ML20045D599

LER 93-003-00:on 930525,primary Containment Isolation Sys Half Group III Isolation Occurred Due to Loss of Jumper to Terminal Continuity During Planned Maint.Automatic Actions Confirmed & Signal Received verified.W/930618 Ltr

ML20045D599
Person / Time
Site:	Duane Arnold
Issue date:	06/18/1993
From:	Kerr J, Denise Wilson IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT
To:	Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
LER-93-003, LER-93-3, NG-93-2505, NUDOCS 9306290196
Download: ML20045D599 (4)

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Iowa Electric Light and Power Company June 18,_1993 NG-93-2502 Mr. John B. Martin Regional Administrator Region III U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137

Subject:

Duane Arnold Energy Center Docket No: 50-331 Op. License DPR-49 L!censee Event Report #93-003 Gentlemen:

In accordance with 10 CFR 50.73 please find attached a copy of the subject Licensee Event Report.

Very truly yours,.

David L. Wilson Plant Superintendent - Nuclear DLW/JK/eah cc: Director of Nuclear Reactor Regulation Document Control Desk U.S. Nuclear Regulatory Commission Mail Station P1-137 Washington, D. C. 20555 NRC Resident Inspector - DAEC 1: 800.1C 9306290196 930618

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{DR ADOCK 0500 General Oflim

• P.O. Box 351

• Cedar Rapids, Iowa 5240G

• 319 39M411 l

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5C FORP 366 U.S, NUCLEAR REGULATORV COMMISSION APPROVED BV OMB NO. 3150-0104 rs oa) EXPIRES 5/31/95 ESTtMATED BURDEN PER RESPONSE TO COMPLY WITH TH?S INFORMATION COLLECTION REQUEST: 50.0 HRS FORWARD LICENSEE EVENT REPORT (LER) COMMEMS REGARONG BURDEN ESTIMATE TO THE INFORMATCN AND RECORDS MANAGEMENT BRANCH (MNBB T714), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PRCklECT (3150 0104), OFFICE OF (See reverse for required number of digits / characters for each block) MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

F ACILITY NAME p) DOCKET NUMBER (2i PAGE (3)

Duane Arnold Eneroy Center 05000 331 1 OF3 TITLE m Primary Containment Isolation System Half Group III Isolation due to Loss of Jumper to Terminal Continuity During Planned Maintenance EVENT DATE (5) LER HUMBER (6i REPORT NUMBER (7) OTHER FACILITIES INVOLVED (8)

FAGIUTY NAME DOCKET NUMBEH SEQUE NTIAL REV!SION uomH DAv vEAR vtAn M WH DAY YEAR NUMBER NUMBER 05000 FACLUTY NAME DOCKET NUMBER

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05 25 93 93 ~ 003 00 06 18 93 05000 OPERATING "THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR 1: fCheck one or more)(11)

MODE (9) N 20.402tb> 20.405(c) )( 50.73(a)(2)(iv) 73.71(b) ,

POWER 20 405(a)(1)(i) 50.36(c)(1) So.73(a)(2)(v) 73.71(c)

LEVEL (10) 088 20AoSta)(ti(n) 50 36(c)(2) 5013(a)(2)(vii) oTHER 20.405(a)(1)(iii) 50.73(a)(2)(i) ppech m Atistract 50.73(a)(2)(viii)(A) 20 405(a)(1)(iv) SJ.73(a)(2)(ii) 50.73(a)(2)(vtii)(B) For 366A 20 405(a)(1)(v) 50.73(a)(2)(iii) 50.73(a)(2)(x)

LICENSEE CONTACT FOR THIS LER (12) _

NAvt TELEPHONE NUMBEH [metuce Area Coce)

John D. Kerr, Technical Support SDecialist (319) 851-7492 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13) cAusE sesTEM CoMPoNrNT MANUFACTUAER CAUSE SYSTEM COMPONENT MANUF ACTURER 0 PRD SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED "O*" DA' YLAR yEs SUBMISSION (1yes, wwe EXPECTED SUBMCON DATO DATE (1;)

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ABSTRACT (Limit to 1400 spaces, i e,, approximately 15 smgte-spaced typewntten lines) (16)

On May 25, 1993 the plant was operating at 88% power when a "B" side Primary Containment Isolation System (PCIS) Group III isolation occurred along with the initiation of the "B" Standby Gas Treatment (SBGT) System. This event occurred during pre planned maintenance that had been identified as having the potential to cause the PCIS isolation and SBGT initiation. Jumper to terminal continuity was lost in a control room back panel during maintenance to install standoff Jacks. Plant systems responded as expected, the PCIS isolation was reset, and ,

SBGT was secured. There was no effect on safe operation of the plant.

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FACILJTY NAME {U DOCKET NUMBE R (2) LER WUMBERis) PAGE(3)

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'Z%"/R "23" Duane Arnold Energy Center 0 5 0 0 0 3 3 1 93 -

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00 2 0F 3 ItKT (19 mera space os requoted, use addittwat NRC 1erm 300A)(17)

I. DESCRIPTION OF EVENT:

On May 25, 1993 the plant was operating at 88% power coasting down for a refueling outage. The plant was in day 2 of a 7 day limiting condition for operation (LCO) on the "A" ioop of Residual Heat Removal (RHR) and in day 2 of a 30 day LCO on the "A" RHR pump. Pre planned maintenance was to be performed to install standoff Jacks in a back panel in the control room to facilitate the performance of a surveillance test procedure (STP) that would demonstrate the operability of the refuel pool exhaust radiation monitors. Standoff jacks are connection hardware for wires or jumpers. The maintenance work request and a risk evaluation sheet both stated that there was the possibility of a Primary Containment Isolation System (PCIS) Half Group III isolation and Standby Gas Treatment (SBGT) initiation during this work due to the use of jumpers that were to be held in place by hand. The operations shift supervisor documented this possibility and the operators entered it into their logs at 1548 hours0.0179 days <br />0.43 hours <br />0.00256 weeks <br />5.89014e-4 months <br />.

At 1613 hours0.0187 days <br />0.448 hours <br />0.00267 weeks <br />6.137465e-4 months <br />, during performance of this maintenance, the "B" side PCIS Group III isolation was received and "B" SBGT auto started. This isolation includes reactor building ventilation and several PCIS valves.

Operators confirmed the automatic actions and verified that the signals received were those anticipated to occur during the maintenance. At 1615 hours0.0187 days <br />0.449 hours <br />0.00267 weeks <br />6.145075e-4 months <br /> the isolations were reset and SBGT was secured.

II. CAUSE OF EVENT The cause of the PCIS Half Group III isolation and SBGT initiation was loss of continuity between a jumper and a terminal causing the normally energized logic to de-energize. When de-energized, the refuel pool exhaust radiation monitor logic defaults to the tripped condition. The cause of the loss of continuity was the difficulty in maintaining jumper contact on the terminal. This possibility was recognized and documented during maintenance planning.

III. ANALYSIS OF EVENT This event had no effect on personnel safety or safe operation of the plant. The Group III isolation function is designed to ensure that no effluent releases to the public occur by isolating the reactor building and portions of primary containment from the outside environment. Its actuation does not negatively affect safe plant operation. The Group III isolation and SBGT initiation functioned as designed in response to the signal received. Had this event occurred under different plant conditions, the effect on safe operation would have been the same.

hRC FORM 3B6A !$ 92)

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F ACIUI f NAME (1)

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DOCKET NUMBER (2) LER NUMBER 18) PAGk{3)

• IFM."c'f' C'fR Duane Arnold Energy Center 0 5 0 0 0 3 3 1 93 -

003 -

00 3 0F 3 i w cro ..,. ...e. .. .w. a. . .u,u .o uRc F.,- mas <m IV. CORRECTIVE ACTIONS Immediate corrective actions were to confirm the automatic actions, verify the signals received, reset the isolations, and secure SBGT as discussed above. The maintenance work to install standoff Jacks was successfully completed. This eliminates the need to hold jumpers in place by hand during future testing. The future use of jumpers will be more reliable due to the improved connection hardware installed during this maintenance.

V. ADDITIONAL INFORMATION A. Previous Similar Events A review of DAEC LERs since 1984 identified the following Half Group III Isolations: LER 92-05, 91-06, 90-08, 90-11, 88-03, 88-11, 88-17, 87-10, 87-11, 87-14, 87-15, 87-17, 87-29, 86-09, 85-08, 85-12, 85-22, 84-07, 84-22.

LERs 90-08, 87-11, 85-22 report events similar to this one.

B. EIIS System Codes PCIS--JM SBGT--BH RHR---80 This report is being submitted pursuant to 10CFR50.73(a)(2)(iv).

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I NRC FORM 306 A ik,h l

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