ML20244C419
| ML20244C419 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 06/05/1989 |
| From: | Sears P Office of Nuclear Reactor Regulation |
| To: | Frizzle C Maine Yankee |
| References | |
| NUDOCS 8906140290 | |
| Download: ML20244C419 (4) | |
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d UNITED STATES NUCLEAR REGULATORY COMMISSION E.
q wAsmwoTON. D. C. 20555 e
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June 5, 1989 Docket No. 50-309 i
Mr. C. D. Frizzle, President Maine Yankee Atomic Power Company 83 Edison Drive Augusta, Maine 04336
Dear Mr. Frizzle:
i By letter dated ifarch installed capacitor bank 31,(1989, you transmitted the design report on the recently YAEC-1666,115KV Capacitor Bank Design Report, February 1989).
You also stated that Maine Yankee (1) is prepared to install a redundant transformer in parallel to the existing X-14 transformer, and (2) is evaluating a second design enhancement involving replacement of the electromechanical relays in the auto bus transfer logic.
Your letter further stated that:
"We are proceeding with the design of the redundant transformer and evaluation of improvements to the auto bus transfer system.
We would like to implement the eventual improvements by the end of the spring, 1990 refueling outage. However, prior to installing these changes, we request NRC concurrence that these enhancements will full resolve NRC's concerns regarding Maine Yankee's offsite power system. "
The staff has not yet completed its review of the design report on the capacitor bank. However, our preliminary review indicates that this design modification may significantly improve offsite power (Surowiec line) availability. We expect to complete this review in the near future; this may entail a meeting at your office to attain a more detailed understanding of the design and the design verification testing that has been performed.
In regard to the two additional design enhancements being considered, the staff believes that these modifications, if properly implemented, could be i
major steps towards resolution of the previously documented staff concerns regarding offsite power supply to the emergency buses.
However, your March 31 submittal clearly stated that your design and evaluation of these enhancements was not completed, and it provided no information on which the staff could j
base a conclusion that the proposed modifications would provide a complete resolution of the staff concern.
For example, the effect that the added paralleled transformer has on bus voltage and on bus and breaker fault current capacity was not addressed, nor was an analysis provided addressing the operation of the auto bus transfer with the proposed replacement relays.
Therefore, the staff cannot unequivocally state that the proposed enhancement would resolve all staff concerns.
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June 5,1989 We recommend acceleration of your evaluation and design efforts for these enhancements, a'nd propose that a meeting in your offices be scheduled as soon 1
as your design is complete to review the final designs and resolve any
, J remaining' issues. The staff is. prepared to do everything possible to support youri. schedule for final design and procurement in order to effect installation d
during the~1990 refueling outage;.
If you have any questions on this matter please contact Patrick Sears at 1
(301)492-1437.'
Sincerely, i
Original signed by:
i Patrick M; Sears, Project Manager j
Project Directorate I Division of Reactor Projects I/II
- i cc:
D. Limroth, RIL
.C. Anderson, RI L. Tripp,'RI F. Rosa, SELB (8D20) l
[MY0.FFSITEPOWER/LTR]
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DATE :L/s/89
- G/6/89
- 5/f /89 l
OFFICIAL RECORD COPY i
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Mr. C. D. Frizzle Maine Yankee Atomic Power Company Maine Yankee Atomic Power Station cc:
l Mr.> C. D. Frizzle, President Maine Yankee Atomic Power Company Mr. P. L. Anderson, Project Manager i
83 Edison Drive Yankee Atomic Electric Company Augusta, Maine.04336 580 Main Street
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Bolton, Massachusetts 01740-1398.
Mr. Charles B. Brinkman Mr. G. D. Whittier, Manager Manager - Washington Nuclear Nuclear Engineering and Licensing Operations Maine Yankee Atomic Power Company Combustion. Engineering, Inc.
83 Edison Drive 12300 Twinbrook Parkway, Suite 330 -
Augusta, Maine 04336 Rockville,'Md.-20852 John A. Ritsher, Esquire Ropes & Gray 225 Franklin Street l
Boston, Massachusetts 02110 l
State Planning Officer Executive Department 189 State Street i
Augusta, Maine 04330 j
Dr. E. T. Boulette, Vice President Operations and Plant Manager j
Maine-Yankee Atomic Power Company P. O. Box 408 4
Wiscasset, Maine 04578 l
i Mr. J. H. Garrity, Vice President I
Licensing and Engineering I
, Maine Yankee Atomic Power Company l
83 Edison Drive l
Augusta, Maine 04336 Regional Administrator, Region I U.S. Nuclear Regulatory Commission i
475 Allendale Road j
-King of Prussia, Pennsylvania 19406 First Selectman of Wiscasset Municipal Building U.S. Route 1 Wiscasset, Maine 04578 Mr. Cornelius F. Holden Resident Inspector c/o U.S. Nuclear Regulatory Commission P. O. Box E Wiscasset, Maine 04578
e DISTRIBUTION: MY OFFSITE POWER /LTR Docketd ue NRT & Local PDRs PDI-3 r/f S. Varga B. Boger R. Rushbrook:.
P. Sears OGC E.-Jordan c<-
B. Grimes ACRS (10)
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Maine Yankee Folder D. Limroth, RI C. Anderson, RI L. Tripp, RI F. Rosa, SELB (8020) i l
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