test 2-Manual Scram .

[$ }j C-Refueling 3-Automatic Scram '

rn D-Kegulatory Restriction 4-Cont. of Existing '

hj55 E-Operator. Training & License Exam Outage SS 4, ,

F-Administrative 5-Reduction , bd

'C-Operational. Error (Explain) 9-Other. I CD H-Other (Explain) l-

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ATTACHMENT t ST HL lie. 3772.

PAGF - B ~

0F B f0RVs and Safety Valves Sunduary There were no PORV or Safety Valves challenged during the reporting period.

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All ACHMENT A ST HL AE- 31n PAG E _ L.__ 0 F _t._.

SOUTil TEXAS PROJECT ELECTRIC GENERATING STATION UNIT 2 MONTilLY OPERATING REPORT APRIL 1991 Il0USTON LIGitTING AND POWER CO.

NRC DOCKET NO. 50-499 LICENSE NO. NPF-80 Reviewe y: -

- S ' 7 !4 i Supervisor Date Reviewed By:*# bf -

'F/ 9 / 9 7 PfanykSintering na,er Date Apptoved By Mih ~, s I!/ 9/

Plant Ma uiger 'Date

Ail ACAMENI 2 ST Hl. AE- 311'A 4

Honthly Summary PAGE A- 0F G--

STPECS Unit 2 was returned to service for normal operation on 4/2/91 at 0716 following a trip that occurred on 3/30/91. The unit operated for the remainder of the reporting period with no shutdowns or significant power reductions.

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. ST til. AE- 3'l" PAGE._3_ OF h ..

OPERATING DATA REPORT DOCKET NO. 50 499 UNIT 2 DATE May. 7. 1991 COMPLETED BY A.P. Kent TELEPilONE $12/972 778h OPERATING STATUS

1. REPORTING PERIOD: (M/0.1 Q'iHQ CROSS ll0URS IN REPORTING PERIOD: 719

2. CURRENTLY AUTil0RIZED POWtP. LEVEL (MWt): 3800 l HAX. DEPEND. CAPACITY (MWe Net): 1250.6 DESIGN ELECTRICAL RATING (MWe Net): 1250.6

3. POWER LEVEL TO WilICll RESTRICTED (IF ANY)(MVe Net): None 1

4. REASONS FOR RESTRICTION (IF ANY): N/A TilIS MONTil YR TO DATE CUMUIATIVE l

5. NUMBER OF !!OURS REACTOR WAS CRITICAL. . . . . 719.0 2784.5 11765.8

6. REACTOR RESERVE SilVTDOWN ll0URS .......... 0 0 0

7. Il0URS CENERATOR ON LINE.................. 687.7 2690.6 11036.2 l 2

8. UNIT RESERVE SilUTDOWN 1100RS . . . . . . . . . . . . . . 0 0 0

9. CROSS TilERMAL ENERGY GENERATED (MWt).... 2578032 9984814 39690082

10. CROSS ELECTRICAL ENERGY CENERATED (MVil)., 873470 3390780 _ 13413250

11. NET ELECTRICAL ENERCY CENERATED (MWili . . . . 835220 3239149 12687917

12. REACTOR SERVICE FACTOR.................. 100.01 96.7% 72.0%

13. REACTOR AVA11 ABILITY FACTOR . . . . . . . . . . . . . . 100.0% 96.7% 72.0%

14. UNIT SERVICE FACT 0R.................... . 95.7% 93.5% 67.5%

15. UNIT AVAILABILITY FACTOR................. 95.7% 93.5% 67.5%

16. UNIT CAPACITY FACTOR (Using MDC)......... 92 9JL 90.0% 62.1%

17. UNIT CAPACITY FACTOR (Using Design MWe).. 92.9% 90.0% 62.1%

18. UNIT FORCED OUTACE RATE........ ... ..... 4.3% 6.5% 17.9%

19. SliUTDOWNS SCliEDULED OVER NEXT 6 MONTHS (TYPE, DATE AND DURATION OF EACli):

Refueling and scheduled maintenance outage to begin September 28, 1991.

20. IF SMUT DOWN AT END OF REPORT PERIOD, ESTIMATED DATE OF STARTUP: N/A

1

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ATI ACHMEtiT 2.

ST-HL AE 3111 FAGE__4 _ 0F_k~ = - ~-

AVERAGE DAILY UNIT POWER LEVEL-DOCKET NO. 50 499 UNIT 2 DATE Mav. 7. 1991 COMPLETED BY A.P. Kent TELEPilONE 512/972-11% )

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MONTil APRIL DAY AVERAGE DAILY POWER LEVEL DAY AVERAGE DAILY TOWER LEVEL (MWe Net) (MWo Net) 1 0 17 1248 2 196 18 1246 3 1067 19 1246 4 1243 20 1245 5 1246 21 1246 6 1237 22 1247 ._

7 1252 23 1246 8 1254 24 1246 9 1246 25 1250 10 1242 26 1244 11 1239 27 1248 12 1242 28 1248 13 1239 29 1247

_14 1249 30 1243 15 1248 31 __

N/A 16 1249 r

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UNTI SHUTDOWNS AND FOWER REDUCTIONS  ;

. DOCKET NO. 50-499 i UNIT 2 DATE May. 7. 1991 COMPLETED BY A.P. Kent TELEPHONE 512/972-7786 REPORT MONTH APRIL 1 2 3 4 5 No. Date Type Duration Reason Method of Licensee System Component Cause & Corrective Action to (Hours) Shutting Event Code Code Prevent Recurrence i Down Report

• Reactor

]

91-05 910330 F 11.3 A 4 2-91-004 EL RLY-86 Reactor /Turbir.2 trip due to Main l Cenerator Lockout. The lockout occurred at the same time Unit I closed switchyard l breaker Y510. The actuation of the Main l Cenerator Isophase Bus relay and

{ subsequent Main Generator Lockout was i

caused by a difference in the saturation rates of the Current Transformers

l. associated with the Isophase Bus Relay.

! The evaluation of the test data {

j collected for the Main Generator Isophase ~

Bus relay and the associated Current Trans formers is expected to be completed by July 31. 1991. Temporary modifications have been implemented to remove the trip capability of the Isophase Bus relays. An' i'

evaluation will be completed by September.

1991 to determine methods to minimire current transients during switchyard cirp- g cuit breaker switching operations.

'1 ::9 t-,33),

1 2 3 4 5 f'if "

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{j F: Forced Reason: Method: IEEE 805-1983 IEEE 803A-1983 -p E- fr. --

S: Scheduled A-Equipment Failure (Explain) 1-Manual  : l (p hii B-Maintenance or Test 2-Manual Scram  ; -$ ~C C-Refueling 3-Automatic Scram L 7' v> L)

D-Regulatory Restriction 4-Cont. of Existing , [g-

, E-Operator Training & License Exam Outage , ,

F-Administrative 5-Reduction [j G-Operational Error (Explain) 9-Other  !

, H-Other (Explain) i '

4 ..

ATTACHMENT 2 ST-Hl AE-3771 f0RVs and Safety Valves Summary .. . ' ' . -: r _. h__,,__

There were no PORV or Safety Valves challenged during the reporting period. j l

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