ML17285B082

LER 89-033-01:on 890811,RWCU Isolation Occurred When Fuse in Power Supply to Leak Detection Monitor Blew,Giving False High Alarm Signal to Isolation Logic.Cause Unknown.Fuse Replaced & RWCU Sys Restored to operation.W/900302 Ltr

ML17285B082
Person / Time
Site:	Columbia
Issue date:	03/02/1990
From:	Fies C, Powers C WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-89-033, LER-89-33, NUDOCS 9003140383
Download: ML17285B082 (5)

Text

t ACGELERATED DISTRIBUTION DEMON~)TMTION SYSTEM t

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS) 0 ACCESSION NBR:9003140383 DOC.DATE: 90/03/02 NOTARIZED: NO DOCKET FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe. 05000397 AUTH. NAME AUTHOR AFFILIATION FIES,C.L. Washington Public Power Supply System POWERS,C.M. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 89-033-01:on 890811,RWCU delta flow isolation due to blown fuse.

W/8 ltr. D DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

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

NOTES:

A RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL D PD5 LA 1 1 PD5 PD 1 1 SAMWORTH,R 1 1 D INTERNAL: ACNW 2 ' ACRS 2 2 AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 2 DEDRO 1 1 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB9H3 1 1 NRR/DET/ESGB 8D 1 1 NRR/DLPQ/LHFB11 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 NRR B8D1 1 1 NRR/DST/SRXB 8E 1 1 R RH 1 1 RES/DSIR/EIB 1 1 RGN5 FILE 01 1 1 EXTERNAL EGGG WILLIAMSg S 4 4 L ST LOBBY WARD 1 1 LPDR NSIC MAYS,G NUDOCS FULL TXT 1,1 1

1 1

1 NRC PDR NSIC MURPHY;G.A 1

1 1

1 R A

D NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASIKl CONTACT THE DOCUMENT CONTROL DESK, ROOM PI-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISIRIBUTION FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 37 ENCL 37 Y

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@~i WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968 ~ 3000 George Washington Way ~ Richland, Washington 99352 Docket No. 50-397 Harch 2, 1990 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

NUCLEAR PLANT NO. 2 LICENSEE EVENT REPORT NO. 89-033-01

Dear Sir:

Transmitted herewith is Licensee Event Report No. 89-033-01 for the WNP-2 Plant. This revised report is submitted to correct a format error on the abstract page oF the report.

Very truly yours,

$ 74/4~

C. H. Powers (H/0 927H)

WNP-2 Plant Hanager CHP:lr

Enclosure:

Licensee Event Report No. 89-033-01 cc: Hr. John B. Hartin, NRC Region V Hr. C. J. Bosted, NRC Site (H/0 901A)

INPO Records Center Atlanta, GA Hs. Dottie Sherman, ANI Hr. 0. L. Williams, BPA (H/0 399)

(/ ~suot0 rgag.g 9003i40383 900302 PDR ADOCK 05000397 PDC

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 31504)104 (669)

EXPIRES: 4I30/92 ESTIMATED BURDEN PEA RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST: 50.0 HAS. FORWARD LICENSEE EVENT REPORT (LER) COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (P6301, V.S. NUCLEAR REGULATO AY COMMISSION. WASHINGTON. DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (31500104). OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503.

DOCKET NUMBER 12) PAGE FACILITY NAME (11 Washin ton Nuclear Plant - Unit 2 0 5 0 0 0 3 9 7 1 OF 0 3 TITLE (4)

Reactor Water Cleanu Delta Flow Isolation Due to Blown Fuse EVENT DATE (5) LFR NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED ISI SEQUENTIAL @Xs REVISION MONTH OAY YEAR FACtLITY NAMES DOCKET NUMBERISI MONTH OAY YEAR YEAR NUMSER 0: NUMSER 0 5 0 0 0 0 8 8 9 8 9 0 Ill(3 3 0 1 0 3 0 2 9 0 0 5 0 0 0 THIS REPORT IS SUBMITTED PURSUANT T0 THE REQUIREMENTS OF 10 CFR gr IChecfr one or more of the forrovnnfrI 111 OPERATING MODE (9) 20.402 (6 l 20.405(cl 50.73(sl(2) (ivl 73.71)6) 1 POWER 20AOS(sl(1)(l) 50.36 (cl (I I 60,73(s) (2)(vl 73.71(cl LEYEL oTHER Ispecify in Aostrect 0 0 20.405 (4) )I) 50.36(c) l2) 50.73(sH2)(vill Oerovv end In Test, HIIC Form 20A05(s l(1)(ill) 50.73(sl (2)(ll 60.73(s ) (2) (vill)(AI 3SSAI 20AOS( ~ )(1)(lv) 60.73(sl(2) (ill 50.73(s) (2) (villi(B) 20AOS(el(1) (v) 50.73(sl(2)(ill) 60.73( ~ ) l2) lrr)

LICENSEE CONTACT FOR THIS LER (121 NAME TELEPHONE NUMBER AREA CODE C. L. Fies Com liance En ineer 5 0 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFAC TURER REPOATABLE M CAUSE SYSTEM COMPONENT MANUFAC.

TUAER EPORTABLE TO NPADS I'4QN' SUPPLEMENTAL REPORT EXPECTED (14)

(~~'

Il MONTH M4':OAY YEAR EXPECTED SUBMISSION DATE (15I YES IIIyes, compiete EXPECTED SUSsrlSSIOH OA TEI NO ABSTRACT (Limit ro ICOO sprees. I e.. epproeimetefy fifreen slnfffe specs typewritten lined (16)

On August ll, 1989 at 0254 hours0.00294 days <br />0.0706 hours <br />4.199735e-4 weeks <br />9.6647e-5 months <br />, with the plant at 80K power, a Reactor Water The isolation occurred when a fuse in the Cleanup System (RWCU) isolation occurred.

power supply to the leak detection monitor blew, giving a false high flow signal to the isolation logic. There was no apparent cause for the blown fuse. As an immedi-ate corrective action, the fuse was replaced and the RWCU:system was restored to operation. Since all safety systems operated as designed, this event posed no threat to the health and safety of plant personnel or the public.

NRC Form 366 (669)

NRC FORM 358A US. NUCLEAR REGULATOAYCOMMISSION APPROVED OMB NO. 31500104 (64)9)

E X PI A ES. 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT (LER) INFORMATION COLLECTION REQUEST? 504) HRS. FORWARD COMMENTS REGARDING BUADEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPOATS MANAGEMENT BRANCH (P4)30), U.S. NUCLEAR REGULATORY COMMISSION. WASHINGTON, DC 20555. AND TO

, THE PAPERWORK REDUCTION PROJECT (31504)(04), OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, OC 20503.

FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (5) PAGE (3)

SEOUENTIAL '3'I REVISION

?

NUMBER r?Prr NUMBER Washin ton Nuclear Plant - Unit 2 0 5 0 0 0 3 OF TEXT//Inde Speed/4/BBBSed, B>> Bdd//4?ne/HRC Form JSSAB/(IT)

Plant Conditions a) Power Level - BOX b) Plant Mode - 1 Event On August ll, 1989 at 0254 hours0.00294 days <br />0.0706 hours <br />4.199735e-4 weeks <br />9.6647e-5 months <br />, with the plant at 8(C power, a Reactor Water This isolation is part of a Nuclear Steam Cleanup (RWCU) System isolation occurred.

Supply Shutoff System (NS4) Group 7 isolation. The isolation was caused by a blown fuse (E31A-F18) in the power supply to the leak detection flow switch (LD-FS-605B) which provides input to the isolation logic. When LD-FS-605B lost power, it closed, giving a false high flow signal to the downstream isolation logic (relays K7B and K26). This in turn caused RWCU Inboard Isolation Valve RWCU-V-1 to close and the running RWCU pump, RWCU-P-1A, to trip.

Immediate Corrective Action At 0339 hours0.00392 days <br />0.0942 hours <br />5.605159e-4 weeks <br />1.289895e-4 months <br />, the blown fuse was replaced with an identical unit (Bussman 5 amp type MIN). At 0458 hours0.0053 days <br />0.127 hours <br />7.572751e-4 weeks <br />1.74269e-4 months <br />, Plant Reactor Operators returned RWCU-P-lA to service after proper warmup in accordance with plant procedures.

Further Evaluation and Corrective Action A. Further Evaluation

1. This event is being reported as an event that resulted in automatic actua-tion of an Engineered Safety Feature under the requirements of 10CFR50.73 (a)(2)(iv).

2. The ESF actuation was caused by a blown fuse. The root cause of the fuse blowing has not been determined. A quarterly review of all fuse failures is performed per plant procedure. Historical records associated with this fuse were reviewed with no indication that the fuse had blown previously in this circuit. In addition, plant drawings were reviewed to evaluate the current load on the fuse compared to its rating. The fuse was rated at 5 amps and equipment downstream of the fuse was well below 1 amp.

3. As a further investigation, the actual current being drawn through the fuse was measured at 0.15 amp.

B. Further Corrective Action No further corrective action is planned.

NAC F omv 3R(rt (G4)S)

NRC FORM 356A (669)

LICENSEE EVENT REPORT ILER)

TEXT CONTINUATION U.S. NUCLEAR REGULATORY COMMISSION i APPROVED OMB NO. 31500104 EXPIRESI 4/30/92 ESTIMATED BURDEN PEA RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST: 500 HRS. FORWARD COMMENTS REGARDING BUADEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (P430), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO 1HE PAPERWORK REDUCTION PROJECT (31504)104). OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (5) PAGE (3)

YEAR SEQUENTIAL REVISION NUMBER NUMBER Washington Nuclear Plant - Unit 2 o s o o o3 97 8 9 0 3 3 010 3 OF 0 3 TEXT /// mo/B <<seem /4 /equ/Ied, use edI//o'one/NRC Form 35649/ (17)

Safet Si nificance The RWCU system and NS4 systems functioned to initiate isolation per the design requirements. Short outages of the RWCU system have no impact on plant operations.

There is no safety significance to this event as it posed no threat to the safety of plant personnel or the public.

Similar Events There have been a number of other LERs dealing with RWCU differential flow isola-tions. None of these, however, are associated with a blown fuse.

EIIS Information Text Reference ~Ss tern ~Com onent RWCU System CE NA NS4 JC NA Fuse E31A-F18 CE FU LD-FS-605B CE FS RWCU-P-1A CE P RWCU-V-1 CE V NRC Form 355A (669)