ML20050B423

Interim Deficiency Rept Re ex-core Neutron Monitor Poor Readings Due to Cable Length & Attenuation Greater than Design,Initially Reported on 820216.Cable of Proper Length & Attenuation to Be Purchased

ML20050B423
Person / Time
Site:	Palo Verde
Issue date:	03/18/1982
From:	Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	Faulkenberry B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
10CFR-050.55E, 10CFR-50.55E, ANPP-20462-GHD, DER-82-1, NUDOCS 8204050314
Download: ML20050B423 (3)

Text

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Docket Nos. 50-528/529/530

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M 3T.L7.[ M E 1F U41 U 31.l D N G Yd D T$3 CO D M M R T P. O. D O X 216 6 6 PHOENIX. ARIZON A 85036 March 18, 1982 ANPP-20462-GHD/BSK m

U. S. Nuclear Regulatory Commission O Region V @

Creekside Oaks Office Park 2 1450 Maria Lane - Suite 210 - FIECE!if'O -

Walnut Creek, California 94596-5368 APR2 7982Asi Attention: Mr. B.11. Faulkenberry, Chief g Utuar,l TC6 $ff Reactor Construction and g Engineering Support Branch A -

Subject:

Interim Report - DER 82-1 A 50.55(E) Potentially Reportable Deficiency Relating to Ex-Core Neutron Monitors May Give Poor Readings Due to Cables Having Greater Length and Attenuation than Design File: 82-019-026 D.4.33.2

Reference:

Telephone Conversation between J. Eckhardt and G. Duckworth on February 16, 1982

Dear Sir:

The NRC was notified of a potentially reportable deficiency in the referenced telephone conversation. At that time, it was estimated that a determination of reportability would be made within thirty (30) days.

Due to the extensive investigation and evaluation required, an Interim Report is attached. It is now expected that this information will be

finalized by May 18, 1982, at which time a complete report will be i submitted.

Very truly ours, \

j 00 Ug , ctQ h LLC h h E. E. Van Brunt, Jr.

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r MAR 25 i9822

- APS vice President Nuclear Projects

& ANPP Project Director EEVBJr/GHD:ske 3 Attachment '& 1 cc: See Attached Page 2 C204050314 820318 $ I(

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U. S. Nuclear Regulatory Commission Attention: Mr. B. H. Faulkenberry, Chief ANPP-20462-GHD/BSK March 18, 1982 Page 2 cc: Richard DeYoung, Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555 J. A. Roedel D. B. Fasnacht G. C. Andognini F. W. Hartley J. M. Allen A. C. Rogers B. S. Kaplan W. E. Ide J. Vorces J. A. Brand A. C. Gehr W. J. Stubblefield W. G. Bingham R. L. Patterson R. W. Welcher R. M. Grant D. R. Hawkinson L. E. Vorderbrueggen R. L. Greenfield Assistant Attorney General j Bataan Memorial Building Santa Fe, New Mexico 87503 Ms. Patricia Lee Hourihan 6413 South 26th Street Phoenix, Arizona 85040 b

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INTERIM REPORT - DER 82-1 POTENTIAL REPORTABLE DEFICIENCY ARIZONA PUBLIC SERVICE COMPANY (APS)

PVNGS UNIT 1 1

I. Potential Problem The Excore Neutron Monitoring System design is currently impacted-by the following facts concerning the installed cable.

1. Combustion Engineering interface criteria specify a maximum cable length of 500 feet using cable meeting RG71 B/U elec-trical characteristics or equivalent. The 500 foot length is controlled by the attenuation of the cable which is approximately - 0.8dB/100 feet (at 3.0 MHz).

2. Due to the physical configuration of the system, the cable

~' lengths - preamplifier to processing drawer are in the 700 to 800 foot range.

3. The Project Design Criteria requires that cabling be fully qualified for Class 1E application in the LOCA/MSLB environ-ment and meet flamability requirements per IEEE-383. The cable purchase by Bechtel Procurement ~ Specification 10407-13-EM-060 meeting the design criteria is Brand-Rex Part Number CD95146; however, this cable is significantly higher in attenuation than-that specified in MIL-C-17E B/U Coax Cable. Using this cable, the installed length cannot exceed 340 feet for proper system operation.

Higher attenuation, when coupled with excessive cable lengths, can result in Excore signals being reduced in amplitude below the normal noise levels. The start-up/ logarithmic power channels may be affected to the extent thm' no signal or a minimum signal is available, which would defeat the logarithmic power level trip function of the moni-toring system.

II. Approach To and Status Of Proposed Resolution Currently, the project is. attempting to. purchase cable which has acceptable attenuation characteristics for 700 to 800 foot cable lengths. It is anticipated that this will bring the design into compliance with Chapter 15 of CESSAR-F.

III. Projected Completion of Corrective Action and Submittal of the Final Report Evaluation of this condition and submittal of the Final Report is forecast to be completed by May 18, 1982.

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