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ACCESSION NBR:9203200356 DOC.DATE: 91/03/13 NOTARIZED: NOFACIL:50-323 Diablo Canyon Nuclear Power Plant, Unit 2, Pacific Ga

AUTH.NAME AUTHOR AFFILIATIONHUG,M.T Pacific Gas & Electric Co.RUEGER,G.M. Pacific Gas & Electric Co.

RECIP.NAME RECIPIENT AFFILIATION

DOCKET05000323

SUBJECT: LER 92-002-00:on 920211,Tech Spec 3.3.3.2,action 20 of Table3.3-3,for steam flow channel to be inoperable exceeded.Caused by personnel error. Responsible personnel counseled.W/-920313 ltr.

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RECIPIENTZD CODE/NAME

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L ST LOBBY WARDNSIC MURPHY,G.ANUDOCS FULL TXT

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Pacific Gas and Electric Company 77Beale Street

San Francisco. CA 94106415/973-4684

Gregory M. Rueger

Senior Vice President andGeneral ManagerNuclear Pov er Generation

March 13, 1992

PGirE Letter No. DCL-92-058

U,S. Nuclear Regulatory CommissionATTN: Document Control DeskWashington, D.C. 20555

Re: Docket No. 50-323, OL-DPR-82Diablo Canyon Unit 2Licensee Event Report 2-92-002-00Technical Specification 3.3.2 Action Requirement Not Met When aSteam Flow Channel Was Calibrated Using an Incorrect Data SheetDue to Personnel Error

Gentlemen:

Pursuant to 10 CFR 50.73(a)(2)(i)(B), PG&E is submitting the enclosedLicensee Event Report concerning a Technical Specification ActionRequirement not met when a steam flow channel was calibrated using anincorrect data sheet due to personnel error.

Sincerely,

VGregory M. Rueger

cc: Ann P. HodgdonJohn B. MartinPhilip J. MorrillHarry RoodHoward J. WongCPUCDiablo DistributionINPO

DC2-92-TI-N009

Enclosure

5681S/85K/PJT/2246

9203200356 920313PDR ADOCK 05000323S PDR

~y n~P~ /

LICENSEE EVENT REPORT (LER)

FACIUTYNAME111

DIABLO CANYON UNIT 2

DOCKET NQI4BIN 2

0 5 0 0 0 3 2 3 1'

TITLE(41 TECHNICAL SPECIFICATION 3.3.2 ACTION RE(UIREHENT NOT MET WHEN A STEAN FLOW CHANNEL WAS

CALIBRATED USING AN INCORRECT DATA SHEET DUE TO PERSONNEL ERROR

EVENT DATE (61 L01 NUMBOI(BI REPORT DATE LYI OTHER FACILITIES INVOLVED (B)

MON DAY 3 EOUDITIALNUMBQY

REVISIONNUMBDI

MON DAYFACIUTYNAMES

DOCKET NUMB'3)

0 5 0 0 0

02 11 92 92 0 0 2 0 0 03 13 92 0 5 0 0 0OPERATINGHOOE (9)

POHER1 0 0

(IO)

THIS REPORT IS SUBHIYYED PURSUANT TO THE RE IREHEHTS OF IO CFR: ll

X 1D CFR 5D.73 a 2 I B

OTHER(Spec((y In Abstract be(OH and In text, HRC Form 366A)

UCEHSEE CONTACT FOR THS LBI 12

HARTIN T. HUG, SENIOR REGULATORY COMPLIANCE ENGINEER

COMPLETE ONE UNE FOR EACH COMPONENT FAILURE DESCIBBED IN THB REPORT 1131

AREA CODE

545-4005805

TELEPHONE NLB48ER

CAUSE SYSIEH COHPOHEHT HAHUFACTUBER

REPORTABLETO NPRDS

CAUSE SYSTEH COHPOHENT HAHUFACTURER

REPORTABLLTo HPROS

SUPPLEMENTAL REPORT EXPECTED (14)

I I YES (I F YES COMPLETE EXPECTED SUSHI SSI OH DATE) X HO

ABSTRACT (I6)

EXPECTEDSUSHI SS IOH

DATE (15)

HONTH DAY YEAR

On February ll, 1992, at 0442 PST, with Unit 2 in Mode 1 (Power Operation) at 100

percent power, the six hours allowed by Technical Specification (TS) 3.3.2, Action20 of Table 3.3-3, for a steam flow channel to be inoperable, was exceeded.

A calibration of steam flow channel 532, completed February 10, 1992, at 2242 PST,

used an incorrect data sheet/scaling calculation which resulted in the channelbeing out of acceptance specifications. This condition was discovered on February13, 1992, following the calibration of redundant channel 533.

Bistable 532 was immediately placed in the tripped position in accordance withAction 20 of TS Table 3.3-3. Channel 532 was recalibrated/adjusted on February15, 1992, and returned to service.

This event was caused by personnel error, cognitive, in that non-licensed IIICengineering personnel made an error calibrating channel 532. The responsiblepersonnel were counseled. An incident summary was written and distributed toapplicable personnel. All affected procedures and scaling calculations werecorrected to reflect the proper calibration data.

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DIABLO CANYON UNIT 2

DOCKET HVHBER (E)

0500032392

LER NLMSER

SCOVORW.MAI8TR

-00 2 0 0 2 " 6

I. Plant Conditions

Unit 2 was in Node 1 (Power Operation) at 100 percent power during thisevent.

II. Descri tion of Event

A.

B.

Summary:

On February 11, 1992, at 0442 PST, with Unit 2 in Hode 1 (PowerOperation) at 100 percent power, the six hours allowed by TechnicalSpecification (TS) 3.3.2, Action 20 of Table 3.3-3, for a steam flowchannel to be inoperable, was exceeded. A calibration of steam flowchannel 532, completed February 10, 1992, at 2242 PST, using STPI-12B6, "Calibration - Comparators Steam Generator Feedflow, Steamflowand Pressure Channels," resulted in the channel being out ofacceptance specifications. This condition was discovered onFebruary 13, 1992, following the calibration of redundant channel 533.Bistable 532 was immediately placed in the tripped position inaccordance with Action 20 of TS Table 3.3-3. Channel 532 wasrecalibrated/adjusted on February 15, 1992, and returned to service.

Background:

Each unit at Diablo Canyon has eight (8) steam flow channels, two (2)per loop, which are used for indication, control, and input to theSolid State Protection System. The two channels per loop are totallyredundant. Channels 532 and 533 are redundant to each other in loop 3

of Unit 2. Either channel can supply the one of two logic for loop 3.TS 3.3.2, "Engineered Safety Features Actuation SystemInstrumentation," Table 3.3-3, requires two steam flow channels to beoperable in each loop. Action 20 of Table 3.3-3 allows continuedoperation if the inoperable channel is placed in the tripped conditionwithin 6 hours.

Surveillance Test Procedure (STP) R-42, "Steam and Feedwater FlowCalibration Data," is performed following power ascension to IOOXrated thermal power to verify calibration data for the steam andfeedwater flow transmitters.

Data gathered during the performance of STP R-42 is used by I&Cengineering to update the transmitter calibration values provided inSTP I-12B7, "Calibration Transmitters Steam Generator Steam Flow."The revised STP I-12B7 is then used to recalibrate/adjust all 8 steamflow channels (512, 513, 522, 523, 532, 533, 542, and 543).

Since the calibration of steam flow channels using STP I-12B7 requiresa containment entry at power, an alternate method for incorporatingthe new STP R-42 calibration values was developed. STP I-12B6 was

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DIABLO CANYON UNIT 2 05 0 0 0 3 2 3 92 002 0 0 3 " 6

revised to allow electronic adjustment of the steam flow channelsoutside of containment (in the Hagan Racks).

C. Event Description:

On November 5, 1991, STP R-42 was performed following power ascensionto IOOX rated thermal power after completion of the fourth refuelingoutage on Unit 2, to verify calibration of the steam and feedwaterflow transmitters (JB)(FT).

On November 7, 1991, STP I-12B7 was revised by I&C engineering tocorrect the transmitter calibration values to the new STP R-42 data.A review of the STP R-42 data showed that seven of the eight steamflow channels were within required limits. Only loop 3 steam flowchannel 532 (JB) did not meet the acceptance criteria. Channel 532was declared inoperable.

On November 8, 1991, a containment entry was made and steam flowtransmitter FT-532 was recalibrated to the new revised STP I-12B7 andreturned to service. The other seven steam flow channels were notcalibrated since their as-found data was within specifications.

On February 4, 1992, STP I-12B6 was revised to incorporate the newmethodology of adjusting the steam flow channels in the Hagan Racksinstead of at the transmitters. This revision incorporated an errorin the data sheet/scaling calculation for channel 532. All eightsteam flow channels were required to be'recalibrated using the revisedprocedure.

On February 10, 1992, steam flow channel 532 was calibrated inaccordance with STP I-1286 using the incorrect data sheets/scalingcalculations and returned to service. (Note: A channel check betweensteam flow channels 532 and 533 did not identify any noticeabledisparity on the control board analog indications following thiscalibration.)

On February 12, 1992, steam flow channel 533 calibration was completedand the channel was returned to service. A channel check betweensteam flow channels 532 and 533 did not identify any noticeabledisparity on the control board analog indications following thiscalibration. Following the return to service, the I&C techniciannoted a minor disparity between channels 532 and 533 on the plantprocess computer. The technician immediately notified his supervisorand I&C engineering and an investigation ensued. This was the firstindication that a problem existed.

On February 13, 1992, an investigation determined that FT-532 was notwithin specifications. Bistable BS-532 was placed in the tripped

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DIABLO CANYON UNIT 2 0 5 0 0 0 3 2 3 92 002- 0 0 4 of 6

condition in accordance with TS Table 3.3-3, Action 20, and channel532 declared inoperable.

On February 14, 1992, the revision of STP I-12B6 was completed tocorrect the scaling error.

On February 15, 1992, steam flow channel 532 was recalibrated usingthe revised procedure and returned to service.

D. Inoperable Structures, Components, or Systems that Contributed to theEvent:

None.

E. Dates and Approximate Times for Major Occurrences:

1. February ll, 1992; 0442 PST:

2. February 13, 1992:

3. February 15, 1992:

Event Date. Six hour ActionRequirement was exceeded.

Discovery Date. Channel 532was discovered to be outsiderequired specifications.

Channel 532 was calibrated andreturned to service.

F. Other Systems or Secondary Functions Affected:

None.

G. Hethod of Discovery:

On February 12, 1992, a channel check performed by, I&C techniciansfollowing calibration of steam flow channel 533 identified anunsatisfactory disparity between channels 532 and 533. Furtherinvestigation on February 13, 1992, determined that Channel 532 wasout of specifications.

H. Operator Actions:

Upon discovery of the condition; the control room operator declaredsteam flow channel 532 inoperable and placed bistable 532 in thetripped condition in accordance with TS Table 3.3-3, Action 20.

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DIABLO CANYON UNIT 2 05000323 92 002 0 0 5 " 6

I. Safety System Responses:

None.

III. Cause of the Event

A. Immediate Cause:

The immediate cause for failing to meet the TS Action Requirement wasthe improper calibration of steam flow channel 532.

B. Root Cause:If

The root cause of the improper calibration of steam flow channel 532was personnel error, cognitive, inattention to detail, in that thechannel was calibrated using an incorrect data sheet. The data sheetwas incorrect because a non-licensed I&C engineer relied on verbalinformation and failed to verify which channel had been calibrated inNovember prior to performing additional procedure modifications(revising STP I-12B6). The non-licensed I&C engineer, acting as theindependent reviewer for the procedure revision, relied on the sameverbal information. The calculation sheet for channel 532 did nottake into account the calibration/adjustment made in November toChannel 532.

C. Contributory Cause:

None

IV. nal sis of the EventI

Each unit at Diablo Canyon has eight (8) steam flow channels, two (2) perloop, which are used for indication, control, and input to the Solid StateProtection System. The two channels per loop are totally redundant.Channels 532 and 533 are redundant to each other in loop 3 of Unit 2.Either channel can supply the one of two logic for loop 3.

During refueling outages, all steam flow transmitters are calibrated tothe previous cycle's values. After power ascension to 100 percent power,STP R-42 is performed to determine new calibration values for 100 percentsteam flow for the new cycle. An on-the-spot change is generated for STP

I-12B7 with the new calibration data and STP I-12B7 is performed on alleight steam flow channels. If Reactor Engineering determines that a

channel is inoperable, that channel is immediately tripped and receivesthe highest priority for calibration and return to service. After theNovember performance of STP R-42, channel 532 was declared inoperable,calibrated to the new setpoint, and returned to service. The otherchannels were within acceptable range, so no calibrations were performedfor the other seven channels.

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DIABLO CANYON UNIT 2 05000323 92 00 2 0 0 6 DR 6

V.

For this event, the February 10, 1992, calibration/adjustment using STPI-12B6 to channel 532 made the channel sense a steam flow approximately0.5 percent lower than actual steam flow at 100 percent power. RedundantChannel 533 was sensing correctly during the entire time 532 wasincorrectly adjusted except for approximately eight hours on February 12while channel 533 was being calibrated. For those eight hours, channel533 was in the tripped position (the one of two logic for loop 3 wasactivated). The tripped position is a more conservative position requiredby the TS when a channel is made inoperable.

Thus, the inoperability of steam fiow channel 532 did not adversely affectthe health and the safety of the public.

Corrective Actions

A. Immediate Corrective Actions:

Steam f1ow channel 532 was declared inoperable and bistable BS-532 wasplaced in the tripped condition in accordance with Action 20 ofTable 3.3-3.

B. Corrective Actions to Prevent Recurrence:

1. STP I-12B6 and its associated scaling calculations were correctedto reflect the proper calibration data and steam flow channel 532was recalibrated to the correct values.

2. An incident summary was written and distributed to all applicableII|C personnel.

3. Counseling has been provided to all applicable personnel. Thiscounseling included the importance of attention to detail and theresponsibilities of the procedure writer and the technicalreviewer,

VI. dditional Information

A. Failed Components:

None.

B. Previous Similar Events:

None.

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