ML17341B533
| ML17341B533 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 12/27/1982 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17341B532 | List: |
| References | |
| NUDOCS 8212300071 | |
| Download: ML17341B533 (10) | |
Text
ENCLOSURE 1
SAFETY EVALUATION TURKEY POINT NUCLEAR, GENERATING PLANT UNITS.'3 AND 4 DOCKET NO. 50-250/251 ADEQUACY OF STATION.ELECTRIC DISTRIBUTION SYSTEM VOLTAGES INTRODUCTION AND
SUMMARY
Florida, Power and Light Company (FPL) was requested by NRC letter dated August 8, 1979 to'review the electric power system at Turkey Point Nuclear Generating Plant Units 3 and 4.
The review was to consist of:
a)
Determining analytically the capacity and capability of the offsite power system and onsite distribution system to automatically start as well as operate all required loads within their required voltage ratings in the event of 1) an anticipated transient, or
- 2) an accident (such as LOCA) without manual shedding of any electric loads.
b)
Determining if there are any events or conditions which could result in the simultaneous or, consequential loss of both required circuits from the offsite network to the onsite electric distribution system and thus violating the requirements of GDC 17.
The August.8, 1979 letter included staff guidelines for performing the required voltage analysis and the licensee was further required to r
perform a test in order to verify the validity of the analytical results.
FPL responded by letters dated November 9, 1979, December 18, 1980, June 10, 1981, February 24, 1982 and Hay 20, 1982.
A detailed review sa~asooo7~
a2~a~7 PDR ADOCK 05000250 P
0 e
2 and technical evaluation of the submfttals was performed by LLL under contract to the NRC, with general supervision by NRC staff.
This work fs reported by LLL in Technical Evaluation Report (TER), "Adequacy of Station Electric Distribution System Voltages, Turkey Point Nuclear Generating Plant Units 3 and 4," dated August 8, 1982.
Me have reviewed this report and concur in the conclusions that the offsite power system and the onsite distribution system are capable of providing acceptable voltages for worst case station electric load and grid voltages.
The licensee in a submittal dated November 16, 1982 provided the results of a review reaffirming compliance with GDC 17.
We have reviewed the licensee's submittal and find it to be acceptable.
EVALUATION CRITERIA The criteria used by LLL in this technical evaluation of the analysis includes GDC 5 ("Sharing of Structures,
- Systems, and Components" ),
GDC 13 (".Instrumentation and Control"),
GDC 17 ("Electric Power Systems" )
of Appendix A. to 10 CFR 50; IEEE Stan'dard 308-1974 ("Class lE Power Systems for Nuclear Power Generating Stations" ), ANSI C84.1-1977 ("Voltage Ratings'for, Electric Power Systems and Equipment - 60 Hz"), and the staff I
positions and guidelines in NRC letter to FPL dated August 8, 1979.
ANALYSIS AND TEST'FEATURES FPL analyzed the power requirements of the onsite distribution system when supplied:by the unit's startup transformers (offsite power sources) under maximum and minimum loading conditions with the 230 'kV grid, normally operated at 240 kV, at its maximum (244 kV) and minimum (235 kV) expected voltage.
In addition to the various loading configurations, the foll'owing assumptions were used in the analysis:
~ '
l.
All safety loads start simultaneously upon receipt of a safety
,in5ection. signal {SIS).
2.
A SIS initiates an automatic fast transfer from the unit auxiliary, to the startup transformer.
3.
Running loads prior to a SIS were based on highest recorded'.load values.
4.
Power factor for running,load of, 0.85.
5.
Power factor for starting loads of; 0.20 for 4 kV motors; 0.42 for emergency containment fan cooler; 0.35 for emergency containment
.filtens; and 0.60 for motor operated valves (HOVs).
6.
Starting -current of six times full load amperage (FLA) for motors and 2.1
'FLA for NOV's.
7..
Running, loads assumed as constant KVA.
S.
The steam generator feedwater pumps trip automatically on a SIS.,
The analysis results showed that.the worst case Class 1E equipment voltages occur under the following conditions:
~,
1.
Maximum voltage occurs when the offsite grid is at its maximum expected value of 244 kV, minimum equipment is running on the 4160 volt buses and one-half normal. loads are operating on the 480 volt buses.
2.
Minimum voltage occurs when the offsite grid is at its minimum expected value of 235 kV, and a SIS results in the automatic fast transfer of loads from the unit auxiliary transformer to the startup transformer with all Class 1E equipment starting simultaneously.
The voltage analysis has established that acceptable voltages will be provided to all Class lE equipment under the worst case conditions analyzed.
The voltage analysis was verified by measuring the, voltage and current at all Class lE buses while both, units were operating at full power.
A comparison showed the analytical values were, within 3X of the measured values and that all analytical values were conservative.
This close correlation verifies the accuracy of the analysis submitted.
The licensee in a submittal dated November 16, 1982 provided the results of their review affirming compliance with GDC 17.
In.his response, the licensee has determined no single event or condition could exist which would result in the simultaneous or consequential loss of both offsite power to the onsite distribution system.
iO
- CONCLUSIONS Me have reviewed the LLL'echnical Evaluation Report and concur in the findings that:
1.
FPL has provided verified voltage. analyses to demonstrate that Class 1E equipment voltages will remain within acceptable operating limits for the worst case conditions analyzed.
2.
The test used to verify the analysis was valid and showed the
\\
analysis to be conservative.
3.
The licensee's reaffirmation of compliance to.GDC 17 requirements is acceptable.
c'
l5 J
~,