05000296/LER-1978-027-03, /03L-0 on 781012:during Refueling Outage,Panel 3-25-327 Was Inoperable,Placing 2 Smoke Detector Zones Out of Svc.Caused by a Contact on Power Transfer Relay Which Failed to Close After Short Power Interruption

/03L-0 on 781012:during Refueling Outage,Panel 3-25-327 Was Inoperable,Placing 2 Smoke Detector Zones Out of Svc.Caused by a Contact on Power Transfer Relay Which Failed to Close After Short Power Interruption

ML18024A527
Person / Time
Site:	Browns Ferry
Issue date:	11/08/1978
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML18024A526	List: 05000296/LER-1978-027, Forwards LER 78-027/03l-0 05000296/LER-1978-027-03, /03L-0 on 781012:during Refueling Outage,Panel 3-25-327 Was Inoperable,Placing 2 Smoke Detector Zones Out of Svc.Caused by a Contact on Power Transfer Relay Which Failed to Close After Short Power Interruption
References
LER-78-027-03L, LER-78-27-3L, NUDOCS 7811140195
Download: ML18024A527 (3)

LER-1978-027, /03L-0 on 781012:during Refueling Outage,Panel 3-25-327 Was Inoperable,Placing 2 Smoke Detector Zones Out of Svc.Caused by a Contact on Power Transfer Relay Which Failed to Close After Short Power Interruption

Event date:
Report date:
2961978027R03 - NRC Website

text

,(7-77)

(:ONTROL BLOCK:

I LICENSEE EVENT REPORT Qi (PLEASE PRINT OR TYPE ALLREQUIRED INFORMATION)

I 8

<J LICENSEE CODE CAN' 14 15 LICENSE NUMBER I

II 0

2 IIEPOR1 ~Q0 1

SOURCE GO Gl DOCKET NUMBER 68 69 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES QIO 25 26 LICENSE TYPE 30 57 CAT 58 0

0 1

2 EVENT DATE 6

1 1

0 6

7 8 Q 74 75 REPORT DATE 80 3

Q~Q

~0 3

lolacin two zones of smoke detectors out of service T.S.3.11.C.1

. There are no redun-occurrences

~05 None.

~06 0

7 1

II !I 80 SYSTFM

CAUSE

CAUSE CODE CODE SUBCODE

~LjQll ~ Q12 ~ Q13 7,

8 9

10 I I I?

SEOUENTIA I I Illa(J EVENT YEAR REPORT NO, 017 Hi PUB I NIIM8FR 2l 27 23 24 ACTION.FUTURE EFFECT SHUTDOWN TAKEN ACTION ON PLANT METHOD

~CQIB ~Z QIB

~ZQ20

~Z Q21 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS Q27 0

A contact on the ower transfer caela American Zett e Co AZ2-COMP.

VALVE COMPONENT CODE SUBCODE SUBCODE Q14 ~ 65 ~ gl6 l3 IB I9 20 L

OCCURRENCE REPORT REVISION CODE TYPE NO.

L0O~J

~L

~0 26 27 28 29 30 31 32 ATTACHMENT NPRDX PRIME COMP.

COMPONENT HOURS ~22 SUBMITTED FORM SUB.

SUPPLIER MANUFACTURER Q>> ~Q2'J 05 40 41 42 43 44 47 panel 3-25-327 failed to close followin a momentar ower interru tion occ~ur-rence was caused 3

detectors returned to o eration.

The failure was an isolated event and no <<cur<<n<<

4 control action will be taken.

8

'I FACILITY

~30 M

STATUS 00 POWER OTHER STATUS ~

O

~II Qc ~00 0

Qrc N A I

II 0

10 12 I'I 44 ACTIVITY CONTENT RELEASED OF RELEASE AMOUNTOF ACTIVITYQ35 6

~Z Q33

~ZQ34 N A 7

6 9

10 44 PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION Q39 K3 ~~Q37 LKJQ38 7

8 9

11 12 13 PERSONNEL INJURIES NUMBER DESCRIPTION Q41

~pp Qco A

~AQ31 45 45 I

8 9

11 12 LOSS OF OR DAAIAOETo FACILITYQ43 TYPE

DESCRIPTION

~ZQ42 9

10 P U8 L IC ITY DESCRIPTION~

L~JQ44 2

0 I

8 9

10 NAME OF PREPARER I

ETHOD OF ISCOVERY 80 80 80 80 80 PHONE:

68 69 80 NRC USE ONLY tl O

80 cc 0

O DISCOVERY DESCRIPTION Q3'2 erator observat on LOCATIONOF REI.EASE Q36

Form BF-17 BF 15.2 6/09/78 LER SUPPLEMENTAL INFORMATION BFRO 296 / 7827 Technical Specification Involved Reported Under Technical Specification Date of Occurrence 10/12/7g Time of Occurrence unknown Unit Identification and Descri tion of Occurrence:

'I'wo zones of smoke detectors became inoperable.

Conditions Prior to Occurrence:

Unit shutdown for refueling.

The reactor head was off.

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

Describe.

A patrolling f5re watch was established.

A arent Cause of Occurrence:

A contact on the power transfer relay (American Zettler Co., Type AZ421-70-1H/

24VDC) in panel 3-25-327 failed to properly close during operation, thus deenergizinp.

the smoke detector circuits.

Anal sis of Occurrence:

The most probable cause of failure of the relay was insufficient contact ADf pressure or excessive oxide accumulation on the relay contacts, resulting in'n electrical discontinuity.

Corrective Action

The power transfer relay was replaced

'and the smoke detectors returned to service.

Subsequent operation was satisfactory.

Failure Data; None previous causing inoperable detectors.

Tennessee Valley Authority - Browns'erry Nuclear Plant