ML20237H412
| ML20237H412 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 04/23/1987 |
| From: | Brewer C, Epperson J TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML20237H133 | List:
|
| References | |
| AOI-21.7, NUDOCS 8708170200 | |
| Download: ML20237H412 (9) | |
Text
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-l TENNESSEE VALLE,Y AUTHORITY .
SEQUOYAH NUCLEAR PLANT ABNORMAL OPERATING INSTRUCTION AOI-21.7-I LOSS OF 125V DC VITAL BATTERY t. BOARD III i Unit 2 Revision 7 PREPARED BY: C. O. Brewer
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. RESPONSIBLE SECTION. Operations REVISED BYi ,Jeff Epperson SUBMITTED BY: . . Il 41
.sp'onsible Section Supervisor PORC REVIEW DATE: TPR '2 31987 APPROVED BY:
P,lant Manager DATE APPROVED: APR 23 ID87 Reason for revision (include all Instruction Change Form Nos.): [ Revised to correct annunciations; delete PD charging pump reference; relocate immediate actions.
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_ .The last page of this instruction is number: 7
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7________. SEQUOYAH NUCLEAR PLANT f-PLANT INSTRUCTION REVISION LOG I - ABNORMAL OPERATING INSTRUCTION OI-21.7 REVISION Date Pages REASON FOR REVISION (INCLUDE COMMIT-LEVEL Approved Affected MENTS AND ALL ICF FORM NUMBERS) 1 11/08/79 ALL 2 06/17/80 5 3 12/19/80 2 - 4 07/26/83 All 5 08/13/84 2,3,5 Revised to add V Vital Battery to plant vital power, sources and make correction. . - 6 8/29/86 All to automa' tic action sections. Revised to correct- annunciations; delete P harging pump reference; relocate 7 APR 2 3 1987 All immediate actions. l . L L I
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AOI-21.7 Page 1-Revision 7 - I.- SYMPTOMS .
'A. Possible Alarms
- 1. 125V DC VITAL CHARGER III FAILURE OR VITAL BATTERY III DISCHARGE. p
- 2. 125V DC VITAL BATTERY BOARD III ABNORMAL.
- 3. 6900V SHUTDOWN BOARD 1A-A FAILURE OR BUS / NORMAL FEEDER UNDERVOLTAGE OR OVERVOLTAGE (1-M-1). -
- 4. 6900V SHUTDOWN BOARD 1A-A FAILURE OR BUS / NORMAL FEEDER UNDERVOLTAGE (0-M-26).
5.480V SHUTDOWN BOARD 1Al-A FAILURE .A UNDERVOLTAGE (1-M-1 and 0-M-26). , [ 6. 480V' SHUTDOWN BOARD 1A2-A FAILURE OR UNDERVOLTAGE (1-M-1 and
'l- 0-M-26). . 7. 6900V SHUTDOWN BOARD 2A-A FAILURE OR BUS / NORMAL FEEDER 1
UNDERVOLTAGE OR OVERVOLTAGE (2-M-1).
- 8. 6900V SHUTDOWN BOARD 2A-A FAILURE OR BUS / NORMAL FEEDER UNDERVOLTAGE (0-M-26).
- 9. 480V SHUTDOWN BOARD 2Al-A FAILURE OR UNDERVOLTAGE (2-M-1 and 0-M-26). -
- 10. 400V SHUTDOWN BOARD 2A2-A FAILURE OR UNDERVOLTAGE (2-M-1 and 0-M-26).
k l L 11. PANEL 2-L-39 GENERATOR AUXILIARY ANNUNCIATOR OPERATED OR BUS ! POWER FAILED (2-M-2). 1 B. Indications ,
- 1. Voltmeter on 1-M-1 and 2-M-1 indicates failure on 125V dc bus III. j
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- 2. Ammeter on 1-M-1 and 2-M-1 for bus III battery shows zero.
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.. 3. Breaker position indicating lights for equipment feeding from 6.9kV shutdown board 2A-A and 480V shutdown boards 2Al-A and 2A2-A will all be out. -
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{ AOI-21.7 Page 2 Revision 7' f;.;- -L 'f: II. AUTOMATIC ACTIONS . A. Reactor trip - Turbine trip due to all four main feed' water regulating valves, all four MSIVs, and number 2-and 4 S/G main g feedwater regulating bypass valves failing closed resulting in
; ; - loss of feedwater, and low steam generator water level in - E coincidence with steam flow / feed flow (SF/FF) mismatch and/or low-low steam generator water level.
B. Motor driven auxiliary feedwater pump 2B-B and turbine driven auxiliary feedwater pump start on a low-low generator water'
; level.
C. Steam dump valves and steam generator blowdown valves fail !
. closed.
D. Normal letdown' isolation valves FCV-62-69 and 62-70 and orifice , isolation valves FCV-62-72, 62-73, and 62 -73 fail closed. l E. 'All four. diesel generators start but do not, tie onto the shutdown boards. III. IMMEDIATE OPERATOR ACTICN A. Refer to emergency instructions.
.IV. SUBSEQUENT OPERATOR ACTION A. Dispatch personnel to diagnose problem and attempt to restore power to 125" de vital battery board from:
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- 1. 125V de Battery III or
- 2. 125V de Vital Battery Charger III or 1
- 3. 125V de Vital Battery Charger 2-S or
- 4. Spare Vital Battery III with Battery V per SOI-250.5 f'
(. - B. Initiate REP per IP-1 (Engineered Safety Features) as required. C. Maintain the reactor in hot standby.
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- 1. Motor driven auxiliary feedwater pump 2B-B will supply feedwater to steam generators 3 and 4 and turbine driven pump 2A-S will supply all four steam generators. Steam l- ,_ .
generator level should control automatically at E33 percent.
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NOTE: Motor driven auxiliary feedwater pump 2A-A will not start. ,
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f~ , SQN A01-21.7 -' Page 3 l Revision 7
.l IV. SUBSEQUENT OPERATOR ACTION (continued)
- 2. All four steam generator atmospheric relief valves may be 1 used for RCS heat removal (modulating control only on steam 1 generators 1 and 3). Steam generator relief valves can be )
adjusted to contro) RCS temperature at s547'F. NOTE: Steam dump valves, main steam isolation valves, and f til main feedwater regulating valves to all four I- steam generators failed closed. , p 3. Place steam dump mode selector switch in pressure _ mode. I '~ i
- 4. Isolate charging flow by closing FCV-62-90 or 62-91. Verify '
- . or adjust reactor coolant pump seal water flow. 28-8
-Centrifugal charging pump may be started to establish seal i injection. ,
[. -5. Reactor coolant pumps can be stopped to reduce the heat 1 Input; however, reactor coolant pump No. 2 should be left on l to supply pressurizer spray. r:
- 6. Place excess letdown heat exchanger _in service per S01-62.1.
NOTE: Volume control tank makeup system valves have failed closed. Charging pump suction will divert from VCT to RWST if VCT level decreases to 5,71.. D. Verify pressurizer pressure normal and level being maintained. NOTE: Both pressurizer spray valves are operable and pressurizer relief valve PCV-68-334 is operable; however, pressurizer relief tank.ranrot be drained cr
- [-- vented and tank spray valve has failed closed.
Pressurizer backup heater groups 2C and 28-B are j operable. > E. Have local inspection performed on 125V dc vital battery board III to determine the cause of the failure. Try to restore voltage. Initiate maintenance if necessary. t 01578/peb ' u________________ . ._.
e SQN A0I-21.7 - Page 4 Revision 7 ,, IV. SUBSEQUENT OPERATOR ACTION (continued) F. Transfer the following 125V dc buses to alternate feed. CAUTION: When transferring the 125V dc bus to alternate or back to noymal, have someone hold the 8.0. reset f- button pushed in located in panel 4 of 6.9kV logic panel 2A-A. This will prevent the 8.0. relays from (, going to a B.0. condition, which would sequence the t CCP, AFHP, ERCH, PZR heaters, and fire pumps if auto signal is present. ~ 5 NOTE: After de is restored to this bus, auxiliary f feedwater pump 2A-A can be used to supply water to 1 and 2 steam generators. Xfer to Alt Return to Normal , [ 1. 6.9kV shutdown board 2A-A l normal bus.
- 2. 480V shutdown board 2Al-A l
f normal bus.
- 3. 480V shutdown board 2A2-A normal bus.
G. Trip auxiliary building general supply and exhaust fans 2A and g 2B and fuel-handling area exhaust fans A and B. Place auxiliary [ building gas treatment system train B in service. H. Trip containment annulus vacuum fans and pla'ce EGTS train B in service for Unit 2. { -
- 1. Open EGTS train B suction salve FCV-65-30.
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- 2. Open EGTS train B discharge vaive FCV-.5-45.
- 3. Open EGTS train B PC0 isolation valve PC0-65-83 and PCV-65-87 (HS-65-83 on M-27B).
l 4. Start EGTS for B-B (HS-65-42A on M-278). u 0157B/peb
SQN AOI-21.7 - Page 5 Revision 7 .. IV. SUBSEQUENT OPERATOR ACTION (continued) Stop containment instrument room cooler that is operating. I. J. If containment purge was in progress, stop containment purge air supply and exhaust fany. f-K. Depending upon the amount of time required for restoring 125V dc bus voltage, the diesel generators can be left running or diesel f_: generators IB-8, IA-A, and 28-B can be stopped.by the following. procedures: . f .i. CAUTION: Coordinate this work with Unit 1 operator.
- 1. Place 43T(L) switch (located on diesel generator logic panel 2A-A) in TEST position and leave it in TEST.
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- 2. Place all 43T(L) switches-(located co diesel generator
' logic panels 18-B, IA-A, and IB-B) in the TEST position simultaneously and then return them to NORMAL.
- 3. Reset the emergency start lockout relays for diesel generators 18-B, IA-A, and 2B-B (located on each
- f. respective diesel generator relay panel in diesel generator building).
- 4. .Stop diesel generators 18-8, lA-A, and 2B-B by placing HS-82-44, HS-82-il4, and HS-82-104 in STOP position.
- 5. Diesel generator 2A-A should be left running.
L. Verify boron injection temperature 1145F' by TI-63-27 on panel l M-6. l [.
. H. Depending upon the cause of the failure, or after repairs, l voltage can be restored to the bus by placing the normal charger L -
or 2-S spare charger in service or by connecting the battery to the bus by closing breaker 107. CAUTION: If restoring voltage after a fault on the bus, use a battery charger for energizing the bus, if possible. t NOTE: If board cannot be restored within two hours of L loss, refer to Technical Specification 3.8.2.3. .) l 0157B/peb .
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.a , 'h SQN A01-21.7 u Page 6 Revision 7 ..
IV. SUBSEQUENT OPERATOR ACTION (continued) N. After normal voltage is restored to the bus:
- 1. Transfer the de buses back to normal that were change in step IV.F of this procedure. Observe the same t f- precautions (check off when normal). !
[- 2. Place 43T (L) switch (located on D.G. logic panel 2A-A)
-I to NORMAL position.
- g. 3. Reset the emergency lockout relay for D.G. 2A-A,_ then stop diesel generator 2A-A. ..
l. L . Return the following systems to normal operation by {; their respective SOIs.
- a. CVCS System .501-62/1
- b. Reactor Coolant System - S01-68.1, 68.2, 68.3
- c. Auxiliary Feedwater System - S0I-3.2
- d. Main Steam System - S0I-1.1 Steam Dump Control - SOI-1.2 e.
- f. Diesel Generators - S01-82.1, 2, 3, 4
- g. Boron Concentration Control - SOI-62.2
- h. Emergency Core Cooling System 'S01-63.1
- 1. Containment Vent and Cooling System - S0I-30.2,
. 20.3, 30.4 u j. Auxiliary Building Heating and Vent System and Auxiliary Building Gas Treatment System - SOI-30.5 and 30.6
- k. Emergency Gas Treatment System - S0I-65.1
- 1. Control Building and Control Room Heating, m Ventilating, and Air Conditioning System - S01-30.1 i
- m. ERCW System - SOI-67.1
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- n. Component Cooling Water System - S01-70.1 ,
- o. Water Disposal System - S01-77.1, 77.2, 77.4 '
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A01-21.7 Page 7 Revision 7 .. IV. SUBSEQUENT OPERATOR ACTION (continued)
- p. Ice Condenser System - S0I-61.1
- q. Steam Generator Blowdown System - S01-15
- r. Reactor Protection System - S0I-99.1 f 0. In the event of'a change in rated thermal power level exceeding l 15% in one hour, notif" the Chem Lab to initiate the conditional.
portions of SI-407.2 e SI-415 due to the thermal power change. V. REFERENCES
.. A. Technical Specifications 3.8.2.3 B. FSAR 8.3.2 C. Electrical Prints: 45N703-3 ~
45N703-7 45N724-1 I- 45N749-1 45N749-2 45N765-3, 4 45N767-5
-f 45N779-6 45N600 thru 45N699 VI. DISCUSSION s This instruction covers the loss of 125V de vital battery board III - [~
voltage. This instruction assumes that Unit No. 2 is at power operation at the time of the event. The other~thr.ee vital battery boards remain in normal operation throughout the duration of the ! event. The unit can be placed in and maintained in a safe shutdown
-{- condition. Each 125V de circuit is protected by a fuse or breaker to clear a fault. The'125V de board is also divided into branch buses l which are supplied with fuses or breakers to provide redundant L -
protection for a fault and prevent a loss of the board due to a fault in one circuit. In any situation involving loss of a part of, or a whole 125V dc bus, actions should be taken to determine the cause and I- extent of the loss and restore as much of the bus to normal as soon as possible. " "- - r In general, 125V de battery board III supplies control power for unit L_ _No. 2 train A equipment and solenoid valves. 125V bus III can be energized by 125V dc battery III, from 125V de vital battery charger III, from 125V dc vital battery charger 2-S, or from 5th vital battery. 0157B/peb __m_ _ _ _ . _ _ ___._}}