ML17279A622

LER 84-091-01:on 840823,RHR Isolation & Reactor Low Water Level Trip Occurred While Placing Sys in Shutdown Cooling (SDC) Mode.Caused by High SDC Suction Flow.Suction Isolated, Sys Inspected & Mods Made to hardware.W/871120 Ltr

ML17279A622
Person / Time
Site:	Columbia
Issue date:	11/20/1987
From:	Davison W, Powers C WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
LER-84-091, LER-84-91, NUDOCS 8711250267
Download: ML17279A622 (7)

Text

REGULATORY INFORMATION DISTRIBUTION SYSTEM (BIDS)

ACCESSION NBR: 8711250267 DOC. DATE: 87/11/20 NOTARIZED: NO DOCKET ¹ FACIL: 50-397 WPPSS Nuclear Pro Ject> Unit 2> Washington Public Poee 050003'P7 AUTH. NAME AUTHOR AFFILIATION DAVISON> W. S. Washington Public Power Supply System POWERS> C. M. Washington Public Power Supply System RECIP. NAME RECIPIENT AFFILIATION

SUBJECT:

LER 87-091-01: on 840823> RHR isolation h reactor louj eater level tr ip occurred ujhile placing sos in shutdoujn cooling mode. Shutdoujn cooling suction isolated 5 full insp of sos conducted to determine leakage. W/871120 ltr.

DISTRIBUTION CODE: IE22D COPIES RECEIVED: LTR Q ENCL TITLE: 50. 73 Licensee Event Report (LER)> Incident Rpt>

g etc.SIZE:

NOTES:

RECIPIENT COP IES REC IP IENT 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 1 1 ACRS MOELLER 2 2 AEOD/DOA 1 1 AEOD/DSP/N*S 1 1 AEOD/DSP/ROAB 2 2 AEOD/DSP/TPAB 1 1 ARM/DCTS/DAB 1 1 DEDRO 1 NRR/DEST/ADS 1 0 NRR/DEST/CEB 1 1 NRR/DEST/ELB 1 1 NRR/DES3'/ICSB 1 1 NRR/DEST/MEB 1 1 NRR/DEST/MTB 1 1 NRR/DEST/PSB 1 1 NRR/DEST/RSB 1 1 NRR/DEST/SGB 1 NRR/DLPG/HFB 1 1 NRR/DLPG/GAB 1 1 NRR/DOE*/EAB 1

.NRR/DREP/RAB 1 1 NRR/DREP/RPB . 2 2 NRgJJ) SIB 1 1 NRR/PMAS/ ILRB 1 1 EG I LE 02 1 1 RES DEPY GI 1 1 RD> J 1 1 RES/DE/E IB 1 1 RGN5 FILE 01 1 1 EXTERNAL: EG8cG GROH> M 5 5 H ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC HARRIS> J 1 1 NSIC MAYS> G 1 1 TOTAL NUMBER OF COPIES REQUIRED: LTTR 45 ENCL 44

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NRC Form 388 U.S. NUCLEAR REQULATORY COMMISSION (943) r APPROVEO OMB NO. 3)SOOIOC LICENSEE EVENT REPORT ILER) EXPIRES: 8/31/88 FACILITYNAME (I) DOCKET NUMBER (2) PA 8 3 TITLE (Cl clear Plant - Unit 2 0 5 0 0 0,97 1OFO 2 RHR Isolation and Reactor Low Water Level Tri EVENT DATE (8) LER NUMBER (BI REPORT DATE (7) OTHER FACILITIES INVOI.VED (BI BEQUENTiAL srcvrBIQN MONTH DAY YEAR YEAR NUMBER rg MONTH OAY YEAR FACILiTYNAMES DOCKET NUMBER(SI 0 5 0 0 0 082 38 84 0 q 1 0 1 2 0 0 5 0 0 0 THIS REPOAT IS SUBMITTED PURSUANT T 0 THE REQUIREMENTS OF 10 CF R (I: (Check one or more ol the lollop/op) (11 OPERATINQ MODE (9) 20A02(b) 20A05(cl 50.73( ~ ) 12) (iv) 73.71(B)

POWER 20A05( ~ I (I I (il 50.38(c) )1) 50.73(t) (2) (v) 73.71(c)

LEVEL (10) 20AOS( ~ ) (1)(iil 50.38(cl(2) 50.73(t) (2) (vB) OTHER ISptclly In Ahsrrtct helolN tnd In Text, HRC Form

,~jg;;"Io @Itn 20AOS( ~ I (I l(iii) 50.73(c)12)(il 50,73(t)(2)(viii)(AI JSEAI 20AOS ( ~ I (I I (iv) 50.73(cl(2)(ii) 50,73(t ) (2) (viIiI (8 I k.4. v. c:2csx ., (Pg~  ??: 20AOS(tl(1) iv) 50.734)(2) (iiil 50,73( ~ )(2)(x)

LICENSEE CONTACT FOR THIS LEA (12)

NAME TELEPHONE NUMBER AREA CODE W.S. Davison Com liance En ineer 50 93 77- 250 1 COMPLETE ONE LINE FOll EACH COMPONENT FAILURE DESCAIBEO IN THIS REPORT (13) Ext ~ 2726 yo'Y )jan'r.

CAUSE SYSTEM COMPONENT MANUFAC TURER EPORTABLE TO NPADS CAUSE SYSTEM COMPONENT MANUFAC-TUAER EPOATABLE TO NPADS RP~"

0 N SNMI y 3 Pits

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SUPPLEMENTAL REPORT EXPECTED (111 MONTH DAY YEAR EXPECTED SUBMISSION DATE II5)

YES (lf yts, compltrt EXPECTED SVBhiISSIDN DA TEI NO ABSTRACT ILlmlr to ttOO sptctt, l.e., tpproxlmtrely llfretn slnp!septet typtvrrlnen llntsl (18)

With the reactor shutdown, an RHR isolation and a reactor low water level trip

(+13") occurred while placing the RHR system in the shutdown cooling mode.

EI7i iPSO2b7 8~>q7 7g jP.O PDR gDOCK 0 PDR S

NRC Form 358 (9 83 I

P NRC Form 3ddA U.S. NUCLEAR REGULATORY COMMISSION (Nl31 LICENSEE EVENT REPORT ILER) TEXT CONTINUATION APPROVEO OMB NO. 3150M)0d EXPIRES: 8/31/88 FACILITY NAME 11) OOCKET NUMBER (2) LER NUMBER Ld) PAGE I3)

YEAR:(3: SEQVENTIAL REVISION NVM ER @P NVMSER Washington Nuclear Plant - Unit 2 o s o o o 3 9 7 0 9 0 1 0 2oF TEXT l)P mare e/>>oe * /r/rrier/ Iree ////a'a>>/HRC fanrr JSSA'e) (IT)

Plant Conditions a) Power Level - O'A b) Plant t1ode - 3 Event With the reactor, shutdown and at 60 psig, RHR Loop 8 was being warmed up for shutdown cooling (SDC) operation when RHR-V-8 shut automatically. The cause of this -isolation was apparently high SDC suction flow. However no annunciation was provided for by design, and the isolation went unnoticed for approximately 15 minutes. During this time, the RHR Loop 8 partially drained (flowpath was to radwaste through the warmup line via RHR-V-40). When RHR-V-8 was reopened, a low reactor water level RPS actuation occurred.

When RHR-V-8 was loop.

reopened, RHR-V-8 was immediately shut by reactor water began to fill the partially drained RHR the control room operator when reactor water'evel started to decrease at a rapid rate. The lowest reactor water level recorded was +10" 'during this event.

Immediate Corrective Action After the reactor water level dropped to +10U and the shutdown cooling suction was isolated, a full inspection .of the system was conducted to determine system leakage; none was found. After determining the cause of the level decrease the reactor level was increased to approximately +50" and the shutdown cooling flowpath was reestablished.

Further Evaluation and Corrective Action Subsequent hardware modifications have resulted in improving the reliability of the low pressure alarm instrumentation associated with the partial draining of RHR following an isolation. '1he annunciator response procedures have been revised to include an inadvertant isolation as a potential cause for the low pressure condition. No further action is considered necessary.

Safety Si nificance

~ This event did not compromise the health and safety, of the public. All systems functioned as per design and an analysis of a similar. postulated event (which bounds the event described here) indicates that level would not have decreased below 417M. This is approximately 40" above low reactor water level l(-,129M).

This analysis was orig'inated as a result of our Operating Experience Review Program.

NRC FORM Sddo e U 5 GPO 1088 0-524 538/d55 (543)

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WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968 ~ 3000 George 11'ashington Way ~ Richland, N'ashington 99352 Docket No. 50-397 November 20, 1987 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

NUCLEAR PLANT NO. 2 LICENSEE EVENT REPORT NO. 84-091-01

Dear Sir:

Transmitted herewith is Licensee Event Report No. 84-091-01 for the WNP-2 Plant. This report is submitted in response to the report requirements of 10CFR50.73 and discusses the items of reportabi lity, corrective action taken, and action taken to preclude recurrence.

Very truly yours,

~l t r55)'

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/

C.H. Powers (H/D 927M)

WNP-2 Plant Manager CHP:db

Enclosure:

Licensee Event Report No. 84-091-01 cc: Hr. John B. Hartin, NRC - Region V Mr. C. J. Bosted, NRC Site (H/D 901A)

INPO Records Center - Atlanta, GA Hs. Dottie Sherman, ANI Hr. D. L. Williams, BPA (M/D 399)

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