ML20034C783
| ML20034C783 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 04/19/1990 |
| From: | PUBLIC SERVICE CO. OF COLORADO |
| To: | |
| Shared Package | |
| ML20034C092 | List: |
| References | |
| AOP-N, NUDOCS 9005100049 | |
| Download: ML20034C783 (8) | |
Text
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AOP-N 1ssue 56
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Pub llC FORT ST. VRAIN NUCLEAR CENERATIN3 STATION Page 1 of 2
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' PUsuc sanwcs consPAmy or colorado TITLE:
LOSS OF AN INSTRUMENT BUS
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4 RESPONSIBLE fl k f NDuljW FOR= r n-h AUTHO Q l
BY d u. (J u EEiEw PORC 8 7 7 APR 111990 ll.,E,CTIVE DCCF NUMBER (S) hD-Q1h 6 i
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FT. ST. VRAIN j
NON-CONTROLLED COPY VERIFY ISSUE STATUS J
WITH SITE DOCUMENT
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CONTROL CENTER PRIOR TO USE ~
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AOP-N I
.lssue 56 Page 2 of 2 (N)
LOSS OF AN INSTRUMENT BUS SYMPTOM-ACTION MATRin l
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p 1
i SYMPTOMS I
8 j
8 l
I 1.1 1
1.2 8
1.3 I
I I
18nstrument Bus **nstrument Bus linstrument Bus t t
t ACTIONS IUndervoltage IUnde rvol tage IUndervoltage f
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I INon-interrupt. I Non-Inte r rtept. I lnterrteptable I l
8 I
Bus i l'
Bus 2 I
Bus 3 f
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l-06G, 2-1 1
3-06G, 2-1.
I I-06G, 2-1 I
t I
8 (El-92217) 8 (El-92218)
I (08-92219)
I 1
I i
f f
I l
l i
I I
i 8
i OPERATOR ACTIONS I
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i 2.1 ^~
E I
5 8
1 Termenate Derueling I XX i XX 1 XX i
l t activities.
1 I
I I
l f
8 I
i i
i 2.2 I
I I
I I Dispatch Operator to I
XX i XX 8 XX l I restore power to failed I
i i
I bus i
I I
I i
I I
I I
I 2.3 I
I I
I I Refer to TABLE N.4, 1
I
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1 " Effects of Loss or I XX XX i XX XX 1 XX XX 1 I instrument Bus" for i
8 8
I I effects or loss of a 1
i i
i i particular but i
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l AOP APP N Issue 56 Public FORT ST. VRAIN NUCLEAR GENERATING STATION service
- PusuC saRWCa COMPANY OF COLORADO O
INTRODUCTION Four separate 120 Volt AC Instrument Buses supply power for the Plant Protective System (PPS) and various control systems.
Non-Interruptible Buses 1 and 2 are energized from the 125 Volt DC buses via power inverters (DC-AC). Loss of the DC bus or failure of the inverter will cause an automatic no-break switch to transfer to a dedicated instrument power transformer for backup power. The transformers are energized from 480 Volt Bus 1 for Instrument Bus 1 and 480 Volt Bus 3 for Instrument Bus 2.
Non-Interruptible Bus 3 is supplied from a dedicated set of batteries via a power inverter.
These batteries are kept charged by. a battery charger fed from 480 Volt Bus 2.
Failure of the inverter or loss of DC power will cause an automatic no-break switch to a dedicated instrument power transformer fed from 480 Volt Bus 1.
Interruptible Bus 3 is fed normally from 480 Volt Bus 3.
Failure of this source will cause an automatic switch to another transformer from 480 Volt Bus 1.
DISCUSSION OF SYMPTOMS SYMPTOMS I
1.1 Instrument Bus Undervoltage Non-Interrupt. Bus 1.
I-06G 2-1 (El 92217)
O-1.2 Instrument Bus Undervoltage Non-Interrupt. Bus 2.
1-06G, 2-1 (El 92218) l 1.3 Instrument Bus Undervoltage Interrupt. Bus 3, I-06G, 2-1 (El 92219)
These alarms indicate that an undervoltage condition exists at any one of the four A.C. instrument busses. A visual check of the four voltmeters located on I-06 will provide immediate identification of the effected bus.
DISCUSSION OF OPERATOR ACTION OPERATOR ACTION l
l 2.1 Terminate Defueling Activities.
I If power supply to non-interrupt. Bus 1 or Bus 2 is lost, l
a single channel scram will lock in due to hinderance i
logic of startup channels 1 and 2.
Loss of Interrupf..
l Bus 3 will result in loss of ability to move control rods.
O FOHMion372 22 3643
AO' APP N j
P
.l',
Issue 56--
0" A Public.
FORT ST. VRAIN NUCLEAR GENERATING STATION W Service
- pusuc sanwes couramy or cotonAno j.
2.2 Dispatch operator to restore power to failed bus.
NON-INTERRUPTIBLE BUS 1 8
If power has been lost. to the non-interrt.ptible bus, the static transfer to the dedicated backup transformer has
. failed. The operator.should verify operability of the transformr. and switch the manual bypass switch to the alternate power source. Refer.to SOP 92-05 for transferring instructions.
- 1 NON-INTERRUPTIBLE BUS 2 If powtr has been lost to the non-interruptible bus, the static transfer to the dedicated backup transformer has failed. -The operator should verify operability of the transformer and switch the manual bypass switch to the alternate power source. Refer to S0P 92-05 for transferring instructions.
l INTERRUPTIBLE BUS 3
. I
. 1.
If normal power supply to Interruptible Bus 3 has been lost, an automatic transfer.to a backup power-supply.should take place. Dispatch an Operator to confirm this action locally.
2.
If the transfer does not take place-~ automatically due to any reason, the Operator will need to perform a manual. transfer by depressing the TEST pushbutton and moving the " RETURN SELECT" to " MAN".
Also, while maintaining the TEST' pushbutton
, l depressed, move the manual bypass switch to the j
"BYP-PREF" position. The TEST switch may. cow be i
released.
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AOP APP N-1 Issue 56 Page 3 of 6 A Public FORT ST. VRAIN NUCLEAR GENERATING STATION
'.1 1 -
%F Servico*
Pusuc senvece couramy or cotonaoo l
2,3-Refer to table N.4 " Effects of 1.oss of Instrument Bus" for
,eyectsoflossofapart_icularbus.
The effects of a loss c.f particular instrument bus on critical plant equipment is listed.in Table N.4.
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AOP-N' Issue 56 Public FORT ST. VRAIN NUCLEAR GENERATING STATION SerVICO' PUBUC SERVICE COMPANY OF COLORADO,
.O TABLE N.4 EFFECTS OF LOSS OF INSTRUMENT BUS B
1 tFFECT OF I
EFFECT OF l
EFFECT OF l
EFFECT OF l
LOSS OF NON.1 LOSS OF NON-l LOSS OF l
LOSS OF NON-
-FUNCTION 1 INTERRUPTIBLE l INTERRUPTIBLE l INTERRUPTIBLE I INTERRUPTIBLE l
INSTRUMENT l INSTRUMENT l INSTRUMENT i
-7NSTRUMENT l
BUS 1 l
BUS 2-l BUS 3 l
BUS 3 I
l l
I CIRCUL-l LOOP 1 l
LOOP 2 i LOOP 1 & LOOP 21 NO EFFECT<
ATOR IBuffer He suplyl Buffer He Suplyl NO EFFECT l
AUXIL-Ifail open, buf-ifail open, buf-l l
IARIES Ifer He return Ifer He return-l l
lFC, thus cire. IFC, thus cire. I l
ltrips on high Itrips on high I l
l buffer /mid-lbuffer/mid-l l
lbuffer delta P.lbuffer delta P.l l
l 1
l I
l.
LOOP 2, I
LOOP 1, l
l g
i NO EFFECT l
NO EFFECT l l
W l
l 1
I l Bearing water l Bearing water l
i isupply & returntsupply & return l Flow control l Flow control lvalve on brng Ivalve on brng l l
l water F0, drain l water F0, drain l-l-
l controls all icontrols all l
l
] pneumatic, no [ pneumatic,no I l
Ifailure.
Ifailure.
l l
1 l
l l
L I
I I
I CIRCUL-l LOOP 1 l
LOOP 2 l
NO EFFECT
'l_-
-NO EFFECT i
ATOR l Controls FAI l Controls FAI l
l 4
SPEED lshutdown by bufl shutdown by bufl
.l CONTROL lfer as above.
lfer as above.
l l
1 I
i l
l l
LOOP 2 l
LOOP 1 l
l lNo effect on.
lNo effect on l
l Iwater turbine l water turbine i I
i l drives.
l drives.
l l
___I i
l 1
I I
NOTE: Abbreviations - FC = Fail Closed
~ ~ ~
F0 = Fail Open-FA = Fail "as is"
{
SD = Shutdown f
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W lL AOP'-N
~
Issue 56?
'i age 5 of E,
Public FORT ST 'VRAIN NUCLEAR GENERATING STATION SerVICO'
'Pusuc 'ssavecs comPAmy.or'coLonApo-p
.(
i TABLE N.4 j
EFFECTS OF LOSS OF INSTRUMENT BUS
'l
)
~
l EFFECT OF l=
EFFECT OF l
EFFECT OF
-l EFFECT OF l
LOSS OF NON--l -LOSS OF NON-I
. LOSS OF.
l LOSS OF.NON.
1 FUNCTION-l INTERRUPTIBLE 1 INTERRUPTIBLE.1 INTERRUPTIBLE-1 INTERRUPTIBLE C
I INSTRUMENT 1:
INSTRUMENT ~l INSTRUMENT ~
l INSTRUMENT I
BUS I I
. BUS 2 l
BUS 3 1
BUS 3 l
I I
.I i
l- -
I l-I
.PPS ILose trip capa-flose trip capa-l-N0'EFFECT-l Single channel SYSTEM lbility from 'A'Ibility from 'B'l
_l trips.and sin-11ogic. Single l logic. Single-l Jgle channel Ichannel scram. l channel scram l lscram.
I I
l l
I I
l l
l CIRCUL-l Loss of cire.
l Loss of cire.
lResults in 1 ATOR TRIPltrip & Loop SD.l trip &-Loop SD l l single channel-l & LOOP jfrom "A" Logic lfrom "B" Logic l l trips, l SD CAPA-l capability Icapability I
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O' l BILITIES l l
l l
I i
1 l
1 l
lShould not re-lShould not re-l l
f isult in trip orlsult in trip orl-1 lloss of trip l loss of trip l1
-l leapability.
Icapability.
l_
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l l
l l
CONTROL l Lose digital l Lose analog posilose capability l NO EFFECT ROD l position indic-lition indicate lof moving CRD's l L
DRIVES lation.
l lwith hand
[
]
l l
lswitches or fluxl l
l l
l controller.
l l
I I
I I
'n l-l l
l AUX.
l Lose PCV 5201 ILose all boiler l NO EFFECT l
a BOILER l control (FO) l controls.
l l
i.
l(Can control l
l l
l manually).
l l
l l
l 1
l'
'l 1.
}
l
(
NOTE: Abbreviations - FC = Fail Closed F0 = Fail Open FA = c ll "as is" a
[L-SD = Shutdown 1
l FORM (D)372 22 3643
^'
o-1:
AOP-N Issue 56 1
Public' FORT ST. VRAIN NUCLEAR GENERATING STATION "9' SerVIC9'
- PUBUC SERVICE COMPANY OF COLORADO TABLE N.4 i+'~
. EFFECTS OF LOSS OF INSTRUMENT BUS j
l EFFECT OF l
.EFFECT OF l, EFFECT OF l
EFFECT OF1 l
LOSS-0F NON-l LOSS OF NON-l LOSS OF l
LOSS'0F NON-FUNCTION l INTERRUPTIBLE 1: INTERRUPTIBLE l.INTERRUPTIBLE l INTERRUPTIBLE I
INSTRUMENT l INSTRUMENT l INSTRUMENT l
INSTRUMENT l
BUS 1 l
BUS 2 l
BUS 3 i
BUS 3 I
l l~
l l
I l
l 1
i ALARMS.lAll switched IA11 sw Mched
.lA11 switched-l NO EFFECT lalarms function l alarms function l alarms function l lnormally. All lnormally. All-Inormally. All l
l tcularms: fed laccularms fed Iaccularms fed l
1 Irrom Bus 1 faillfrom Bus 2 faillfrom Bus 3 fail l 1(no alarm).
l(noalarm).
l(no alarm).
l l
_1 I
I l
I I
I
.i REACTOR l Lose Fan 11
' Lose Fan 1B, IC]
NO EFFECTS l
NO EFFECT
- BLOG, l controls.
.:ontrols.
l l
G EXHAUST l l
l l
FANS l
l l
l I
I I
l I
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I COMMUNI-l Loss of tele-l Loss of public l NO EFFECT l
NO EFFECT.
CATIONS [ phone system l address system l-l l(no' bell).
l l
l 1
1 I
l NOTE: Abbreviations - FC = Fail Closed F0 = Fail 0 pen j
FA = Fail "as is" SD = Shutdown FORM (01372 22 3643 4..
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