ML20076H896
| ML20076H896 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 08/30/1983 |
| From: | William Jones OMAHA PUBLIC POWER DISTRICT |
| To: | Clark R Office of Nuclear Reactor Regulation |
| References | |
| LIC-83-199, NUDOCS 8309060240 | |
| Download: ML20076H896 (14) | |
Text
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[
Omaha Public Power District 1623 Harney Omaha, Nebraska 68102 402/536 4000 August 30, 1983 LIC-83-199 Mr. Robert A.
Clark, Chief U.
S.
Nuclear Regulatory Commission Of fice of Nuclear Reactor Regulation i
Division of Licensing Operating Reactors Branch No. 3 Washington, D.C.
20555
Reference:
Docke t No. 50-285
Dear Mr. Clark:
Adequacy of the Fort Calhoun Station j
Electrical Distribution System Voltages The Omaha Public Power District, in a letter dated April 22, l
1983, provided responses to questions raised in the Commis-sion's letter of March 7, 1983.
As part of the District's response to Question 3, the District committed to performing an updated load flow analysis.
The results of this analysis are now available.
The new analyais, as expected, contains no significant changes with respect to the grid system voltage levels and their relationship to the undervoltage protection schemes at the Fort Calhoun Station.
The results of the new analysis, in tabular form, are at-tached (Appendix A), together with the corresponding tables from the original analysis done in 1978 (Appendix B).
The new analysis is based upon the District's 1983 summer load flow model.
Comparison of the two tables shows that of all the minimum expected voltages, in only one case is the now value lower than the original analysis (see Table 1, Ap-pendix A, and Table 1, Appendix B, outage from Sub 1209 to Sub 1226 with Tekamah in).
In this instance, the new ex-pected minimum grid voltage is 151 KV, as opposed to 152 KV from the earlier analysis.
This is a decrease of 0.7%.
The District estimates that this projected decrease will lower the minimum bus and notor terminal voltage calcu-lations by approximately 1% for that outage condition.
8309060240 830830 D I I
PDR ADOCK 05000285
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PDR p
45 5124 Employment with Equal Opportunity Male. F emale
Mr. Robert A. Clark LIC-83-199 Page Two The District wishes to point out, as has been stated in pre-vious submittals to the Commission, that the accident under-voltage protection scheme at the Fort Calhoun Station is based upon the voltage levels the safety-related equipment can tolerate without damage, not the voltage level the off-site grid might supply.
The design intent is not to rely on the stability of the offsite grid, but instead to make im-mediate use of the onsite power supply (diesel generators) before damage to plant equipment would be possible.
Sincerely, h
W.
C.
ones Divis n Manager Produ tion Operations WCJ/DJM:jmm Attachments cc:
LeBoeuf, Lamb, Leiby & MacRae 1333 New Hampshire Avenue, N.W.
Washington, D.C.
20036 Mr.
E.
G. Tourigny, Project Manager Mr.
L.
A.
Yandell, Senior Resident Inspector j
1
-,-.._.-_._.-. _ _- - -. _... - -. _ _. _ -.. ~ -.. _, _ _ -. _, - _ _ _ - - _ _ _. _, _ _ _ ~ _ - -. _ - _ - _ _ _ _ - - _.. - - - _ _ _
APPEIDIX A
~
- August 1,1983 Table 1 i
Voltage and Line Flows with Outage and Heavily Loaded System Outage Location S1209 - $1226 51209 - S1226 Tekamah' with Tekamah with Tekamah Raun Out in Voltage Voltage at (Condition 1)
(Condition 2)
(Condi tion 3)
Per Unit /kV S1251 968/156.
936/151.
997/161.
2 S1226 972/156.
941/152.
1.001/161.
S1209 1.040/167 1.04 /167 1.036/167 S1211 1.04 /167 1.04 /167 1.039/167 Tekanah 161 965/155.
989/159 Raun 161 1.03 /166.
1.03 /166.
1.03 /166.
Bus IA3 911/3.79
.877/3.65 941/3.92 Bus 1A4 900/3 74
.865/3.60 932/3.88 b.
S1226 to S1251 42 32 +J25.39 42.33 +J25.79 42.30 +J25.10 S1226 to S1209
-111.19 -J30.10 S1226 to Raun 161
-44.12 -J25.99 S 1226 to Tekamah
-44.13 -J26.39 67.09 +J 4. 39 Tekamah 161/115 kV 82.44 +J 1.52 66.45 +J 4.35 c.
System Load and Generation System Load Gene ra t i on NW MVAR MW OPPD 1388.
2 76. 8 1372.5 NPPD 2918.
596.6 2224.5 IPS 1070.
154.4 1385.8 IPL 1363.8 276. 7 872.2 ISU 412.2 21.0 798.9 i
l-1 1
-,__,,.__...---..m_-.
Table 1 - Continued d.
Relevant OPPD Loads MW MVAR MW MVAR 51226 1.8
.6 S1251 Di s t ributi on 3 ( 4. 7 33(8.0
.8 Blair (13.9
(
- 18.6
- 8.8 T1A3 10.8 6.6 TIA4 12.7
- 7. 8 e.
Regulated Voltages s3451 1.03 Sub. 911 1.04 s1211 1.04 Raun 161 1.03 m
)
h.
Table 2 Voltage and Line Flows with no Outage and Heavily Loaded System a.
Voltage Location
" Normal" Peak Load Condition Per Unit /kV S1251 1.011 S1226 1.015 S1209 1.037 S1211 1.039 Tekamah 1.012 Rabn 161 1.03 Bus -1A3 0.957 Bus 1A4 0.947 r
b.
S1226 to S1251 42.30 +J24.95 51226 to S1209
-54.74 -J25.77 51226 to Raun 161
^
S1226 to Tekamah 10.65 +J
.22 Tekamah to 161/115 kV 102.41 -J 1. 45 e
Y ml.
Table 3 Voltage and Line Flows with no Outage and Lightly Loaded System
~
a.
Voltage Found (Per Unit) (kV)
Loads MW MVAR S1251 = 1.051 S1226 4.5 1.3 S1226 = 1.051 S1251
, 2. 2 0.3 S1209 = 1.055 TIA3 0
0 S1211 = 1.05 T1A4 0
0 Raun 161 = 1.045 1A3 = 1.051 1A4 = 1.051 b.
Line Flow MW MVAR S1226 - S1209 26.7
-13.8 S1226 - S1251 2.22
-1.18 S1226 - Tekamah
-33.42 13.61 c.
System Load and Generation Load Generation System MW MW OPPD 553.8 527.0 NPPD 1167.2 474.7 IPS 428.0 743.8 IPL 545.5 53.9 ISU 412.2 79 8. 9
.]-
161 kV Network Adjacent to Ft Calhoun IPS System Raun 161 kV P
NPPD 3
)
8 S*
l N
Y jo0.57 +j 14.041.
Tekamah 161 kV (not included in all cases) 3.63 +jl6.82 et 3 02 MVAR
~
~ 165 kV tap 09.2 +j 175.02!"' ^
Sub 1251 Sub 1226 4f6o y g
.437 +j 3 9473'
?
g 4
Fort Calhoun
~
1.474 MVAR i
5nacion load &
l v
load 165 kV tap Bus 1A4 3.455 +j 16.004 11 09.2 +j 173.2
4/60 v 2.876 MVAR Sub 1209 OPPD System Line impedances shown in emhs and line charging capacitance in MVAR 5-
APPEfiDIX B GSE B-2-2 FORM Calculation Sunanary:
161 KV PREPARED OY g'C l
~
CHECKED BY Off Site Power at Ft. Calhoun gg /
CONT ON SH A
~
g APPROVED
\\
REV O DATE Bhj/7s C11AHA PU3LIC pol'!ER DISTRICT h--
TASK NO GERERATING STA ENG j
Aug a st, i 97e l
TABLE 1
~
Voltage and Line Flows With Outage And 11eavily Loaded System Outage Location S1209-51226
.S1209-S1226 Tekamah-Raun With Tekamah With Tekamah I
Out In I
a.
Voltage Voltage At (Condition 1)
(Condition 2)
(Condition 3)
(Per Unit)/KV Sub. 1251
.960/155
.945/152
.995/160 Sub. 1226
.965/156
.950/153
.995/161 Sub. 1209 1.030/166 1.030/166 1.030/166 Sub. 1211 1.040/167 1.040/167 1.040/167 Tekamah 161
.075/157
.990/159 Raun 161 1.030/166 1.030/166 1.030/166 Bus 1A3
.880/3.67
.865/3.59
.915/3.80 Bus 1A4
.880/3.67
.865/3.59
.915/3.80 b.
Line Flows (f4W & 14 VAR)*
C S1226 to S1251 39.04+j25.81 39.05+j25.98 39.03+j25.53 51226 to S1209
-87.43-j30.89 S1226 to Raun 161 -48.91-j27.25 S1226 to Tekamah
-48.92-j27.42 38.53+j3.92 l
Tekamah 161/115 KV 59.81 -j 3.16 38.31+j5.92 fl0TE S:
1.
All 161 KV Bus Voltages on a 161 KV Base 2.
All 4.16 KV Bus Voltages on a 4.16.KV Base 3.
- liegative sign indicates flow opposite direction from that indicated.
i
(
i l
GSE-0 2-2 FORu Calculation Suninary:
161 KV PREPARED BY I ', r Off Site Power at FL. Calhoun gg g CONT ON SH T CHECXED DY F
APPROVED C
REV. o DATE g/gg JAHA PUOLiC pot'!ER DISTRICT FC-//-40 GEPGRATING STA El1G TASK NO c.
System Load & Generation Load Generation System MW MVAR MU OPPD 1286.67 398.86 1187.0 HPPD 2007.21 1123.98 1498.0 IPS 637.60 166.50 1136.0 IPL 1069.00 158.70 561.8 ISU 411.30 12.10 302.0 Equivalent Areas-
-328.30
-9.10 629.7-634.5 d.
Relevant OPPD Loads MW MVAR MW MVAR S1226 9.87 1.44 S1251 Distribution 5.47 2.91
)
Blair 13.00 8.06
)
18.47 10.97 T1A3 10.20 6.64
(
T1A4 10.20 6.64 e.
Regulated Vol taces Sub. 3451 1.03 Sub. 911 1.04 Sub. 901 1.04 Sub. 1211 1.04 Sub. 906 1.04 b
L
,-t.
...m...x - a z,,
....Wh. _41 '- h-
' O ~. ~.4 If2 _-
- 4
.. ~.
. w. 4 ~....
--v.,
Calculation Sununary:
161 KV GSE-0 2-2 FOnu It' PREPARED DY Off Site Power at Ft. Calhoun CKICr.ED DY 3
gg CONT ON SH APPROVED REV. _.J2 D ATE 81g/W C AHA PU3LIC pot'!ER DISTRICT,
g_jj_h GENERATING STA ENG.
l TASK NO TABLE 2 Voltaae & Line Flows With No Outages & fieavily Loaded System a.
Voltage (per unit /(V,V)
Location
" Normal" Peak Load Conditions Sub. 1251 1.003/161 Sub. 1226 1.007/162 Sub. 1209 1.030/166 Sub. 1211 1.040/167 Tekamah 161 1.005/162 Raun 161 1.030/166 Bus 1A3
.925/3.85 Bus 1A4
.925/3.85 b.
Line Flows
(
S1226 to S1251 39.03+j25.44 S1226 to S1209
-12.57-j35.74 S1226 to Raun 161 S1226 to Tekamah
-36.32+j8.82 Tekamah 161/115 KV 73.12+j6.80 NOTES:
1.
All 161 KV Bus Voltages on a 161 KV Base.
2.
All 4.16 KV Bus Voltages on a 4.16 KV Base.
3.
- Negative sign indicates flow opposite direction from that indicated.
c.
System Load & Generation Load Generation System MW MVAR MW OPPD 1286.67 398.86 1037.0 NPPD 2007.21 1123.98 1498.0 IPS 637.60 166.50 1236.0 IPL 1069.00 158.70 561.8 ISU 411.30 12.10 302.0 Equivalent Areas
-328.30
-9.10 681.3 d.
Relevant OPPD Loads
(
~
MW MVAR MW MVAR S1226 9.87 1.44 S1251 Distribution 5.47 2.91
)
Blair 13.00 8.06
)
18.47 10.97 TIA3 10.20 6.64 T1A4 10.20 6.64
GSE-B-2 2 TORu PREPARED BY l 1'/
Calculation Summary:
161 KV Off Site Power at Ft. Calhoun CHECKED DY
,.c r.
H & CONT ON SH f
APPROVED TASK NO K-//-49 REV O DATE 9//6/79 034HA PU3LIC POWER DISTRICT
(
GEPERATING STA EiJG TABLE 3 Voltage And Line Flows With tio Outage And Lightly Loaded System N
a.
Voltages Found (per unit)/(KV)
Loads fjiW MVAR l
51251 = 1.050/169 S1226 4.52 1.33 j
S1226 = 1.050/169 S1251 Distribution 2.21
.25 I
51209 = 1.050/169 T1A3 0
0 S1211 = 1.050/169 TIA4 0
0 Raun 161
= 1.045/168 1A3
= 1.025/4.27 1A4
= 1.025/4.27 b.
Line Flows fW MVAR j
S1226-51209 18.21
-5.11 51226-S1251 2.21
-1.84 S1226-Raun 161
-24.95 5.62 c.
System Load & Generation
(
Load Generation System MW MVAR MW MVAR OPPD 520.39 88.36 550.
51.10 flPPD 1003.60 337.19 1249.3
-290.92 IPS 315.30 49.95 923.00 55.76 IPL 534.50 47.61 331.00 23.00 ISU 411.30 12.10 411.30 12.10 Equivalent
-356.30
-25.87
-787.21 2458.58 L
's Calculation Summary:
345 KV GSE-B-2-2 FORM PREPARED BY. h a.
Off-Site Power at Ft. Calhoun CHECKED BY SH. S CONT. ON SH.
APPROVED R E V..S.__ D AT E p/w?f OMAHA PUBLIC POV/ER DISTRICT TASK NO FC-//-40 GENERATING STA. ENG.
CALCULAT10f! SUMf1ARY:
345 KV 0FF-SITE POWER AT FORT CAlliOUfl 1.
SCOPE The purpose of triis attachment is to provide summary of results obtained from analysis done to determine the maximum and minimum limits of 345 KV Grid system voltage at Sub. 3451, Fort Calhoun Unit 1.
2.
IllTRODUCTI0rt As shown in Fig.1 Generator at Fort Calhoun Unit 1 feeds into 345 KV system through Sub. 3451.
Provision exists to start up the plant from 345 KV side, which under normal plant running conditions feeds Bus 1Al and 1A2 loads.
During normal plant running conditions should loss of 161 KV off-site power occur, provision has been made to transfer Bus 1A3 and 1A4 loads to 345 KV automatically.
It is, therefore, important, to find maximum and minimum limits of 345 KV, to ensure sequential starting of engineered safeguard systems, should LOCA occur while plant is operating from 345 KV side i.e. in start up mode from 345 KV side.
i
(
s
I GSE-0-2-2 FORM
'( tc Calculation Sunmary:
3 PREPARED BY Off-Site Power at Ft. C-CHECKED BY I*'
SH d. CONT. ON SH.$.
APPROVED
~
OMAHA PUBLIC POWER REv. _f DATE ft/alys GENERATING STA i IC-//-40 TAsx no C'.
to System to System (lj (Iowa Public Servi,cc)
\\/
Raun 161 kV l
l Raun 3-l
~
Tekamah
'O To 115 kV 4 (in service system stuamer 1978)
.O 8
.g u
I Sub 3451 1
For-I r,
i,
__g I Cal 6 Sub 1251
__ I 5
tSub.
(
f1226 \\I I
r, u
4 genc Ft. Calhoun U
'o tran house service i
transformers 50 w
i
{
U N
ra
- ~
g a
k d
to 1.incoln
- - o;.7;.. --
j i
i I
Sub 3459 l
Sub'1209
'IllT I\\
\\
?
t l
to Syst em to Syntem Fig, el Transmission System in Vicinity of Fort Calhoun Station 1
GSE Oo2-2 fonu Calculation Sunmary:
345 KV PREPARED OY f ' '-
Of f-Site Power at Ft. Calhoun CHECKED BY f"*'
SH 7 CONT ON SH APPROVED 1
C'AAHA 'PUBLIC POWER DISTRICT REV 8
DATE f/ 4/7/
C Tl.SK NO FC-//-40 GENER ATING STA ENG 3.
LOWER LIMIT - FORT CALHOUf1 Uf1IT I 0T C0!!f;ECTED For a lower limit on the voltage, a load flovi was run modelling the trans-mission system in the immediate vicinity of the Fort Calhoun Station (See Figure 1).
In this case the 345 KV voltage at the Raun Substation was held at 1.0 per unit; Sub. 1211 voltage was held at 1.02 per unit; and 604 MVA was f1 wing on Circuit 3431 from Raun to Sub. 3451.
In this severe case, the voltage at Sub. 3451 dropped to 0.975 per unit (336 KV). This is an extren.ely heavy flow on the line.
4.
UPPER LIMIT - FORT CALHOUN UNIT f!0T CONNECTED For an upper limit with Fort Calhoun unit off, it was assumed that there was no load on the generatse auxiliary transformer and that the plant was connected to the 345 KV system through Circuit 3431 to Raun only.
This would mean that Circuits 3422 and 3424 were out of service, or that the ring
~
bus was split at Sub. 3451. A voltage of 1.045 per unit was assumed at Raun and voltage rise along the line results in a voltage of 1.054 per unit (363.6 KV) at Sub. 3451.
5.
LOUER AND UPPER LIMIT UlTH FORT CALHOUN UNIT CONNECTED
(
Under normal conditions, the Sub. 3451 voltage will be regulated between 1.02 per unit and 1.035 per unit by the Fort Calhoun generator.
It is also assumed that Iowa Public Service would attempt to hold the 345 KV voltage at Raun bettleen 1.00 and 1.02 per unit.
6.
ANALYSIS From Paragraph 3 above it can be concluded that under worst conditions voltage on 345 KV side will drop down to 336 KV.
Similarly from Paragraph 4 higher limit of voltage would be 363.6 KV.
Both these are important when Fort Calhoun is not cnnnected to the system, once this is connected, voltage at 345 KV would be regulated.
It is there-fore important to set higher and lower limits of voltage on 345 KV side to start the plant.
7.
SUMMARY
(
i.)
Lower limit with Fort Calhoun not connected is 0.975 pu or 336 KV.
( ii.)
Upper limit with Fort Calhoun not connec'ted is 1.045 per unit or 363.6 KV.
(
( i i i..)
With Fort Calhoun unit connected voltage will be regulated between l.02 and 1.035[.J.
8.
REFEREf;CE - July 10, 1978 Letter f rom K. A. Birt to P. K. Mazumder