ML20099F216
| ML20099F216 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 11/12/1984 |
| From: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | Bishop T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| ANPP-31093-TDS, DER-84-65, NUDOCS 8411260313 | |
| Download: ML20099F216 (4) | |
Text
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Arizona Public Service Company 3?% f0?;! S Ri _ l: l3 November 12,.1934 _.,,,
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ANPP-31093-TDS/TRB "'2, *",h r s
U. ' S. Nuclear Regulatory Commission Region V Creekside Oaks Office Park
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~ 1450 Maria Lane - Suite 210 Walnut Creek; California 94596-5368 Attention: Mr. T. W. Bishop,1 Director Division of Reactor Safety and Projects
Subject:
Final Report - DER 84-65 A 50.55(e) Reportable Condition Relating To Instrument Leads Removed From The UGS Are Split.
File 84-019-026; D.4.33.2
Reference:
A) Telephone Conversation between D. Hollenbach and T. Bradish on September 4,1984 B) ANPP-30735, dated October 3,1984 (Interim Report)
C) ANPP-30952, dated Octoh r 25; 1984 (Time Extension)
Dear Sir:
Attached is our final written report of the deficiency referenced above, which has been determined to be Not Reportable under the requirements of 10CFR50.55(e).
Very truly yours, b
b E. E. Van Brunt, Jr.
APS Vice President Nuclear Production ANPP Project Director EEVB/TRB/nj Attachment cc:
See Page Two
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Mr. ~ T. W. Bishop DER 84-65 Page'Two-cc:
. Richard DeYoung, Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C.
'20555
.T. G. Woods, Jr.
.D. B. Tarner W. E. Ide D. B. Fasnacht A. C. Rogers L. A. Souza -
D. E. Fowler
- T. D. Shriver C. N. Russo B. S. Kaplan J. Vorees J..R. Bynum J. }t. Allen A. C. Gehr W.'J.' Stubblefield W. C. Bingham R. L. Patterson R. W. Welcher H. D. Foster D. R. Hawkinson R. P. Zimmerman L. Clyde it. Noods T. J. Bloom D. N. Stover J. D. Houchen J. E. Kirby D. Canady Records Center Institute of Nuclear Power Operations 1100 circle 75 Parkway, Suite 1500 Atlanta, CA 30339 1
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FINAL REPORT - DER 84-65 DEFICIENCY EVALUATION 50.55(e)
ARIZONA PUBLIC SERVICE COMPANY (APS)
PVNGS UNIT 1 I.
Description of Deficiency Regulatory Guide 1.20 requires that a comprehensive preoperational vibrations monitoring program be implemented for all first-of-a-kind reactors.
In accordance with this regulation, the PVNGS Unit 1 reactor Upper Guide Structure (UCS) and Core Support Barrel (CSB) assembly are instrumented vith pressure transducers, accelerometers, and strain gauges. These instruments are part of the Precritical Vibration Monitoring Program (PVMP). In addition to the instruments installed for PVMP, other instruments were installed on the UGS f or monitoring during the Reactor Coolant System Demonstration Test. The PVMP and demonstration test instruments are not intended to be used during operation of the plant. Same of the above instruments were intended to remain attached to te UGS and CSR for the life of the plant with their leads cut and crimped and the remainder of the instruments were intended to bu removed atter completion of testing.
One of the reasons for leaving some instrumentation in the reactor was that removal required stages of disasnenbly that were not planned to take place af ter testing. For this reason, this instrumentation was provided and installed in accordance with the sane code es the vessel internals (ASME Boiler and Pressure Vessel Code, 1974 Edition,Section III).
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While inspecting the leads of the instruments that had been removed i
f rom the UGS, it was discovered that the outer shielding hed split, exposing the ceramic insulating material and the wire. NCR SM-4706 was issued to document this condition.
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Evaluation Concern over the splitting of the wiring insulation prompted Combustion Engineering (C-E) to evaluate the instrumentation that was to remain in the UCS and the CSE to determine if it should remain in place for the life of the plant.
C-E determined that the instrument leads to the three pressure transducers remaining on the UGS will not present a problem. The sheath, insulating material aad wire for these instruments do not contain substances that would be detrimental to the Reactor Coolant System (RCS).
C-E has concluded that instrument leads would not break into small pieces. However, if a lead should sever, Lt would fall to the bottom of the conduit into the instrumert housing and be t rapped. Since this is a low /no flow area, the leads, if broken, would be trapped in the housing for the life of the plant.
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. Instrumentation located on the CSB was intended to remain with-the CSB for the life-of the plant. -However;;C-E has determined that this instrumentation should be removed..In reaching this decision, C-E considered both chemical'and mechanical concerns.
a.
The chemical concern identified was that of copper-wire used in the strain gauges. The concern was that the copper could plate out on the fuel rods and affect heat transfer properties of the rods in the plated areas. The cumulative weight.of copper in the reactor from possible instrument leads breaking off is estimated to be 118 grams. The quantity-involved is very small and is~
considered to constitute no safety significance, b.
From a mechanical perspective, C-E has postulated that, under worst-case conditions, a small piece of copper wire could become lodged between the fuel rods and the spacer grids. Under this condition local fretting may occur in an individual rod; but no gross failures would occur. Damage would be at most minimal.
II.
Analysis of Safety Implications Based on the above; this condition is evaluated as not reportable under the requirements of 10CFR50.55(e) and 10CFR Part 21; since, if this deficiency were to remain uncorrected, it would not represent a significant safety condition.
III.
Corrective Action NCR SM-4706 has been dispositioned to leave the instrument lealt in the Upper Guile Structure (UGS) and to remove the leads from the Core Support Barrel (CSB).
No action is required for Units 2 and 3 since the subject instrumentation was installed on Unit 1 only.
IV.
References Letter V-CE-30975, September 19, 1984 Letter V-CE-31146, October 11, 1984
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