05000315/LER-1979-015-03, /03L-0 on 790302:while Operating at Full Power, Pressurizer Relief Tank Rupture Disc Blew Out,Causing Ice Condenser Inlet Doors to Open.Caused by Pressure Fluctuations Resulting in Weakened Rupture Discs

/03L-0 on 790302:while Operating at Full Power, Pressurizer Relief Tank Rupture Disc Blew Out,Causing Ice Condenser Inlet Doors to Open.Caused by Pressure Fluctuations Resulting in Weakened Rupture Discs

ML17317B050
Person / Time
Site:	Cook
Issue date:	03/28/1979
From:	Chadwell H INDIANA MICHIGAN POWER CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML17317B048	List: 05000315/LER-1979-014, Forwards LER 79-014/03L-0 & 79-015/03L-0 05000315/LER-1979-014-03, /03L-0 on 790301:while in Mode 1,indicated Position of Rod F-6 Discovered to Be Oscillating within 15 Steps of Bank Demand Position.Caused by Signal Conditioning Module Connector.Cleaning & Reinstallation Corrected Limits 05000315/LER-1979-015-03, /03L-0 on 790302:while Operating at Full Power, Pressurizer Relief Tank Rupture Disc Blew Out,Causing Ice Condenser Inlet Doors to Open.Caused by Pressure Fluctuations Resulting in Weakened Rupture Discs
References
LER-79-015-03L, LER-79-15-3L, NUDOCS 7904030262
Download: ML17317B050 (4)

LER-1979-015, /03L-0 on 790302:while Operating at Full Power, Pressurizer Relief Tank Rupture Disc Blew Out,Causing Ice Condenser Inlet Doors to Open.Caused by Pressure Fluctuations Resulting in Weakened Rupture Discs

Event date:
Report date:
3151979015R03 - NRC Website

text

U. S.INUCLEAR REGULATORY COMMISSION Q3 04~

Oo 25 26 LICENSE TYPE 30 57 CAT 58 09 NRC FORM 366 I7.77)

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LICENSEE EVENT REPORT

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Qi (PLEASE PRINT OR TYPE ALLREQUIRED INFORMATION)

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LICENSEE CODE 14 15 LICENSE NUMBER CON'T soURGE MO 0 5

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0 3

1 5 Q Q

3 2

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=60 61 DOCKET NUMBER 68 69 EVENT DATE 74 75 REPORT DATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES Q10

~02 WHILE OPERATING AT 100%

POWER A PRESSURIZER RELIEF TANK RUPTURE DISC BLEW OUT.

~03 AS A RESULT OF THE PRESSURE SURGE CREATED IN THE LOWER CONTAINMENT, THE ICE

~04 CONDENSER INLET DOORS WERE SHOWN TO BE IN THE OPEN POSITION BY THE CONTROL PANEL

~OS INDICATION.

THIS IS NOT CONSISTENT WITH THE REOU IREMENTS OF T.S. 3.6.5.3.

A

~06 RAPID SHUTDOWN WAS MADE IN ORDER TO ENTER THE CONTAINMENT TO CLOSE THE DOORS.

~07 DURING THE POWER REDUCTION THE AXIAL FLUX DIFFERENCE WAS FORCED OUT OF THE TARGET

~DB BAND SPECIFIED IN T.S. 3.2.1n FOR SEVEN MINUTES ABOVE CONTINUED PAGE 2

7 8

9 80

~09 SYSTEM

CAUSE

CAUSE COMP.

VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUBCODE

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10 11 12 13 18 19 20 SEQUENTIAL OCCURRENCE REPORT REVISION LERiRP EVENT YEAR REPORT NO.

CODE TYPE NO.

07 8840111

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QQ 21 22 23 24 26 27 28 29 30 31 32 ACTION FUTURE EFFECT SHUTDOWN ATTACHMENT NPRDP PRIME COMP.

COMPONENT TAKEN ACTION ON PLANT METHOD HOURS Q22 SUBMITTED FORM SUB.

SUPPLIER MANUFACTURER

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9 Qo 33 34 35 36 37 40 41 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS Q27 o

REPEATED PRESSURE FLUCTUATIONS ON THE PRT CAUSED THE RUPTURE DISC TO WEAKEN AND BLOW OUT AT A PRESSURE BELOW ITS DESIGN.

AS A RESULT SOME ICE CONDENSE WERE OPENED SLIGHTLY.

AFTER THE UNIT WAS REMOVED FROM SERVICE THE DOORS WERE CLOSED.

TOTAL TIME OPEN WAS TWO HOURS NINE MINUTES.

THE POWER REDUCTION WAS MADE BY CONTROL ROD INSERTION WHICH CAUSED THE AFD TO LEAVE THE CONTINUED PAGE 2 7

8 9

FACILITY STATUS 99 POWER OTHER STATUS Q 1

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28 1

0 0

29 NA 7

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11 12 LOSS OF OR DAMAGETO FACILITY TYPE

DESCRIPTION

Z Q42 NA 9

CO LJO ~O ACTIVITY CONTENT RELEASED OF RELEASE AMOUNTOF ACTIVITY 6

Z Q33

~ZQ34 NA 7

8 9

10 44 45 PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION Q39

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0 031 Z

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11 12 13 PERSONNEL INJURIES NUMBER DESCRIPTIONQ41 8 ~00 0

Q4o NA l ~@0 DISCOVERY DESCRIPTION

+32 OPERATOR OBSERVATION LOCATIONOF RELEASE Q NA 80 80 80 80 80 80 7

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9 10 PUBLICITY ISSUED DESCRIPTION~

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10 NAMF OF PREPARER H'. CHADWELL NRC USE ONLY 68 69 PHQNE (616) 465 5901 X 316 83 144a 8

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CONTINUATION OF LER $9-015/03L-0 PAGE 2 EVENT DESCRIPTION AND PROBABLE CONSE UENCES:

75 PCT POWER AND AN ADDITIONAL TWENTY TWO MINUTES ABOVE 50 PCT POWER.

SIMILAR OCCURRENCES 013/03L-O, 78-089/03L-0 AND 79-006/03L-O.

CAUSE DESCRIPTION AND CORRECTIVE ACTIONS:

TARGET BAND.

NO FURTHER ACTION IS PLANNED.

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