ML20136H129

Special Rept:On 970103,LPDS Declared Inoperable.Caused by Defective Latch Board.Board Replaced & ST Procedure Was Completed Satisfactorily on 970114

ML20136H129
Person / Time
Site:	Limerick
Issue date:	03/10/1997
From:	Boyce R PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9703190059
Download: ML20136H129 (2)

Text

e R:bart W.Boycs l Plant Manager

. , Limerick Generating Station

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PECO NUCLEAR Po m en e nv Limerx;k Generating Station A Unit of PECO Energy Po Box 2300 Sanatoga, PA 19464-0920 610 718 2mM l ,

? l l T.S. 3.3.7.10 l T.S. 6.9.2 March 10,.1997 Docket No. 50-353 l- License No. NPF-85 U.S. Nuclear Regulatory Commission i Attn: Document Control Desk-Washington, DC 20555

SUBJECT:

Limerick Generating Station, Unit 2 Special-Report for the Inoperability of a Loose-Part Detection System Channel for More Than 30 Days This Special Report is being submitted pursuant to the-requirements of Limerick Generating Station (LGS), Unit 2 Technical Specifications ~ (TS) Section 6.9.2 as required by

TS Section 3.3.7.10, " Loose-Part Detection System." TS l

Section 3.3.7.10 requires that with one or more of the required Loose-Part Detection System (LPDS) channels j inoperable for more than 30 days, a Special Report must be l prepared and submitted within 10 days outlining the cause of the malfunction and the plans for-restoring the channel (s) l to operable status. The LPDS is required to be operable in Operational Condition (OPCON) 1 (Power Operation) and OPCON 2 (Start-up).

On January 3, 1997, with Unit 2 operating in end of cycle 'j conditions at approximately 87% power, the Unit 2 LPDS was declared inoperable for the performance of Surveillance Test ig (ST) procedure ST-2-036-408-2, " Loose-Part Detection System

- Loose Part Instrumentation Channel Calibration -

Detectors." During performance of the ST procedure, a defective latch board was identified. The defective latch /, ((kG j l

board was replaced and the ST procedure was completed A satisfactorily on January 14, 1997, with Unit 2 operating at

. approximately 80% power. The Unit 2 LPDS was not declared l operable at this time since intermittent low level alarms

! were being received on Channel 5. This channel / detector 9703190059 970310

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. . March 10, 1997 Page Two monitors the acoustic level on the 'N4A' feedwater nozzle.

Station personnel attributed the low level alarms to insufficient signal-to-noise ratio created by low reactor power level. A work order was initiated to inspect the Channel 5 instrumentation within the Primary Containment during the fourth Unit 2 refueling outage (2R04).

At 1601 hours0.0185 days <br />0.445 hours <br />0.00265 weeks <br />6.091805e-4 months <br /> on January 30, 1997, Unit 2 entered OPCON 3 (Hot Shutdown) for commencement of 2R04. The LPDS is not required to be operable in OPCON 3.

During 2R04, the Channel 5 accelerometer was found properly mounted with all hardware attached. However, the accelerometer cable shielding was found embrittled. The accelerometer and cable were replaced and satisfactorily tested.

At 0354 hours0.0041 days <br />0.0983 hours <br />5.853175e-4 weeks <br />1.34697e-4 months <br /> on February 26, 1997, Unit 2 was placed in OPCON 2 (Start-up). The 30 day time clock of TS Section 3.3.7.10 continued upon start-up. At 2158 hours0.025 days <br />0.599 hours <br />0.00357 weeks <br />8.21119e-4 months <br /> on February 28, 1997, the 30 days expired. Since Unit 2 was operating at approximately 23% power, station personnel were unable to

! perform a channel functional test of the LPDS because of insufficient signal-to-noise ratio.

At 1951 hours0.0226 days <br />0.542 hours <br />0.00323 weeks <br />7.423555e-4 months <br /> on March 3, 1997, with Unit 2 operating at approximately 93% power, the LPDS was declared operable i

following satisfactory completion of procedure ST-2-036-640-2, " Loose Parts Monitoring System Channel Functional Test."

The Unit 2 LPDS is operable at this time. The inoperable LPDS had no impact on plant operation.

. If you have any questions or require additional information,

! please contact Mr. James L. Kantner at (610) 718-3400.

Very truly yours, w

DMS:cah

! cc: H. J. Miller, Administrator Region I, USNRC N. S. Perry, USNRC Senior Resident Inspector, LGS