ML17227A437

LER 92-002-00:on 920430,containment Pressure Channel C Sensing Line for Containment Pressure Instrument PT-07-2C Process Line in Containment Capped.Caused by Personnel Error.Cap on Channel C removed.W/920527 Ltr

ML17227A437
Person / Time
Site:	Saint Lucie
Issue date:	05/27/1992
From:	Sager D, Sienkiewicz S FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-92-156, LER-92-002-03, LER-92-2-3, NUDOCS 9206020321
Download: ML17227A437 (6)

Text

ACCELERATED DISTRIBUTION DEMONS~TION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9206020321 DOC.DATE: 92/05/27 NOTARIZED: NO DOCKET N FACIL:50-389 St. Lucie Plant, Unit 2, Florida Power & Light Co. 05000389 AUTH. NAME AUTHOR AFFILIATION Florida SIENKIEWICZ,S. Power & Light Co.

SAGER,D.A. Florida Power & Light Co.

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 92-002-00:on 920430,containment pressure channel "C."

sensing line for containment pressure instrument PT-07-2C process line in containment capped. Caused by personnel error.Cap on channel "C" removed.W/920527 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR TITLE: 50.73/50.9 Licensee Event Report (LER),

! ENCL 2 SIZE:

incident Rpt, etc.

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 D NORRIS,Z 1 1 INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DS P 2 2 NRR/DET/EMEB 7E 1 1 NRR/DLPQ/LHFB10 1 1 NRR/DLPQ/LPEB10 1 1 NRR/DOEA/OEAB 1 1 NRR/DREP/PRPB11 2 2 NRR/DST/SELB 8D 1 1 NRR/DST/SICB8H3 1 1 BST-. B8D1 1 1 NRR/DST/SRXB 8E 1 1 02 1 1 RES/DSIR/EIB 1 1 GN2 FILE 01 1 1 EXTERNAL: EG&G BRYCE,J.H 3 3 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHYiG A 1 1 NSIC POORE,W. 1 1 NUDOCS FULL TXT 1 1 D

A D

D NOTE TO ALL "RIDS" RECIPIENTS:

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

FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 32 ENCL 32

P.O. Box 128, Ft. Pierce, FL 34954-0128 May 27, 1992 FPL L-92-156 10 CFR 50.73 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 Re: St. Lucie Unit 2 Docket No. 50-389 Reportable Event: 92-002 Date of Event: April 30,. 1992 Containment High Pressure Channel "C" Ino erable due to bein ca ed The attached Licensee Event Report is being submitted pursuant to the requirements of 10 CFR 50.73 to provide notification of the subject event.

Very truly yours, Qin1 D. A. ager Vice P esident St. Lucie Plant DAS/JWH/kw Attachment cc: Stewart D. Ebneter, Regional Administrator, USNRC Region II Senior Resident Inspector', USNRC, St. Lucie Plant DAS/PSL 8704-92 9206 2i 9P0 PDR R ADOCK 05000389 PDR an FPL Group company

Ua. NUCLEAR REGULATORY COMMSSGN NWCWDCSH ILLtll04IN FPL FacslNle ol NRC Form 36B tM8)

LICENSEE EVENT REPORT (LER)

FACILITYNAME (1) DOCI<ET NUMBER (2) PAGE 3 St. Lucie Unit 2 050003891 0 3

'~ ( ) Containment Pressure Channel Inoperable Resulting in a Condition Prohibited by Technical Specifications due to Personnel Error EVENT DATE (5) LER NUMBER (6) REPORT DATE m OTHER FACILmES INVOLVED(8)

MONTH DAY YEAR FACILITYNAMES DOCKET NUMBER(S)

MONTH DAY YEAR YEAR N/A 0 4 30 9 2 9 2 0 0 2 0 0 0 5 2 7 9 2 N/A THIS REPORT IS SUBMITIED PURSUANT TO THE REQUIREMENTS.OF 10 GFR:

OPERATING Check one or more of the folowin (11)

MODE (9) 73.71 (b) 20.402(b) 20.405(c) 50.73(a)(2)(iv)

POWER 50.73(a)(2)(v) 20.405(a)(1)(i) 50.36(c)(1) 73.71(c)

LEVEL (10) 0 0 20.405(a)(1)(ii) 50.36(c)(2) 50.73(a)(2)(vii) OTHER (Specifyin Abstract 20A05(a)(1)(iii) 50.73(a)(2)(i) 50.73(a)(2)(vIII)(A) below and in Text 20.405(a)(1)(iv) 50.73(a)(2)(viii)(B) NRC Form 366A) 50.73(a)(2)(ii) 20.405(a)(1)(v) 50.73(a)(2)(iii) 50.73(a)(2)(x)

LICENSEE CONTACT FOR THIS LER 12 TELEP E NUMBER AREA CODE Scott W. Sienkiewicz, Shift Technical Advisor 4 0 7 465 -3550 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT 13 MANUFAC- REPORTABLE MANUFAC- REPORTABLE CAUSE SYSTEM COMPONENT TURER TO NPRDS CAUSE SYSTEM COMPONENT AIRER TO NPRDS SUPPLEMENTAL REPORT EXPECTED 14 EXPECTED MONTH DAY YEAR SUBMISSION YES '(Ifyes, complete EXPECTED SUBMISSION DATE) DATE (15)

ABSTRACT (Limit to 1400 spaces.i.e. approximately fifteen single-space typewritten lines) (1 6)

On April 30, 1992, the NRC site resident identified that penetration ¹58, the containment pressure channel "C" sensing line for containment pressure instrument PT-07-2C, had its process line in containment capped, rendering the pressure instrument inoperable. Containment pressure instrument PT-07-2C provides 1 of 4 containment pressure signals to initiate Engineered Safety Features Actuation System and Reactor Protection System trip actions. A review of this event identified that containment pressure channel "C" is estimated to have been inoperable since 4-13-89. This is the earliest date that documented evidence vermed that channel C" was uncapped.

The root cause of containment pressure channel "C" being inoperable is the inadvertent capping of the sensing line inside of containment due to personnel error. Contributing factors were inadequate identificathn of open ended process lines that are required to be'kept open and the lack of procedure to check the lines to ensure they are open prior to unit stattup. a

1) The cap on containment pressure channel "C" was removed.

2) All four of the instrument lines were blown down to ensure they were not obstructed. 3) The corresponding Unit 1 instrument lines were bhwn down to ensure they were not obstructed. 4) Open ended process lines will be appropriately identified with tags/stickers to ensure that the lines are not inadvertently capped.

5) A procedure will be devehped to Inspect/verify that other open ended process lines inside of containment that are required to be open are unobstructed prior to going into mode 4.

FPL Facsimile of NRC Form 366 (6-89)

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FPL Faalnfle ol U.S. NUCLEAR REGULATORYCOMMlSSlON ATTIDACOCRDICLOIDCIII

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EQUENTIAL REVISIO St. LLICie Unit 2 NUMBER NUMBER 0 500 0389 9 2 0 0 2 0 0 0 2 0 3

'TEXT (Ifmore spaceis requfred, use additional NRC Form 366A's) (1 7)

On April 30, 1992, St. Lucie Unit 2 was in mode 5 for a refueling outage. During a routine con-tainment (EIIS:NH) inspection, the NRC Site Residents found that penetration ¹58, the containment pressure channel "C" sensing line for containment pressure instrument PT-07-2C (EIIS:

IK), had its process line in containment capped. This prevented the transmitter from detecting containment pressure, thereby rendering the instrument inoperable.

The cause of containment pressure channel "C" being inoperable was the inadvertent capping of the sensing line inside containment due to personnel error. Investigation of this event did not indicate who installed the cap or the classification of the individual involved. Therefore, it is not possible to determine whether the personnel error was cognitive or procedural. Contributing factors to this event included unusual characteristics to the work location that directly related to the error, Le., inadequate klentification on the open ended process lines that are required to be kept open, and the absence of an approved plant procedure for checking the lines to ensure that they are op'n prior to unit startup.

Penetration ¹58 provides'1 of 4 containment pressure signals to initiate Engineered Safety Features Actuation System (ESFAS) (EIIS:BQ) and Reactor Protection System (RPS) (EIIS:JC) trip actions. Extensive investigation did not reveal who installed the cap nor did it indicate when or why the cap was installed. The containment pressure channel is estimated to have been inoperable since 4-1349. This conservative date is the earliest date that documented evidence identifies that the channel was operable. On 4-1349 a flow test was perfomed by pressurizing the process line which verified flow through the line with no obsttuctions.

During the period of time that channel "C" was inoperable (4-13-89 to 4-22-92) other channels were taken out of service for maintenance/testing. Plant Technical Specifications 3.3.1 and 3.3.2 require that with the number of operable channels one less than the minimum operable channels (3), one channel is to be placed in bypass and the other placed in the tripped condition within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. Also, all functional units affected by the bypassed/tripped channel shall be placed in the bypassed/tripped condition. This action statement was not adhered to. Therefore, this event is reportable under 10 CFR 50.73.a.2.i as "any operation or condition prohibited by the Plant Technical Specifications."

During the 36 month period since the last satisfactory test, plant records indicate that the total percentage of time that another channel was bypassed was approximately 0.5%. A review of the Unit 2 Final Safety Analysis Report (FSAR) for the effects on the RPS/ESFAS with one channel effectively isolated indicates that the RPS /ESFAS would still function in a two-out-of-three coincidence logic. The fourth channel is essentially an installed spare to allow for on line testing/

maintenance of the system. If another channel was rendered out of service, the RPS/ESFAS logic would be twowut-of-two coincidence logic and would still provide adequate protection.

FPL Facsimile of NRG Form 366 (6-89)

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EQUENTIAL REVISIO NUMBER NUMBER St. Lucie Unit 2 0 500 0389 9 2 0 0 2 0 0 0 3 0 3 TEXT (Ifmore spaceis required, use additional NRC Form 368A's) (17)

Since the RPS and ESFAS are designed for redundancy and diversity, the loss of a containment pressure signal does not compromise plant safety. During an accident condition, the containment pressure signaI is considered a back up signal for the initiation of RPS signals and ESFAS signals, with the exception of the containment spray actuation signal (CSAS). CSAS receives its input from containment pressure high-high ooincklent with a safety injection actuation signal (EIIS:BQ). If CSAS does not automatically actuate then plant procedures and training direct the plant operators to manually actuate protective systems when required by plant conditions.

This event was evaluated assuming a loss of automatic initiation of the containment spray system (EIIS:BE), a conservative worst case scenario. Containment spray is not credited with preventing or mitigating core damage in the case of a main steam line break (MSLB) event. When analyzing the loss of coolant accident (LOCA) the lack of containment spray results in lower peak clad temperatures, due to increased containment pressure acting back on the RCS leak. In addition, no increase in radiological consequences is expected since fission product control systems remain intact. A Probabilistic Risk Assessment (PRA) was performed to assess the potential risk impact of PT-07-2C sensing line being capped. The PRA showed that the estimated change ln mean core damage frequency is 3.9E-8/ reactor year. The estimated core damage frequency contribution due to this event is not considered important as defined by the IPE Generic Letter 88-20 screening criteria. Conclusions from this evaluation indicated that for both a LOCA and a MSLB, containment integrity would be preserved and the public health and safety would not be affected.

1. The cap on containment pressure channel "C" was removed .

2. All four of the instrument lines were blown down to ensure they were not obstructed. An evaluation determined that if the other open ended process lines were inadvertently capped the condition would be self klentified due to blockage of the process flow .

3. The corresponding Unit 1 instrument lines were blown down to ensure they were not obstructed.

4. Open ended process lines will be appropriately identified with tags/stickers to ensure that the lines are not Inadvertently capped.

5. A procedure will be developed to inspect/verify that other open ended process lines inskle of containment that are required to be open'are unobstructed prior to going into mode 4

1) Component Failures None

2) Previous Similar Events None FPL Facsimile of NRG Form 366 (6-89)