ML20028F584
| ML20028F584 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 01/24/1983 |
| From: | Clark R Office of Nuclear Reactor Regulation |
| To: | Garrity J Maine Yankee |
| References | |
| NUDOCS 8302020243 | |
| Download: ML20028F584 (3) | |
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DGS(SS-ol(o DISTRIBUTION JAN 2 41983 geket File Local PDR ORB #3 Rdg Docket No. 50-309 D.Eisenhut JHeltemes RAClark PKreutzer(3)
Mr. John H. Garrity, Senior Director OELD Nuclear Engineering and Licensing NSIC Maine Yankee Atomic Power Company E.L. Jordan 83 Edison Drive J.M. Taylor (1)
Augusta, Paine 04336 ACRS (10)
KHeitner
Dear Mr. Garrity:
Gray File
SUBJECT:
OFFSITE POWER SUPPLIES - MAINE YANKEE.
This letter concerns the low voltage condition experienced at the Maine Yankee Atomic Power Station on December 14, 1982. The purpose of this letter is to provide the NRC with a basis for evaluating this event. Our major concerns are:
The applicability of General Design Criteria -7, The relationship to MPA -823 (Degraded Grid Voltage), and Are the incoming lines currently as described in the Maine Yankee FSAR l
The enclosed questions reflect these conce ns in greater detail.
Please provide us with your response to these questions within 30 days of receipt of this letter. This request for information affects fewer than 10 respondents, therefore OMB clearance is not required under P. L.96-511.
Sincerely.
Original signed by Robert A. Clark Robert A. Clark, Chief Operating Reactors Branch #3 Division of Licensing l
Enclosure:
As stated cc: See next page 8302020243 830124 PDR ADOCK 05000309 l
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NRC FORM 318 (10-80) NRCM 024o OFFICIAL RECORD COPY usa m - _us..
Maine Yankee Atomic Power Company cc:
E. W. Thurlow, President Mr. Robert H. Groce e
Maine Yankee Atomic Power Company Senior Engineer - Licensing Edison Drive Maine Yankee Atomic Power Company Augusta, Maine 04336 1671 Worcester Road Framingham, Massachusetts 01701
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Mr. Donald E. Vandenburgh Vice President - Engineering U. S. Environmental Protection Agency Yankee Atomic Electric Company Region I Office 1671 Worcester Road ATTN: Reg. Radiation Representative Framingham, Massachuse'.ts 01701 JFK Federal Building Boston, Massachusetts 02203 John A. Ritsher, Esq.
Ropes & Gray 225 Franklin Street Boston, Massachusetts 02110 State Planning Officer Executive Department 189 State Street Augusta, Maine 04330 Mr. E. C. Wood, Plant Manager Maine Yankee Atomic Power Company
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P. O. Box 3270 Wiscasset, Maine 04578 Regional Administrator U.
S,. Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, Pennsylvania 19406 b
First Selectman of Wiscasset Municipal Building U. S. Route 1 l
Wiscasset, Maine 04578
'Mr. Paul Swetland Resident Inspector
- c/o. U. -S. Nuclear Regulatory Commission P. O. Box E Wiscasset, Maine 04578 l
Mr. Charles B. Brinkman Manager - Washington Nuclear Operations l
Combustion Engineering, Inc.
l 4853 Cordell Avenue, Suite A-1 l
Bethesda,. Maryland 20014 l
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ENCLOSURE In response to the degraded vo!tage conditions which existed with the offsite power supplies at Maine Yankee station on. December 14. 1982, provide the following:
1.
Maine Yankee FSAR states either of the two 115 kV incoming lines are independently capable of supplying the plant auxiliary power requirements. This was reaffirmed in your letter WMY 79-14 (March,1979). In view of the December 14, 1982 occurrence at Maine Yankee, describe how your system satisfies these previous design criteria regarding the capability of the offsite power sources and the requirement of GDC 17.
2.
Provide a detailed description of the December 14, 1982 incident including the voltage conditions which existed prior to, during and after the incidents on the following transmission lines and buses:
A.
POWNAL 345 and 115 kV B.
MASON 115 kV C.
MAINE YANKEE 345,115, 6.9 (Bus 1-2) and 4.16 kV (Bus 3-6), and 480V (Bu.j; 7-14).
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Describe whether there were any unusual ongoing system disturbances on the high voltage transmission grid either on your system or in the interties with the neighboring utilities which may have contributed to the incident, such as voltage reduction, bad weather condition, transmission outages, etc.
~3.
Were ~the voltage levels experienced at the switchyard with'in.the extremes assumed in your degraded grid onsite distribution system analyses? Describe how the degraded voltage effects on equipment performance have been accounted for in the verification of those voltage analysis calculations or' point out any potential discrepancy.
Has this system condition been considered in any of the studies previously submitted to NRC7 If so, please identify the document.
4.
Provide a list of in-plant equipment which indicated high current and the duration of this abnormal condition and a list of all equipment compromised as a result of tripping breakers, motor over loads, fuses blowing etc.
5.
Describe'the nature 'o'f the maintenance activities required on the MASON 115 kV line at the time. Was MYAPCO system under a light or heavy load condition (state load magnitude)? 'What was the generation capacity at the MASON plant at that time?
6.
When will you be capable of demonstrating this condition has been corrected or provide justification for continued operation under the t
existing system condition?
7.
What is the status of your capability to backfeed the plant from the t
345 kV lines in an emergency?
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