ML20107L250

Special Rept:On 960312,two loose-part Detection Sys Channels Inoperable for More than 30 Days.Caused by Failure of Sensor.Repaired Control Rod Housing 02-31 Lpds Channel Sensor

ML20107L250
Person / Time
Site:	Limerick
Issue date:	04/23/1996
From:	Boyce R PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9604290245
Download: ML20107L250 (2)

Text

l H:bert W.B ryc2 l Plant Manager

_A Lirnenck Generatng Staton t <

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PECO NUCLEAR recO en c-ev Limenck Generaung Stat!on A Unit of PECO Energy PO Box 2300 Sanatoga PA 19464-0920 610 718 2000 l

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TS 3.3.7.10 ,

TS 6.9.2 l April 23, 1996 Docket No. 50-352 License No. NPF-39 l

l U.S. Nuclear Regulatory Commission i Attn: Document Control Desk Washington, DC 20555

SUBJECT:

Limerick Generating Station, Unit 1 Second Special Report Supplement for Inoperability of Two Loose-Part Detection System Channels for More Than 30 Days This second Special Report supplement is being submitted pursuant to the requirements of Limerick Generating Station (LGS), Unit 1 Technical Specifications (TS) Section 6.9.2 as required by TS Section 3.3.7.10, " Loose-Part Detection System." TS Section 3.3.7.10 requires that with one or more of the required Loose-Part Detection System (LPDS) channels inoperable for more than 30 days, a Special Report must be prepared and submitted within 10 days outlining the cause of the malfunction and the plans for restoring the channel (s) to operable status.

On April 19, 1994, the original version of this Special Report was submitted and provided information regarding two (2) LPDS channels that were identified to be inoperable on

March 12, 1994. Troubleshooting isolated the malfunctions l

to the inaccessible Unit 1 Prituary Containment and an outage was necessary to determine the cause and corrective actions.

The original version of this S)..ecial Report stated that inspections of the inoperable L,PDS channels would be l

performed during the next Unit 5 outage of sufficient duration.

The first supplement to this Special Report dated July 7, 1995, provided information regarding repairs to the LPDS channel sensor on the 1A Recirculation Pump suction nozzle during a Unit 1 outage that was performed between May 7 and 10, 1995. The other LPDS channel sensor on the control rod 9604290245 960423 PDR ADOCK 05000352 S PDR }fE% g

l t: s l April 23, 1996 Page Two housing 02-31 could not be inspected during this short outage because of the location of the sensor.

This second supplement to the Special Report provides the details concerning repairs to the control rod housing 02-31 LPDS channel sensor. This sensor was inspected on February 2, 1996, during the sixth Unit 1 Refueling Outage (1.e.,

1R06). The sensor was found properly mounted with all hardware attached. A worn spot was found in the sensor cable shielding that penetrates through the Primary l Containment floor; however, the cable was later determined '

! to be functional. Tne accelerometer, sensor cable, and line driver were original plant equipment and were replaced.

Following the replacements, a shake test of the new equipment was satisfactorily performed. An analysis revealed that the line driver had failed due to normal fatigue. The control rod housing 02-31 LPDS channel sensor l was made operable on March 4, 1996, following successful completion of its surveillance test at rated power.

The Unit 1 LPDS is operable at this time. This is the final supplement to the Special Report.

If you have any questions or require additional information, please contact us.

Very truly yours, i

W DMS:bdd cc: T. T. Martin, Administrator Region I, USNRC N. S. Perry, USNRC Senior Resident Inspector, LGS t

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