ML17285A711

LER 89-033-00:on 890811,RWCU Delta Flow Isolation Occurred When Fuse in Power Supply to Leak Detection Monitor Blew, Giving False High Flow Signal to Isolation Logic.Cause Unknown.Fuse Replaced & Sys Returned to svc.W/890911 Ltr

ML17285A711
Person / Time
Site:	Columbia
Issue date:	09/11/1989
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 8909150239
Download: ML17285A711 (6)

Text

ACCEL'ZRATED D1STKBUTJON DEMONS~ON SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:8909150239 DOC.DATE: 89/09/11 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 RFQIP. NAME RECIPIENT AFFILIATION

SUBJECT:

LER 89-033-00:on 890811,RWCU delta flow isolation due to blown fuse.

W/8 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

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

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD 1 1 SAMWORTH,R 1 1 INTERNAL: ACRS MICHELSON ACRS MOELLER- 2 . 2 ACRS WYLIE AEOD/DOA 1 1 AEOD/DSP/TPAB AEOD/ROAB/DSP 2 2 DEDRO IRM/DCTS/DAB 1 1 NRR/DEST/CEB 8H NRR/DEST/ESB 8D 1 1 NRR/DEST/ICSB 7 NRR/DEST/MEB 9H 1 1 NRR/DEST/MTB 9H NRR/DEST/PSB 8D 1 1 NRR/DEST/RSB 8E NRR/DEST/SGB 8D 1. 1 NRR/DLPQ/HFB 10 NRR/DLPQ/PEB 10 1 1 NRR/DOEA/EAB 11 PB 10 2 2 NUDOCS-ABSTRACT REG FILE 02 1 1 RES/DSIR/EIB E 01 1 1 EXTERNAL EG&G WILLIAMSg S 4 L ST LOBBY WARD 1 1 LPDR 1 NRC PDR 1 1 NSIC MAYS,G 1 NSIC MURPHY,G.A 1 1 NUDOCS FULL TXT 1 NOTE 'IO ALL RZDS ~ZZNIS.

PZKBE HELP US 'ZO REDUCE HASTE.'CT THE DOCUMEÃ7 CONTROL DESK~

ROC'l-37 (EXT. 20079) IO ELIMINATE Y00R NARK FACY DISTfGBVZIQN LISTS FOR DOCK~IS YOU DON'T NEEDt FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 40 ENCL 40

WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968 ~ 3000 George N'ashinglon N'ay 'ichland, N'ashington 99352 Docket No. 50-397 September ll, 1989 I

Document Control Desk U.S. nuclear Regulatory Commission Washington, D.C. 20555

Subject:

NUCLEAR PLANT NO. 2 LICENSEE EVENT REPORT t<0.89-033

Dear Sir:

Transmitted herewith is Licensee Event Report tlo.89-033 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 yours, 5AA.

C. tl. Powers (h/D 927hl)

WHP-2 Plant flanager CtlP: 1 r

Enclosure:

Licensee Event Report No,89-033 cc: Hr. John B. tlartin, NRC - Region V )g((I tlr. C. J. Bosted, NRC Site (t4/D 901A) ~)5 INPO Records Center - Atlanta, GA tls. Dottie Sherman, ANI h1r. D. L. Williams, BPA (f~l/D 399)

AP~

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NRC Form 388 V.S. NUCLEAR REGULATORY COMMISSION (9-83)

APPROVED OMB NO, 3(500104 EXPIRES', 6/31/88 LICENSEE EVENT REPORT (LER)

DOCKET NUMBER (2) PA E 31 FACILITY NAME (I)

Washington Nuclear Plant Unit 2 0 s 0 o o39 .7> o)03 TITLE (41 Reactor Water Cleanup Delta Flow Isolation Due to Blown Fuse EVENT DATE(5) LER NUMBER (8) REPORT DATE (71 OTHER FACILITIES INVOLVED ISI SE.QVENTIAL REVsSION DAY YEAR FACILITYNAMES DOCKET NUMBER(SI MONTH DAY YEAR YEAR NVMPER NUMBER MONTH 0 5 0 0 0 0 8 11 89 8 9 0 3 3 0 0 0 9 1 1 8 9 0 5 0 0 0 THIS REPORT IS SUBMI'TTED PURSUANT T 0 THE REQUIREMENTS OF 10 CFR gi /Cnecrr one or more of tne fotlovrinpl (11 OPERATING MODE (1) 20.402(hl 20.405(cl 60.73(el(21(iv) 73.71(m)

POWE R 20.405 I ~ I (1)(il 50.38(c1(11 50,73( ~ l(21(v) 73.71(c)

LEYEL (101 0 8 0 20.405 ( ~ l(11(iil 50.38(c) (21 50,73( ~ ) (21(viil OTHER /Specify rn Aottrect end/n Test, HIIC Form Oerorr 20.405 ( ~ I (11(iiil S0.73( ~ I (2) Ill 60,73( ~ )(2)(viiil(A) 366AI 20.405(el(1)(iv) 60.73( ~ ) (21(iil 60,73( ~ l(2)(viiil(BI

20. 405 ( ~ ) (11(v) 50.73(e) (21(iii) 50.73( ~ )(2)I!I LICENSEE CONTACT FOR THIS LER (121 NALIE TELEPHONE NVMBER AREA CODE C. L. Fies, Compliance Engineer 509 377 -2 039 COMPLETE ONE LINE'OR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

MANUFAC REPORT*8(.E COMPONEN'T MANVFAC. REPORTABLE CAVSE SYSTEM COMPONENT 'TO NPRDS CAUSE SYSTEM TURER TO NPRDS TVRER SUPPLEMENTAI. REPORT EXPECTED (141 arONTrt DAY YEAR EXPECTED SUBMISSION DATE i(5 YES Hf yet compiete EI(PECTED st/Sattss/Dn/DATE NO ABSTRAC'I /Limit to l400 gmcn r e eppror mete > A/teen tinp'e /pete typenrrtten inert 1181 On August 11, 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 SMl power, a Reactor Water Cleanup System (RWCU) isolation occurred. The isolation occurred when a fuse in the 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.

Plant Conditions a) Power Level - 805 b) Plant tloae - 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 (RNCU) System Isolation occurred.

Supply Shutoff System (NS ) 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-u05B) which provides input to the isolation logic. When LD-FS-605B lost NRC Form 35(r In t

C s I

l

NRC FOIm,dddA US. NUCLEAR REOULATORY COMMISSION (94(31 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED OMB NO. 3160M(04 EXPIRES: 8/31/88 FACILITY NAME (11 DOCKET NUMBER (21 LER NUMBER (61 PACE (3)

YEAR '~kgr4 SEQUENTIAL REVISION NUMBER NUMBER P a t - Unit TEXT ///mone space ie ner/re/ed, Bee eddnenN NRC Form 366A'e/ (IT(

2 05000397 8 9 0 3 3 0 0 0 2 QF 0 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)(i v).

2.'he 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 equip ent 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.

4 Safety 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.

NRC FORVI 366A "".6. CFOI (dndd 6" ~ SFB PF' l9 83r

(943)

'ICENSEE NRC Forn,388A EVENT REPORT (LER) TEXT CONTINUATION US. NUCLEAR REOULATORY COMMISSION APPROVED OMB NO. 3IEOW104 EXPIRES: 8/3(/BB FACILITYNAME I'l DOCKET NUMBER (2)

LER NUMBER (8) PAGE (3)

YEAR ('EQVE NTIAL e N NVMBBR Rf VISION NVMBfR Washin ton Nuclear Plant - Unit 2 o3 97 89 0 3 3 0 0 3 OF 0 3 TEXT /I/ more e/reef /e required, rree eddr(/one/ NRC Form N('e/ ((7)

EIIS Information Text Reference System Component 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 eORM 300A V S CP0r )999 S20 SB9 00070 (9-83 I