ML17223B170

LER 91-003-00:on 910426,2A Shutdown Cooling Heat Exchanger Out of Svc Due to Mispositioned Component Cooling Water Valve.Caused by Personnel Error.Valve Correctly Realigned & Redundant Train Valve checked.W/910430 Ltr

ML17223B170
Person / Time
Site:	Saint Lucie
Issue date:	04/30/1991
From:	Lauver C, Sager D FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-91-133, LER-91-003, LER-91-3, NUDOCS 9105060103
Download: ML17223B170 (9)

Text

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

'ACCESSION NBR:9105060103 DOC.DATE: 91/04/30 NOTARIZED: NO DOCKET FACIL:50-389 St. Lucie Plant, Unit 2, Flor'ida Power & Light Co. 05000389 AUTH. NAME AUTHOR AFFILIATION, LAUVER,C. Florida Power & Light Co.

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

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 91-003-00:on 910426,2A shutdown cooling heat exchanger out of. svc due to mispositioned component cooling water valve. Caused by personnel error. Valve correctly realigned

& redundant train's valve checked.W/910430 ltr.

,.

1 J

TITLE: 50.73/50.9 Licensee Event Report (LER), IncidentJ Rpt, etc.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

NOTES: A 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,J 1 1 INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 ~ AEOD/DS P/TPAB 1 1

.AEOD/ROAB/DSP 2 2 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB 7E 1 1 NRR/DLPQ/LHFB11 1 1 NRR/DLPQ/LPEB10 1 1 NRR/DOEA/OEAB 1 1 NRR/DREP/PRPB11 2 2 NRR/DST/SELB 8D 1 1

'RR/DST/SICB 7E 1 1 NRR/DST 2LBBJ31 1 1 NRR/DST/SRXB 8E 1 1 RE 0M 1 1 RES/DS IR/EIB 1 1 RGN2 FILE 01 1 1 EXTERNAL: EG&G BRYCE,J.H 3 3 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHY,G.A 1 1 NSIC POOREEW 1 1 NUDOCS FULL TXT 1 1 D

D D

NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM P 1-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 33 ENCL 33

P.O. Box 128, Ft. Pierce, FL 34954-0128 FPL APR 3 0 199'-91-133 10 CFR 50.73 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 Gentlemen:

Re: St. Lucie Unit 2 Docket No. 50-389

'Reportable Event 91-03 Date of Event: April 26, 1991 2A Shutdown Cooling Heat Exchanger Out of Service Due to Mispositioned Component Coolin Water Outlet Valve Caused b Personnel Error The attached Licensee Event Report is being submitted pursuant to the requirements of 10 CFR 50.73 to provide notification of the subject event. A supplemental report will be submitted at the usual 30 day time interval.

Very truly yours, D. A. S ger Vice sident St. Lucie Plant DAS:GRM:kw Attachment cc: Stewart D. Ebneter,.Regional Administrator, USNRC Region Senior Resident Inspector, USNRC, St. Lucie Plant II DAS/PSL N423 9g0c0rr0i03 910430 PDF ADOCK 0 000~89 PDR

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FPL FacsilliIC OI. U.S. NUCLEAR REGULATORY COMMISSION ~ AffNOIIOCAO NO 01 004100 NRCFNITT 666 4000%4: lOtH0 CSTNHITO 000OOI POI IKKOOCIO DC040T 00TN TN0 04Cf0AATTITIDCUE CDITI

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' (4) 050003891 0 0 4 2A Shutdown Cooling Heat Exchanger Out of Service Due to Mispositioned Component Cooling Water Valve Caused by Personnel Error EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED(8)

MONTH DAY YEAR YEAR S IAL MONTH DAY YEAR FACILITYNAMES DOCKET NUMBER(S)

N/A 5 0 0 0 4 2 6 9 1.

~

9 1 0 0 3 0 0 4 3 0 9 1 THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR:

N/A 05000.

OPERATING Check one or more of the followin (11)

MODE (9) 201402(b) 20.405(c) 50.73(a)(2)(iv) 73.71(b)

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

(10) 1 0 0 20.405(a)(1)(ii) 50.36(c)(2) 50.73(a)(2)(vii) OTHER 20.405(a) (1)(iii) (Specify in Abstract 50.73(a)(2)(i) 50.73(a)(2)(viii)(A) beloIvandin Text 201405(a)(1)(iv) 50.73(a)(2) (ii) 50.73(a)(2)(viii)(B) NRC Form 366A) 20.405(a)(1)(v) 50.73(a)(2)(iii) 50.73(a)(2)(x)

LICENSEE CONTACT FOR THIS LER 12 NAME TELEP ONE NUMBER Catherine Lauver, Shift Technical Advisor AREA CODE COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT 13 4 0 7 465 -3550 CAUSE SYSTEM COMPONENT MANUFAC- REPORTABLE CAUSE SYSTEM COMPONENT REPORTABLE TURER TO NPRDS TO NPRDS B E I S V P 3 4 0 I I I SUPPLEMENTAL REPORT EXPECTED 14 MONTH DAY YEAR EXPECTED YES (Ifyes; complete EXPECTED SUBMISSION DATE) SUBMISSION NO DATE (15) 0 5 2 6 9 ABSTRACT (Limit to f400 spaces.i.e. approximately fifteen single-space typewritten lines) (16)

This is an interim report. A followup report will be submitted.

At 0110 on April 26, 1991, with Unit 2 at 100% power, Operations personnel began searching for a DC ground.

At 0400, per plant procedure, Operations cycled HCV-14-3A, Component Cooling Water (CCW) outlet from the 2A Shutdown Cooling (SDC) Heat Exchanger (HX) to de-energize its solenoid operator in an effort to locate the DC ground. After the valve opened, no flow through the heat exchanger was indicated. Upon investigation, the 2A SDC HX CCW return isolation valve SB-14365 was found to be locked closed. This valve is required to be Locked Open. It had been entered into the Valve Switch Deviation Log on October 23, 1990 as Locked Throttled and restored November 29, 1990. As this is the most recent documented manipulation date, it is assumed to have been mispositioned at this time. The valve position pointer was broken and indicated open.

The cause of the mispositioning is under investigation.

Corrective actions include: the valve was correctly realigned; the redundant train's valve was checked; both units performed a full Valve Status Check.

FPL Facsimile of NRC Form 366 (6-89)

FPL Facslmra or ~ U.S. NUCLEAR REGULATORY COMMISSION ASSASNTO CAO ISA$ 150 0105 NRO Form 666 EITf saba AITI505 (6-69)

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FACILITYNAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR EQUENTIAL REVISION St. Lucie Unit 2 NUMBER NUMBER 05000389 TEXT (Ifmore spaceis reriuired, use additional NRC Form 366A's) (17) 9 1 0 0 3 0 0 0 2 0 0 4 This is an interim report. A followup report will be submitted At 0110 on April 26, 1991, with Unit 2 at 100% power, Operations personnel began to search for a DC ground. To find a ground, plant toads are individually isolated. Per plant procedure, Operations cycled HCV-14-3A, Component Cooling Water (CCW) (EIIS:CC) from the 2A Shutdown Cooling (

SDC) Heat Exchanger (HX) (EIIS:BP). During normal operations there is no flow through the shutdown heat exchanger; opening the valve should have resulted in 4000 gpm flow. There was no flow indicated through the HX. Operations. locally verified movement of HCV-14-3A and position of CCW inlet isolation valve SB-14348. CCW outlet isolation valve SB-14365 is required to be Locked Open, was indicating open by its valve position indicator, but was in fact Locked Closed.

The valve was reopened to its proper position. The redundant train's CCW outlet isolation valve position was checked as a precaution. The valve was in its proper Locked Open position, but its position indicator was also faulty.

An investigation revealed that SB-14365 was entered into the Valve Switch Deviation Log on October 23, 1990, when placed in a Locked Throttled position to balance CCW flow. On November 25, 1990, as Unit 2 was completing a refueling outage, the CCW system was placed in its operating alignment. Operating Procedure 2-0310020, "Component Cooling Water-Normal Operation," was performed. SB-14365 was verified to be Locked Open at this time; On November 29, 1990, the Valve Switch Deviation Log showed that the valve was restored to its Locked Open position. As November 29 is the last recorded date that SB-14365 was manipulated, it is assumed that the valve has been mispositioned since this time. The lack of an OPERABLE 2A SDC HX causes the 2A train of the Containment Spray System (EIIS:BE) to be administratively out of service.

From 0455 on February 19 through 0315 on February 20 and 2208 on February 20 through 1700 on February 21, 1991, the 2B Containment Spray System was out of service for routine maintenance and testing. Plant records are being reviewed to see if there are any other periods of time where both trains of the Containment Spray System were out of service.

CCW outlet isolation valve SB-14365 is a manually operated butterfly valve located in a horizontal line about twelve feet above the floor. Valve position indication is provided by a pointer which is supposed to move with the valve stem. The pointer was broken. A Plant Work Order was written October 21, 1990 to repair the pointer and was apparently worked January 17, 1991. At the time the mispositioning was discovered, the pointer erroneously indicated Open. Investigation into this valve position indicator failure will continue.

A Standing Night Order states that to check the position of a Locked Open valve, the valve shall be unlocked, closed slightly, reopened, and relocked. While the position indicated by the pointer was inaccurate and misleading, the handwheel on the valve indicates which way to turn to open the valve.

Since November of 1990, the position of this valve has been checked twice during the quarterly performance of Administrative Procedure 2-0010123, "Administrative Control of Valves, Locks, and Switches," and weekly during Administrative Procedure 2-0010125A, "Surveillance Data Sheets,"

FPL Facsimile of NRC Form 366 (6-69)

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FACILITYNAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR EQUENTIAL REVISIO St. Lucie Unit 2 NUMBER NUMBER TEXT (lfmore spaceis required, use additional NRC Form 0500038991 366A's)'17) 0 0 3 0 0 0 30 0 4

...

Data Sheet 36, I At all times it was reported to be Locked Open.

The root cause of the event is under investigation. A review of plant records, including operator logs, clearances, and Plant Work Orders, is being conducted. Personnel will be interviewed to determine the specific nature and cause of the error. An INPO Human Performance Enhancement System evaluation will also be performed.

V NT This event is reportable under the requirements of 10CFR50.73.a.2.i.B, any condition or operation prohibited by Technical Specifications. Technical Specification 3.6.2.1 "Containment Spray System" requires two independent Containment Spray Systems to be OPERABLE with an OPERABLE Shutdown Cooling Heat Exchanger.

A While the exact date of the mispositioning of the CCW outlet isolation valve to the 2A SDC HX is not yet known, November 29, 1990 is the last recorded date of a manipulation of the valve and is assumed to be the date of the mispositioning. Over a three day period in February 1991, the 2B Containment Spray System was taken out of service for routine maintenance and testing.

The SDC HX is not used until the recirculation phase for decay heat removal. The 2A Containment Spray System was always available to receive cool water from the Refueling Water Tank and deliver it to containment to mitigate a post-LOCA containment pressure rise. An alternate safety system for Containment Heat Removal, the Containment Cooling System, is being further evaluated for decay heat removal capability.

St. Lucie equipment sizing is such that the four containment fan coolers will provide the containment heat removal capability necessary to limit and reduce accident containment pressure and temperature during the recirculation phase. Additional analysis are in progress, assuming a single failure, to demonstrate that two containment fan coolers can also remove Large Break LOCA containment heat load during the recirculation phase. This result is expected because of the PSL containment design in which the free standing steel vessel will transfer heat to the environment.

FPL Engineering has performed a first order risk assessment of the CCW to the SDC HX valve being in the closed position. For a medium or large break LOCA, the frequency associated with the loss of the decay heat removal function only increases from 3.6E-8 per reactor year with a normal SDC HX lineup, to 5.8E-7 per reactor year with the shutdown heat exchanger isolated. With operator action to open the valve, the frequency is reduced to 1.5E-7 per reactor year.

Therefore, the health and safety of the public was not affected during this condition.

FPL Facsimile of NRC Form 366 (6-89)

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FACILITYNAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR EQUENTIAL REVISION St. Lucie Unit 2 NUMBER NUMBER 0500038991 TEXT (Ifmore spaceis rerluired, use additional NRC Form 366A's) (17) 0 0 3 0 0 0 4 0 0 4

1. Operations restored SB-14365 to its proper position and verified the position of the redundant train's CCW outlet isolation valve.

2. Plant Work Orders were submitted to repair the faulty pointers on each valve and determine the root cause of the faulty pointer.

3. All Operations personnel were counseled on the use of the Standing Night Order. Operations is investigating further methods to enhance independent verification.

4. Operations performed the entire Weekly Valve Status Check on both Unit 1 and Unit 2. No further discepancies were noted.

5. An INPO Human Performance Enhancement System evaluation will be performed on this event.

review will include human factors and work conditions.

'he Affected Component Identification:

Henry Prat t 14H Butterfly Valve Nuclear MK II with Manual Operator MDT-3 HW Model Number 1001 78 Serial Number C140 Previous Similar Licensee Event Reports:

335-89-002 "Inoperable 1B Diesel Generator Due to Fuel Oil System Valve Misalignment" 335-87-012 "Loss of Component Cooling Water Redundancy-1A and 1B Component Cooling Water Cross-tie Valves in Open Position" FPL Facsimile of NRC Form 366 (6-69)