ML20024D834

LER 83-055/01T-0:on 830719,one 1/8 by 1/16-inch Hole Found on Bellows Seal on Torus to Drywell Vacuum Breaker Line Containing Breakers 2-1601-32A & B.Cavity Filled to Original Thickness & Surface buffed.W/830728 Ltr

ML20024D834
Person / Time
Site:	Dresden
Issue date:	07/28/1983
From:	Scott D, Wee D COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
83-738, LER-83-055-01T, LER-83-55-1T, NUDOCS 8308080271
Download: ML20024D834 (4)

Text

NRC FOEM 366 U. S. NUCLEAR REGULATORY COMMISSION (7 77I /

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(FLEASE NINT OR TYPE ALL REQUIRED INFORMATION) 13 l 31 9l l I I LICENSEE 7

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L'[?,% l L l@l 0 l S I 0101 O l 21 31 7 @l 01 7l 1191813l@l0l7l2l8I8l3l@ 74 8 6C 61 OOCK ET %VB ER 68 69 EVENT DATE ~5 PE* ORT QATE 30 EN ENT DESCRIPTION AND PRCBABLE CONSEQUENCES h I o I 2 I l During norrni oneration a 1/8 inch by 1/16 inch hole was discovered on a bellows seall IoI3IIon the torus to drvwell vacuum breaker line that contains vacuum breakers 2-1601-32Al 1014IInna R. En1cnineions indicated thne nrfm9rv coneninmant lenknge did nor ovcond ehn l IoI5IITech Spec limit (3.7.A.2) of 13.7 SCF'4. Safety sinnificance was considered minimal I 10161 I since combined leakage torn 1 cas lemm ehnn the mnvimum n11oenblo Tech Spec limit - i 1317 I i (13.7 SCFM). There was no effect on public health or safety. Last occurrence of l t 0 i s ! l arc strike reported by R.O. 83-13 on Docket 50-237. I

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44 CAUSE DESCRIPTION AND CORRECTIVE ACTICNS h it 19IIThe are strike was considered accidental. The cavity was filled to the orfeinal l It !t i Ieection thickness and thz urface was huffad to remova erroEe rinorm. Tha ennniv I It iOf lwelds were examined by vicual and licuid nenetrant methode and the line was air i ii 13l l tested to verifv no lanknco- Unikdown of conmernction nrenn vill bo i r'n l aman t e d I I1 11l l rn review the nend for nreennefons to nrevent recurrence. I

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• 4 ATTACHMENT TO LICENSEE EVENT REPORT #83-55/01T-0 COM!!ONWEALTH EDISON COMPANY (CWE)

DRESDEN UNIT 2 (ILDRS-2)

DOCKET # 050-237 During normal operation, a 1/8 inch by 1/16 inch hole was discovered on the bellows in the torus to drywell vacuum breaker line for vacuum breakers 2-1601-32A and B. The leakags through the hole was calculated to be 6.9 SCFM based on 48 PSIG and 98 F. The combin'ed leakage total based on the as lef t leakage af ter the :cfueling outage from the primary containment was 11.84 SCFM. These calculations indicate that the leakage from the primary. containment to the secondary containment was less than 1.6 weight percent per day at 48 PSIG (Tech Spec 3.7.A.2); the maximum allowable limit is 13.7 SCFM. Based on the breech'of primary containment an unusual event was declared at 1525 hours0.0177 days <br />0.424 hours <br />0.00252 weeks <br />5.802625e-4 months <br /> on 7/19/83 and Unit 2 was shutdown. Reactor temperature was less than 2120F and the unusual event was terminated at 0537, hours on 7/20/83. Safety significance was considered minimal since the combined leakage total was less than the maximum allowable limit, and all ECCS systems were available. The last occurrence involving an arc strike to the containment was reported by R.O. 83-13 on Docket 50-237.

According to Station Construction personnel construction work for the Fbrk I modification in the vicinity of the leak was in progress from 6/13/83 until 6/24/83. On 6/17/83, the unit.was shutdown for nitrogen leaks and a snubber inspection and returned to service on 6/19/83. One day later a U-2 generator problem forced the unit to shutdown. Generator repairs were completed and the unit was critical on 7/13/83. On 7/19/83 the arc strike was discovered. From the facts above, the maximum number of days that the primary containment was required is 12.

The arc strike was considered to be accidental due to the type of work in the immediate area. A repair program was prepared and approved by the station. The cavity was filled to the original section thickness

-and-the surface was buffed to remove stress risers. The repair was examined by visual and liquid penetrant method. The vacuum breaker line was also air tested and the repaired area was tested for leaks.

Station Construction management will conduct a review of each job and conduct job site walkdowns of werk in progress to inform contractor management personnel of systems and for components within a given work area which impact on plant safety, such that additional precautions to personnel working in said areas can be issued.

In addition, a directive has been issued to all contractor management personnel stating that no installed structural members can be' removed during the course of any job without specific owner permission.

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r-DEVIATION REPORT C6mmonwe:lth Edison P ART 1 l TITLE OF DEVIATION DVR MO.

12 STA 2

UNIT 83 YEAR 102 NO.

OCCURRED 7/19/83 1525 Vac. Breaker 2-1601-32A & B Bellows Leak caTr mr SYSTEM AFFECTED 1600 PLANT STATUS AT TIME OF EVENT TESTING Primary Containment 23cg Run , PnR(uwT) 2368 , t040tuaE3 759 O O cESCRIPTION OF EVENT vicuum breaker line bellows. Hole was located on line containing; vacuum breakers

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2-1601-32 A & B. Unusual event declared and orderly unit shutdown c menced in accordance with DGP 2-1.

10 CFR50.72 J.PC RED PH01,E 8 0 NOTIF ICATtON MADE YES N3 E00lPMENT F AILURE D29167 GvEs O No wCRx aroursT No. aF sPnNs i etF seneRvise, F1. Korchynsky 3 77 7/19/83 P ART 2 l 0PERATING ENGINEER'S C0hNENTS The leakage through the hole was calculated to be 6.9 SCFM at the accident pressure of 48 psig. The Tech Spec limit for primary containment is 13.7 SCFM.

Reactor temperature was less than 2120F, and the unusual event was terminated at 0537 on July 20. 1983.

O EVENT OF PUBLIC INTEREST @ 24-HOUR NRC NOTIFICATION REQ'D TECH. SPEC. VIOLATION TELEPH T. Tongue UWM UU REGION lli DATE TIME O NON REPORTABLE OCCURRENCE TELEG'A/TEL ECODY J.G. Keppler 7/20/83 1000

@ 14 DAY REPORTABLE /T.S. 6.6.B.1.c REGION lli DATE TIME 30 DAY REPORTABLE /T.S. Revispd Telecopy .................... 7/20/82 1707 CEwo CORPORATE NOTIFICATION MADE ANNUAL /SPECL REPORT REQ'D IF ABOVE NOTIFICATION IS PER 10CFR21 i

A.I.R.

• O 5* DAY WRITTEN REPORT REQ'D PER 10CFR21 L.E.R. ,83-55/01T-0 Telecopy Revised telecopy 7/20/83 1600 Tacccx Dennis P. Galle 7/20/83 1005 CECO CORPORATE OFFICER DATE TIME "b'

C l A V EWED John M. Almer OPER ATING ENGihEER

,7/20/83

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[ ~o INVESTIGATED REPORT & RESOLUTION 1.CCEPTED BY STATION REVIEW A_. . -W 8 -

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RESOLUTION APPROVED AND AUTHORIZED FOR DISTRIBUTION bkh w] ///

86 3176 (FORM 15.$1 1) 10-81 STATION SUPERINTENDEQ DATE'

t Commonwealth Edison Dresden Nuclear Power Station RA #1 Morris, Illinois 60450 Telephone 815/942-2920 July 28, 1983 DJS Ltr #83-738 James G. Keppler, Regional Administrator Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137 Reportable Occurrence Report #83-55/0lT-0, Docket #050-237 is being submitted to your office in accordance with Dresden Nuclear Power Station Technical Specification 6.6.B.1.(c), abnormal de-gradation discovered in fuel cladding, reactor coolant pressure boundary, or primary containment.

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W D.J. Scott 6 Station Supe intendent Dresden Nuclear Power Station l

DJS/kjl Enclosure cc: Director of Inspection & Enforcement Director of Management Information & Program Control U.S. NRC, Document Management Branch File /NRC AUG 0 21983 0

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