ML19242A209
| ML19242A209 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 06/11/1979 |
| From: | Reid R Office of Nuclear Reactor Regulation |
| To: | Stewart W FLORIDA POWER CORP. |
| References | |
| NUDOCS 7907310611 | |
| Download: ML19242A209 (3) | |
Text
- j s nacq 'o UNITED STATES
~,j NUCLEAR REGULATORY COMMISSION g '-
E WASHINGTON, O. C,20555 2
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%, ' v+... f June 11, 1979 Docket No. 50-309 Mr. W. P. Stewart Director, Power Production Florida Power Corporation P. O. Box 14042, Mail Stop C-4 St. Petersburg, Florida 33733
Dear Mr. Stewart:
We have reviewed your submittal of July 25, 1977 regarding degr:ded grid voltage and have determined that the additional infor:r.9 fon identifled in the enclosure is necessary to continue our review.
Please respond within 60 days from the date of this letter.
Sincerely, d e-Robert W. Reid, Chief Operating Reactors Branch #4 Division of Operating Reactors
Enclosure:
Request for Additional Infon::ation cc w/ enclosure: See next page 59C059 g o ov310/o (I
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Florida Power Corporation ec: rir. 5. A. Brandimore Vice Presicent and General
._L Counsel M*~"~~~~
P. O. Box 14042 St. Petersburg, Florida 33733
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Mr. Robert B. 'Borsum Babcock & Wilcox
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Nuclear Power Generation Division E,
Suite 420, 7735 Old Georgetown Road E
Bethesda, Maryland 20014 i=
Crystal River Public Library Crystal River, Florida 32629 Mr. Jack Shreve b
Office of the Public Counsel Rocm 4, Holland Building Tallahas;ee, Florida 32304 J.
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590060
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Enclosure REQUEST FOR ADDITIONAL INFORMATION CRYSTAL RIVER UNIT NO. 3 DEGRADED GRID VOLTAGE (TAC 10017)
Based upon a review of your submittal of July 21, 1977, we conclude that the use of existing undervoltage relaying to protect against a sustained degraded grid condition is not acceptable.
-1.
-In attachment 1 of Mr. Stolz's letter of June 6,1977 it is stated that a second level of undervoltage protection is required. The setpoints of this second level of undervoltage protection must protect the safety related equipment, including but not limited to, the motors, busses, contac-tors, and control circuits from a sustained low voltage condition.
The undervoltage protection must assure that a voltage below that needed to start and accelerate motors, pull in contactors, or blow control circuit fuses is not present on the bus when this equipment is call upon.
Provide your response to the above position.
2.
Your proposed setpoint, 2375V for the 4160V bus, is far below the voltage required to start and accelerate safety related motors, close in contactors, and could possibly bicw control circuit fuses. A second set of under-voltage relays, in addition to the loss-of-voltage relays, are required to sense the degraded condition.
It should be noted that these relays trust r:eet ' the requirements of IEEE 279/1971 including that they be seismically qualified, Class IE qualified, and documented as such. Provide your response to the above position, j
3.
The chosen voltage setpoint and time delay associated with second level undervoltage prote.ctioc must assure that the safety related equipment is not subjected to a voltage below that recomended by the manufacturer for a period of time icng enou@ to cause pemanent damage.
Provide your
~
response to the above position.
4.
Please furnish with your proposal any analysis or calculations to substantiate your choice. This may include voltage profiles of safety busses in the minimum and maximum loaded conditions, motor heat curves, contactor drop-out and pull-in voltages, control circui t fuse characteristics,
logic diagrams to show your choice of coincident logic, or schematics of relaying circuits. Refer to Mr. Stolz's letter of June 6,1977 and attachments for full criteria.
i j
5.
Accordingly, your submittal for Technical Specification Change No. 6 is not in compliance with our oositicn as stated in Mr. Stolz's letter, namely tne proposed setpoints and limits for undervoltage protection.
Provide i
revised proposed technical specification changes.
590C M
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