05000369/LER-1981-161, Forwards LER 81-161/01T-0.Detailed Event Analysis Encl

Forwards LER 81-161/01T-0.Detailed Event Analysis Encl

ML20032C682
Person / Time
Site:	McGuire
Issue date:	10/30/1981
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20032C683	List: 05000369/LER-1981-161, Forwards LER 81-161/01T-0.Detailed Event Analysis Encl 05000369/LER-1981-161-01, /01T-0:on 811001,Rockbestos Coaxial Cable Found by Vendor to Fail to Meet Environ Qualification Criteria.Caused by Deterioration at High Temp as Determined by Ga Co. Replacement Cable Being Developed
References
NUDOCS 8111100736
Download: ML20032C682 (2)

LER-1981-161, Forwards LER 81-161/01T-0.Detailed Event Analysis Encl

Event date:
Report date:
3691981161R00 - NRC Website

text

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DUKE POWE l O N

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WILLI AM 0, PAR M ER.J R.

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3,3..o 6L! Mf Mr. J. P. O'Reilly, Director

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- U. S. Nuclear Regulatory Commission

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Region II 9

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/YOpg O 101 Marietta Street, Suite 3100 14 1,

/Sgg i Atlanta, Georgia 30303 u&rmy

,I Re: McGuire Nuclear Station Unit 1 q,j-gy i

Docket No. 50-369

Dear Mr. O'Reilly:

Please find attached Reportable Occurrence Report R0-369/81-161. This report concerns T.S.6.9.1.12(i), " Performance of Structures, Systems, or Components That Requires Remedial Action or Corrective Measures to Pravent Operation in 1

a Manner Less Conservative Than Assumed in the Accident Analyses.

This incident was considered to be of no significance with respect to the health and safety of the public.

This report was inadvertently categorized as a 30-day report whereat, it should have been a 14-day report. Consequently, this report is being submitted 15 days late.

4 Very truly yours, I j

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pa d.

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William O. Parker, Jr.

PBN/smh Attachment cc: Director Records Center Office of Management and Program Institute of Nuclear Power Operations Analysis 1820 Water Place i

U. S. Nuclear Regulatory Commission Atlanta, Georgia 30339 Washington, D. C.

20555 i

Ms. M. J. Graham Resident Inspector-NRC McGuire Nuclear Station 1100736 811o3o dd 4

S ADOCK 05000369 OFFh

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PDR

McGUIRE NUCLEAR STATION REPORTABLE OCCURRENCE REPORT NUMBER:

81-161 REPORT DATE: October 30, 1981 OCCURRENCE DATE: October 1, 1981 FACILITY: McGuire Unit 1; Cornelius, N.C.

IDENTIFICATION OF OCCURRENCE:

Rockbestos coaxial cable #RSS-6-104, furnished by General Atomics for use with Unit 1 Containment high radiation monitors, 1 EMF-SlA and 1 EMF-51B, was determined by vendor investigation to fail to meet the environmental qualification requirements of the purchase order and referenced Design Engineering specifications.

CONDITION PRIOR TO OCCURRENCE: Not applicable.

DESCRIPTION OF OCCURRENCE: The redundant high radiation monitors, 1 EMF-51A and lEMF-51B, were installed to comply with provisions of NUREG 0737, which will be effective for operating plants on January 1, 1982. The instruments are required for post-accident monitoring purposes and must be capable of surviving the ex-treme environmental conditions accompanying the postulated worst case accident.

Although the cable associated with the monitors passed the original cualifica-tion testing by Rockbestos and General Atomics, subsequent testing by 'eneral Atomics has revealed that the cable is fallible under high temperature conditions.

APPARENT CAUSE OF OCCURRENCE: Testing has shown that Rockbestos RSS-6-104 coaxial cable tends to deteriorate at high temperature allowing failure by short circuit.

ANALYSIS OF OCCURRENCE: This incident has seen determined to be a manufacturer deficiency.

SAFETY ANALYSIS

The affected monitors are required for post-accident conditions only and provide no control functions.

Existing cables are enclosed in conduit, which should provide some protection beyond the environmental limit for the un-protected cables tested by General Atomics. This condition has no effect on safe plant operation or the health and safety of the public.

CORRECTIVE ACTION

Replacement cable meeting the environmental qualification criteria is currently being developed by the vendor with an estimated date of receipt in December, 1981. The cables will be replaced at the first convenient outage after receipt of the new cable from General Atomics.