05000316/LER-1979-031-03, /03L-0:on 790912,elevation Containmment Airlock Interlock at 612 Ft Did Not Prevent Opening of Outer Door W/Inner Door Open.Caused by Flexing of One Interlock Support Bracket.Gusset Added to Bracket

/03L-0:on 790912,elevation Containmment Airlock Interlock at 612 Ft Did Not Prevent Opening of Outer Door W/Inner Door Open.Caused by Flexing of One Interlock Support Bracket.Gusset Added to Bracket

ML17326A282
Person / Time
Site:	Cook
Issue date:	10/10/1979
From:	Michael Brown INDIANA MICHIGAN POWER CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML17326A281	List: 05000316/LER-1979-031-03, /03L-0:on 790912,elevation Containmment Airlock Interlock at 612 Ft Did Not Prevent Opening of Outer Door W/Inner Door Open.Caused by Flexing of One Interlock Support Bracket.Gusset Added to Bracket 05000316/LER-1979-032-03, /03L-0:on 790911,during Surveillance Test,High Pressure Reactor Trip Bistable Found to Trip at Setpoint Corresponding to 2417 Psig.Caused by Defective Bistable. Bistable Replaced ML17326A280
References
LER-79-031-03L-01, LER-79-31-3L-1, NUDOCS 7910160506
Download: ML17326A282 (2)

LER-1979-031, /03L-0:on 790912,elevation Containmment Airlock Interlock at 612 Ft Did Not Prevent Opening of Outer Door W/Inner Door Open.Caused by Flexing of One Interlock Support Bracket.Gusset Added to Bracket

Event date:
Report date:
3161979031R03 - NRC Website

text

U. S. NUCLEAR REGULATORY COMMISSION ICENSEE EVENT REPORT Q1 (PLEASE PRINT OR TYPE ALLREQUIRED INFORMATION) 6 p

p p

p p

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y i i i Q4~QE LICENSE NUMBER 25 26 LICENSE TYPE 30 57 CAT 58 NRC FORM 366

{7.77)

CONTROL BLOCK:

1

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2 Q2 0

0 7

8 9

LICENSEE'CODE 14 15 CON'T

~01 soURGE LLJQB 0

5 0

0 0

3 1

6 07 0

9 2

7 9

QS 1

0 1

0 7

9 QB 7

8 60 61 DOCKET NIJM9ER 68 69 EVENT DATE 74 75 REPORT DATE 80 EVENT DESCRIPTION AND PROBABI.E CONSEQUENCES +10 WHILE PERFORMING STP.010'HE 61'LEVATION CONTAINMENT AIRLOCK INTERLOCK

~O3

~04

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~OB DID NOT PREVENT THE OPENING OF THE OUTER DOOR WITH THE INNER DOOR OPEN.

THIS OCCURRED ON BOTH 9-11-79 AND 9-12-79, CONSTITUTING AN INOPERABLE AIRLOCK PER TECH.

SPEC. 3.6.1.3.

AT LEAST ONE DOOR REMAINED SHUT PER ACTION ITEM.

PUBLIC HEALTH AND SAFETY WERE NOT JEOPARDIZED.

SIMILAR EVENTS:

78-014/03L-0; 78-066/03L-Op 79-016/03L-0 p AND DOCKET 050-315

~OS 79-004/03L-O.

7 8

9 80 7

8 SYSTEM

CAUSE

CAUSE COMP.

VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUBCODE 7E Q>>

B Q72

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~EE Q75

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10 11 12 13 18 19 20 SEQUENTIAL OCCURRENCE REPORT R EV IS I ON LERIRO EVENTYEAR REPORT NO.

CODE TYPE NO.

QlL REpoRT

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21 22 23 24 26 27 28 29 30 31 ACTION FUTURE EFFECT SHUTDOWN ATTACHMENT NPRDP PRIME COMP.

COMPONENT TAKEN ACTION ON PLANT METHOD HOURS +22 SUBMITTED FORM SUB.

SUPPLIER MANUFACTURER

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2 QE 33 34 35 36 37 40 41 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS Q27 0

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THE CAUSE OF FAILURE WAS FOUND TO BE ONE INTERLOCK SUPPORT BRACKETS 1

W J'OOLEY DETAIL 30234-6, WAS 11FLEXINGIIi PREVENTING THE INTERLOCK SIGNAL FROM ENGAGING THE INTERLOCK PAWL.

A GUSSET WAS ADDED TO THE BRACKET AND TESTED SATISFACTORILY.

A LONGER TRAVEL DRIVE SPRING WILL BE ADDED-TO 3

IMPROVE THE OVERALL PERFORMANCE OF THE MECHANISM.

7 8

9 FACILITY STATUS

% POWER OTHER STATUS QBO 5

~E QEE ~0QR 8

9 10 12 13 44 ACTIVITY CONTENT RELEASED OF RELEASE AMOUNTOF ACTIVITY 6

Z Q33 Z Q NA 7

8 9

10 44 PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION Q39 7

~00 0

Q37 ~Q38 NA 7

8 9

11 12 13 PERSONNEL INJURIES 7

8 9

11 12 LOSS OF OR DAMAGETO FACILITYQ43 TYPE

DESCRIPTION

Z Q42 NA 8

9 10 PUBLICITY 7

8 9

10 M. S.

BROWN NAME OF PREPARER 80 80 45 80 80 80 NRC USE ONLY 80 68 69 80' (616) 465-5901 EXT.'98 PHONE:

a METHOD OF DISCOVERY DISCOVERY DESCRIPTION Q32 Q31 SURVEILLANCE TESTING 45 46 LOCATIONOF RELEASE Q

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