ML18024A820

LER 79-005/01T-0 on 790506:when RHR Svc Water Supply to 2B RHR Heat Exchanger Was Isolated for Maint,Standby Coolant Supply to Unit Was Also Isolated.Caused by Lack of Administrative Control Over Sys cross-connect Valves

ML18024A820
Person / Time
Site:	Browns Ferry
Issue date:	05/18/1979
From:	TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML18024A819	List: ML18024A817 ML18024A820
References
LER-79-005-01T, LER-79-5-1T, NUDOCS 7905310427
Download: ML18024A820 (3)

Text

NAC FORM 366 I7.771

~U. S. NUCLEAH ktuULATLIAYCOMMISSION

"'r LICENSEE EVENT REPORT CONTROL BLOCK: QI tPLEASE PRINT OR TYPE ALL AEQUIAEO INFORMATION)

I 6

~OI 7 8 9 A L B LICENSEE CODE R F 3QE 14 0 0 0 0 0 lICENSE NUMBER 0 0 0 0 25 Q84 26 1 1 LICENSE TYPE 1 1 30 Q<~QE57 CAT 58 CON'T

~O SOURCE I

60 LI~B 61 0 5 0 0 0 DOCKE'T NUMBER 2 9 6 68 7

G<J 0 5 0 EVENT DATE 6 9 74 6

75 0 5 l REPORT DATE 8 7 9 Qs 80 EVENT DESCRIPTION AND PROBABLE CONSEQUEIVCES QIO During normal unit 3 operation, the RHR service water su l to ex-changer was isolated for maintenance. The isolation of the water supply also isolated Lthe standby coolant supply to unit 3. (T.S. 3.5.C.3 and 3.5.C.5) There was no hazard to the public health or safety. Previous occurrences: None.

~O7

~OB 7 8 9 80 SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SUBCODE CohIPONENT CODE SUBCODE SUBCODE

~OB ~CF Qll ~D QIE ~A QIE H T E Z 0 H Ol< ~C OIE ~Z OIE 7 8 9 10 II I2 13 18 19 20 SEQUENTIAL OCCURRENCE REPORT REVISION Qll LERiRO II<PORE ACTION FUTURE EVENT YEAR

~79 21 22 EFFECT

~

23 SHUTDOWN

~00 24 REPORT NO.

5 26

~M 27

~01 28 ATTACHhlENT CODE 29 NPRDA TYPE

~T 30

~

PRIME CohIP.

31

~0 NO.

32 COMPONENT TAKEN ACTION 33 QIB ~COO 34 ON PLANT

~Q2O 35 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS Q27 METHOD

~Q2 36 37 HOURS +22 40 SUBMITTED

~Y 41 Q23 FORM SUB.

~NQ24 42

~

SUPPLIER 43 Q25 44 hlANUFACTURER 9

47 Q26 o The isolation of the unit 3 water supply during unit 2 maintenance was caused by a lack of administrative control over system cross connect valves. Upon discovery of the error, RHR heat exchanger 2B was returned to service within four hours and the

~3 water supply restored.Administrative controlshave been improved 7 8 9 80 F AC I LITY METHOD OF OTHER STATUS DISCOVERY D SCOVEIIY DESCRIPTION Q32

~IE 7 8 STATUS 9

E Q28 ~0028 10 PR POWER 12 13 QP 44 45 Q31 46 Operator Inspection Tour 80 ACTIVITY CONTENT 7 8

~Z 9 '0 RELEASEO OF RElEASE Q33 ~ZQ34 PERSONNEL EXPOSURES NUhIBER TYPE "

AIIIOUNTOF ACTIVITYQD NA DESCRIPTION Q39 44 NA LOCATION OF RELEASE Q36 80

~00 0 QOP ~ZQ3II NA 7 8 9 11 12 13 80 PERSONNEI. INJURIES NUMBER DESCRIPTIONQ41 8 ~00 O Qo NA 7 8 9 I 11 12 80 LOSS OF OR DAhIAGE TO FACILITY TYPE DESCRIPTION Q43

~zQ4, NA 9 10 80 ISSUED PUBLICITY DESCRIPTION LP/

7 908 81 0937 NRI USE ONL.Y

~NQ<<NA 9 10 68 69 7 8 0

NAME OF PREPARER PHONF: L 0

Form BF-17 BF 15.2 6/09/78 LER SUPPLEi>IENTAL INFORMATION BFRO 96 / Technical Specification Involved 3 5 C 3>>d 3.5.C.5

)

Reported Under Technical Specification

" Time of Occurrence l300 Unit Date of Occurrence Identification and Descri tion of Occu'rrence:

The RHR service water supply to t: he 2B RHR heat exchanger was isolated for maintenance.

The isolation of the water supply also isolated the standby coolant supply to unit 3.

Conditions Prior to Occurrence:

Unit 2 - r ef ueling outage in px ogress Unit 3 operating normally at 75% power Action specified in the Technical Specification Surveillance Requirements met due to ino erable e ui ment. Describe.

,Place the unit in cold shutdown with 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

A arent Cause of Occurrence:

The isolation of the water supply for maintenance was the direct cause; however, lack of administrative .controls over cross connect valves was the proximate cause of the incident.

Anal sis of Occurrence:

There was no hazard to the public health or safety<

Corrective Action:Upon determining that the standbycoolant supply had been isolated, act on-was mme ately taken to restore the heat exchanger to an operable status so the service water supply to'he standby coolant could be reopened. Standby coolant was returned to service in four hours. The standby 'coolant supply valve has. been painted

'a distinctive color and strict administrative controls imposed on its-operation. System

, piping changes to permanently prevent recurrence are planned during the next unit 3

'ailure Data: outaF e.

None previous.

Tennessee Valley Authority - Browne Ferry Nuclear Plant

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