ML17221A662

LER 88-002-00:on 880210,discovered That Leakage on Containment Radiation Monitor Isolation Valve FCV-26-1 Exceeded Tech Spec Limits.Caused by Dirt Accumulation & Stem Corrosion.Valve Actuator Stem cleaned.W/880310 Ltr

ML17221A662
Person / Time
Site:	Saint Lucie
Issue date:	03/11/1988
From:	Conway W, Mendoza V FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
L-88-124, LER-88-002-02, LER-88-2-2, NUDOCS 8803140389
Download: ML17221A662 (6)

Text

ACCELERATED D1, BUTION DEMONSYPIT1ON REGULATORY INFORMATION DISTRIBUTION SYSTEM .(RIDS)

ACCESS1ON NBR:8803140389 DOC.DATE: 88/03/11 NOTARIZED: NO DOC@ET g FACIL:50-335 St. Lucie Plant, Unit 1, Florida Power & Light Co. 05000335 AUTH. NAME AUTHOR AFFILIATION MENDOZA,V.N. Florida Power & Light Co.

CONWAY,W.F. Florida Power & Light Co.

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 88-002-00:on 880210,total bypass leakage on containment radiation monitor isolation valve exceeded Tech Specs.

W/8 DISTRIBUTION CODE: IE22D COPIES RECEIVED:LTR ENCL SIZE:

TITLE: 50.73 Licensee Event Report (LER), Incident Rpt, etc.

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-2 LA 1 1 PD2-2 PD 1 1 TOURIGNY,E 1 1 h INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER 2 2 AEOD/DOA 1 1 AEOD/DSP/NAS 1 1 AEOD/DS P/ROAB 2 2 AEOD/DS P/TPAB 1 1 ARM/DCTS/DAB 1 1 DEDRO 1 1 NRR/DEST/ADS7E4 1 0 .NRR/DEST/CEB8H7 1 1 NRR/DEST/ESB 8D 1 1 NRR/DEST/ICSB7A 1 1 NRR/DEST/MEB9H3 1 1 NRR/DEST/MTB 9H 1 1 NRR/DEST/PSB8D1 1 1 NRR/DEST/RSB 8E 1 1 NRR/DEST/SGB 8D 1 1 NRR/DLPQ/HFBlOD 1 1 NRR/DLPQ/QAB10A 1 1 NRR/DOEA/EAB11E 1 1 NRR/DREP/RAB10A 1 1 NRR/DREP/RPB10A 2 2 N DRI SIB9Al 1 1 NRR/PMAS/ILRB12 1 1 EG 02 1 1 RES TELFORD,J 1 1 RES/DE/EIB 1 1 RES/DRPS DIR 1 1 RGN2 FILE 01 1 1 EXTERNAL EG &G GROH I M 5 5 FORD BLDG HOY,A 1 1 H ST LOBBY WARD 1 1' LPDR 1 1 NRC PDR 1 NSIC HARRIS,J 1 1 NSIC MAYS,G 1 1 h

TOTAL NUMBER OF COPIES REQUIRED: LTTR 46 ENCL 45

~ aRC cat~ 255 0 5 'IUCI.EAR REGULATORY COaaMISSIOh IY 51 AppROYEO OMS NO 7150010a LICENSEE EVENT REPORT (LER) EXPIRES 5 11 M FACILITY NAME 111 DOCKET NUMSEII (2( PAGE t1t 5't. Lucie, Unit 1 0 5 0 0 0 3 3 ) OF ITLE <

'OTAL BYPASS LEAKAGE ON CONTAINMENT RADIATION MONITOR ISOLATION VALVE FCV-26-1 EXCEEDED TECHNICAL SPECIFICATION LIMIT DUE TO STEM CORROSION EVENT OATE ISI LER NUMSER (~) REPORT OA'TE (71 OTHER FACILITIES INVOLVEO (SI MONTH OAY YEAR YEAR SSQVChtlul FACILtTY hAMES OOCKET VUaaSERtSI hvaaoER hVMOER MON'TH OAY YEAR N/A 0 5 0 0 0 0 2 1 088 8 8 0 2 0003 11 0 5 0 0 0 THIS RCPORT IS SUSMITTCO PURSUANT T 0 THE REOUIREMENT5 OF 10 CFII : ICaaca o<<a ot >>ota ot tua toto>><<tt (11 OPCRATINO $

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NAME TELEP>ONC hLVSER Victor N. Mendoza, Shift Technical Advisor AREA CQOE 30 468 -41 5 COMPLETE ONE LINE FOR EACH COMtONENT FAILURC OCSCRISCO IN THIS REtORT (12)

CAUSE SYSTEM COMPONENT MANUFAC. EPOIITASLE VAhUFAC. EPORTASL TURER TO hPROS CAUSE SYSTEM COMPONENT YLRER TO,'IPIIOS J M I V A 3 9 1 SUPPLEMENTAL REPOIIT ~ XtECTCO (la) MONT>> DAY +EAR EXPECTEO SI 5'MISSION DATE (15)

YCS ttt Tot, awvataao CXPECTCO SUSMISSION OAPCI NO N A ACCTRACT (Lttult to to00 toacat. IA. apauoauuataty uhoau uupta aoaca ttpawuttao )a*act l)SI On February 10, 1988, St. Lucie Unit 1 was in Mode 1, 100% power, and at steady state conditions. During the local leak rate test performed by the plant's test group, the inside containment isolation valve for the containment atmosphere radiation monitor, FCV-26-1 (EIIS-JM), was found to have a leakage rate of approximately 100 standard cubic feet per minute (SCFM). This was in excess of the plant's Technical Specification limit of 0.27 La (equal to 245,153 standard cubic centimeters per minute, SCCM). The outside containment isolation valve was immediately closed, deactivated and secured in the isolation position by removing the fuse to its power source. (in order to comply to the Technical Specification requirement).

The root cause of the event was dirt accumulation and corrosion build-up on the actuator stem seal housing assembly, which resulted in a momentary binding of the stem which prevented the valve from fully closing. A contributing factor for the failure may have been due to the unique design of the actuator, which is a reverse acting actuator with a diaphragm plate for a direct acting actuator.

The actuator stem was cleaned and the stem seal housing assembly was refurbished.

Also, the diaphragm was replaced with a new diaphragm. The valve was stroke tested satisfactorily. Post maintenance leak test was performed and the leakage rate was found to be 450 SCCM, well within the Technical Specification limit.

At no time during the event was the health and safety of the public endangered.

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NRC Form S44A U S. NUCLEAR REQULATOR+ COMMISSION I94SI LICENSEE E T REPORT (LER) TEXT CONTINUA APPROVED OVd Nd 5 AIC4 EXPIRES: did(r(6 FACILITY NAME (I> DOCKET NUMEER (ll LEA NUMSEA (4l FACE il)

YEAR SEQUENTIAL ,Ig IIEVISIQN NVMEER NVMEEII St. Lucie, Unit 1 o 5 o o o' 8 002 0 0 OF TUCT (Ifmort ((MCE e IFEvsrd, vFF admen( FVAC FcmI l(E(A'Fl ((7(

DESCRIPTION OF THE EVENT At 0215, on February 6, 1988, operations personnel were performing the quarterly periodic stroke test on the containment isolation valve for the containment radiation monitor (EIIS-JM). During this test, valve FCV-26-1 had a dual open/close indication. This was indicative of the it was found out that the valve not being in its full closed position. The outside containment isolation valves FCV-26-2 and PCV-26-4 were immediately closed to comply with the Technical Specification action statement. At 0756, the valve PCV-26-1 was re-stroked for evaluation and it was noted to have fully closed. The FCV-26-1 was declared back in service and the valves PCV-26-2 and FCV-26-4 were opened.

At 1010, on February 9, 1988, operations personnel stroked valve PCV-26-1 for Instrument and Control (IaC) maintenance personnel for troubleshooting purposes. It was noted that the valve did not fully close. Again, the outside containment isolation valves FCV-26-2 and FCV-26-4 were immediately closed.

I (' personnel made a containment entry to adjust the FCV-26-1 actuator limit switch and re-stroked the valve. The valve indicated fully closed.

On February 10, 1988, the plant test group performed a total bypass leak test on valve FCV-26-1 as part of post maintenance testing and found the total bypass leakage rate was approximately 100 standard cubic feet per minute (SCPM) which exceeded the Technical Specification limit of 0.27 La (equal to 245,153 standard cubic centimeter per minute, SCCM). Immediately, the outside containment valve FCV-26-2 was tested to ensure containment integrity. The leakage rate of the valve PCV-26-2 was found to be 1100 standard cubic centimeter per minute (SCCM) which was well within the Technical Specification limit. The outside containment isolation valve was immediately closed and maintained closed until the valve FCV-26-1 was repaired and satisfactorily tested.

CAUSE OP THE EVENT The root cause of the event was due to dirt accumulation and corrosion build-up on the actuator stem seal housing assembly. This resulted in a momentary binding of the stem which prevented the valve from fully closing. A contributing factor for the failure may have been due to the unique design of the actuator, which has a reverse acting actuator with a direct acting diaphragm plate.

NRC FORM 444A (9441

NRC eorm 388A V.S. NVCLEAR REGULATORY COMMISSION (9481 LICENSEE E T REPORT (LER) TEXT CONTINUA U8 NO l(50-GIGrr '>oROUEO EXPIRES. 8ISI 88 FACILITY NAME (1I COCK ET NVM8EA Ill LER NVMEER (8) eAGE Il(

8EGUKNTIAL j~ REVISION YEAR NUM448 ~-'UM444 St. Lucie, Unit TEXT litmore Aoeoe e norrrrerf. Uoe ~ HRC 1

%%dnII GGSA 8 I (IT(

p 5 p p p 3 35 88 0 0 2 0 0 03 OF 0 4 ANALYSIS OP THB EVENT Technical Specification 3.6.3.1, requires that containment isolation valves shall be operable while in Mode 1 through Mode 4. With one or more of the isolation valves inoperable, restore the inoperable valve within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> or isolate the affected penetration within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> by the use of at least one deactivated automatic valve secured in the isolation position. During the time when containment isolation valve FCV-26-1 failed to fully close, the outside containment isolation valve PCV-26-2 was immediately closed, deactivated and secured in the isolation position by removing the fuse. This ensured that valve FCV-26-2 would remain in the isolation position while the valve PCV-26-1 was inoperable. The satisfactory test result (leakage rate of 1100 SCCM) of the outside containment isolation valve FCV-26-2 was an assurance that containment integrity was maintained during the event. When performing a local leak rate test on penetrations with a pair of isolation valves, it is assumed that the valve with the lower leakage rate fails open, thus the leakage across the penetration is governed by the valve with the higher leakage rate.

The as found leakage rate of 100 SCFM was a very conservative amount based on the calculation that the leakage rate was equal to the maximum air discharge flow on a 3/8 inch tubing supply line with make-up air at 35 psig without any flow restriction from a partially closed valve. The calculated leakage rate of 100 SCFM did not take credit for the valve being in the partially closed position but rather conservatively assumed that it was full open.

In the event of an accident, both of the isolation valves PCV-26-1 and FCV-26-2 are designed to fail closed, thus the actual governing leakage rate would be the leakage rate of PCV-26-2, which was found to be 1100 SCCM, well'elow the Technical Specification limit of 0.27 La (245,153 SCCM). Therefore, at no time was the health and safety of the public endangered. St. Lucie Unit 1 remained at mode 1, 100 percent power, and at steady state condition during the entire event.

CORRBCTIVB ACTIONS

l. Operations personnel immediately isolated the affected penetration by it closing the outside containment isolation valve and maintaining fn the secured isolation position by removing the fuse on the automatic isolation valve.

2. The outside containment isolation valve FCV-26-2 was immediately tested for integrity and was found to have leakage well within the Technical Specification limit.

3. The valve actuator stem for pCV-26-1 was cleaned and the corrosion build-up was removed. The actuator stem seal housing assembly was refurbished, and the valve actuator diaphragm was replaced with a new diaphragm. The valve was satisfactorily stroke tested after the repairs.

NRC ROAM 844A (843 I

NRC Foam 344A U $ . NUCLEAR RECULATORY COMMISSION

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LICENSEE T REPORT (LER) TEXT CONTINUA APPROV EO OMe NO 3(SOW(OI EXPIRES: E/3(I(e FAC(LITY NAME (1( OOCKET NUMEER (ll LER NUMEER (4( PACE (31 YE*A y;I SEOVENTIAL rP> IIEVISION NVV EII NVVSEA St. Lucie, Unit 1 0 5 0 0 0 3 3 5 8 8 0 0 04OF04 TEXT (Ifmee 4Pece N Ieeveed. we achene( iVRC %%dmI 3(E(A 3 I I (Tl CORRECTIVE ACTIONS (CONTINUED )

4. The valve was leak tested after the repairs were completed. The leakage of 450 SCCM was satisfactory.

5. St. Lucie Plant Reliability Maintenance Department searched for similar industry wide failures. This identified a failure of similar nature but of different model number and size valve. No trend of this type of seal housing assembly failure has been noted on the specific actuator model and size.

6. The Instrument and Control Department has initiated a Request for Engineering Assistance (REA) for Engineering Department to evaluate the applicability of the unique design of this type of actuator and diaphragm configuration for all of the containment atmosphere radiation monitor isolation valves of similar design FCV-26-1, -2, -3, -4, -5, and -6.

ADDITIONAL INFORMATION Failed Component Identification:

Component: Actuator Seal Housing Assembly Actuator Model No.t 70-13-1R ~

Actuator Diaphragm Size: 35 Square Inches Valve Model:, 70-27-1DRTX Valve Size/Type: 1 Inch - 1504, Glove Valve Manufacturer: W K M (Anchor/Darling Company)

Previous Similar Event:

For most recent similar event, see Licensee Event Report 335-87-005, which pertains to excessive penetration leakage across the valve seal on FCV-25-3.

NRC FORM 344A (043)

P. O. BOX 14000. JUNO BEACH, FL 3340B.0420 MARCH 1 0 1988 L-88-124 10 CFR 50.73 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 Gentlemen:

Re: St. Lucie Unit 1 Docket No. 50-335 Reportable Event: 88-02 Date of Event: February 10, 1988 Total Bypass Leakage on Containment Radiation Monitor Isolation Valve FCV-26-1 Exceeded echnica S eci 'cat'o Limit Due to Stem Corrosion 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, W. F. Conw Acting Group Vice President Nuclear Energy WFC/GRM/gp Attachment cc: Dr. J. Nelson Grace, Regional Administrator, Region II, USNRC Senior Resident Inspector, St. Lucie Plant USNRC, GRM/001. LER r>~

an FPL Group company