ML20043F128

LER 90-009-00:on 900511,apparent Ruptured Diaphragm Found on Pressure Differential Switch in RCIC Steam Line.Caused by Torn Diaphragm Inside Switch.Replacement Switch Installed, Calibr & Functionally Tested satisfactorily.W/900608 Ltr

ML20043F128
Person / Time
Site:	LaSalle
Issue date:	06/01/1990
From:	Diederich G, Tennyson M COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-009-01, LER-90-9-1, NUDOCS 9006140181
Download: ML20043F128 (5)

Text

- . . . .. . ... - - - -. . - _

/ Commonwealth Edison * ,

.* [ _. LaSalle County Nucitar Station

• *l _

J. Rural Route #1, Box 220

• ' +

\ Marseilles, Illinois 61341 Telephone 815/357-6761 June 8, 1990 ,

Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission '

Mail Station P1-137 Washington, D.C. 20555

Dear Sir:

Licensee Event Report #90-009-00, Docket #050-373 is being i l submitted to your office in accordance with 10CFR50.73 l' (a)(2)(v).

I Y O L G. J. Diederich l- , [StationManager i LaSalle County Station GJD/fttT/1s I. Enclosure l

xc: Nuclear Licensing Administrator j NRC Resident Inspector 6

WRC Region III Administrator INPO - Records Center 9006140181'900601 )

PDR ADOCK 05000373 s PDC

. LICENSEE EVENT REPORT (LER) p, g g Docket thsuber (2) Pese (3) facility N me (1)

LaSalle County Station Unit 1 015101010131713 1lof!0l4 Title (4)

Mlled Olfferential Pressure Switch - RCIC isolation Instraent 5 t Date (7) Other Facilltles involved (8) twent Date (5) LER Number (6)

Revision Month Day Year Facility Nees (Mcket thster(s)

Month Day Year Year // fJSequential /j// ff/

/T/ thauber / thster__

01 51 01 01 01 I I 91 0 01019

~~

010 016 01 1 91 0 01 51 01 01 01 I I 01 5 11 i 91 0 THIS REPORT IS SUBMillED PURSUM110 THE REQUIREMENTS OF 10CFR OPERAllK J, (Check one or more of the followinn) (11) g 20.405(c) 50.73(a)(2)(l v) 73.71(b) 20.402(b) _ _.,,,,

poler 20.405(a)(1)(l) _ 50.36(c)(1) . X,_ 50.73(a)(2)(v) ,,_ 73.71(c) 50.36(c)(2) 50.73(a)(2)(vil) other (Specify LEVEL _ 20.405(a)(1)(ll) _,, _, _

0 20.405(a)(1)(lli) 50.73(a)(2)(l) 50.73(a)(2)(vill)(A) in Abstract (10) 1 0 __ ,,

20.405(a)(1)(lv) ___ 50.73(a)(2)(ll) 50.73(a)(2)(vill)(8) below and in ff///f///fff//ff/////////

j f ff f 50.73(a)(2)(x) Text) 20.405(a)(1)(v) ,,_,,,50.73(a)(2)(lli) _,

f

/ / / / _

f LICENSEE CONTACT FOR THIS LER (12)

TFLEPHONE NUPBER Nme AREA CODE Michael Tennyson. Technical Staff Enoineer. Ext. 2704 8 l 1 15 31 51 fl -l 61 71 61 1 COPFLETE ONE LINE FOR EACH C0890NENT FAILURE OFSCRIBED IN THIS REPORT (13)

SYSTEM COMPONENT MANUFAC- REPORTA8LE CAUSE SYSTEM COMPONENT MMUFAC- ' REPORT ABLE TO NPRDS f/ f

/ CAUSE TURER TO WPRDS TURER I I l l I I I X 8iN I I I I I I Y I I I I I I l //f I I I I I l l Expected Month l Day l Year SUPPLEMENTAL REPORT EXPECTED (14)

Submission lyes (if ves, canelete EXPECTED SUBMISSION DATE) IlNO I l l ABSTRACT (Limit to 1400 spaces, i.e, approximately fif teen single-space typewritten lines) (16)

On May 11,1990 at 0240 hours0.00278 days <br />0.0667 hours <br />3.968254e-4 weeks <br />9.132e-5 months <br />, during perfonnance of LaSalle Instroent Surveillance, LIS-Al-301, " Unit 1 Stem Line High flow Reactor Core Isolation Cooling (RCIC) Isolation Functional Test," Pressure Differential Switch (PDS) 1E31-#013AA was found to have an apparent ruptured diaphrs p. Unit I was in operational condition 1 (Run) at 1001 power level.

The switch functions to provide a Division 1 (Outboard) isolation of the RCIC Stem Line under a high stem flow condition. The switch PDS 1E31-#013AA was made non-functional by the ruptured diaphrap, therefore the Division I isolation from this switch was unavailable.

However, pressure differential switch PDS 1E31-W0138A was still available to provide Olvision 11 (inboard) "

isolation.

RCIC system was declared inoperable on May 11, 1990 in order to perform the required surveillance. The High Pressure Core Spray remained operable throughout the duration of this event.

A replacement switch was installed, calibrated, and functionally tested satisfactorily. RCic system was declared operable on May 11, 1990 at 1900 hours0.022 days <br />0.528 hours <br />0.00314 weeks <br />7.2295e-4 months <br />.

This event is reported to the Nuclear Regulatory Consission as a Licensee Event Report in accedance with 10CFR50.73(a)(2)(v) due to RCic belne declared inoperable and loss of a safety system function.

Fosie Ren 2.0

• Lle-i"**f EVENT REPORT (LER) TEXT CONTlWATION LER NWSER (6) Pane (3)

FAtlLITY NAM (1) DOCKET NUPSER (2)

Year //,! Sequential

/ /,// Revision W/ Number W/ thaber o I $ 1 o I o I o 1 31 71 3 910 oIo19 - oI o el 2 0F 01 4

% )1e County Station unit ? -

TEK1 EnergyIndustryIdentificationSystem(Ells)codesareidentifiedinthetestas[KK)

PLANT AND SYSTEM IDENTIFICA110N General Electric - talling Water Reactor Energy industry identification System (Ells) codes are identified in the text as [XX).

A. CON 0lil0N PRIOR 10 EVENT Event oate: 5/11/90 Event time: 0240 Hours unit (s): )

Reactor Mode (s): 1 Mode (s) Name: ggL Powertavel(s): M S. DESCRIPTION OF EVENT Reactor Core Isolation Cooling (RCIC, RI) [RN) Stem Line High Flow Isolation (PC) [.1M] Switch (P05)-1E314013AA was found to be non-functional on May 11, 1990 at 0240 hours0.00278 days <br />0.0667 hours <br />3.968254e-4 weeks <br />9.132e-5 months <br />. The problem was noted while a functional test was being perfomed per LaSalle Instrument Surveillance LIS-RI-30), " Unit 1 Ste m Line High Flow RCic Isolation Functional Test." This surveillance calls for applying a test pressure to switch P05-1E31-#013AA to check that the proper actuations occur at the proper setpoints.

During this survel11ance, the instrement Maintenance Technician (CST) could not actuate the instrument and detemine the setpoint. The switch would not hold the applied pressure. RCIC was declared inoperable per Degraded Equipment Log (DEL) thaber 327-09-1-125.

A high differential pressure condition for P05-1E31-#013AA automatically closes valve IE51-F008, "RCic Stem Line Outboard Isolation Valve."

The design function of POS 1E314013AA is to initiate an outboard contalament isolation (close valve IESI-F008) in the event of a stem line break downstrem of valve IESI-F000.

No other inoperable equipment / systems contributed to this event. No automatic or manual safety system actuations occurred and none were required. No Operator actions contributed to the causation or severity of this event. Actions taken to correct the cause of this event were timely and appropriate.

This event is reported to the Nuclear Regulatory Commission as a Licensee Event Report in accordance with 10CFR50.73(a)(2)(v) due to RCic being declared inoperable and loss of a safety system function.

I . LICENSEE EVENT REPORT (LER) TEXT CONilemAT10N Form Rev 2.0 FAClllTY teAME (1) DOCKET NumER (2) LER Nu mER (6) Pane (3)

Year /// Sequential ff//j/ Revision ffj/

// Nueer /// Nueer

%11e County Station unit 1 oI5IoIoIo 1 31 71 3 9Io - oIol9 - oI o 01 3 or . 01 4 TEXT Energy Industry Identification System (Ells) codes are identified in the text as (XX)

C. APPARENT CAUSE OF EVENT The differential pressure switch was dismantled and inspected at the station in order to determine cause of failure.

POS-1E3141013AA failed to function because of a torn diaphrop inside the differential pressure switch.

The tear occurred between the cylinder disk outside dimeter and the 0-Ring sealing surface (approximately 3/8 inch long). During the inspection there was nothing abnonnel found inside the pressure switch which caused the diaphrap to tear.

The diaphrap divides the two halves of the differential pressure switch into a "high" side and a " low" side. As system flow increases, the difference in pressures between the sides of the switch also increases. This causes the diaphrap to flex. A piston assembly is affixed to the diaphrap and drives '

a microswitch which trips when the deflection of the diaphrap is sufficient. Due to the tear in the diaphrap, no deflection is possible and this renders the trip function of the switch inoperable.

l l

D. SAFETY ANALYSIS OF EVENT l

! During the time that PDS-1E31-N013AA was inoperable, the outboard isolation functions whic) occur as a l result of Inne break could not have occurred as designed. The torn diaphra p of PDS-1E31-N013AA would allow for the equalization of pressure between the high and low stem lines. However, separate equipment (pressure differential switches PDS-1E31-N0130A) remained fully operable, and would have provided the inboard isolation of valves 1E514063 and IE514076, 'RCic Inboard Isolation Valve and RCic Wannup Bypass Valve."

The isolation signals due to high RCic stem line area temperature and differential temperature were also operable. Previous testing which verified this switch to be operable, LIS-RI-30), " Unit 1 Stem Line High Flow RCIC isolation Functional Test," was perfonned on April 4,1990.

The corrective action for this event was performed as required by Technical Specifications. This resulted in RCic being declared inoperable. During this time, however, High Pressure Core Spray (HPC5, HP) [BG) was operable.

E. CORRECTIVE ACTIONS 1

Because the P05-lE31-N013AA switch was inoperable, the appilcable action of Technical Specification 3.3.2 was entered. Inboard Isolation valves 1E51-F063 and 1E51-F076 were secured closed prior to the start of the surveillance which met the requirements of Technical Specification 3.3.2.

RCIC was entered as inoperable in Degraded Equipment Log (DEL) Weber 327-89-1-125. Action Statement b.

of Technical Specification 3.7.3 allows fourteen days to restore operability to RCIC, provided HPCS remains operable.

i.

j LHCENSEE EVENT REPORT (LER) TEXT CONTINUATION Fonn Rev 2.0 DOCKET NUSER (2) LER IRpSER (6) Pose (3)

FACILliY NAPE (1)

Sequential Revision Year //f f

/T/ thster //j/

ff

//

/

Weser taSalle County Station unit 1 015101010131713 910 - 01019 - 01 0 01 4 0F 01 4 TEXT Energy Industry Identification System (Ells) codes are identified in the text as [XX]

A new SOR differential pressure switch identical to the failed one was certified for use in the RCic i l

stem line high flow application using LIP-4M-952, " Static-0-Ring Differential Pressure Switch Operability Test," and LIP-GM-956, " Analysis of Static-0-Ring Olf ferential Pressure Switch Data.'

This new switch was installed per LIP-GM-946, " Installation Procedure For SOR Model 103/102 Environmentally Quallflod Olfferential Pressure Switches" under LaSalle Work Request L98867 on May 11, 1990.

The switch was calibrated per LIS-R!-101, " Unit 1 Stem Line High Flow RCIC isolation Calibration."

Operability was restored to RCIC on May 11, 1990 at 1900 hours0.022 days <br />0.528 hours <br />0.00314 weeks <br />7.2295e-4 months <br />.

The inoperable switch was disassembled and inspected per LIP-GM-%2, "Disassenbly and Inspection of SOR Model 102 and 103 Delta-P Switches."

F. PREVIOUS EVENTS LER Naser Title 374/86-018-01 Failure of Reactor Core Isolation Cooling Stem Line Flow isolation Switch Due to Torn Diaphrap 374/87-016-01 Defective Low Pressure Core Spray Minlaan Flow Swltch i

l 374/87-019-01 Failure of Static-0-Ring Differential Pressure Switch Due to Leakage Across i

Diaphrap 373/88-009-01 High Pressure Core Spray Low Low Level Initiation Static-O-Ring Level Switch Diaphrap Rupture 373/89-012-01 RCIC Hi Stem Flow Isolation 50R Failure / Leak in Olaphrap G. COMPONENT FAILURE DATA Nomenclature Model themer MFG Pa -

t Nweer Manufacturer Differential 103AS-8203 h/A SOR, Inc.

l Pressure Switch WX-JJTTx6

--