ML19318D263
| ML19318D263 | |
| Person / Time | |
|---|---|
| Site: | FitzPatrick  |
| Issue date: | 07/01/1980 |
| From: | Bayne J POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK |
| To: | Ippolito T Office of Nuclear Reactor Regulation |
| References | |
| JPN-80-33, NUDOCS 8007080332 | |
| Download: ML19318D263 (11) | |
Text
.
POWER AUTHORITY OF THE STATE OF NEW YORK 10 Cot.uusus Circle NEW YORK. N. Y. loo 19 4212) 397 6200 otono,e T,. sEnny ops R 4 TI NG OFFICER TRUSTEES JOHN W. WOSTON JOHN S.oVSON in a nacTom
****"a""'"*
ozonas t.iNoatts JOSEPH R C (EDER vlCS SMASAMAN PRES DENT & CM18F RICH ARD M. FLYNN no.ent i. uittoNn t en og,.,s,m etag,,,,,,
July 1, 1980
. c ier riaa=Ci 6 annosaica n. cuans JPN-80-33
,,,,,',7,,,,
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Director of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Attention:
Mr. Thomas A. Ippolito, Chief Operating Reactors Branch No, 3 Division of Operating Reactors
Subject:
James A. FitzPatrick Nuclear Power Plant Docket No. 50-333 Additional Information on Adequacy of Station Electric Distribution System Voltage
Reference:
Letter, Thomas A. Ippolito (NRC) to George T.
Berry (PASNY) dated May 8, 1980 Dear Sir Attached are the Authority's responses to the NRC request for additional information regarding adequacy of station electric distribution system voltage which was enclosed with the referenced letter.
Very truly
- yours,
\\
. P. Bayfle Senior Vice President Nuclear Generation
/5
\\
-8007080 El p
RESPONSE TO QUESTION NO. 1 OF NRC LETTER DATED MAY 8, 1980 QUESTION Guideline 6 requests that the voltage should be calculated at the terminals of each safety' load.
Your previous analysis only shows bus voltages.
Please provide safety load terminal voltages in accordance with Guideline 6.
RESPONSE
At least one worst case of voltage drop between bus and load terminals (worst possible ' combination of load size and leads length) for each safety related bus has been recalculated and reverified.
New Figure Nos, lA and 2A attached to this letter show the worst case load terminal voltages of the selected cases described above.
For case of comparison, these figures have been drawn in the same manner as Figure Nos. 1 and 2 respectively, which were attached to the report " Evaluation of Operability of Safety-Related Equipment During a Degraded Voltage Condition" presented by the Authority with our letter of October 18, 1976.
These results support our previous recommendation to change taps in the 600 V emergency load center transformers, contained in the above mentioned report.
~
e t
A
FIGURE NO. lA JAMES A.
FITZPATRICK NUCLEAR POWER PLANT VOLTAGE PROFILE - ESSENTIAL LOADS EXISTING TRANSFORMER TAP SETTINGS Y
z M
o LOAD VOLTAGE LOAD VOLTAGE E
A NO FULL NORMAL NO FULL NORMAL LOAD LOAD LOAD LOAD LOAD LOAD 122KV=106.1 105.8 105 (4232V)
N' ' ~ w' 104.69 (602V)
-y ll7KV=101.7 101.75 (4070V) ll5KV=100 9
')
.98 60
- 97. 27 (3891V)
[l*~
9 5. 4 N
95 s
95.13
'N (3808V) (3816V)
(547V) $1 94.08 ss N s __
93.32 (541V)
(3733V) 91:82
)
(528V) 90 90.08 (518V)
__87.65 (504V) 85
-e ll5KV DASE 3
=
4000V BASE T
575V BASE (MOTOR NAMEPLATE)
(MOTOR NAMEPLATE)
Reserve Transf.
Load Center Tap =119KV Transf. Tap =4050V I)
)
r*1b u ttr., NU. 4A JAMES A. FITZPATRICK NUCLEAR POWER PLANT VOLTAGE PROFILE - ESSENTIAL LOADS PROPOSED LOAD CENTER TRANSFORMER TAP SETTING i
LOAD VOLTAGE LOAD VOLTAGE z
s_
NO FULL NORMAL NO FULL NORMAL LOAD LOAD LOAD LOAD LOAD LOAD b
t!
$~
107. 3'u (617V) 122KV=106.1 7-105 N
W 105.8 (4232V) e ll7KV=101.7 101.75 (4070V) ll5KV=100
-140'17#
N 99.87 (576V) 3995V)
~
97.27
-97.il3' (3891V) 558.Sv
- 96.00 N
.95..
95.4 m 2V) 9; (3808V) (3816V) 93.56 93.32 (538V)
(3733V) 92.34 (531V) 90.08 9c (51gV)
I 8'
~
4000V' BASE 575V BASE 115KV BASE (MOTOR NAMEPLATI:;)
Reserve Transf.
(MOTOR NAMEPLATE)
~ l Toad Center Tap =119KV Transf. Tap = 39 50V
/ ~)
RE 'i ONSE TO QUESTION NO. 2 OF NRC LEYfER DATED MAY 8, 1980 QUESTION As per Guideline 3, please provide safety loads terminal voltage for starting of the largest non-safety load concurrent with fully-loaded Class lE buses' and the offsite grid voltage at its minimum value.
RESPONSE
Calculations were performed to establish the worst case voltage level at the safety related load terminals, when starting the non-safety related load producing the largest voltage drops through-out the plant electrical distribution system.
The calculations assumed full load on the plant electrical buses with the off-site power supply grid at its lowest voltage of 115 kV.
It was found that the worst case occurred while starting one 3,000 HP condensate booster pump at the 4,000 V level.
The starting of one of the 7,000 HP Recirculation Pump M-G sets results in a lesser disturbance since these loads are fed from separate windings in the reserve transformers.
The resulting values of load terminal voltages found as described above, are shown in the attached Figure Nos. 1B and 2B, which are also drawn in the same manner as the original Figures 1 and 2.
j s
riuunt hu. Its JAMES A.
FITZPATRICK NUCLEAR POWER PLANT MOTOR STARTING VOLTAGE PROFILE - ESSENTIAL LOADS EXISTING TRANSFORMER TAP SETTINGS
'122KV=106.1 LOAD VOLTAGE LOAD VOLTAGE
~117KV=101.7 115KV=100 4
1 95.
4 A4 3
90 t
zoa E4 s
U i
m 85 N
1 83.35 (3334V):
i l
80 I
l j
78.33 045GC4V)
I 74 I
ll5KV 4000V. BASE 57SV. BASE m
y (MOTOR NAMEPLATE)
J' (MOTOR NAMEPLATE) 2 Reserve Transf.
Load Center
( ') Tap =119KV
,)
Transf. Tap =4050V
.... FIGURE N 2B JAMES A. FITZPATRICK NUCLEAR FOWER PLANT MOTOR STARTING VOLTAGE PROFILE - ESSENTIAL LOADS.
PROPOSED LOAD CENTER TRANSF. TAP SETTINGS LOAD VOLTAGE LOAD VOLTAGE 117KV2101.7 115KV=100 95 L
A N
9O s:c O
E4 b
O 85 ne 83.35
)
(3334V) 80 80.78 (464.5V)'
75
+115KV BASE e
4000V. BASE
- 575V. BASE P-(MOTOR NAME PLATE)
(MOTOR NAME PLATE)
Reserve Transf.
Load Center thTap=119KV j
Transf. Tap
=3950V i
RESPONSE TO QUESTION NO. 3 OF NRC LETTER DATED MAY 8, 1980 QUESTION Reference 2 states that, "The adequacy of the onsite distribution of power from the offsite circuits shall be
/erified by test to assure that analysis results are valid."
Please provide (a) a description of the method for performing this verification and
- (b) the test results.
RESPONSE
The voltage calculations performed for the JAF plant will be veri-fled by field tests in the following manner:
1.
Objectives of Test a.
Verify the calculations by establishing that the actual plant distribution system impedance network and the inpedance network used in the calculations are equal within acceptable tolerances.
b.
Obtain data for the actual off-site grid and plant bus voltages encountered during various plant opera-ting modes without disturbing these modes.
2.
Method of Test a.
Appropriate instrumentation will be installed when necessary at various busses, both in the off-site grid'and in the plant auxiliary electrical distribution system to record the necessary voltage, current and load data.
b.
Measured plant bus voltages and loads will be corre-lated with measured off-site grid voltage conditions.
This will establish the actual plant distribution system impedance network values.
c.
Load currents to safety related loads will be measured and,using published impedance data for the associated cables, the load terminal voltages will be established for the measured bus voltages.
3.
Schedule i
No test results exist at the present time.
The test will be scheduled to commence during the late 1980 planned out-age and will be performed for the time necessary to obtain
RESPONSE TO QUESTION NO. 3 (cont)
L OF NRC LETTER DATED MAY 8, 1980 the data required to reach Objective a. above.
The instru-mentation required for Objective b. will be utilized for a longer period of time'to establish actual trends for the off-site. grid and plant bus voltages.
The reascus _ for commencing the test during the late 1980 planned outage are as follows:
a.
Time is-required to purchase and/or rent various items of instrumentation and accessory equipment (potential transformers, current transformers, etc.)
I required to perform the test.
b.
Since this equipment must be connected to " live" buses, it is preferable that this installation be performed during an outage to prevent any inadvertent disruption of normal plant operation.
c.
A report covering the results of the test will be submitted to your offices not later than ninety days from the date of plant s tart-up af ter the late 1980 outage.
l
RESPONSE TO QUESTION NO. 4 OF NRC LETTER DATED MAY 8, 1980 QUESTION Your previous analysis indicates that you have two independent offsite sources for normal and emergency power; NSS Transformer T2 and NSS Transformer T3.
However, Figure 8.2-1 in the FSAR indicates that there raay be several possible cross-ties of the redundant trains which would allow one transformer to supply loads on both trains.
Please provide either safety load terminal voltages for one NSS transformer supplying both trains, or include limiting conditions of operation (LCOs) in plant technical specifications to prevent any cross-tie of the redundant trains during operation.
RESPONSE
The redundant safety buses are neither cross-tied, ncr transferable, and any one reserve station service transformer does not supply loads on both safety trains for any mode of JAF Plant operation; i.e.,
full load, start-up, standby or shutdown.
Please refer to Figure 8.2-1 and the Technical Specifications, Part 3.9 Limiting Conditions for Operation, Auxiliary Electrical Systems of the FSAR, for the following explanation:
a.
The total auxiliary load of the JAF Plant at 100%
generation conditions is approximately 25 MW and at shutdown conditions, approximately 10 MW.
b.
During normal operation, the normal s tation service transformer T4 supplies all plant loads, while reserve transformers T2 and T3, although energized at the 115kV level, are disconnected from the 4.16kV plant buses.
c.
During shutdown, transformer T4 is de-energized and its 4.16kV breakers are open.
The 4.16kV breakers of the two reserve transformers T2 and T3 are closed, and these transformers supply the plant loads which are approxi-mately divided evenly between the two.
From the trans-former ratings shown in Figure 8.2-1 and the actual loads indicated above, transformers T2, T3 and T4 are conservatively rated and are more than adequate to carry their respective loads.
The transfer of loads from transformer T4 to trans-formers T2 and T3 occurs automatically if the unit trips for any reason, or is accomplished manually
RESPONSE TO QUESTION NO. 4 (Cont)
NRC LETTER DAhkD MAY 8, 1980 during the normal shutdown procedures.
In the reverse direction, the transfer is always manual.
Regardless of how or in which direction it is accomplished, after a transfer, either only T4 or both T2 and T3 are con-nected to their respective buses.
Please note that 4.16kV bus 10700 is not transferrad to T2 or T3, since it is tied only to T4.
Under these conditions, with a total plant load of only about 10 MW, both T2 and T3 are loaded to approxi-mately 5 MW each~and no ties will be closed at any plant voltage' level.
d.
Maintenance of transformers T2 or T3 or of the 115kV or 4.16kV breakers serving them requires that one of these transformers be taken out of service.
This maintenance is normally done under shutdown conditions.
In this case, it is possible to transfer some of the non-essential loads from one transformer to the other.
As can be seen in Figure 8.2-1, such partial transfer of loads is possible by various configurations of breaker positions, including transfer through trans-former T4 after opening its primary connection to the generator bus.
If maintenance of transformers T2 or T3 or of the ll5kV off-site supply breakers must, for any reason, be per-formed during normal plant operation, either T2 or T3 may be taken out of service for the' time and under the conditions stated in the Technical Specifications.
No transfer of plant loads is required in this case since reserve transformers T2 and T3 do not supply loads during normal operation.
From the above, it is evident that transformers T2 and T3 are always operated well within their ratings regardless of any load transfer.
The results of the voltage calculations shown on Figure Nos. 1 and 2 of our report on October 18, 1976, as well as on Figure Nos. LA, 1B, 2A and 2B presented here are extremely conservative for the indicated Full Load Conditions, which assume fully loaded plant busses.
Those results shown under Normal Load Conditions are more representative of the actual plant operating modes.
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