ML20138P028
| ML20138P028 | |
| Person / Time | |
|---|---|
| Site: | Fermi, FitzPatrick, 05000000 |
| Issue date: | 12/13/1985 |
| From: | Rudek F EXO SENSORS, INC. |
| To: | Thomas Young NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| REF-PT21-85-510-000 PT21-85-510, PT21-85-510-000, NUDOCS 8512240255 | |
| Download: ML20138P028 (2) | |
Text
1
- E December 13, 1985 n
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_h Administrator, Region V, USNRC 1450 Maria Lane, Suite 210
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I Walnut Creek, CA 94596 5
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Attn:
Mr. Tolbert Young a
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Subject:
Report of Defect Oxygen Sensor Assembly i
Gentlemen:
l A defect has been identified in the two oxygen sensors listed below.
These sensors, manufactured by Exo Sensors, Inc. are installed l
in the Containment Atmosphere Monitoring System.
Details of the reportable item are as noted belows (1)
Component Identification Sensor Assembly, Oxygen Drawing No. 101D014, Rev -; ECN 1, 2,
3 (2)
Manufacturer Exo Sensors, Inc.
l 1220 -B Simon Circle Anaheim, CA 92806 (3)
Nature of Defect The ribbon used to make the connection to the sensing electrode in the oxygen sensor was found to be Nichel Ribbgg2 MIL Ab92b61 91929" uide u 91919" thLsh.
The ribbon is required to be PlatinumfigZ. Rhgdium ribbggi 919_29 " yidg g 93995" thigh.
The significant difference between the two materials relative to this application is the increased thickness of the nickel ribbon (i. e., 0.010" vs 0.005").
The added thickness of the material will eventually cause a failure in the diffusion membrane of the sensor, resulting in signal drift outside of normal limits.
l 8512240255 851213 PDR ADOCK 05000333 S
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1220 B SIMON CIRCLE O ANAHEIM, CA 92806 0 (714) 632-8289 (y CO I TWX NO. 910 5911883 TELEX NO. 880 430 t'
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4 Report of Defect f
O 12-13-85 Page 2
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It should be notad'that material cobpatability is not a r
faci ~r'here since the normal sensor configuration does use p,
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<both materials.
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Date of Confirmed Defect a
y December 50, 1985 (5)
Location of Defective Components t
5.1 James A.
Fitzpatrick NPS New York Power Authority Sensor Serial No. D984, installed in Unit D analyzer
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(SN 4021/4024) 5.2 Fermi 2 NPS x
Detroit Edison Co.
Sensor Serial No. B980, installed in Unit D analyzer
.(SN 4027/4028)
(6) ' Corrective Action
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Additional in-process inspection points and visual material vf.rification steps have been added to the shop travellers and lut reports to preclude recurrence of this discrepancy.
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_ ' Sensors in the field are being replaced.
N.Y.
Power will "have replacements by 12-16; Detroit by 12-23.
(7)
Notifications a
Verbal notification was provided to the following:
7.1 Mr. Di;k Patch
+
QA Superiqtandant James A.
Fi tzpatrick NPS "7 2 Mr. Terry G.
Byrd Supervisor, Procurement Quality Assurance Fermi 2 NPS E
Written t.otification transmitted via this letter.
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Freis P.
Rudek 7
2 VP Quality Assurance
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