LIC-94-0141, Discusses Investigation Re 940422 Discrepancy in Potentiometer & Attachable Switches

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Discusses Investigation Re 940422 Discrepancy in Potentiometer & Attachable Switches
ML20070A556
Person / Time
Site: Fort Calhoun Omaha Public Power District icon.png
Issue date: 06/21/1994
From: William Jones
OMAHA PUBLIC POWER DISTRICT
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LIC-94-0141, LIC-94-141, NUDOCS 9406290078
Download: ML20070A556 (1)


Text

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E Omaha Public Power District omiam c. Jones 444 South 16th Street Mall S"Co ** "'""'

Ornaha, Nebraska 68102-2247 02 6 2000 June 21, 1994 LIC-94-0141 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station PI-137 Washington, DC 20555 1

Reference:

Docket No. 50-285 Gentlemen:

Potentiometer and Attachable Switch Supplied)by ABB-CEConcerning Ohmite Interim Report Pursuant to 10 CFR 21.21(a)(2

SUBJECT:

Omaha Public Power District (OPPD) is investigating a discrepancy in AB type potentiometers and attachable switches manufactured by Ohmite and supplied by Asea Brown Boveri - Combustion Engineering (ABB-CE). These potentiometers / switches are designed for use as a trip test device on the reactor protection systen calibration and indication panel assembly, and the nuclear instrumentation (. vide range and power range) channel drawer assemblies. The potentiometer is mated with an on/off switch, which is supplied under a separate pcrt number. The discrepancy concerns the physical inability of the potentiometer to operate the switch.

On April 22, 1994, OPPD discovered the discrepancy in the )otentiometer/

switch.

The potentiometers and switches were shipped to A3B-CE for avaluation.

The results of ABB-CE's investigation indicate that Ohmite moved the manufacturing of these parts to a different facility. Although the part numbers have not changed, a potentiometer (switch) manufactured at one facility will mate with a switch (potentiometer) made at the other facility, but the switch will not operate. ABB-CE is currently reviewing the safety significance of this condition. OPPD will complete its evaluation of this issue by July 21, 1994.

If you have additional questions, or require further information, please do not hesitate to contact me or members of my staff.

Sincere y, h

enEr!

President WCJ/brh c:

LeBoeuf, Lamb, Greene & MacRae L. J. Callan, NRC Regional Administrator, Region IV S. D. Bloom, NRC Project Manager R. P. Mullikin, NRC Senior Resident Inspector fyl)k l M. J. Sponzo, Manager Nuclear Spare Parts, ABB-CE 7F i

4s 5124 9406290078 940621 M"t *'tn cqua; onuton ty Male /Feme PDR ADDCK 05000285 P

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