ML19225D022
| ML19225D022 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 06/20/1979 |
| From: | Reid R Office of Nuclear Reactor Regulation |
| To: | Cavanaugh W ARKANSAS POWER & LIGHT CO. |
| References | |
| NUDOCS 7908030588 | |
| Download: ML19225D022 (4) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION y
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June 20, 1979
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Docket No. : 313 Mr. William Cavanaugh, III Vice President, Generation and Ccnstruction Arkansas Power & Light Company P. O. Box 551 Little Rock, Arkansas 72203
Dear Mr. Cavanaugh:
We have reviewed all of your submittals related to the Arkansas Nuclear One, Unit No. 1 (ANO-1) power distribution system and the degraded grid voltage problem. The review has included your letters dated August 23, 1978, March 13 and May 21, 1979 and your materials presented at the meeting of February 27, 19'/9. As we have indicated in our discussions with your staff on April 26, 1979 and May 24, 1979, we need additional information in order to complete our review. The information needed is identified in the enclosure.
We request that you provide the information identified in the enclosure within 20 days on receipt of this letter. We also request that you submit proposed technical specifications relating to the modificationswhich have been completed and those modifications which are proposed within 20 days on receipt of this letter.
Sincerely, ldh Y Robert W. Reid, Chief Operating Reactors Branch #4 Division of Operating Reactors
Enclosure:
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Request for Additional Information 7 9 08 0 30 5 8if cc w/ enclosure:
See next page 440
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Arkansas Power & Light Company cc:
Phillip K. Lyon, Esq.
House, Holns & Jewell 1550 Tower Building Little Rock, Arkansas 72201 Mr. David C. Trimble Manager, Licensing
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Arkansas Power & Light Company P. O. Box 551 Little Rock, Arkansas 72203 Mr. James P. O'Hanlon General Manager Arkansas Nuclear One P. O. Box 608 Russellville, Arkan:as 72801 Mr. William Johnson U. S. Nuclear Regulatory Commission P. O. Box 2090 Russellville, Arkansas 72801 Mr. Robert B. Borsum Babcock & Wilcox Nuclear Power Generation Division Suite 420, 7735 Old Georgetown Road Bethesda, Maryland 20014 Troy B. Conner, Jr., Esq.
Conner, Moore & Corber 1747 Pennsylvania Avenue, N.W.
Washington, D.C.
20006 Arkansas Polytechnic College Russellville, Arkansas 72801 l Y>
REQUEST FOR ADDITIONAL INFORMATION ARKANSAS NULCEAR ONE UNIT 1 ( ANO-1)
ELECTRIC POWER DISTRIBUTION SYSTEM AND DEGRADED GRID VOLTAGE PROBLEM 1.
The proposed second level protection includes two-out-of-two coincidence to cause protective action.
Describe the feature (s) of the design which will permit automatic protective action when one of the two channels is out of service (for calibration, repair, etc.)
2.
Describe the design provision to automatically reinstate the degraded voltage protection system (both levels of protection) when the supply breaker from onsite source is opened and, conversely, blocking the under-voltage protection when the onsite source is supplying power to ESF busses.
3.
Describe the features of the under-voltage protection system that facilitate periodic testing.
4.
- a. Describe' the testing to be perfomed on the under-voltage protection system.
- b. Describe how the testing program will demonstrate that, when the grid is at the defined " minimum-normal" condition, no unacceptable voltage is applied to ESF equipment.
(If actual test cannot fully simulate such a grid condition, sufficient tests should be conducted to facilitate extrapolation of the measured '
' with a high confidence level).
- c. Describe how the testing program will demonstrate that, under the defined " minimum-nomal" supply condition, no unacceptable electric power will be applied to ESF equipment duri.g the starting of large non-Class lE motors.
5.
The proposed under-voltage protection includes transfomers tap changes.
Provide the analysis that shows that, under high-normal applied to ESF equipment will not exceed acceptacie,he voltages conditions of grid voltage and no-load conditions t values.
6.
The proposea under-voltage protection modification includes a bypass of the second level protection during the starting of large, non-Class IE motors.
Provide the schematic diagrams involved in this aspect of the proposed modification.
Discuss how :his bypass satisnes IEEE-279, with particular consideration to the fact that the bypass originates in non-lE equipment and operates in both divisions of the Class lE electric power system.
7.
For each section of IEEE 279, describe how the proposed under-voltage protection modification complies with the criteria.
8.
Tne proposed under-voltage protection includes shedding of non-essential loads.
440 ft37 Iq0
- a. What is the maximum load (MVA) that may be transferred to ST-1/ST-2 (worse case)?
- b. Identify specifically which loads must be shed.
- c. Provide appropriate electrical diagrams which portray this shedding.
9.
The ANO-1 analysis assumed that protective action would be executed at (or above) the calculated value of 92% (motor-base) voltage.
Indicate:
(a) nominal value of this setpoint, (b) the allowance (above 92%) used to accomodate all inaccuracies, and (c) allowance (above 92%) used to accomodate drifts.
Describe the basis for determining these allowances.
Describe the bases for determining the nominal setpoint which provides maximum protection consistent with minimum spurious shedding from the preferred power source (i.e., electric grid).
- 10. The AP&L submittal dated August 23, 1978 indicated that the setpoint for the under-frequency trip would be 59.9Hz. We understand this value is erroneous.
Please indicate the correct value for this setpoint.
- 11. We understand that AP&L proposes to use interposing relays to improve control circuitry voltage situation.
Provide typical diagrams showing these circuit changes and state the criteria and design voltage limits that will be imposed.
440 140