ML18010A457

LER 91-019-00:on 911022,containment Ventilation Isolation Signal Generated,Resulting in Unplanned Actuation of ESF Component.Caused by Spike on Three Radiation Monitors.Power Supply Circuitry Repaired & adjusted.W/911121 Ltr

ML18010A457
Person / Time
Site:	Harris
Issue date:	11/21/1991
From:	Richey R, Verrilli M CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
HO-910217-(O), LER-91-019-01, NUDOCS 9111270084
Download: ML18010A457 (6)

Text

ACCELERATED DI RIBUTION DEMONST TION SYSTEM REGULATORY XNFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR: 9111270084 DOC. DATE: 91/11/21 NOTARIZED: NO DOCKET FACIL:50-400 Shearon Harris Nuclear Power Plant, Unit 1, Carolina 05000400 AUTH. NAME AUTHOR AFFILIATION VERRILLI,M. Carolina Power & Light Co.

RXCHEY,R.B. Carolina Power & Light Co.

RECIP.NAME RECIPXENT AFFILXATION

SUBJECT:

LER 91-019-00:on 911022,containment ventilation isolation signal generated, resulting in u'nplanned actuation of ESF D component. Caused by spike on three radiation monitors. Power supply circuitry repaired & adjusted.W/911121 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR I ENCL =/ SIZE TITLE: 50.73/50.9 Licensee Event Report (LER), fncident pt, etc.

NOTES:Application for permit renewal filed. 05000400 A D

RECIPIENT COPXES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID,CODE/NAME LTTR ENCL D PD2-1 LA 1 1 PD2-1 PD 1 1 MOZAFARI,B. 1' INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 AEOD/DS P/TPAB 1 1 AEOD/ROAB/DS P 2 2 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB, 7E 1 1 NRR/DLPQ/LHFB10 1 1' NRR/DLPQ/LPEB10 1 ~

1 NRR/DOEA/OEAB 1 NRR/DREP/PRPB11 2 2 NRR/DST/SELB 8D 1 1 NRR/DST/SICB8H3 1 1 PLB8D1 1 1 NRR/DST/SRXB 8E 1 1 G 02 1 1 RES/DSIR/EIB 1 1 RGN2 FXLE 01 1 1 EXTERNAL EG &G BRYCE i J ~ H 3 3 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHY,G.A 1 1 R NSIC POORE,W. 1 1 NUDOCS FULL TXT 1 1 D

D D

NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE iVASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM P 1-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

FULL -TEXT CONVERSXON REQUIRED TOTAL NUMBER OF COPXES REQUXRED: LTTR 33 ENCL 33

Carolina Power & Light Company P.O. Box t65 ~ New Hill, N.C. 27562 R. B. RICHEY Vice Presidenl Hams Nuclear ProJect NOV 2 f 199)

Letter Number: HO-910217 (0)

U.S. Nuclear Regulatory Commission ATTN: NRC Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NO. 50-400 LICENSE NO. NPF-63 LICENSEE EVENT REPORT 91-019-00 Gentlemen:

In accordance with Title 10 to the Code of Federal Regulations, the enclosed Licensee Event Report is submitted. This report fulfills the requirement for a written report within thirty (30) days of a reportable occurrence and is in accordance with the format set forth in NUREG-1022, September 1983.

Very truly yours R. B. Richey Vice President Harris Nuclear Project MV:dmw Enclosure cc: Mr. S. D. Ebneter (NRC - RII)

Ms. B. L. Mozafari (NRC - RII)

Mr. J. E. Tedrow (NRC - SHNPP)

MEM/LER91-019/1/OS1 9IIi"7v084 Plli2i r

Pore ADOCK 05000400 S F'DP,

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 31504)104 (689)

E XP I 4 E 6'. 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION AEOUEST: 500 HRS. FORWARD LICENSEE EVENT REPORT {LER) COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (F830), U.S. NUCLEAR AEGULATO4Y COMMISSION. WASHINGTON, DC 20555, AND TO THE PAPEAWOAK REDUCTION PRO)ECT (31504)1041, OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503.

DOCKET NUMBER (2) v PA E 3 FACILITY NAME HI Shearon Harris Nuclear Plant Unit /r'1 o 5 o o 04 00 toFO 3

'nplanned ESF Actuation (Containment Ventilation Isolation) due to spike on radiation monitor.

EVENT DATE ISI LEA NUMBER (6) REPOAT DATE (7I OTHER FACILITIES INVOLVED (8)

SEOUENTIAL 4'. FACILITYNAMES DOCKET NUMBER(S)

MONTH DAY YEAR YEAR NUMBER 'iM NUMBER MONTH DAY YEAR 0 5 0 0 0 1 022 91 9 1 019 0'0 112 1 9 1 ol the IollowinP/ (11) 0 5 0 0 0 THIS REPORT IS SUBMITTED PURSUANT TO THE ALDUIREMENTS OF 10 CFR ((: /Check one or more OPERATING MODE (8) 73.7) IB) 20.402(B) 20.405(c) X 50,73(e I (2)(iv)

POWER 20.405( ~ )(I ill) 50.38(cl (1) 60.73(e I (2 I (v I 73.71(el LEVEL

00) 100 20.405(e) ll)(iil 50.38(cl(2) 60.73(el(2) (vii) 60.73(el(2)(villi(AI OTHER ISpecily in Ahrrrect Below end in Tent, HRC Form JPSA/

20.405(e) (1)(iii) 50.73(e) (2)(i I

'p@r Y~R>, 20A05(e I (I) I Iv) 50.73(el(2) (8) 50,73(e) (2 l(villi(8)

. 20,405 ( ~ I (1 I (v) 50.73(el (2) I i(i) 50.73( ~ ) (2)(rrl LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER ARE'A CODE Michael Verrilli Regulatory Compliance Specialist 919 36 2-2 303 COMPLETE ONE LINE FO4 EACH COMPONENT FAILU4E DESCRIBED IN THIS REPORT (13I MANUFAC. REPORTABLE MANUFAC.

CAUSE SYSTEM COMPONENT TURER TO NPADS c*Usr SYSTEM COMPONENT 'TURER I

B IL MO N G 06 3 It((+()74'!

(Wg&kv:,:

SUPPLEMENTAL REPORT EXPECTED (14) MONTH DAY YEAR EXPECTED SUBMISSION YES /II yeL comPlete EXPECTED Si/BBIISSIOH DATE/ NO DATE (15) 012 192 ABST4ACT /Limit to /400 rpeceL l.e., epprorr/meteiy lifteen rlnpie.rpece typewritten linn/ (16)

ABSTRACT:

On '10/22/91, at 1505 hours0.0174 days <br />0.418 hours <br />0.00249 weeks <br />5.726525e-4 months <br />, a Containment Ventilation Isolation signal was generat:ed. This constituted an unplanned actuation of an Engineered Safety Feature (ESF) component. The event occurred, while removing one of the four containment ventilation radiation monit:ors from service during surveillance testing. The cause of the signal was an inadvertent spike on one of the three radiation monitors that remained operable (RM-3561A). The control room staff immediately verified that all associated containment ventilation components had functioned as required and that no abnormal radiation levels actually existed.

The system was then realigned to its normal operating lineup. Corrective actions to prevent recurrence will include needed repairs and/or adjustments to the power supply circuitry for radiation monitor RM-3561A. There were no significant safety consequences as a result of this event as the Containment Ventilation System was in the required emergency mode had an actual event occurred.

This is being reported in accordance with 10CFR50.73 (a)(2)(iv) as an unplanned actuation of an ESF component,.

NRC Form386(689)

l NRC FORM 366A US. NUCLEAR REGULATORY COMMISSION (6B9) APPAOVEO 0MB NO. 31500104 EXPIRES: 4/30/92 LICENSEE EVE REPORT ILER) ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFOAMATION COLLECTION REQUEST: 60.0 HAS. FORWARD COMMENTS REGARDING BUADEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (P4)30), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO 2'HE PAPERWORK REDUCTION PROJECT (31504)104), OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503, FACILITY NAME (1) DOCKET NUMBER (2)

LER NUMBER (6) PAGE (3)

YEAR gag SSOVENZIAL .:cA'j REVISION NVMBER >?rr NUMBER Shearon Harris Nuclear Plant Unit //1 TEXT ///more 4Pece /4 mr/Ir/red, Iree edd/Pone//YRC Form 36M'4/ (17) 0 5 0 0 0 P 0 0 91 019 0 0 0 OF 0 3 EVENT DESCRIPTION:

On 10/22/91, while operating in Mode-1 at 100 percent power, surveillance testing was being conducted on the supply breakers for the four Containment Ventilation Radiation Monitors. This process required securing the power to one radiation monitor at a time, performing an over current trip test on the supply breaker, then restoring the monitor to service. After successful testing an'd restoration of the first two radiation monitors, the supply breaker for the third monitor (RM-3561C) was opened. At this time, the monitor that had just been placed back into service (RM-3561A) spiked into high alarm. This satisfied the two out of four logic that is required to generate a Containment Ventilation Isolation .

signal. The co'ntrol room staff immediately verified that all associated containment ventilation components had functioned as required and that no abnormal radiation levels actually existed. The system was then realigned to its normal operating lineup.

This is being reported in accordance with 10CFR50.73 (a)(2)(iv) as an unplanned actuation of an ESF component.

No events with a similar root cause have" been reported.

CAUSE:

The cause of this event was the inadvertent spike that resulted in radiation monitor ARM-3561A going into high alarm, which subsequently created the Containment Ventilation Isolation Signal. Investigation as to why the monitor spiked into, high alarm is still in progress. Research up to this point has determined that the most probable cause for this spike was a deficiency in the monitor's supply power circuitry. Further testing will be conducted to verify the exact cause by recreating the initial scenario with appropriate monitoring equipment installed. Upon completion of this testing a supplemental report will be issued to provide additional information, including the specific corrective actions taken.

SAFETY SIGNIFICANCE:

There were no significant safety consequences as a result- of this event. No abnormal radiation levels actually existed and the Containment Ventilation System was in the required emergency mode had an actual event occurred.

NRC Form 366A (64)9)

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (64)9) APPROVED OMB NO. 31500104 EXPIRES: 4/30/92 LICENSEE EVEN ESTI TED BURDEN PER RESPONSE TO COMPLY WTH THIS REPORT {LER) INFORMATION COLLECTION REOUESTI 500 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (P.530), U.S. NUCLEAR '"

REGULATORY COMMISSION. WASHINGTON, OC 20555, AND TO 1HE PAPERWORK REDUCTION PROJECT (31500104), OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503, FACILITY NAME (II DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR SEOUENTIAL REVISION Shearon Harris Nuclear Plant Unit II1 NUMSER NUMEER o s o 'o o 400 91 019 0 0 3 OF 0 3 TEXT /// moro Spree /4 ror/Ir/rod, rrro oddr)r'ono/BRC Forrrr 36643/ (12)

CORRECTIVE ACTIONS:

Upon completion of the testing described above and ident'ification of the specific problem, repairs and/or adjustments will be made as necessary, to the supply power circuitry for radiation monitor RH-3561A. These corrective actions will be clearly de'lineated in a supplemental report.

NRC Form 366A (64)9)