ML19343D323
| ML19343D323 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 04/27/1981 |
| From: | Kay J YANKEE ATOMIC ELECTRIC CO. |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| TASK-08-02, TASK-8-2, TASK-RR FYR-81-67, NUDOCS 8105040265 | |
| Download: ML19343D323 (9) | |
Text
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YANKEE ATOMIC ELECTRIC COMPANY
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2.C.2.1 y,f 1671 Worcester Road, Framingham, Massachusens 01701 yyg 81 67 YANKEE m
April 27, 1981 United States Nuclear Regulatory Commission L ashington, DC 20555 1.ttention:
Dennis M. Crutchfield, Chief Operating Reactors Branch #5 Division of Licensing Refere nce s: (1) License No. DPR-3 (Docket No. 50-29)
(2) USNRC Letter to YAEC, dated February 27, 1981 (3) YAEC Letter to USNRC, dated January 20, 1981 (FYR 81-9)
(4) USNRC Letter to YAEC, dated September 15, 1980 Subject :
SEP Topic VIII-2 Diesel Generators
Dear Sir:
I.
As requested in Reference (2), we are supplying the following clarifications and additional information with regard to Reference (3),
our previous submittal on SEP Topic VIII-2 Diesel Generators.
Items 1 thru 4 below respond to Items 1 thru 4 of Reference (2).
1.
For each diesel generator sequence:
(a) Name the sequence (e.g., loss of offsite power) and, (b) List each load (by name) that is connected at each time step and the motor name plate current.
Re sponse :
For each diesel generator there are two loading sequences: loss of of fsite power, and loss of of fsite power with safety injection signal.
The diesel generator loading for the loss of offsite power sequence is shown on Table 1, and the diesel generator loading for the loss of offsite power with safety injection signal is shown on Table 2.
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U.S. Nuclear Regulatory Commission Page Two Attention: 1Mr. Dennis M. Crutchfield 2.
Provide the technical basis for using an assumed motor efficiency of 95%.
Re sponse :
In Reference (3),fYAEC assumed an. efficiency of 95% for the LPSI pump motors and HPSI pump motors. This assumption was based on comparison with efficiencies of motors of similar size and speed.
After the receipt of this request, we have contacted the manufacturers of these motors and have determined that the full load ef ficiency of the LPSI pump motor is 94% and the full load efficiency of the HPSI pump motor is 91%. These figures more accurately represent the ECCS motor efficiencies.
3.
Provide the load lists (by name) and load description-(including currents) for each load on Emergency MCC #1 and Emergency MCC #2.
Re sponse :
The required information is provided in Tables 3 and 4 re spect ively.
4.
Specify the short-term ratings of your diesel generators and provide the basis for this rating.
Re sponse :
We have been unable to determine the short-time rating from available nameplate and manufacturer's catalog information. We believe the diesel generators do have a short-time rating (as defined in IEEE-387-1977); and that this rating can be developed from statistical records, if necessary.
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' U.S. Nuclear. Regulatory Commission Page Three Attention:
Mr. Dennis M. Crutchfield Table 1 Diesel Generator Loading - Loss of Offsite Power Load Motor Nameplate Current Sequence Tims Diesel Generator #1 Emergency MCC #1
-See Table 3 0 seconds Emergency MCC #2 See Table 4 0 seconds Diesel Generator #2
- (No load)
Diesel Generator #3 Emergency MCC #1 See Table 3 0 seconds Emergency MCC #2 See Table 4 0 seconds
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Note: Time 0 is considered to be the time when the diesel generator circuit breaker closes.
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U.S. Nuclear Regulatory' Commission Page Four Attention:. Mr. Dennis M. Crutchfield Table 2 Diesel Generator Loading - Loss of Offsite Power with Safety Injection Signal Load Motor Nameplate Current.
Sequence Time Diesel Generator #1 LPSI Pump #1 386 amps 0 seconds HPSI Pump #1 140 amps.
note 1 Emergency MCC #1 See Table 3 0 seconds Emergency MCC #2 See. Table 4 0 seconds Diesel Generator #2 LPSI Pump f2 386 amps O seconds HPSI Pump #2 140 amps note l' Diesel Generator #3 i
I LPSI Pump #3 386 amps O seconds HPSI Pump #3 140 amps note 1 Emergency MCC #1 See Table 3 0 seconds Emergency MCC #2 See Table 4 0 seconds i
1-
'T 4
Note:
(1) HPSI Pump sequence time is 10 seconds delay commencing af ter I
voltage recovery following start of LPSI pump.
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's U.S. Nuclear Regulatory' Commission Page Five Attention:
Mr. Dennis M. Crutchfield Table 3 Emergency MCC #1 Loading Load Full Load Amps Sequence Time 7.5 kVA Distribution Transformer "B" 9 0 amps O seconds 7.5 kVA Distribution Cabinet "A"
9.0 amps O seconds Control Rod Cam Drives 6.8 amps O seconds By-Pass Valve CS-MOV-534 1.4 amps note 1
- Pressurizer Relief Block Valve PR-MOV-512 1.8 amps manual.
Main Valve CS-MOV-535 10.5 amps manual Loop Fill Valve CS-MOV-537 1 6 amps note 1 Loop Fill _ Valve CS-MOV-536 1.6 amps note 1 Loop Fill Valve CS-MOV-538 1.8 amps note 1 Loop Fill Valve CS-MOV-539 1.6 amps note 1 CH-MOV-523 1.8 amps note 1 CH-MOV-522 1.3 amps note 1 CH-MOV-524 1.8 amps note 1 Main Transformer Oil Pump 23 amps note 2 Notes:
(1) The power supply for these valves is removed whenever main coolant pressure is greater than 1000 psig.
(2) A design changa at the forthcoming refueling will remove this load from emergency MCC #1.
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U. S. Nuclear Regulatory Commission Page Six 4
~ Attention:
Mr. Dennis M. Crutchfield
' Table 4:
Emergency-MCC #2 Loading
' Load Full Load Amps Sequence Time Roof Exhaust Fan 1 PRV-1 4.5 amps-O seconds Roof Exhaust Fan 2 PRV-2 4.5 amps 0 seconds Vent Fan Motor UV 4.0 amps 0 seconds Battery. Charger #3 9.4 kW 14.1 amps 0 seconds DG Auxiliaries Distribution Cabinet 3 kVA 3.6 ampa O seconds Accumulator Isolation Valve MOV-l' 5.2 amps P23 sec-note 2 SI LP Recirc Valve MOV-49 2.3 amps manual SI LP Recirc Valve MOV-532 -
1.4 amps note 1 SI HP/LP Tie Valve MOV-4 2.3 amps note 1 SI Discharge Header Block Valve MOV-46 1.6 amps note 3 Loop 1 Fill Block Valve MOV-25 2.8 amps note 1 Loop 2 Fill Block Valve MOV-24 2.8 amps note'1 Loop 3 Fill Block Valve MOV-23 2.8 amps note 1 Loop 4 Fill Block Valve MOV-22 2.8 amps note 1
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Notes: (1)' The power supply for these valves is removed whenever main cooiant pressure is greater than 1000 psig.
(2) This valve closes automatically on low level in the accumulator which may occur P 23 seconds.
-(3) A design change is in progress that will make this a manually sequenced valve.
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e U.S. Nuclear Regulatory Commission Page Seven Attention:
Mr. Dennis M. Crutchfield 1
II.
Yankee Atomic is providing the following supplemental infremerion regarding diesel generator loading. This information is based on actual pre-operational tests conducted on the HPSI and LPSI motors in 1972.
The actual testa performed and documented in 1972 determined the worse case load of the ECCS motors when supplied by the diesel generators. The tests simulated a loss 'of of fsite power under accident conditions with one diesel generator out of service. The tests demonstrated the capability of the remaining two ECCS trains to deliver the recuired flow rate when supplied by emergency power.
The ECCS flow tests were performed under pump runout conditions. The ECCS pump curves indicate that pump runout is the point of maximum brake horsepower for -the ECCS pumps and therefore these tests represent the maximum duty of the ECCS motors.
The YAEC analysis of the results of the ECCS flow tests indicate that the LPSI pumps draw only 290 amps and the HPSI pumps draw 135 amps. Using the diesel generator voltage recorded during the test (490 volts), and appropriate power factors obtained f rom the manufacturers of 0.875 and 0.88, we calculate the motor load a.s follows:
LPSI pump - 246 kVA or 215 LW HPSI pump - 115 kVA or 101 kW Utilizing this ECCS motor loading and the MCC loading in Tables 3 and 4, we have recalculated the diesel generator loading as follows:
Diesel Gen.
Percent of Continuous Rating Based On kW kVA-kW Load kVA Load DG#1 359.0 413.3 89.8%
82.7%
DG#2 316.4 361.0 79.1%
72.2%
DG#3 359 0 413.0 89.8%
82.7%
The calculation assumes:
1) 0.8 power factor for the MCC load
- 2) Only one manually operated MOV to be actuated at any time j
- 3) The main transformer oil pump is removed f rom Emergency MCC 1
- 4) The loads identified in note 1 of Tables 3 and 4 do not operate
e U.S. Nuclear-Regulatory. Commission Page Eight Atte ntion:
Mr. Dennis M. Crutchfield We trust that this information proves conclusively that the diesel generators are presently operated well within their continuous ratings. If you have any further questiens, please let us know.
Very truly yours, YANKEE ATOMIC ELECTRIC COMPAhT G.
J. A. Kay Senior Engineer - Licensing-ij.
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