ST-HL-AE-5432, Special Rept:On 951204,one of Channels in Upper Rv Collection Region Was Declared Inoperable Due to Loss of Sensor Signal.Repair of Two Channels Will Be Performed During Next Unit 2 Refueling

Special Rept:On 951204,one of Channels in Upper Rv Collection Region Was Declared Inoperable Due to Loss of Sensor Signal.Repair of Two Channels Will Be Performed During Next Unit 2 Refueling

ML20116A564
Person / Time
Site:	South Texas
Issue date:	07/22/1996
From:	Jordan T HOUSTON LIGHTING & POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
ST-HL-AE-5432, NUDOCS 9607260154
Download: ML20116A564 (3)

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The Light company Houston Lighting & Power ut exas rject ectr c Generat ng tat on . O. Box 289 Wadsworth, Texas 77483

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July 22, 1996 ST-HL-AE-5432 i File No.: G26 10CFR50 l

U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 I

l South Texas Project l Unit 2 Docket No. STN 50-499 Inoperable Loose Parts Monitorine System Channels 1

Pursuant to Regulatory Guide 1.133, " Loose Part Detection Program for the Primary System of Light-Water-Cooled Reactor," Section C.5.b, the South Texas Project submits the attached Special Report. This report is required in response to all channels in the upper reactor vessel collection region being inoperable for more than 30 days.

If you should have any questions on this matter, please contact either Mr. P. L. Walker at (512) 972-8392 or me at (512) 972-7902.

'I . . Jordan Manager, Systems Engineering PLW/lf

Attachment:

Special Report Regarding Inoperable Loose Parts Monitoring System Channels 9607260154 960722 PDR S

ADOCK 05000499 PDR 1 h,)Al[

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• Project Manager on Behalf of the Participants in the South Texas Project

l Houston Lighting & Power Company ST-HL-AE-5432 South Texas Project Electric Generating Station File No.: G26 Page 2 Leonard J. Callan Rufus S. Scott Regional Administrator, Region IV Associate General Counsel U. S. Nuclear Regulatory Commission Houston Lighting & Power Company 611 Ryan Plaza Drive, Suite 400 P. O. Box 61067 Arlington, TX 76011-8064 Houston, TX 77208 Thomas W. Alexion Institute of Nuclear Power Project Managei, Mail Code 13H3 Operations - Records Center U. S. Nuclear Regulatory Commission 700 Galleria Parkway Washington, DC 20555-0001 Atlanta, GA 30339-5957 David P. Loveless Dr. Bertram Wolfe Sr. Resident Inspector 15453 Via Vaquero c/o U. S. Nuclear Regulatory Comm. Monte Sereno, CA 95030 P. O. Box 910 Bay City, TX 77404-0910 Richard A. Ratliff Bureau of Radiation Control J. R. Newman, Esquire Texas Department of Health Morgan, Lewis & Bockius 1100 West 49th Street 1800 M Street, N.W. Austin, TX 78756-3189 Washington, DC 20036-5869 U. S. Nuclear Regulatory Comm.

M. T. Hardt/W. C. Gunst Attn: Document Control Desk City Public Service Washington, DC 20555-0001 P. O. Box 1771 San Antonio, TX 78296 J. C. Lanier/M. B. Lee J. R. Egan, Esquire City of Austin Egan & Associates, P.C.

Electric Utility Department 2300 N Street, N.W.

721 Barton Springs Road Washington, D.C. 20037 Austin, TX 73704 Central Power and Light Company J. W. Beck ATTN: G. E. Vaughn/C. A. Johnson Little Harbor Consultants, Inc.

P. O. Box 289, Mail Code: N5012 44 Nichols Road Wadsworth, TX 77483 Cohassett, MA 02025-1166 1

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Attachment ST-HL-AE-5432 l File No.: G26 Page1 ofI I

Special Report Regarding Inoperable Loose Parts Monitorine System Channels Description of Event:

4 l The Loose Parts Monitoring System includes two channels for loose parts monitoring sensors l l located in the upper reactor vessel collection region. Both of these channels in South Texas Project Unit 2 have been inoperable for over 30 days. Pursuant to Regulatory Guide 1.133, l

- Section C.5.b, a special report to the Nuclear Regulatory Commission is required when all l channels in one or more collection regions are inoperable for more than 30 days.

On December 4,1995, one of the channels in the upper reactor vessel collection region was -

I declared inoperable due to loss of the sensor signal. The remaining channel in this collection  ;

! region was determined to be inoperable on June 21,1996, due to a similar malfunction.

l The problem with both of these channels has been determined to be in containment near the i reactor head in an area that is inaccessible while the reactor head package is fully assembled.

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l 2 l Safety Conseauences:

l i No credit is taken for the Loose Parts Monitoring System in accident analyses nor does it serve l as a safety-related protection feature. However, the South Texas Project believes that an operable l Loose Parts Monitoring System is desirable for reliable plant operation and plans to correct the J condition.  ;

! Root Cause:

Since the apparent location of the fault is inaccessible under current conditions, the root cause has not been determined. The next scheduled opportunity for determination of the root cause will be during the next scheduled Unit 2 refueling outage.

I Corrective Actions:

Due to the suspected location of the malfunction being on the reactor head and inaccessibility of  !

i the area under current conditions, repair of these two channels will be performed during the next j Unit 2 refueling. This will occur in early 1997. l l

i sREP-96\5432.w

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