05000260/LER-1979-010-03, /03L-0 on 790510:residual Heat Removal Sys Snubber Came Apart Upon Removal for Testing.Caused by Piston Unscrewing from Rod After Locking Key Vibrated Loose.Snubber Replaced & Other Snubber Tested

/03L-0 on 790510:residual Heat Removal Sys Snubber Came Apart Upon Removal for Testing.Caused by Piston Unscrewing from Rod After Locking Key Vibrated Loose.Snubber Replaced & Other Snubber Tested

ML18024A845
Person / Time
Site:	Browns Ferry
Issue date:	06/07/1979
From:	TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML18024A844	List: 05000260/LER-1979-010, Forwards LER 79-010/03L-0 05000260/LER-1979-010-03, /03L-0 on 790510:residual Heat Removal Sys Snubber Came Apart Upon Removal for Testing.Caused by Piston Unscrewing from Rod After Locking Key Vibrated Loose.Snubber Replaced & Other Snubber Tested
References
LER-79-010-03L, LER-79-10-3L, NUDOCS 7906130288
Download: ML18024A845 (4)

LER-1979-010, /03L-0 on 790510:residual Heat Removal Sys Snubber Came Apart Upon Removal for Testing.Caused by Piston Unscrewing from Rod After Locking Key Vibrated Loose.Snubber Replaced & Other Snubber Tested

Event date:
Report date:
2601979010R03 - NRC Website

text

,<<4RC FORM 366 I7.77)

LICENSEE EVENT REPORT

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8 CON'T

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8 CONTROl BLOCK:

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9 LICENSEE CODE 14 15 5

1 0

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B 0

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+9 EVENT DATE 74 75 REPORT DATE'0 soURCE LLJQB 0

5 0

0 0

2 6

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0 60 GI DOCKET NUMBER GB 69 EVENT DESCRIPTION AND PROBABlE CONSEOUENCES QIO While removin Residual Heat Removal S stem snubber R-20 lower for functional test-Qi (PLEASE PRINT OR TYPE ALLREQUIRED INFORMATION) 6 0

0 0

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1 1 04~

Qs LICENSE NUMBER 25 26 LICENSE TYPE 30 57 CAT 58 ing in accordance with T.

S. 4.6 ~ H.49 thesnubber came apart.

There was no hazard to

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the public health or safety.

Previous occurrences

None.

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~OB 80 7

8 9

SYSTEM

CAUSE

CAUSE COMP.

VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUBCODE F

04' 043 L8013 0

0 P

0 R

F 04 L~JOs Lil0>s 7

8 I

9 10 11 12 13 18 19 20 SEQUENTIAL OCCURRENCE REPORT R EVISION LEAIAO EVENT YEAR REPORT NO.

CODE TYPE NO.

017 sspoRT

~79

+

~01 0

Q~

~03

+L QO 21 22 23 24 26 27 28 29 30 31 ACTION FUTURE EFFECT SHUTDOWN ATTACHMENT NPRDQ PAIME COMP.

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

SUPPLIER MANUFACTURER LJQIB LJQI9

~Q20 LJQ2'~JQ23 L~JQ24 L~JQ26 B

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9 Q26 33 34 35 36 37 41 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS Q27 o

The snubber (Bergen Paterson hydraulic, size HSSA-30) failed due to the piston un-screwing from the rod after a locking key vibrated loose.

In accordance with T.S.

,4.6.H.4.,

ten additional snubbers were tested. All proved satisfactory.

The failure 3

was random and no recurrence contro 1 act ion is appropriate.

The faulty snubber was 4

replaced.

80 7

8 9

FACILITY STATUS

'YiPOWER OTHER STATUS QSO H Qss ~00 0

033 NA 7

8 9

10 12 13 44 ACTIVITY CONTENT RELEASED OF RELEASE AMOUNTOF ACTIVITYQ36 Q33 Z Q34 NA 7

8 9

11 44 PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION Q39 7 ~00 0

Q33 E

Qss NA 7

8 9

~ "

11 12 13 PERSONNEL INJURIES NUMBER DESCAIPTIONQ 3

~00 0

Q43 NA 9.,

11 12 LOSS OF OA DAMAGE'TOFACILITYQ43 TYPE

DESCRIPTION

~ZQ42 NA 9

10 PUBLICITY ISSUED DESCRIPTION~

Q44 7

8 I

43 7

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7 8

9 10 NAME OF PREPARER METHOD OF DISCOVERY DISCOVERY DESCRIPTION

+32

~B Q31 Removing from system for teeing 45 46 LOCATIONOF RELEASE Q 80 NA 45 80 80 80 80 NRC USE ONLY 0a 39

~062 Q~~

68 69 PHONE:

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Form BF-17 BF 15.2 6/09/78 LER SUPPLENENTAL INFORMATION BFRO 260 /

7910 Technical Specification Involved 4-6-H Reported Under Technical Specification 6.7 2 b(2)

Date of Occurrence 5/10/79 Time of Occurrence 1030 Unit Identification and Descri tion of Occurrence:

Residual Heat Removal System snubber R-20 (lower) came apart while being removed for operational testing in accordance with T. S. 4.6.H. 4.

Conditions Prior to Occurrence:

Un'it shutdown for refueling.

Action, specified in the Technical Specification Surveillance Requirements met due to ino erable e ui ment.

Describe.

"'Ten additional snubbers were satisfactorily tested in accordance with T.

S. 4.6.H.4.

A arent Cause of Occurrence:

The snubber (Bergen Paterson, hydraulic, size HSSA-30) failed due to the piston

,unscrewing from the rod after a locking key vibrated loose.

Anal sis of Occurrence:

There was no hazard to the public health or safety.

Corrective Action

The faulty snubber was replaced.

Failure Data:

None previous.

Tennessee Valley Authority - Browns Ferry Nuclear Plant

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