ML19322C371
| ML19322C371 | |
| Person / Time | |
|---|---|
| Site: | Oconee, Crane  |
| Issue date: | 09/27/1977 |
| From: | Culberson D BABCOCK & WILCOX CO. |
| To: | Fairburn G, Janis J, Rogers L BABCOCK & WILCOX CO. |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8001160906 | |
| Download: ML19322C371 (3) | |
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SITE INSTRUCTION NO. 8h v " ^ '.
THE BABCOCK & WILC0X COMPANY DISTRIBUTION 57 8 g ff XWER GENERATION GROUP i
YI RESPONSE REQ'D FROM O ~h # '," --
Distribution APPROV A _
I From
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a D. G. Culberson - Nuclear Service (3615)
,o g m,3 Cust.
File No.
NSS-5,6,7,8, & 11 Met Ed Jersey Centrel, Florida, Arkansas, SMUD or Ref.
T3.17.21 Suej.
Date Loss of Power to ICS Power Panel Board September 27, 1977 l..............,.........................i, Distribution L. C. Rogers-G. T. Fairburn J. T.Janis R. C. Luken
References:
(1) SPR-215 (Oconee II), " Loss of Power to ICS Power Panel Board 2kI."
(2) Memo, D. L. Allison to Distribution, April 23, 1977, Same Subject.
(3) Memo, J. D. Carlton to D. L. Allison, hay 19, 1976, Same Subject.
y (4) Memo, D. L. Allison to Distribution, June 9, 1976, Same Subject.
Some. time.ago an. occurrence at Oconee II, involvingiloss of power _ to.the'.
? customer. electrical' distribution. panel.2kI, resulted in an overpressure greactor trip and loss of the power sources supplied from the 2k1 panel.
^(Loss of 2RI produces an equivalent loss of B&W ICS and NNI systems.)
Those sources supplird by 2kI include the following:
1.
ICS Auto Power 2.
Emergency Steam Generator Level Control 3.
ICS 'dand Power 4.
ICS Emergency Power No. 1 5.
ICS Emergency Power No. 2 This resulted in the following:
1.
No automatic or hand control from the control room.
2.
No control from the emergency shutdown panel.
3.
No operating indicators at the control panel (only RPS variables are available.) or at the shutdown panel.
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(This includes no OTSG level indication l
j' n_o pressurizer level indication s,;Q[jg Q no feedwater flow indication 4.
Pressuri::er heaErs inoperable (Bank #1 of f, 2, 3, and 4 o_n).
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Culberson to Distribution September 27, 1977 5.
Makeup control valve inoperable, letdown control valve inoperable, bypass valves, startup valves, and main feedwater valves are in-operable. A loss of signal to these valves should result in them positioning at the 50% position.
- 6., Spray.. valve,andialectromaticLrelief valves on pressurizer are in.
(: operable but,will. remain'in their last position.
Loss of power to the 2k1 power panel board resulted from en unsuccessful attempt to transfer the 2k1 power source from DC Invertors to regulated AC.
The problem reported in the subject SPR is attributable to having all three powers (hand, auto, and emergency) powered from the same power supply.
,Although this problem appears to be. unique to Bailey 721 type equipment,
- B&W feels that all customers.up.to TECo (NSS-14).should be alerted to review.
their electrical systems for a potential similar problem, in particular fregarding loss of their class 1-E power. sources (fire, explosion, etc.).
If you have any questions regarding this matter, pl. ease do not hesitate to contact me.
DGC/cs cc:
K. R. Ellison W. H. Spangler V
J. D. Phinney J. R. Bohart W. E. Perks Record Center R. J. Finnin J. F. Walters N. M. Seeling REVIEWED FOR ACCURACY ENGINEERING ggaggy DATEg-[fjfry7
" *' ca q SEKVICE: -6 m,.8 - e *d v
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Y SIP 5,6/136 3,
Page 1 of 1 i
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i REDLY The sources of power to the ICS and N:I have been revitved by B&W site,!
personnel and discussed with the Custemer.. The electrical distribution sdesignsicfjboth D I-1.and C I-2_ dei notlappear.toshave the potentiali problen' described in SI #5,6/136. The ICS and IUI power sources for each Unit are listed below:
TMI NSS-5 ICS Iland ICS Auto ICS Auxiliary Feedvater NNI X
NNI Y
1 All of the above are powered from distribution panel ATA. This psnel is A
a vital h160V bus through a battery backed inverter.
supplied fro:
static transfer switch is provided which vill automatically switch panel ATA to a regulated AC bus in the event of inverter failure. A servate manual tie to a rcGulated AC bus has been added to provide switching capability in the event that both the inverter and static switch fail.
TMI-2 NSS 6 ICS - lland Vital Bus 2-12E ICS - Auto Vital Bus 2-22E ICS - Emer. FW Vital Bus 2-22E NNI - X Vital Bus 2-22E UNI - Y Vital Bus 2-12E O
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