ML20085E985

AO BFAO-50-260/757W:manual Valve in Drive Water Supply on Control Rod Drive Module 50-15 Found in Open Position.Cause Unknown.Valve Repositioned to Required Closed Position

ML20085E985
Person / Time
Site:	Browns Ferry
Issue date:	05/30/1975
From:	Eric Thomas TENNESSEE VALLEY AUTHORITY
To:	Rusche B Office of Nuclear Reactor Regulation
Shared Package
ML20085E994	List: ML20085E985 ML20085E996
References
NUDOCS 8308180193
Download: ML20085E985 (2)

Text

o urlo, O re"~essee vauev ^40airv

, f .

h. .

CHATTANOOGA, TENNESSEE 3740'1

'/ro.3916 May 30, 1975 Mr. Benard C. Rusche Director of IIuclear Reactor Regulation i U.S. Nuclear Regulatory Co::miasion Washington, DC 20555 -

Dear Mr. Rusche:

TENNESSEE VALLEY AUTHORITY - BROWNS FERRY NUCLEAR PLANT UITIT 2 -

DOCKET NO. 50-260 - FACILITY OPERATING LICENSE DPR-SP. - ABNORl/AL OCCURRENCE REPORT BFAO-50-260/757W The enclosed report is to provide details concerning the manual  ;

valve in the drive water supply on control rod drive module 50-15 which was found in the open position instead of shut as required by the temporary technical specifications. This report is subutted i in accordance with Appendix A to Regulatory Guide 1.16, Revicion 1, October 1973. This event occurred on Browns Ferry Nuclear Plant unit 2.

i Very truly yours, TERNESSEE VALLEY AUTHORITY g*J _

'N+ W

. F. Thomas ]

Director of Powcr Production Enclosure CC (Enclosure):

Mr. Norman C. Mosclcy, Director U.S. Nuclear Regulatory Commicsion Regional Office 230 Peachtree Street, NW., Suite 818 Atlanta, Georgia 30303 8308180193 750530 PDR ADOCK 05000260 S PDR An Equal Opportunity Empicycr

/o055-)9 -+ .

b

-v.----r--m - -- -. . ,.wv,, ,e . ,.-:, - , , , - -

ABNOR1'AL OCCURRENCE REPORT Report No.: BFAO-50-260/757W Report Date: l'ay 30,1975 Occurrence Date: May 20, 1975 Facility: Browns Ferry Nuclear Plant unit 2 Identification of Occurrence .

The manual valve in the drive water supply on control rod drive module 50-15 was found in the open position instead of shut as required by the temporary technical specifications. ,

Conditions Prior to Occurrence The unit was in cold shutdoun condition with the mode switch locked in the shutdotm position. All control rods were fully inserted and their directional control valves disarmed electrically.

Description of Occurrence During review of surveillance instruction data, the drive vnter supply valve to control rod drive module 50-15 was noted as having been found in the open position during performance of the surveillance inspection.

Apnarent Cause of Occurrence The reason for the valve being open is unknown. The valve had last been verified shut during a surveillance insnection on May 16, 1975. Movement from the shut position had not been authorized. Ho work had been performed in this area except general cleaning. i i

Analysis of Occurrence d

All control rode remained inserted continuously with their directional control valves disarmed clectrical4 There were no adverse effects to the public  !

j health and safety as a result of this occurrence. t Corrective Action The valve was repositioned to its required closed position. A surveillance

' inspection was performed in=cdiately thercafter to ensure that all control i rod drive module manual drive water supply valves on both units were in the .

closed position. -

. t Failure Data i i

None i

?

f 1

l

l l

4 . . ..

. _ ..