ML20085M416

AO BFAO-7346W:on 731206,during Surveillance Test, Recirculation Pump a Indication Switch PdIS-68-85 Malfunctioned.Caused by Setpoint Drift.New Locking Device Installed

ML20085M416
Person / Time
Site:	Browns Ferry
Issue date:	12/14/1973
From:	Eric Thomas TENNESSEE VALLEY AUTHORITY
To:	Oleary J US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20085M419	List: ML20085M416 ML20085M420
References
AO-BFAO-7346W, NUDOCS 8311080462
Download: ML20085M416 (2)

Text

.

, q s, TENNESSEE VALLEY AUTHO AITY r~' !rt 77 -

~/-

CHATTANOOGA, TENNESSEE . _ . . 37401 bl_ ' ./

<b

/\y gY <a Ysiib ~

~y,

~

h L*n p [:c I%

• " i ~ #19 December 14, 1973 C7 I .

i

[%dl~/p.O q g . , sh$Wh'E5 Mis m.c, mnmes-

>f s

n.

OgW,Q jp s _ p. ..

s

. r 4,,yfr-y 9%

-m 4 ki u ;W'&MyJJ'u$l g\ * ?m q q4f Mr. John F. O' Leary, Director D ;. TifEf* g8' W b d>

Directorate of Licensing i(./ ./ . ; T'4 -

Office of Regulation ~"'

U.S. Atomic Energy Cemaission Washington, DC 20545

Dear Mr. O'Ieary:

4 TENNESSEE VALLEY AUTHORITY - BROWNS FERRY NUCLEAR PIANT UNIT 1 -

DOCKET No. 50-259 - FACILITY OPERATING LICENSE DPR ABNORMAL OCCURIENCE REPCfff BFAO-7346W The enclosed report is to provide details concerning recirculation pump A d/p indicating switch malfunction which occurred on Erowns Ferry Nuclear Plant unit 1 on December 6, 1973, and is submitted in accordance with Appendix A to Regulatory Guide 1.16, Revision 1, October 1973 Very tritly yours, TENNF.SSEE VALIEY AUTHORITY Vs ,7 5

/vE.F. Thomas Director of Power Production Enclosure CC (Enclosure):

Mr. Roman C. Moseley, Director Region II Regulatory Operations Office, USAEC 230 Peachtree' Street, NW.

Atlanta, Georgia' 30303 e

V] f I

8996-731214 J

/ e'A J .

i f05000 \ , . [f g , -

J i COPY SENT REGION- -

g 9

ABNORMAL OCCURRENCE REPORT l 1

. . \

Report ITo.--BFAO-7346'J Report Date--December 14, 1973 Occurrence Date--Dacenber 6,1973 Facility--Browns Ferry Nuclear Plant unit 1 Identification of Occurrence Recirculation pump' A d/p indication switch malfunction.

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

Descriptian of Occurrence During accelerated surveillance testing, PdIS-68-85 was found to operate outside the technical specification limit of less than or equal to 2 psid as specified in Table 3 2.3. The switch operated at 2.2 psid.

Analvais of Occurrence Each switch operates a relay having two sets of contacts, which are arranged in a one out of two taken four times logic in each trip system of the LPCI break detection system. The other three d/p switches on recirculation pump A vere tested and found to operate satisfactorily. If the LPCI break detection system had been required, it would have perforced its intended function.

Corrective Action A new type of locking device was installed to minimize setpoint drift. Present testin6 frequency of ence every two weeks will continue until three consecutive tests are satisfactory, at which time the nomal test frequency of once a conth vill be resumed.

Failure Data Barton Model 288 differential pressure indicating switch; serial No. 288-4545 Switch Date Failure Corrective Action PdIS-68-85 10/15/73 Setpoint drift Reset setpoint PdIS-68-85 12/6/73 Setpoint drift Installed new locking device 0

ob l--_._ _ )