ML20085G188

AO BFAO-7327W:on 731016,setpoint of 1.8 Psid for Recirculation Jet Pump Riser Differential Pressure Switch PdIS-68-24 Exceeded Tech Spec Limit.Switch Recalibr,Tested & Frequency Increased to Once Every 2 Wks

ML20085G188
Person / Time
Site:	Browns Ferry, 05000000
Issue date:	10/26/1973
From:	Eric Thomas TENNESSEE VALLEY AUTHORITY
To:	Oleary J US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20085G173	List: ML20085G186 ML20085G188
References
BFAO-7327W, NUDOCS 8308240371
Download: ML20085G188 (2)

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{ T ',- .h TENNESSEE VALLEY AUTHORITY i Ey -

CHATTANOOGA, TENNESSEE o 37401 L 8 3

October 26, 197'2 C I- ANN EAShAY

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OCT301973> y Mr. John F. O'I4ary ,

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Directorate of Licensing i 1 WCH w Office of Re5ulation . Eh4 [I$$l, N

U.S. Atomic Energy Co= mission /

Washington, DC 20545 f) M2

Dear Mr. O'Iaary:

TENNESSEE VALLEY AUTHORITY - BROWNS ERRY NUCIEAR PIMT UJIT 1 -

D0ciGT n0 50-259 - FACILIH OPdRATING LICENSE DPR ABNOEMAL OCCURRENCE REPORT EFAO-732Ta' The purpose of this report is to provide details concerning the malfunction of recirculation jet pump riser d/p switch PdIS-68-24 in unit 1 at Erowns Ferry Nuclear Plant on October 16, 1973 This occurrence was reported by telegram on October 17 to the Region II Directorate of Regulatory Operations, Atlanta, Georgia.

Description of the Incident

• During routine surveillance testing on October 16, recirculation jet l

pumpriserd/pswitchPdIS-68-24wasfoundtooperateoutsidethe technical specification setpoint of greater than 0 5 but less than 1 5 psid as specified in table 3 2.B. The as-found setpoint was 1.8

, psid.

Investigation and Corrective Action Each of the fcur differential pressure switches operate relays whose contacts are arranged'in a one out of two taken twice logic in the RHR injection circuit. The minimum number of channels required for each trip system is two. The other two channels were tested, found to operate satisfactorily, and, if recuired, would have perfomed their intended function. The reactor was in the hot standby condition.

These switches are Earton model 288 differential pressure switches.

The switch mechanisms were inspected for binding misalignment of other irregularities. Hone vas found. The switches were recalibrated cad then functionally tested several times to ensure repeatability. A functional testing frequency of once every 2 weeks has been initiated i e308240371 731106 GD.gV dg ,p/v 1 l PDR ADOCK 050002S9 y y S PDR g COPY SENT REGION < M -

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Mr. John F. O'Icary October 26, 1973 TEICIESSIE VALLEY AUTHORITY - ERO'J::S FERRY !IUCLEAR PIllIT U: LIT 1 -

DOCKET 10 50-259 - FACILITY OPERATI!!G LICE!;SE DPR ABI0FFE CCCURRE* ICE EFAO-732pi for all four switches and will be continued until three consecutive tests prove satisfactory perfor: nance. At that time, the original test schedule of once a month will be resumed. We intend to install, as soon as possible upon receipt, new locking switchplate assemblies recently made available by the vendor to prevent setpoint drift.

Very truly yours, TE:HIESSEE VALL7 AUTHORITY V / W h E. F. Thomas

(' Director of Pcver Production a

CC: Mr. Iionnan C. Monclcy, Director Region II Regulatory Cperations Office, USAEC 230 Peachtree Street, :TJ.

Atlanta, Georgia 30303 .

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