ML20085M507

AO BFAO-7345W:on 731130,during Routine Daily Instrument Checks,Core Spray Sparger to Reactor Pressure Vessel Alarm Delta/Pressure Switches PdIS-75-28 & PdIS-75-56 Found Inoperable.Caused by Misapplication of Switches

ML20085M507
Person / Time
Site:	Browns Ferry
Issue date:	12/10/1973
From:	Eric Thomas TENNESSEE VALLEY AUTHORITY
To:	Oleary J US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20085M471	List: ML20085M478 ML20085M482 ML20085M507
References
AO-BFAO-7345W, NUDOCS 8311080614
Download: ML20085M507 (2)

Text

.-._..........,

W

[kf ., .. . _

,O O TENNESSEE VALLEY AUTHOnlTY m_10 r7 q

,// /' 1i g

CHATTANCOGA, TENNESSEE ij 374O'i L: .

]..

-3

'W '

tr .R b J December 10, 1973 / SE*d BNbs PARTo "r.1 Ship

, t< 9 ,% u

.c v7

• q- [J . t! aJ A v y , % ,jss vu.

u Q, 4 L' P gmA q DEC141973>

i Wnd.nw' Mr. John F. 0%ary, Director *A

,f Directorate of Licensing 4 - >

77 i

Office of Regulation U.S. Atoraic Energy Commission ' / klfl!

"" *I\ p' Washington, DC 205!+5 I

Dear Mr. O' Leary:

l.

TENNESSEE VALLEY AUTHORITY - ERCES FERRY NUCIEAR PIANT UlilT 1 -

DOCKET 110 50-259 - FACILITY OPERATIIU LICENSE DPR ABRORMAL OCCURRENCE REPORT EFAO-7345W The enclosed report is to provide details concerning core spray sparger to reactor pressure ' vessel alam d/P switches that were found outside 1- their required setpoint which occurred on Browns Ferry Nuclear Plant unit.1 on I!ovember 30, 1973, and is submitted in accordance with Appendix A to Regulatory Guide 1.16, Revision 1, October 1973

')

l Very truly yours, l1 TENNESSEE VALLEY AUTHORITY h*,:9 W E. F. Thomas Director of Power-Production Enclosure CC(Enclosure):

Mr. Ifoman C. Moseley, Director -

Region II Regulatory Operations Office, USAEC' 230 Peachtree Street, IM.

Atlanta, Georgia 30303 ,

Y.

. i f(

sattoso614 74otaa

1. -f h 8898

-E _ Db . p' f ~

.. . ,. + _ l - . -. -.. -~ ;wx m uwown

/

A ABNORI'AL OCCURRENCE REFORi -

l Report No.: BFAO-7345W Report Date: December lo, 1973-Occurrence Date: November 30, 1973 Facility: Erowns Ferry Nuclear Plant Identification of Occurrence Unit 1 core spray sparger to reactor pressure vessel alarm d/p switches were found inoperable.

Conditions Prior to Occurrence Reactor was at 25. percent thermal power during startup testing.

Description of Occurrence During routine daily instrument checks, core spray sparger to reactor pressure vessel d/p indicating switches FdIS-75-28 and IdIs-75-56 were observed downscale.

Designation of Aprarent Cause of Occurrence Misapplication of switches.

Analysis of Occurrence ,

Eachd/pswitchsensesthepressurebetweena.coresprayspargerandthelower core pInte. In the event that a core spray loop. piping breaks between the core chroud and reacter vessel, an additional pressure drop due to the steam separator -

and dryer will be sensed by the switch. Component -location requires that a water leg offset exceeding the capability of the switch _be set into the switches. -

Because of this, they were incapable of performing their intended function.

Although the alarm would not have actuated, daily instrument checks and

, pericdic pressure measures have ensured that the' core spray loop piping is i sound.

'Correetive Action- '

Daily in:trument' checks and periodic pressure measurements will continue until' a perranent resolution is made. s Failure Data-

-None' JRC: CHB .

.._A .___.