ML19312C256
| ML19312C256 | |
| Person / Time | |
|---|---|
| Site: | Oconee, Mcguire, McGuire  |
| Issue date: | 01/06/1975 |
| From: | Thies A DUKE POWER CO. |
| To: | Moseley N NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 7912120596 | |
| Download: ML19312C256 (3) | |
Text
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O Letter to H. C. Moseley from Duke Power Co:::pany dated January 6,1975 DT.ETPEUTION:
50-269 H. D. Thornburg, FD 50-270 RO:liQS (5) 50-287 Regulato n Standards Reply to R0B 15 D
DR Central Files Directorate of Licenshg (23)
J. Ri::co, OG, R0 PDR Local PDR ISIC TIC Chief, Regulatory News Branch, OIS, liQs 4
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)DuxE POWER COMPANY
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Powen Dunarwo 4aa SouTu Cut:ncu STnerT, CHANTATTE, N. C. 28208 A. C. 'nn es 56..oe wc c P=e s.es.,
P. O. Box 0170
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January 6, 1975 Mr. Norman C. Moseley, Director Directorate of Regulatory Operations U. S. Atomic Energy Commission Region II - Suite 818 230 Peachtree Street, Northwest Atlanta, Georgia 30303 Re:
RO:II:NCM 50-269, 50-270, 50-287 50-369, 50-370
Dear Mr. Moseley:
In response to your letter of December 6, 1974 which transmitted Directorate of Regulatory OperationsBulletin 74-15, we wish to advise we have conducted a design review of the use and planned use of Cutler-Hammer three position maintained switches of lasic model No.10230T in safety-related systems in both the Oconee and McGuire Nuclear Stations.
We have determined that six (6) switches of the type described are in use in Oconee Nuclear Station and forty-six (46) switches were planned for use in the design of the McGuire Nuclear Station.
The six switches at the Oconee Nuclear Station are used for periodic circuitry continuity tests in the emergency power load shed logic circuitry.
An analysis of these circuits has been made, and it has been determined that the safety function of the circuitry will not be defeated for any operating mode of the switch including any " dead-band" area.
Therefore no corrective action is considered to be required.
At the McGuire Nuclear Station the forty-six switches were used in the design rarious control circuits. These switches will be replaced by a direct u
replacement switch of a new design by the same manufacturer.
The new design will be available in December,1975, with installation scheduled to be completed by June, 1976 well in advance of the August, 1977 fuel loading date for McGuire Unit 1.
j PEN 2
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January 6, 1975-I Mr.,NormanC.Mosalsy-]
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f We conclude that the actions we have taken and plan to take will prevent malfunctions of the type discussed in Directorate of Regulatory Operations r
Very truly yours, i,, /f-' :
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A. C. Thies ACT:gj e i
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