ML19326E144
| ML19326E144 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 07/01/1980 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Counsil W CONNECTICUT YANKEE ATOMIC POWER CO. |
| References | |
| NUDOCS 8007280103 | |
| Download: ML19326E144 (5) | |
Text
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UNITED STATES c
g NUCLEAR REGULATORY COMMIS310N y
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WASHINGTON. D. C. 20555 e
July 1, 1980 Docket No. 50-213 Mr.'W. G. Counsil Nuclear Engineering & Operations Connecticut Yankee Atomic Power Company P.O. Box 270 Hartford, Connecticut 06101
Dear Mr. Counsil:
You are requested to provide the information specified in the enclosure to this letter regarding the adequacy of station electric distribution system voltages for the Haddam Neck Plant.
A copy of the enclosure was telecopied to you on June 19, 1980.
Receipt of your response is requested within 45 days of your receipt of this letter.
Sincerely, 711. $
Dennis M. Crutchfield, Chi Operating Reactors Branch #5 Division of Licensing
Enclosure:
Request for Additional Information cc w/ enclosure:
See next page 8007280 PO 3 P
Mr. W. G. Counsil July 1, 1980 Day, Ber y [Howard U. S. Environmental Protection Counselors at Law Agency One Constitution Plaza Region I Office Hartford, Connecticut 06103 ATTN:
EIS COORDINATOR JFK Federal Building Superintendent Boston, Massachusetts 02203 Haddani Neck Plant RFD #1 Post Office Box 127E East Hampton, Connecticut 06424 Mr. James R. Himmelwright Northeast Utilities Service Company P. O. Box 270 Hartford, Connecticut 06101 Russell Library 119 Broad Street Middletown, Connecticut 06457 Board of Selectmen Town Hall Haddam, Connecticut 06103 Connecticut Energy Agency ATTN:
Assistant Director Research and Policy Development Department of Planning and Energy Policy 20 Grand Street Hartford, Connecticut 06106 Director, Technicai \\ssessment Division Office of Radiation Programs (AW-459)
U. S. Environmental Protection Agency Crystal Mall #2 Arlington, Virginia 20460 l
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I REQUEST FOR ADDITIONAL INFORMATION HADDAM NECK ADEQUACY OF STATION ELECTRIC DISTRIBUTION SYSTEM VOLTAGES I
Ref. 1: NRC Letter (W. Cammill) to all Power Reactor I
Licensees, dated August 8, 1979 Ref. 2: Attachment 1 of Northeast Utilities letter (W. G. Counsil) to WC (D. L. Ziemann),
dated November 15, 1979 f
Ref. 3:
Connecticut Yankee Atomic Power Co. letter (D. C. Switzer) to NRC (A. Schwencer), dated July 21, 1977 l
1.
Guidelines 1 and 7 (Ref. 1) require that a separate analysis be per-formed for all available connections to the offsite network and that the analysis be adequately documented for each condition analyzed.
Ref. 2 does not fully meet these requirements. To confirm the accepti-bility of the voltage conditions on the station electric distribution i
system, submit adequate voltage analysis documentation for each case 1
and condition analyzed in Ref. 2 and additional documentation, l
specifically:
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a.
Requirements of Guidelines 6 and 11 as well as 5 and 13 (Ref. 1) l must be included in each separate case analyzed.
These guide-l lines refer to the use of minimum and maximum expected grid l
l voltages, maximum loads asnumed for each analyzed case and a list of assumpticus made for each analyzed case.
b.
Supply the calculated voltages for all low voltage AC (less than 480 volts) Class lE buses (including all available source connec-tions) for each analyzed case. Do these buses supply instrumenta-tion or control circuits as required by GDC 137 If so, is all equipment capable of sustaining the analyzed voltages without
. blowing fuses, overheating, and without affecting the equip-ment's ability to perform the required function?
c.
Per Guidelines 3 and 9 (Ref. 1), compare the effect of starting and running the largest non-Class lE load on all Class lE buses and loads with the required voltage range for normal operation of all Clacs lE equipment (starters, contactors, motors, etc.) for each available connection of offsite power.
This comparison should occur after the Class lE buses are fully loaded.
d.
By the use of disconnect links or other means, is it possible to backfeed from the 345 KV switchyard through the main transformer (319) and the service station transformer (309) to the Class 1E buses?
If this is a viable connection, an analysis is required for this source connection or identify limiting conditions of operation.
2.
Ref. 2, Page 5, Paragraph 2 refers to a proposal for installing a second second-level of undervoltage protection for the Class lE equipment when only one of two service station transformers is available (389 or 399).
Tiie operation of this second seccnd-level protection scheme is stated to be the same as that of the first second-level scheme detailed in Ref. 3.
The design of the second-level of undervoltage protection (NRC Staff Position 1, June 2,1977 letter) is to protect all Class 1E equipment from grid voltage degradation under all modes of operation.
Explain l
in detail why this second second-level protection scheme is necessary.
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i 3.
Ref. 2, Page 3 identifies that overvoltages can occur on the Class 1E f
buses under einimum load and high offsite grid voltage conditions.
I Installation of overvoltage alams will be added to initiate operator l
corrective action. Credit will be given for this corrective action
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I only if the overvoltage monitors and alarms are Class lE and in the
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Il interim period of correction, the overvoltage condition does not I
shorter, equipment life or affect the Class lE equipment's ability to perform the required function. Provide documentation which demon-strates the equipment can meet these overvoltage conditions.
- Also, a
provide the calculated overvoltages on all Class lE equipment for each case anulyzed.
4.
Per Gaidelines 10 and 12 (Ref. 1), submit the undervoltage protection scheme setpoints (voltage and time delay) in terms of Class lE nominal bus voltage, not in terms of switchyard voltage as stated in Ref. 2.
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