ML17285B047

LER 90-003-00:on 900126,HPCS Sys Pump Suction Valve Switchover Occurred During Performance of Procedure for Draining Ref Leg.Caused by Plant Configuration.Sys Restored to pre-event Lineup status.W/900223 Ltr

ML17285B047
Person / Time
Site:	Columbia
Issue date:	02/23/1990
From:	Arbuckle J, Powers C WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-003, LER-90-3, NUDOCS 9003020127
Download: ML17285B047 (14)

Text

ACCELERATED D UTION DEMON KTION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9003020127 DOC.DATE: 90/02/23 NOTARIZED: NO DOCKET FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION ARBUCKLE,J.D. Washington Public Power Supply. System POWERS,C.M. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 90-003-00:on 900126,HPCS sys pump suction valve switchover during surveillance testing.

W/8 DISTRIBUTION CODE XE22T COPIES RECEIVED:LTR ENCL SIZE:

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

NOTES:

RECIPIENT COPIES RECXPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD 1 1 SAMWORTH,R 1 1 INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DS P 2 2 DEDRO 1 1 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB9H3 1 1 NRR/DET/ESGB 8D 1 1 NRR/DLPQ/LHFBll 1 1 NRR/DLPQ/LPEB10 1 1 NRR/DOEA/OEAB11 1 1 NRR/DREP/PRPB11 2 2 NRR/DST/SELB 8D 1 1 NRR/DST/SICB 7E 1 1 /JETS LB8Dl 1 1 NRR/DST/SRXB 8E 1 1 EG L ,

02 1. 1 RES/DSIR/EIB 1 ~ 1. RGN5 FILE 01 1 1 EXTERNAL EGGG WILLIAMSi S 4 4 L ST LOBBY WARD 1 LPDR 1 1 NRC PDR 1 1 NSXC MAYS,G 1 1 NSIC MURPHY,G.A 1 1 NUDOCS FULL TXT 1 1 NOTE TO ALL "RIDS" RECIPIENTS:

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

FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED:,LTTR '7 ENCL 37

0 WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968 ~ 3000 George Washington Way ~ Richland, Washington 99352 February 23, 1990 Docket No. 50-397 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

NUCLEAR PLANT NO. 2 LICENSEE EVENT REPORT NO.90-003

Dear Sir:

Transmitted herewith is Licensee Event Report No.90-003 for the WNP-2 Plant.

This report is submitted in response to the report requirements of 10CFR50.73 and discusses the items of reportability, corrective action taken, and action taken to preclude recurrence.

Very truly ours, C. . Powers (H/D 927H)

W -2 Plant Hanager JDA:lr

Enclosure:

Licensee Event Report No.90-003 cc: Hr. John B. Hartin, NRC Regi'on V Hr, C. J. Bosted, NRC Site (H/0 901A)

INPO Records Center Atlanta, GA Hs. Dottie Sherman, ANI Hr. D. L, Williams, BPA (H/0,399) got.>st.)20l 27 5'v0223 PDR ADOCK 0-40035'7 PDC

B NRC FOFTM 366 U.S, NUCLEAR REGULATORY COMMISSION (666) APPROV ED OMB NOB 31504)104 EXPIRES: 4/30/62 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REOUESTt 50.0 HRS. FORWARD LICENSEE EVENT REPORT (LER) COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (F630). U.S. NUCLEAR REGULATORY COMMISSION. WASHINGTON, DC 20555. AND TO THE PAPERWORK REDUCTION PROJECT (31500104). OFFICE OF MANAGEMENTAND BUDGET. WASHINGTON. DC 20503.

FACILITY NAME H) DOCKET NUMBER l2) PA E 3 Washin ton Nuclear Plant - Unit 2 o s o 0 039 7~oF06

"'"'" High Pressure ore pray ystem ump uc ion a ve w> c over ur>ng urve> ance Testing Due to Instrument Indicated Level Excursion EVENT DATE IS) LER NUMBER I6) REPORT DATE (7) OTHER FACILITIES INVOLVED (SI MONTH DAY YEAR YEAR corAO: SEOVENTIAL :(RS: REVS~ MONTH OAY YEAR FACILITYNAMES DOCKET NUMBER(6) x('coS NUMBER 'R'UMBER 0 5 0 0 0 01 269 090 0 0 3 000 223 90 0 5 0 0 0 THIS REPORT IS SUBMITTED PURSUANT TO THE RLOUIREMENTS OF 10 CFR (I: ICheck one or more of the followinBI (11)

OPERATING MODE (6) .1 20A02(bl 20.40S(c) 50.73(ol(2)(ivl 73.71(8)

POWER 20A05( ~ ) (Il(i) 50.38(c)(1) 50,73(ol(2) (vl 73.71(cl LEYEL 1 0 0 20.405(ol(1 I(QI 50.35 (c) (2) 60.73(o I (2)(rill OTHER ISpecrfy in Abttrect

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LICENSEE CONTACT FOR THIS LER (12I NAME TELEPHONE NUMBER AREA CODE J . D. Arbuckle, Com liance En ineer 5 093 77 -21 15 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

MANUFAG MANUFAC REP0RTABLE CAUSE SYSTEM COMPONENT TURER TO PP ROB

)gj2Pj4(II o BEE SYSTEM COMPONENT TURER

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'~'UPPLEMENTAL REPORT EXPECTED (14) MONTH OAY YEAR EXPECTED SUBMISSION DATE I15)

YES Ilfyet, complete EXPECTED SUBMISSIDEY DATE) X NO ABSTRACT I(.lmlt to f400 rpecei. I e., eppioxlmerely fifteen tingle rpece typewritten linnl (16)

On January 26., 1990 at 0100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> a High Pressure Core Spray (HPCS) System pump suction valve switchover occurred during the performance of a procedure for draining the reference leg of Suppression Pool Narrow Range Level Transmitter CMS-LT-l.

Plant Equipment.Operators (non-licensed) were draining the reference leg in accor-dance with the procedure, when level indication increased from +1H to +8". Plant configuration at the time was such that HPCS suction was lined up to the Condensate Storage Tanks (the normal lineup, with .HPCS-V-1 open) and Suppression Pool Suction Valve HPCS-V-15 was closed (reference Figure 1). When the instrument level excur-sion occurred, it caused an Engineered Safety Feature suction valve transfer (due to a sensed high Suppression Pool level) and, by design, HPCS-V-1 automatically closed and HPCS-V-15 automatically opened.

Following the suction transfer, Plant Operators reviewed the procedure and repeated the activity. This time a level excursion of +20 inches was noted. The valve lineup was thenPverified and, because drywell pressure was +0.5 psig, the procedure was repeated with a positive pressure capture device over the vent to evaluate reference leg blockage. Crew Equipment Operators were also consulted for the NRC Form 366 (64)9)

NRC FORM 368A U.S. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO.31500104 (8$ 9)

EXPIRES; E/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT (LER) INFORMATION COLLECTION REOUEST: 60A) HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (P430), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO 1'HE PAPERWORK REDUCTION PROJECT (31500)0EI. OFFICE OF MANAGEMENTAND BUDGET. WASHINGTON, DC 20503.

FACILITY NAME (I) DOCKET NUMBER Il) LER NUMBER (8) PAGE (3)

YEAR,Rg+ EEOVENTIAL IE4'EVISION k: ~

NVMSER NVMEE4 Washington Nuclear Plant - Unit 2 0 s o o o 3 9 7 90 0 03 0 0 02 OF 0 6 TEXT /lfmoro EPoco /E Togo/rod, rrro odrfflforro/NRC Form 38849/ (17)

Abstract (Continued)

"normal" performance of this evolution because the procedure and valve lineup were

'orrect, all local conditions appeared normal, and the procedure had successfully been performed on a weekly basis. The concensus was that the normal range observed

,is approximately 1 to 2 inches and this has not 'previously caused a suction transfer to occur. Plant Equipment Operators then procee'ded to the second level transmitter (CMS-LT-2), performed the test, and observed a similar magnitude shift,and suction transfer.

As an imediate correcti've action, because no moisture was observed, Plant Operators restored the system to pre-event lineup status. further corrective action consists of changing the procedure to transfer HPCS suction from the Condensate 'Storage Tanks to the Suppression Pool prior to draining the reference legs.

The preliminary cause of this event appears to be a pressure differential between Primary Containment and the Reactor Building, which caused pressure in the reference leg to decrease during the draining process. However, the root cause analysis for this event has not yet been completed. If any new substantive information develops as a result of completion of the root cause effort, mental LER.

it will be reported in a supple-This event posed no threat to the health and safety of either the public or Plant personnel.

Plant Conditions Power Level - 10(C Plant Mode - 1 Event Descri tion On january 26, 1990 at 0100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> a High Pressure Core Spray (HPCS) System pump suction valve switchover occurred during the performance of Plant Procedure, PPM 2.4.2, HResidual Heat Removal System." The section of the procedure being performed at the time of the event was, "Suppression Pool Level Transmitter Reference Leg Draining." This procedure section provides guidance for draining the reference legs when directed by the Scheduled Maintenance System (SMS). This activity has been performed routinely on a weekly basis.

NRC Form 388A (889)

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III t 8

NRC FORM 366A (64)9)

LICENSEE EVENT REPORT ILER)

TEXT CONTINUATION U.S. NUCLEAR REGULATORY COMMISSION t APPROVEO 0MB NO. 31600104 EXPIRES: 4f30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REOUEST: 60JI HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (P630), US. NUCLEAR REGULATORY COMMISSION. WASHINGTON, DC 20666, AND TO THE PAPERWORK REDUCTION PROJECT (31604)(04), OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20603.

FACILITY NAME (1I DOCKET NUMBER (2I LER NUMBER (6) PAGE (3) 6(Sr SEovENTIAL Rj)J RevrsroN 2>> <<o NVMSSrr I. JS NVMSErr Washington Nuclear Plant - Unit 3 9 7 9 0 0 03 00 03 OF 0 TEXT IIImare <<>>ce Je mrlrdred, rr>> edrlldarrel NRC Farm 36649) ((7)

Plant Equipment Operators (non-licensed) were draining the reference leg for Sup-pression Pool Narrow Range Level Transmitter CMS-LT-1 in accordance with the proce-dure, when level indication increased from +1" to +8". Plant configuration at the time was such that HPCS suction was lined up to the, Condensate Storage Tanks (the normal line up, with HPCS-V-1 open) and Suppression Pool Suction Valve HPCS-V-15 was closed (reference Figure 1).

When the instrument level excursion occurred, it caused an Engineer ed Safety Feature suction valve transfer (due to a sensed high Suppression Pool level) and by design, HPCS-V-1 automatically closed and HPCS-V-15 automatically opened.

Following the suction tr'ansfer, Plant Operators reviewed the procedure and repeated the activity. This time a level excursion of +20 inches was noted. The valve lineup was then verified and, because drywell pressure was +0.5 psig, the procedure was repeated with a positive pressure capture device over the vent to evaluate reference leg blockage. Crew Equipment Operators were also consulted for the "normal" performance of this evolution because the procedure and valve lineup were correct, all local conditions appeared normal, and the task had been perfor'med suc-cessfully on a weekly basis. The concensus was that the normal range observed is approximately 1 to 2 inches, and this has not previously caused a suction transfer to occur. Plant Equipment 'Operators then proceeded to the second level transmitter (CMS-LT-2), performed the test, and observed a similar magnitude shift and suction transfer.

Since no moisture was observed, the system was restored to the pre-event lineup.

Imediate Corrective Action Plant Operators (Licensed) restored the system to pre-event lineup status (HPCS-V-1 was opened and HPCS-V-15 was closed).

Further Evaluation and Corrective Action A. Further Evaluation

l. This event is reportable under 10CFR50. 79(a)(2)(iv) as an event or con-dition that resulted in manual or automatic actuation of any Engineered Safety Feature (ESF).

2. There were no structures, systems or components that were inoperable at the start of this event that contributed to the event.

NRC Form 366A (64)9)

Al I

NRC FO(IM 366A U.S, NUCLEAR REGULATORY COMMISSION APPROVEO OMB NO.31600104 (64)9)

EXPIRES: 4/30/62 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT (LER) INFORMATION COLLECTION REOUESTI 500 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (P4)30), U.S. NUCLEAR

. REGULATORY COMMISSION. WASHINGTON, DC 20555, AND TO 1HE PAPERWORK REDUCTION PROJECT (31500104), OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1) DOCKET NUMBER (21 LER NUMBER (6) PAGE (3)

SEQUENTIAL ~ REvrsloN NUMBER ~.4Ã NUMBER Washin ton Nuclear Plant - Unit 2 '3 9 7 0 0 OF TEXT ///mBIB 4/IBce /4/I//rrrd, Ir>> Bdd/6/rn4/HRC Form 86642/ (17)

3. This particular level instrument is unique in that it has an air reference leg that is drained periodically because a moisture buildup could cause an incorrect level indication. Most level instruments in the Plant have reference legs that are filled with water.

4. A troubleshooting plan was prepared and implemented as an attempt to determine if the method of valve operation, when draining the reference leg, would affect indicated level. The plan was written to open Test Valve PI-V-905 slightly, then close the valve immediately when air flow was noticed. Directions were 'then given to fully open the test valve and then close it. When the valve was opened slightly, the narrow range suppression pool level instrument indicated an increase in level of 1 - 2 inches. However, when the valve was fully opened the instrument indicated approximately +6.5 inches, which would have been sufficient to cause a suction valve switchover. During the troubleshooting efforts, HPCS suc-,

tion was aligned to the Suppression Pool.

As a result of the troubleshooting activity, it was determined that two options were available to resolve the problem, at least until such time that the root cause analysis has been completed. These options were 1) providing guidance in the procedure to open the test valve slightly when draining the reference leg, or 2) changing the procedure to transfer HPCS suction from the Condensate Storage Tanks to the Suppression Pool prior to performing the activity.

5. The preliminary cause of this event appears to be a pressure differential between Primary Containment and the Reactor Building, which caused pres-sure in the reference leg to decrease during the draining process. How-ever, the root cause analysis for this event has not yet been completed.

If any new substantive information develops as a result of completion of the root cause effort, it will be reported in a supplemental LER.

B. Further Corrective Action Plant Procedure (PPM) 2.4.2 has been changed to transfer HPCS suction from the Condensate Storage Tanks (normal lineup) to the Suppression Pool prior to draining Suppression Pool level transmitter reference legs.

Safet Si nificance There is no safety significance associated with this event. There was no actual Suppression Pool level change and the event was limited to an instrument transient.

Furthermore, all systems operated as designed to cause the HPCS System pump suction valve switchover.

15 Accordingly, this event posed no threat to the health and safety of either the public or plant personnel.

NRC Form 366A (689

0 E l,

NRC FOPM 368A (649) t LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION U.S. NUCLEAR REGULATORY COMMISSION t APPROVED 0M B NO. 31500)04 EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REOUEST: 60J) HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE fIECORDS AND REPORTS MANAGEMENT BRANCH (F4130), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (316041)04). OFFICE OF MANAGEMENTAND BUDGET. WASHINGTON. DC 20503.

FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (5) PAGE IS) g SCQVCNTIAL REVISION NVMSCA NVMSCA Washin ton Nuclear Plant - Unit 2 0 s 0 0 o 3 9 7 9 0 OF TEXT illrmore Cpece ls erlrdred, Iree edd/dome/ NRC Feern 3664 2/ ((7)

Similar Events None EIIS Information Text Reference EI IS Reference

~Sstem ~Com onent High Pressure Core Spray (HPCS) System BG Residual Heat Removal (RHR) System BO CMS-LT-1 IK LT Condensate Storage Tanks (CSTs) KA TK HPCS-V-1 BO V HPCS-V-15 BO V CMS-LT-2 IK LT Suppression Pool NH Primary Containment NH Reactor Building R PI-V-905 IK TV NfIC Form 368A (6$ 9)

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