ML20237H298
| ML20237H298 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 05/14/1987 |
| From: | Epperson J, Jacqwan Walker TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML20237H133 | List:
|
| References | |
| AOI-21.2, NUDOCS 8708170137 | |
| Download: ML20237H298 (10) | |
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TENNESSEE VALLEY AUTHORITY
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...-i SEQUOYAH NUCLEAR PLANT 7-ABNORMAL OPERATING INSTRUCTION F
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AOI-21.2
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LOSS OF 125V DC VITAL BATTERY BOARD II t
Unit 1 Revision 11 PREPARED BY.:
J. R. Walker 31.
RESPONSIBLE SECTION:
Operations REVISED BY:
mJeffEpperson[
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SUBMITTED BY:
Respo6sible Section-Supervisor PORC REVIEW DATE:
MAY 141987
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APPROVED BY:
Plant Manager MAY T41987 DATE APPROVED:
Reason for revision (include all Instruction Change Form Nos.):
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Revised to correct annunciations, delete PD charging pump reference, and to reduce immediate-actions.
The last page of this instruction is number:
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SEQUOYAH NUCLEAR PLANT
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PLANT INSTRUCTION REVISION LOG ABNORMAL OPERATING INSTRUCTION AOI-21.2 m
REVISION Date Pages REASON FOR REVISION (INCLUDE COMMIT-j' LEVEL Approved Affected MENTS AND ALL ICF FORM NUMBERS)
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04/22/76 All
..s, 1
05/16/77 2-4,7
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2 10/03/78 3,7 3
09/25/79 All 4
06/16/80 7
5 08/26/80 All 6
12/19/80 2
7 07/21/83 All 8
07/31/84 4
9 07/31/84 2,6,7 Revised to add Vital Battery V to plant 10 08/29/86 2,8 vital power sources.
Revised to correct. annunciations, delete MAY1 4 1007 P
harging pump reference, and to 11 All reduce immediate actions.
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'Page 1 of 7:
Rbvision 11' I.
SYMPTOMS
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7 J-A.
Possible Alarms
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-1.
125V DC VITAL CHARGER II FAILURE OR VITAL BATTERY II DISCHARGE.
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2.
125V DC. VITAL BATTERY BOARD II ABNORMAL.
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3.
6900V SHUTDOWN BOARD.IB-B FAILURE OR BUS / NORMAL FEEDER
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,UNDERVOLTAGE OR OVERVOLTAGE (on panel 1-M-1).
4.
6900V SHUTDOWN BOARD 1B-B FAILURE OR BUS / NORMAL FEEDER UNDER-VOLTAGE (0-M-26).
5.
480V SHUTDOWN BOARD IB1-B FAILURE OR UNDERVOLTAGE (1-M-1 and 0-M-26).
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6.
480VSHUTDOWNBOARD'IB2-BFAILUREORUNDERVOLTAGE(1-$-l'and 0-M-26).
7.
6900VSHUTDOWNBOARD2B-BFAILUREORUNDERiOLTAGEOROVERVOLTAGE (2-M-1).
8.
6900V SKUTPOWN BOARD 2B-B FAILURE OR-BUS / NORMAL FEEDER UNDERVOLTAGE (0-M-26).
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9.
480V SHUTDOWN BOARD 2B1-B FAILURE OR UNDERVOLTAGE (2-M-1 and
~0-M-26).
10.
480V SHUTDOWN BOARD 2B2-B FAILURE OR UNDERVOLTAGE (2-M-1 and 0-M-26).
11.
SERVICE AIR COMPRESSOR SEQUENCER UNDERVOLTAGE OR CO ALARM (1-M-15).
B.
Indications 1.
Voltmeter on 1-M-1 and 2-M-1 indicates failure on 125V de board II.
2.
Ammeter on 1-M-1 and 2-N-1 for board II battery shows zero.
3.
Breaker position indicating lights for equipment feeding from 6.9kV shutdown board IB-B and 480V shutdown boards 1B1-B and IB2-B will all be out.
'II. AUTOMATIC ACTIONS A.
Reactor trip - Turbine trip due to all four main feedwater regulating valves, all four MSIVs, and #1 and #3 S/G main feedwater reg. bypass valves failing closed resulting in loss of feedwater and low steam generator water level in coincidence with steam flow / feed flow (SF/FF) mismatch and/or low-low steam generator water level.
2.
1 SQN AOI-21.2 Page 2 of 7' Revision 11 II.
AUTOMATIC ACTIONS (Continued)
B.
Motor driven auxiliary feedwater pump 1A-A and turbine driven auxiliary feedwater pump starts on low-low steam generator water le7el.
NOTE:
IB-B auxiliary feedwater pump will NOT start.
C.
Steam dump valves and steam generator blowdown valves fail closed.
D.
Letdown line isolation valve FCV-62-77 fails closed resulting in loss of"~
t E.
All four diesel generators start but do not tie onto the shutdown boards.
F.
All control and service air compressors will unload, resulting in decreasing control air pressure (VBB II supplies normal power to the compressors' sequencer).
III. IMMEDIATE OPERATOR ACTION
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A.
Refer to emergency instructions.
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IV.
SUBSEQUENT OPERATOR ACTION Dispatch personnel to diagnose problem and a'ttempt to restore power to A.
125V de vital battery board from:
1.
125V de Battery II or 2.
125V de Vital Battery Charger II or 3.
125V de Vital Battery Charger 1-S 4.
Spare Vital Battery II with Battery V per S0I-250.5.
B.
Initiate REP per IP-1 (Engineered Safety Features) as required.
C.
Maintain the reactor in hot standby.
L 1.
Motor driven auxiliary feedwater pump 1A-A will supply feedwater to steam generators 1 and 2 and turbine driven pump 1A-S will supply all four steam generators.
Steam generator level should control automatically at equal to or approximately 33 percent.
l NOTE: Motor driven auxiliary feedwater pump 1B-B will not start.
)
2.
All four steam generator atmospheric relief valves may be used for RCS heat removal (modulating control only on steam generators 2 and 4).
Steam generator relief valves can be adjusted to control RCS temp-erature at equal to or approximately 547 F.
NOTE:
Steam dump valves, main steam isolation valves, and all main feedwater regulating valves to all four steam generators failed closed.
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SQN A0I-21.2 Page 3 of 7' Revision 11 IV.
SUBSEQUENT OPERATOR ACTION (Continued)
C.
(Continued)
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3.
Dispatch personnel to air compressors and transfer 125V dc to alternate power supply from vital battery beard IV.
4.
Place steam dump mode selector switch in pressure mode.
5.
Isolate charging flow by closing FCV-62-90 or FCV-62-91.
Verify or~ ~
adjust reactor coolant pump seal water flow in operating band.
r (FCV-62-90 or 91 may be used for PZR level control as needed.)
1A-A centrifugal charging pump may be started to establish seal injection.
6.
Reactor coolant pumps can be stopped to reduce the heat removal requirements; however, reactor coolant pump No. 2 should be left on to supply pressurizer spray.
D.
Verify pressurizer' pressure normal an'd level increasing slowly.
NOTE: Excess letdown is not available since FCVs 62-54 and 55 fail closed on loss of battery board II.
Also normal letdown is not available as FCV-62-77 is failed closed.
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NOTE:
If high pressure - both pressurizer spray valves are operable and pressurizer relief valve PCV-68-340A is operable; however, pres-surizer relief tank spray and RCDT pump discharge is isolated.
If low pressure pressurizer heaters control group ID and backup group 1A-A are operable.
NOTE:
See Appendix A for equipment not available.
E.
Transfer the following 125V de buses to alternate feed.
l CAUTION:
While transferring the 125V de bus to alternate or back l
to normal, have someone hold the B.O. reset button pushed in, located in panel 4 of 6.9kV logic panel IB-B.
This will prevent the B.O. relays from going to B.O. condition, which would sequence the CCP, AFWP, ERCW, CCSP, PZR heaters and fire pumps if auto start signal is present.
NOTE:
After de is restored to this bus, auxiliary feedwater pump 1B-B can be used to supply water to steam generators 3 and 4.
Xfer to Alt Ret rn Normal 1.
6.9kV shutdown board IB-B normal bus.
2.
480V shutdcwn board IB1-B normal bus.
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SQN A0I-21.2 Page 4 of 7 Eevision 11 IV.
SUBSEQUENT OPERATOR ACTION (Continued)
E.
(Continued)
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CAUTION: Control and service air compressor B will trip when de is restored to this bus. Must be reset locally.
3.
480V shutdown board IB2-B normal bus.
F.
Trip auxiliary building generator supply and exhaust fans 1A and IB and luef'"-
handling area exhaust fans A and B.
Place auxiliary building gas treatment l'
system train A in service.
G.
Trip containment aasulus vacuum fans and place EGTS train AI in service -
for Unit 1.
1.
Open EGTS train A suction valve FCV-65-10.
2.
Open EGTS r. rain A discharge valve FCV-65-26.
! 3.
Open EGTS train A PC0 isolation valv'es FCV-65-81 and PCV-65-86
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(HS-65-81 on M-27B).
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4.
Start EGTS fan A-A (HS-65-23A on M-27B).
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H.
Stop containment instrument room cooler that is operating.
I.
If containment purge was in progress, stop containment purge air supply and exhaust fans.
J.
Depending upon the amount of time required for restoring 125V de bus voltage, the diesel generators can be left running or diesel generators 1 A-A, 2A-A, and 2B-B can be stopped by the following procedure:
CAUTION: Do not allow diesel generator to run unloaded for greater than 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.
CAUTION: Coordinate this work with Unit 2 operator.
1.
Place 43T(L) switch (located on diesel generator logic panel IB-B) in TEST position and leave it in TEST.
2.
Place all 43T(L) switches (located on diesel generator logic panels 1A-A, 2A-A, and 2B-B) simultaneously to TEST position and then return them to NORMAL.
3.
Reset the emergency start lockout relays for diesel generators IA-A, 2A-A, and 2B-B (located on each respective diesel generator relay panel in diesel generator building).
4.
Stop diesel generators IA-A, 2A-A, and 2B-B from 0-M-26 panel by placing HS-82-14, HS-82-74, and HS-82-104 in STOP position.
5.
Diesel generator IB-B should be left running.
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SQN.
A0I-21.2 Page 5 of 7-Rovision 11 a.-
IV.
SUBSEQUENT OPERATOR ACTION (continued)
K.
1.
If power cannot be restored to the 125V de vital board, proceed to cold shutdown per GOI-3B.
NOTE:
The following equipment called for in GOI-3B will not be available due to the loss of the 125V de board.
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Steam Dumps to Condenser
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2.
Main Feedwater
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4.
RCS Hot Leg Sample Lines
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5.
RHR Cooler Outlet Sample Lines' 6.
The following pumps will be unavailable until their breaker control power is transferred.
a.
IB-B charging pump b.
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c.
IB-B Aux FWP
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S/G Sample Lines 2.
If power has been restored proceed to step L of this procedure.
L.
Pressurizer level will slowly increase due to reactor coolant pump seal water l-supplied to the RCS; it may take as little as two hours (assuming 40 gpm I
total seal water flow) to fill the pressurizer.
If pressurizer level reaches 92%, trip the reactor coolant pumps and stop charging pump.
M.
Verify boron injection temperature equal to or greater than 145 F by TI-63-37 on panel M-6.
NOTE:
Boric acid recirculation valves through BIT have failed closed.
N.
Depending upon the cause of the failure, or after repairs, voltage can be
^ l restored to the bus by placing the normal charger or 1-S spare charger in
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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.
NOTE:
If board cannot be restored within two hours or less, refer to Technical Specification 3.8.2.3.
After normal voltage is restored to the bus:
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1.
Transfer the de buses back to normal that were changed in step IV.E of this procedure. Observe the same precautions (check off when
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normal).
1 2.
Place 43T(L) switch (located on diesel generator logic panel IB-B) to NORMAL position.
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Page 6 of 7'
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Revision 11 IV.
SUBSEQUENT OPERATOR ACTION (Continued)
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(Continued)
I 3.
Reset the emergency start lockout relay for diesel IB-B; then stop diesel generator IB-B.
r 4.
Transfer 125V de to normal suurce on control and station air compressor f
panel.
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5.
Return the following systems to normal lineup and operation by their c
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respective SOI.
a.
b.
Reactor Coolant System - S01-68.1, 68.2, 68.3 c.
Auxiliary Feedwater System - S0I-3.2 d.
Main Steam System - S01-1 1..
e.
Steam Dump System S01-1.2 f.
Diesel Generators - SOI-82.1, 2, 3, 4
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g.
Boron Concentration Control - S0I-62.2 h.
Emergency Core Cooling System - S0I-63.1 i.
Containment Vent and Cooling Systems - S01-30.2, 30.3, and 30.4 j.
Emergency Gas Treatment System - SOI-65.1 k.
Auxiliary Building Heating and Ventilating System and Auxiliary Building Gas Treatment System - S0I-30.5 and
- 30. 6..
1.
Control Building and Control Room Heating, Ventilation, and Air Conditioning System - SOI-30.1 m.
Component Cooling Water System - SOI-70.1 o.
Waste Disposal System - S0I-77.1, 77.2, and 77.4 p.
Ice Condenser System - SOI-61.1 q.
Steam Generator Blowdown System - S0I-15 r.
Reactor Protection System - S01-99.1 b I
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AOI-21.2 Page 7 of 7'
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Eevision 11 IV.
SUBSEQUENT OPERATOR ACTION (Continued)
P.
In the event of a change in rated thermal power level exceeding 15% in one hour, notify the Chem Lab to initiate the conditional portions of SI-407.2 and'SI-415 due to the thermal power change.
V. REFERENCES f
A.
Technical Specification 3.8.2 3 e
B.
FSAR 8.3.2 L
C.
Electrical Prints: '45N703-2 45N703-6
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45N724-2 45N749-3 45N749-4 45N765-3,4
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45N767-5 45N779-6 45N600 thru 45N699 VI. DISCUSSION This instruction covers the loss of 125V de vital' battery board II voltage.
This instruction is for. Unit 1 operation only and assumes that Unit 1 is at. power operation at the time of the event. The other three vital battery boards remain in normal operation throughout the duration of this 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 which are supplied with fuses or. breakers to provide redundant 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 de bus, actions should be taken to determine the cause and extent of the loss and restore as much of the bus to normal as soon as possible.
In general, 125V de vital battery board II supplies control power for unit a train B equipment and solenoid valves.
125V bus II can be energized by 125V de battery II, from 125V de vital battery charger II, from 125V de vital battery charger 1-S, or from 5th vital battery.
The loss of control power causes the breakers on the affected boards to fail "as is."
As a result it will be necessary to use auxiliary control power if breaker
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operation is needed.
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Appendix A Page 1 of 1 Revision 11
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The following equipment will be unavailable until power is restored:
1.
Main Feedwater Regulating Valves 2.
Main Feedwater Regulating Bypass Valves for #1 and #3 S/Gs i
3.
All Twelve Steam Dump Valves to the Condenser (FCV-1-103 thru FCV-1-114) 4.
Automatic Mode of #2 and #4 S/Gs PORV (Modulating Mode not Affected) r 5.
All Four S/G Blowdown Isolation Valves 6.
Main Steam Isolation Valves 7.
Auxiliary Building Exhaust Fans 1A and IB 8.
Fuel Handling Exhaust Fans IA and IB 9.
Upper and Lower Rx Building Purge Fans 10.
Incore Instrument Room Cooler Isolation Valves 11.
RCS Hotleg Loops 1-4 Sample Valves 12.
1,2,3 and 4 Accum. Tank Sample Valves 13.
1,2,3 and 4 S/G Blowdown Sample Valves 14.
MDI Cooler Outlet Sample Valves (Both Coolers) 15.
PZR Liquid and Gas Space Sample Valve 16.
Main Feed Water Pumps 17.
CVCS Normal and Excess Letdown 18.
Boric Acid Transfer Pump to BIT (FCV-63-38) 19.
B Train EGTS 20.
Pressure Relief Tank Vent Isolation 21.
PZR PORV (PCV-68-334) 22.
Rx Building Sump Pumps A and B to Tritiated Drain' Tank 23.
RCDT to Tritiated Drain Tank 24.
RE-90-112 and RE-90-106 25.
IB-B Diesel Generator 26.
CRDM Control p
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B 3
4 3
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