ML18024A845

LER 79-010/03L-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

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: ML18024A843 ML18024A845
References
LER-79-010-03L, LER-79-10-3L, NUDOCS 7906130288
Download: ML18024A845 (4)

Text

,<<4RC FORM 366 I7.77)

LICENSEE EVENT REPORT CONTROl BLOCK: Qi (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 04~

'I 6

~O A L B R F 2 0 0 0 0 0 0 0 0 0 Q3 4 1 1 1 1 Q2 Qs 7 8 9 LICENSEE CODE 14 15 LICENSE NUMBER 25 26 LICENSE TYPE 30 57 CAT 58 CON'T

~O 7 8 soURCE LLJQB 60 GI 0

EVENT DESCRIPTION AND PROBABlE CONSEOUENCES QIO 5 0 0 0 DOCKET NUMBER 2 6 0 GB 7

69 0 5 1 EVENT DATE 0 7 9 74 B

75 0 6 0 REPORT DATE 7 7

'0 +9 While removin Residual Heat Removal S stem snubber R-20 lower for functional test-ing in accordance with T. S. 4.6 H.49 thesnubber

~ came apart. There was no hazard to

~o 4 the public health or safety. Previous occurrences: None.

~OB

~OB 7 8 9 80 SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUBCODE 7 8 I 9 F

10 04' 11 043 L8013 12 13 0 0 P 0 R F 04 18 L~JOs 19 Lil 20 0>s SEQUENTIAL OCCURRENCE REPORT R EV ISI ON 017 LEAIAO EVENT YEAR sspoRT ACTION FUTURE

~79 21 22 EFFECT

+

23 SHUTDOWN

~01 24 REPORT NO.

0 26 Q~

27

~03 28 ATTACHMENT CODE 29 NPRDQ TYPE

+L 30 PAIME COMP.

31 NO.

QO COMPONENT TAKEN, ACTION LJQIB LJQI9 33 34 ON PLANT

~Q20 35 LJQ2'~JQ23 METHOD 36 37 HOURS +22 SUBMITTED 41 FORM SUB.

L~JQ24 42 SUPPLIER L~JQ26 43 44 MANUFACTURER B 2 o 9 47 Q26 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 faul ty snubber was 4 replaced.

7 8 9 80 FACILITY METHOD OF STATUS 'YiPOWER OTHER STATUS QSO DISCOVERY DISCOVERY DESCRIPTION +32 H Qss ~00 0 033 NA ~B Q31 Removing from system for teeing 7 8 9 10 12 13 44 45 46 80 ACTIVITY CONTENT RELEASED OF RELEASE Z

AMOUNT OF ACTIVITYQ36 NA NA LOCATION OF RELEASE Q Q33 Q34 7 8 9 11 44 45 80 PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION Q39 7 ~00 0 Q33 E Qss NA 7 8 9 ~ " 11 12 13 80 PERSONNEL INJURIES NUMBER DESCAIPTIONQ 3 ~00 0 Q43 NA 7 8 9 ., 11 LOSS OF OA DAMAGE'TO FACILITY 12 80 TYPE DESCRIPTION Q43 I 43

~ZQ42 NA 7 8 9 10 80 o

ISSUED PUBLICITY Q44 DESCRIPTION ~ ~062 Q~~

NRC USE ONLY 7 8 9 10 68 69 0

NAME OF PREPARER PHONE: a 39

c 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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