ML20046A116
| ML20046A116 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 07/14/1993 |
| From: | Hampton J DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-79-27, NUDOCS 9307260214 | |
| Download: ML20046A116 (2) | |
Text
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l DukeIbwer Company J W Hw7tw
{konee NudvarSee Vice hesident P0. Box 109 (8n1)MS349900 ice
~ Seneca. SC29679
{80318853364 Fax DUKEPOWER July 14, 1993 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555
Subject:
Oconee Nuclear Station Docket Nos. 50-269,-270,-287 IE Bulletin 79-27, Revision to Supplemental Response By letter dated January 28, 1993 a supplemental response to IE Bulletin 79-27,
" Loss of Non-Class lE I&C Power System Bus During Operation" was provided for Oconee Nuclear Station. The supplemental response included the assessment of the Keowee Hydro Station auxiliary power systems and the 230kV switchyard 125VDC power system in accordance with IE Bulletin 79-27.
As discussed with the NRC staff reviewer, the following is a revised response regarding Keowee Hydro Station,'wer panelboards KA, KB, KC, and KD:
i Keowee Unit 1 Power Panelboard #KA - Indication of loss of loads Keowee Unit 2 Power Panelboard #KB - Indication of loss of loads Keowee Control Room Power Panelboard #KC - Indication of loss of loads Keovee Control Room Power Panelboard #KD - Indication of loss of loads
. j
.I The above listed Power Panelboards are separated by Keowee Unit and an assessment of the loads concluded that these panelboards are not required for Oconee to reach a cold shutdown condition.
Loads attached to these j
panelboards have been confirmed by Keovee personnel and Oconee Engineering
]
as being insignificant and not required for Keowee Unit operation. A test has been performed to verify that the Keowee units can emergency start and continue to run for at least one hour without power from any of its AC sources.
The loss of power to either KA, KB, KC, or KD can be deduced directly from the loss of its associated loads.
Local alarms and equipment operation indication (Power On/Off lights) are available for loads fed from each of these panelboards.
In the case of an emergency i
start actuation signal, the Keowee operator would be directed to identify the loss of power per the appropriate Abnormal Procedure (AP).
Keowee i
auxiliary switchgears (LX and 2X) are monitored for Power Supply Trouble 1
and Lockout Relay actuation by a Keowee control room statalarm to provide indication of loss of power to the operator. Because of the separation of
-unit power and sufficient indication of loss of power to specific loads, no loss of power alarms or indications are necessary for the panelboards downstream of the switchgears.
The remainder of the response to IEB 79-27 is unchanged.
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e Doct$mentControlDesk July 14, 1993 Page 2 Very Truly Yours, f{
J. W. llampton T
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L. A. Wiens, Project Manager ONRR S. D. Ebneter, Regional Administrator Region II 6
P. E. 11armon, Senior Resident Inspector s
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