ML19289C969
| ML19289C969 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 01/18/1979 |
| From: | Schwencer A Office of Nuclear Reactor Regulation |
| To: | Dunn C DUQUESNE LIGHT CO. |
| References | |
| TAC-10007, NUDOCS 7901290052 | |
| Download: ML19289C969 (3) | |
Text
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NUCLEAR REGULATORY COMMISSION I
o WASHINGTON, D. C. 20555 o
January 18, 1979 sv/
Docket 50-334 Mr. C. N. Dunn, Vice President Operations Division Duquesne Light Company 435 Sixth Avenue Pittsburgh, Pennsylvania 15219
Dear Mr. Dunn:
By letter dated July 22, 1977, Duquesne Light Company presented information we requested on the Beaver Valley Unit No. 1 onsite emergency power systems. The enclosure to this letter identifies additional information that we require to complete our review of your protection from degraded grid voltage conditions.
Your response within 30 days of receipt of this letter is requested.
Sincerel,
[t(446'MC A. Schwencer, Chief Operating Reactors Branch Division of Operating Reactors
Enclosure:
Request for Additional Infonnation cc: W/ enclosure See next page 7 9 012 9 0 OSE
s Duquesne Light Company
-2 January 18, 1979 cc: Gerald Charnoff, Esquire Mr. James A. Werling Jay E. Silberg, Esquire Plant Superintendent Shaw, Pittman, Potts & Trowbridge Beaver Valley Power Station 1800 M Street, N.W.
P. O. Box 4 Washington, D. C.
20036 Shippingport, Pennsylvania 15077 Karin Carter, Esquire Special Assistant Attorney General Bureau of Administrative Enforcement 5th Floor, Executive House Harrisburg, Pennsylvania 17120 Mr. J. M. Cumiskey Stone & Webster Engineering Corporation P. O. Box 2325 Boston, Massachusetts 02107 Mr. J. D. Woodward R&D Center Westinghouse Electric Corporation Building 7-303 Pittsburgh, Pennsylvania 15230 B. F. Jones Memorial Library 663 Franklin Avenue Aliquippa, Pennsylvania 15001 Mr. Jack Carey Technical Assistant Duquesne Light Company P. O. Box 4 Shippingport, Pennsylvania 15077 Mr. R. E. Martin Duquesne Light Company 435 Sixth Avenue Pi ttsburgh, Pennsylvania 15219 Marvin Fein Utility Counsel City of Pittsburgh 313 City-County Building Pittsburgh, Pennsylvania 15219
EEZEST FG1 ACITIC"AL IldCD'ATICI!
BEAVER VALLEY FCE:. STATIO :
UI:IT NO.1. DOGET KO. 50-ML 1.
The second level of undervoltage protection has a setpoint at a value of 80% of the system nominal voltage.
It is stated on page 2 of your July 22, 1977, submittal that neither thermal damage nor malfunction will occur to the safety equipmerit as a result of a sustained undervoltage condition of greater than 80% of the syste:h voltage. According to ANSI C84.1-1970, the continuous operatin e range for 60 Hz electric equipment is described 'as 90g voltag% of the rated voltage.
p to 13,0 The setpoint of the second level undervoltage protection system for Beaver e
Valley Unit No. 1 is lower than the minimum allowable operating voltage as per ANSI C84.1-1970.
Therefore, we requests that the design basis for the setpoint selected for the second level
.undervoltage relays be documented.
Specifically, justify that the safety equipment is between the 80% and 90% protected from sustained undervoltage level.
2.
Submit the voltage drop calculation or m'easurements at various voltage levels of the onsite rystem.
The voltage drop calculation should include the transient (in-rush) voltage at the Class IE buses during the time the automatic transfer of the plant load (including the Class IE buses) is.made from the unit auxiliarytransformertotheoffsitepowerstartuptransformer(s).
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