ML20008F420

Interim Deficiency Rept 22,originally Reported on 810206,re Inadequate Electrical Insulation on ex-core Neutron Flux Detectors.Corrective Action Mods to Be Provided After Rework Location Determined.Final Rept to Be Submitted by 810731

ML20008F420
Person / Time
Site:	Waterford
Issue date:	03/06/1981
From:	Aswell D, Milhiser R, Wills J LOUISIANA POWER & LIGHT CO.
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
10CFR-050.55E, 10CFR-50.55E, W3K81-0105, W3K81-105, NUDOCS 8103130417
Download: ML20008F420 (4)

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LOUISIANA P O W E R & L I G H T! A c. scx soca. 7.(W ORLE.ANS, LOUSANA 70174. (SO4J 386-2343

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W3KSI-0105 Q-3-A35.07.22 Q-3-A35.

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Mr. K. V. Seyfrit, Director, Region IV

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U. 3. Nuclear Regulatory Coraission Office of Inspection and Enforcement j

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SUBJECT:

Waterford SES Unit No. 3 4

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Dockac No. 50-382 4, "s f

Interis Report of Significant Construction Deficiency No. 22

" Inadequate Electrical Insulation on Ex-Core Neutron Flux Detectors"

REFERENCE:

Telecen - L. L. Bass (LP&L) to B. Crossman (NRC) on 2/6/81

Dear Mr. Seyfrit:

In accordance with the require =ents of 10CTR50.55(e), we are hereby providing two copies of the Interim Report of Significant Construction Deficiency No. 22, " Inadequate Electrical Insulatic on Ex-Core Neutron clux Detectors."

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If you have any questions, please advise.

l Very truly yours, D. L. Aswell DLA/LL3/grf cc: [ Director D/[

Office of Inspection & Enforce =ent U. S. Nuclear Regulatory Comission

.5 Washington, D. C. 20555 (with 15 copies of report)

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Director Office of Management Infor=ation and Program Control U. S. Nuclear Regulatory Co==ission Washington, D. C. 20555 (vich 1 copy of reporr) 8103130ftf 5

LOUISIRIA PC'ald & LI2T COMP /JU WATERFORD SES UNIT NO. 3 Interim Report of Significant Construction Deficiency No. 22 Inadequate Electrical Insulation on Ex-Core Neutron Flux Detectors Reviewed by

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Rf J. Milhiser I Site Ma5ager

' Date Reviewed by J.' Wills - Project Superintendent Date Reviewed by

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f. H rt - Profect' Licensing Engineer '

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!8!$I L. Af Stinson = Site Q. A. Program Manager Date March 5, 1982

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SIGNIFICANT CONSTRUCTION DEFICIENCY NO. 22 INTERIM RIPORT INADEQUATE ELECTRICAL INSULATION ON EX-CO2E NEUTRON FLUX DETECTORS INTRODUCTIOM This report is submitted pursuant to 10CFR50.55(e).

It describes deficiencies in the electrical insulation of the Ex-Core Neutron Flux Detectors.

DESCRIPTION Combustion Engineering Incorporated (C.E.) notified the Ebasco Site Manager, through letter No. C-CS-9270-263 dated 12/24/30, that the present insula-tion between the Ex-Core Detector and the holder assembly (Astroquartz) is inadequate to maintain proper electrical insulation over the life of the detector and that the irgulation will be replaced by a more durable material (Refrasil). Additionally, C.E. submitted procedures for the removal of the present insulation and the rewrap and subsequent testing of the Refrasil insulation.

These detectors were received at Waterford SES Unit No. 3 on February 8, 1980, and are currently in storage in the 1-A Warehouse.

SAFETY IMPLICATIONS Based on the information submitted, Licensing has determined that this con-dicion is a reportable incident because if the insulation had not been re-placed, electrical contact could develop between the detector and the holder assembly.

This could lead to performance degradation and/or total loss of the detector. Since these detectors are used as input to the Reactor Protective System (RPS) to initiate Engineered Safety Features (EST) if off-normal conditions are detected, their uncompromised operation is re-j quired. Therefore, the presence of inadequate insulation could result in a degradation of safety-related systems.

CORRECTIVE ACTION Modifications to effect corrective action have been provided by Combustion Engineering through Field Action Request (FAR) No. 105W. In summary, the modification procedure outlines the following steps:

l The detector assembly must be opened, and the detectors fastened co the stiffener to retain their same relative position with respect to the holder. They are then lif ted from the holder assembly. While the holder is opened, the old astro quartz insulating mat is removed and replaced with the new material.

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. The actual rewrap will require HITCO Type C100-48 woven silica cloth surrounding each detector, insulating it from the detector holder.

Before and af ter the modification, resistance readings are taken to assure the adequacy of the repair procedure.

The final scep involves caulking the entire perimeter of the detector assembly where the two halves come together to prevent debris and other foreign matter from entering the holder assembly.

Discussion between Ebasco and Combustion Engineering is currently under way to determine the location where rework will be accomplished. The location where this rework is effected will be identified in the final report to be submitted on or before July 31, 1981.

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