ML20128R174
| ML20128R174 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 05/29/1985 |
| From: | Whittier G Maine Yankee |
| To: | John Miller Office of Nuclear Reactor Regulation |
| References | |
| 5715L-GDW, GDW-85-152, MN-85-99, NUDOCS 8506040419 | |
| Download: ML20128R174 (2) | |
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MAIRE HARHEE ATOMICPOWERC0HiPARUe nuous ? $ $ $
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May 29, 1985 MN-85-99 COW-85-152 Director of Nuclear Reactor Regulation United States Nuclear Regulatory Commis<:lon Washington, D. C.
20555 Attention:
Mr. James R. Miller, Chief Operating Reactors Bra.ch No. 3 Division of Licensimj
References:
(a) License Na. D)R-36 (Docket No. 50-309)
Subject:
Seismic Qual F4 cation of Electroswitch Switch Corporation, Series 20K Switch with Key-Operated Mechanism Gentlemen:
The Electroswitch Switch Corporation, series 20K switch with a pistol-grip handle has been generically tested to the requirements of IEEE 344-1975 for uses in Class IE applications.
The seismic capabilities of the switch are determined by monitoring the switch contacts to determine that the operation of the switch is not impaired during the seismic test and that the switch will be operable following the test. Maine Yankee has documentation from Electroswitch Switch Corporation confirming acceptable test results.
As discussed with NRC Region I representatives, Maine Yankee has been notified by Electroswitch Switch Corporation that their seismic testing of the series 20K switch did not include the key-operated version. Maine Yankee uses the series 20K switch with a key-operated mechanism in safety-related applications.
A review of the switch design has been performed looking at both the pistol-grip handia and key-operated features.
The internals of both switches are identical - only the operating mechanism is different. Our evaluation indicates that the key-operated mechanism does not introduce a new failure mechanism and it reduces the mass ofrected by seismic forces. We have concluded that the series 20K switch with a key-operated mechanism is at least as seismically rugged as the pistol handle version and is most likely more rugged.
To confirm our evaluation, we conducted a shaker table test of the series 20K switch with a key-operated mechanism on May 22, 1985.
The test was A
successful.
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MAIN 3 YANMC3 ATOMIC POWEQ CCMP2.NY United States Nuclear Regulatory Commission Page Two Attention: Mr. James R. Miller, Chief MN-85-99 Please contact me if you should have any questions in this'. tatter.
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