ML20148E021
| ML20148E021 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 10/25/1978 |
| From: | David Williams ARKANSAS POWER & LIGHT CO. |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| 1-108-9, NUDOCS 7811060075 | |
| Download: ML20148E021 (8) | |
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6 ARKANSAS POWER & LIGHT COMPANY POST OFFICE BOX 551 LiiTLE ROCK. ARKANSAS 72203 (501)371-4000 October 25, 1978 1-108-9 Director of Nuclear Reactor Regulation ATTN:
lir. R. W. Reid, Chief Operating Reactor Branch #4 U. S. Nuclear Regulatory Commission Washington, D. C.
20555
Subject:
Arkansas Nuclear One - Unit 1 Docket No. 50-313 License No. DPR-51 Sequencing Electrical Loads On Start Up Transformer (File:
1510)
Gentlemen:
The following is provided to document our verbal commitment made in an October 24, 1978, telecon between myself and Mr. G. Vissing, et.al., of your staff.
Currently, the safety electrical loads are sequenced c>nto the Diesel Generators but not onto the startup transformer.
By not sequencing the loads onto the =;tartup transformer, we can possibly create an undervoltage situation on the startup transformers sui that all safety loads would be transferred to the Diesel Genera ors.
We had previously identified this situation and havs troposed modifi-cations (which are still under review) to the staff as our " Millstone Modifications". These modifications are scheduled to be implemented during our next refueling outage (currently scheduled for March, 1978) subject to approval by the staff.
As per our verbal commitment in the above referenced telecon, we can implement part of those modifications now which will alleviate the above possible situation.
This will involve connecting the load sequence circuitry used for loading the Diesel Generators such that they will also sequence safety loads onto the startup transformers thereby alleviating the possible undervoltage situation.
Subject to your approval, we will implement this modification by October 31, 1978, per our verbal commitment.
Attached are six schematic diagrams which detail this modification. Due to the haste in which this letter was prepared, only one copy of the drawings was availabic and is enclosed. More copies will be available at a later date should you desire them.
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MEMOC A MioOLE SOUTH UTILifl0s SYSTEM h
Mr. R. W. Reid October 25, 1978 We wish to emphasize that we believe the existing design at ANO-1 meets CDC-17.
Also, your most immediate approval of this modification is imperative for us to support an implementation date of October 31, 1978.
Should your review impact this schedule, we will request relief on the schedule accordingly.
Very truly yours, C>
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, Dantel H. Williams 4
6 Manager, Licensing DHW:JTE:vb Attachment f
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