ML20237H480

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Rev 4 to Abnormal Operating Instruction AOI-25.5, Loss of 120-Volt AC Vital Instrument Power Board 2-I
ML20237H480
Person / Time
Site: Sequoyah  Tennessee Valley Authority icon.png
Issue date: 06/08/1987
From: Eaves H, Epperson J
TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML20237H133 List: ... further results
References
AOI-25.5, NUDOCS 8708170231
Download: ML20237H480 (6)
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a TENNESSEE VAL'_EY AUTHORITY SEQUOYAH NUCLEAR PLANT

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ABNORMAL OPERATING INSTRUCTION I A0I-25.5 i

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LOSS OF 120V AC VITAL INSTRUMENT POWER BOARD 2-1 Unit 2 ,

i Revision 4 I

PREPARED BY: Herb Eaves RESPONSIBLE SECTION: Operations -

REVISED BY: Jeff Epperson SUBMITTED BY: ,

[] y 4 f Responsible Section Supervisor PORC REVIEW DATE: JUN 0 B 1987 APPROVED BY: M2 Plant Manager DATE APPROVED: 3 Il b IU87 Reason for revision (include all Instruction Change Form Nos.):

Revised to constitute a biennial review in accordance with AI-4, Appendix H. Streamline operator actions - delete ,

I erroneous appendices "A" and "B" u

The last page of this instruction is number: 4 0023H/ SAT /sdh

- 8700170231B7[PDR$27 PDR P

ADOCK 1 -

SEQUOYAH N'JCLEAR PLANT PLANT INSTRUCTION REVISION LOG

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, ABNORMAL OPERATING INSTRUCTION AOI-25.5 REVISION Date  ! .Pages l- LEVEL REASON FOR REVISION (INCLUDE COMMIT-Approved Affected MENTS AND ALL ICF FORM NUMBERS)

O 08/04/81 d11

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1 09/12/83 All 2 07/31/84 1 3 10/04/84 2

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Revised to constitute a biennial review in accordance with AI-4, Appendix H.

'JUN 3 8 1987 Streamiine operator actions - delete 4 All erroneous appendices "A" and "B". -

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! SQN A01-25.5 Page 1-2 Revision 4 I. SYMPTOMS A. Alarms

1. 120V AC VITAL INVERTER 2-1 ABNORMAL
2. 120V AC VITAL PWR BD 2-1 UV OR BREAKER TRIP 1"

B. Indications

1. Power Range N-41 failure

~I- 2. Auto and manual rod block and rod stop due to high flux- .

rod stop and C-5 interlock.

3. . Loss of Steam flow portion of signal to feedwater control system resulting in failure to control steam generator level if channel.1 is selected. l
4. Loss or decrease of feedwater flow to all steam generators.
5. Possible reactor trip due to steam generator low-low level.
6. Main feedwater pumps go to minimum speed due to loss of input signal (PT-1-33) to speed controller.
7. Malfunction of trip status lights and safeguards systems i annunciators.

C. System Partial Failures

1. Reduction of feedwater flow due to demand signal from steam generator 1 failing low.
2. Loss of power to solid state protection system input relays ,

I (Trains A and B) for Channel I.

3. If pressurizer level is selected to channel LT-68-339 for j control, pressurizer low level auto actions will occur.
4. If pressurizer pressure.is selected to channel PT-68-340, the sprays will be closed and the backup heaters energized

- until locked out by the low level signal if LT-68-339 was selected for level control.

, i, 5. Loss of condenser steam dump capability.

1 0152H/ SAT /sdh

SON-AOI-25.5 Page-2 Revision 4 I. SYMPTOMS (continued) l C. System Partial Failures (continued) - -

6. Loss of steam generator power operated relief valves PIC-1-13A and PIC-.1-24A if in normal mode.

NOTE: The above failures are of greatest immediate

_ consequences. For a complete loads list of Vital Board 2-I refer to Appendix A.

II. AUTOMATIC ACTIONS A. Possible reactor trip due to low-low S/G 1evel. ,

III. IMMEDIATE OPERATOR ACTIONS A. None IV. SUBSEQUENT OPERATOR ACTIONS A. If reactor trip occurs then refer to emergency instructions.

I B. Dispatch operator to turbine driven AFW pump 2A-S to transfer turbine controller to auxiliary control (located on west wall of room, outside near local control cabinet).

C. If reactor does not trip, then, at the NIS panel, defeat the PR rod stop.

D. Assume and maintain manual rod control (TREF signal is lost).

NOTE: Do not use bank select; use of bank select will cause the bank overlap program to be lost.

E. Dispatch operator to restore power to failed board (transfer to auxiliary power supply).

F. Assume manual control of main feedwater pumps speed to adjust feedwater pressure.

G. Assume manual control of steam generator water level on the affected steam generators.

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SQN A01-25.5 f Page 3 l >

Revision 4 IV. SUBSEQUENT OPERATOR ACTIONS (continued)

H.

Verify pressurizer level and. pressure'are not selected to LT-68-339 and PT-68-340, respectively.

1.. Transfer FCV-62-89 to auxiliary control room.

NOTE: Verify charging line flow controller functioning to restore program level.

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If' power is restored to the failed board return systems to normal operating mode.

J. EvaluateneedtoshutdownperTS3.8.2.1ifpowercannotbe -

restored to the affected board. If necessary, commence orderly shutdown to the hot standby condition per G01-5 and G01-3.

Initiate REP per IP-1 (Engineered Safety Features) as required.

1. Steam Generator power operated relief valves are operable for cooldown using handswitch.

NOTE: Operation in this mode may be continued at the --

discretion of the Manager, operations group, with respect to Tech Spec. Section 3.

2. If shutdown is to continue to mode 5, follow G01-3 with the following exception: FCV-74-1 will require placing transfer switch to aux, position at breaker to open valve when RCS pressure is below 380 psig. Refer to TS 3.8.2.2.
3. Transfer FCV-74-16 and 32 to aux, mode and control RHR cooldown temperature from aux. control room.

V. REFERENCES A. TS 3.8.2.1, 3.8.2.2 B. S01-55 series C. 45N706-1 t

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SQN A01-25.5 Page 4 Revision 4 APPENDIX A . .

Page 1 of 1 j Load List: 120V AC Vital Inst. Power Bd. 2-I .

SSPS (A) CH I input relays (2-R-46)

SSPS (B) CH I input relays (2-R-49)

NIS instr. power CH I NIS control-power CH I Process' protection set I (2-R-1)

UHI accumulator CH I isol. valve FCV-87-21 RCP 1 UV and UF relays AFWP turbine flow controller (normal) FIC-46-57 -

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TDAFWP S/Gs 3 and 4 LIC-3-172, 175 T0AFWP S/Gs 3'and 4 instr. loop I Reactor vessel level instrumentation system (2-R-148)

Incore temp. monitoring system

.g Instr. bus 1 and.PIC-1-6A, 31A l Plugmold instr. bus 1 (2-M-5)

Plugmold instr. bus 1 (2-M-6)

Process control group 1 (2-R-14)

BOP process instr. control rack (2-R-126) _

l- Aux. control panel A instr. bus BOP process instr. control rack (2-R-128)

AB instr. A bus

' I' Aux. relay rack, A bus (2-R-76)

Aux. relay rack, C bus (2-R-76)

NSSS aux relay rack, A bus (2-R-58)

Aux. control panel, A relay bus Aux. relay rack, A bus (2-R-75)

SSPS control room demod.

Aux. control panel, A instr. bus Aux. relay rack, A bus (2-R-72)

Post accident monitoring 1 .

LOCA Hp cntmt flow monitor XI-43-200 UHI instr bus 1

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