ML20059C391
| ML20059C391 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 12/28/1993 |
| From: | Andersen J Office of Nuclear Reactor Regulation |
| To: | Opeka J CONNECTICUT YANKEE ATOMIC POWER CO. |
| Shared Package | |
| ML20059C393 | List: |
| References | |
| TAC-M60207, NUDOCS 9401050159 | |
| Download: ML20059C391 (4) | |
Text
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UNITED STATES
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j NUCLEAR REGULATORY COMMISSION WASHINGTON. D.C. 20555-0001
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December 28, 1993 Docket No. 50-245 Mr. John F. Opeka Executive Vice President, Nuclear Connecticut Yankee Atomic Power Company Northeast Nuclear Energy Company Post Office Box 270 Hartford, Connecticut 06141-0270
Dear Mr. Opeka:
SUBJECT:
WITHDRAWAL OF AMENDMENT REQUEST AND SAFETY EVALUATION RELATED TO DEGRADED GRID V0LTAGE - MILLSTONE NUCLEAR POWER STATION, UNIT 1 (TAC NO. M60207)
By [[letter::05000336/LER-1993-004, :on 930222,reactor Trips on SG Low Water Level Occurred.Caused by Automatic Trip of MFW Pump B on Low Suction Pressure Due to High FW Flow Rates.Classroom Training on Main & Afwc Received by Licensed Operators|letter dated July 2, 1993]], Northeast Nuclear Energy Company (NNECO) provided a description of the conceptual design of the new proposed, split-logic, loss-of-normal-power-detection scheme for Millstone Unit 1.
The enclosed safety evaluation documents our review of this conceptual design information for compliance with General Design Criterion (GDC) 17, and for conformance with Branch Technical Position PSB-1, " Adequacy of Station Electric Distribution System Voltages," as applicable. The evaluation provides a chronology of the degraded grid voltage issue and closes out TAC M60207.
The NRC staff will revisit this issue when NNEC0 submits the final design and associated Technical Specification (TS) amendment request.
In summary, our evaluation concludes that:
1.
The proposed split-logic conceptual design, when properly implemented, I
will detect a low-voltage condition and automatically connect each train to its emergency power source when a loss-of-normal-power (LNP) is sensed on that train alone. This meets the train independence requirements of GDC 17 and is acceptable.
t 2.
The proposed split-logic conceptual design, when properly implemented, provides adequate annunciation of degraded electrical system conditions for supporting required manual operator corrective actions and is acceptable.
3.
The proposed use of operator action instead of automatic disconnection of the Class IE buses from a degraded offsite power _ source under non-accident conditions (which had been found conditionally acceptable' in Reference 1 of Enclosure 2) is acceptable. However, the acceptability of this approach is subject to institution of adequate procedures covering actions to be taken by the operator in this situation.
P 30002s ME HLE CENTEfi MPY 9401050159 931228
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Mr. John F. Opeka December 28, 1993 i
4.
The retention of the administrative controls which are in place to address'the modifications'made during the 1989 refueling outage is
.1 acceptable pending. submission and approval of a TS amendment request.
1 l
The amendment request should cover the setpoints and tolerances, limiting conditions for operation, and the surveillance. testing for the undervoltage protection system.
5.
The schedule for implementation of the split-logic design during the Cycle 15 refueling outage (spring 1996) and the submission of a revised TS amendment request 6 months prior. to that _ implementation is also acceptable.
?
6.
NNECO should include the following information in the documentation 1
package (to be retained by NNECO) supporting the implementation of the final design: Confirmation that the procedures covering actions to be taken by the operator in the event of a degraded offsite power source under non-accident conditions have been instituted. These' procedures should specify the time (s) and degraded voltage condition (s) permitted before operator action is required to disconnect the Class lE buses from the degraded offsite source.
In addition, by letter dated September 10,1993, NNEC0 stat'ed that additional TS would be required for the proposed split-logic design and, therefore, the TS_ amendment request dated December 2, 1988, is withdrawn. The TS amendment request dated December 2,1988, dealt with modifications made to the Hillstone Unit I degraded grid protection scheme during the 1989 refueling outage.
Further information concerning the December 2, 1988, letter is addressed.in the safety evaluation.
The Commission has filed the enclosed Notice of Withdrawal of Application for Amendment to Facility Operating License with the Office of the Federal Register for publication.
Sincerely, 1
Original signed by James W. Andersen, Acting Project Manager Project Directorate I-4 Division of Reactor Projects - I/II:
Office of Nuclear Reactor Regulation-7 1.
Notice of Withdrawal 2.
Safety Evaluation cc w/ enclosures:
See next page DISTRIBUTION:
Docket File SVarga JAndersen ACRS (10)
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OFFICIAL. RECORD COPY Document Name: G:\\ANDERSEN\\60207
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3 l
Mr. John F. Opeka December 28, 1993 4.
The retention of the administrative controls which are in place to address the modifications made during the 1989 refueling outage is acceptable pending submission and approval of a TS amendment request.
The amendment request should cover the setpoints and tolerances, limiting conditions for operation, and the surveillance testing for the undervoltage protection system.
5.
The schedule for implementation of the split-logic design during the Cycle 15 refueling outage (spring 1996) and the submission of a revised TS amendment request 6 months prior to that implementation is also t
acceptable.
6.
NNEC0 should include the following information in the documentation package (to be retained by NNECO) supporting the implementation of the l
final design:
Confirmation that the procedures covering actions to be taken by the operator in the event of a degraded offsite power source under non-accident conditions have been instituted. These procedures should specify the time (s) and degraded voltage condition (s) permitted before operator action is required to disconnect the Class IE buses from the degraded offsite source.
In addition, by letter dated September 10, 1993, NNEC0 stated that additional TS would be required for the proposed split-logic design and, therefore, the TS amendment request dated December 2, 1988, is withdrawn. The TS amendment request dated December 2,1988, dealt with modifications made to the Millstone Unit 1 degraded grid protection scheme during the 1989 refueling outage.
Further information concerning the December 2,1988, letter is addressed in the safety evaluation.
The Commission has filed the enclosed Notice of Withdrawal of Application for Amendment to Facility Operating License with the Office of the Federal j
Register for publication.
4 Sincerely, N
James W.'Andersen, Acting Project Manager Project Directorate I Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation
Enclosures:
1.
Notice of Withdrawal 2.
Safety Evaluation cc w/ enclosures:
)
See next page j
Mr. John F. Opeka Millstone Nuclear Power Station.
Northeast Nuclear Energy Company Unit I cc:
Gerald Garfield, Esquire R. M. Kacich, Director Day, Berry and Howard Nuclear Planning, Licensing & Budgeting Counselors at Law Northeast Utilities Service Company City Place Post Office Box 270 Hartford, Connecticut 06103-3499 Hartford, Connecticut 06141-0270 J. P. Stetz, Vice President J. H. Solymossy, Director Haddam Neck Plant Nuclear Quality and Assessment Services Connecticut Yankee Atomic Power Company Northeast Utilities Service Company 362 Injun Hollow Road Post Office Box 270 i
East Hampton, Connecticut 06424-3099 Hartford, Connecticut 06141-0270 1
Kevin T. A. McCarthy, Director Regional Administrator Monitoring hnd Radiation Division Region I Department of Environmental Protection U.S. Nuclear Regulatory Commission
~
79 Elm Street 475 Allendale Road Hartford, Connecticut 06106-5127 King of Prussia, Pennsylvania 19406 Allan Johanson, Assistant Director First Selectmen
' Office of Policy and Management Town of Waterford Policy Development and Planning Division Hall of Records 80 Washington Street 200 Boston Post Road Hartford, Connecticut 06106 Waterford, Connecticut 06385 S. E. Scace, Vice President P. D. Swetland, Resident Inspector Nuclear Operations Services Millstone Nuclear Power Station Northeast Utilities Service Company c/o U.S. Nuclear Regulatory Commission Post Office Box 270 Post Office Box 513 Hartford, Connecticut 06141-0270 Niantic, Connecticut 06357 H. F. Haynes, Nuclear Unit Director Donald B. Miller, Jr.
Millstone Unit No. 1 Senior Vice President Northeast Nuclear Energy Company Millstone Station Post Office Box 128 Northeast Nuclear Energy Company Waterford, Connecticut 06385 Post Office Box 128 Waterford, Connecticut 06335 Nicholas S. Reynolds Winston & Strawn 1400 L Street, NW Washington, DC 20005-3502 1
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