FAILURE MODES ANALYSIS - nrc.gov · Summaryx Effect Upon Control System Summarya Effect Upon Plant Performance 1. Reactor feed pump turbine Ac I a. Trip circuit-Level 8 I trip contacts

Report No. 02-0160-1102Revision 0

APPENDIX E

FAILURE MODES AND EFFECTS ANALYSIS

8310i8050i 83i014PDR ADQCK 050D0387 fP PDR )3 7

0

Report No. 02.-0160-1102Revision 0

GUIDE FOR USING THE

FAILU'RE MODES AND EFFECTS ANALYSIS (FMEA)

1. The FMEA's contained herein are segregated by commonpower supply or sensor. Each system that 'is affected bythis commonality is then analyzed individually todetermine the appropriate failure information.The two "Effects" columns on the FMEA's provide a summaryof the results of the combined failure of all thecomponents noted in the "Components" column.

Pacilitya Susquehanna Steam Electric StationDocket'0-387, 50-388

PAILURE HODES AND EPPECTS ANALYSIS Sheet 1 of 3

ICommou Power Supply or Sensor:IIControl System

Affected'0615 125VDC

Reactor Peedwater Control S stem

CSIDc 0160 004-001

CDc 0160-004-011

Job No.Prepared byeDateaChecked byeApproved bye

r.wl~-i rl Rev 0DateaDate:

0160-004-671

Component Nameand Number

PailureHode

Symptoms and LocalEffects IncludingDependent Pailures

System InherentCompensating Provision

SummaryxEffect Upon

Control System

SummaryaEffect Upon

Plant Performance

1. Reactor feed pump turbine Ac Ia. Trip circuit - Level 8 I

trip contacts

De-ener-gized

Trip circuit is de-ener-gized

Level 8 trip signalcannot be processed

Trip circuits for feedpump turbines 8 and C arepowered by other DC posersupplies

Loss of ability to tripturbine A on I.evel 8 tripsignal

There is no affect onplant performance unlessLevel 8 trip conditionexists

Pacility: Susquehanna Steam Electric StationDocket'0-387, 50-388

PAILUBE IIODES AND EPPECTS ANALXSIS Shoot 3 of 3

ICommon Powor Supply or Sonsor:I

IControl System Affoctod:

10615 125 VDC

P ~R1 to d '1/d Co trolCSIDs 0160 004-001

CDa 0160-004-011

Job No.Prepared by:DatesChecked byaApproved bye

0160-004-671

Bov. oDatesDa to'c

Component Nameand Numbor

PailureNode

Symptoms and LocalEffects IncludingDopondont Failures

System InhorontCompensating Provision

Summary c

Effect UponControl System

SummarysEffoct Upon

Plant Performance

1. Trip and alarm switchosca. PSL«11981A1, Bl/Thrust

boaring waar detector andlow bearing oil pressure

b. PSL-10180A/Low hyd rau 1 icfluid pressure

c. PSL-11932A/Shaf t pumpdischarge low pressure

d. TSHH-10115AI-CI/Exhausthood high tomporaturagenerator-ond tr ip

o. LSH-10127A. -28A. -29A/Hoisturo separator re-haator drain tank 1A highwater level

Pail High

IPail High

IPail HighI

IIIIPai1 Low I

IPail Low

PSLX-11981 Al, Bl willnot energizes- Contacts remain un-

changed

~ PSLX-10180A will notenergizes- Contacts remain un-

changed

PSIX-11932A will notenergizes— Contacts remain un-

changed

'I'SSH-10119A1-Cl will notenergizes- Contacts remain un"

changed

I.SHX-1027A will notenergizes- Contacts remain un-

changod

Logic arrangomont (2/3)in EHC trip system pre-vents a single powersupply from interruptingthe EHC trip logic

If turbines are shutdown, back-up unit pro-tection available foranti-monitoring

Logic reduced to a 2/2logic arrangomant-bothremaining relays mustenergize to complete thetrip configuration

Loss of primary unitprotection on generator

~ Any genorator malfunc-tions cannot induce anEIIC trip by way of pri-mary unit protection

lLogic for unit protectionlinitiated EHC trip isreduced to 1/1 from 1/2

The loss of power doesnot causa an EHC trip.thus there is no impacton overall plant por-formanco

Facilitya Susquehanna Steam Electric StationDocketc 50-387, 50-388

PAILURE HODES AND EFFECTS ANALySIS Shoot 2 of 3

Common Po«er Supply or Sensors

Control SystemAffected'D615 125VDC

Recirculation Flow Control

CSIDc 0160 004-001

CDs 0160-004-011

Job No.Prepared byeDatesChecked byeApproved bye

0160-004-671

Rev. 0D t ~l/Datea ~


FailureNode .

Symptoms and LocalEffects IncludingDependent Failures


SummarycEffect Upon

Control System

Summary tEffeet .Upon

Plant Performance

1. Temperature switch:.TSll-14021A2

2. Peedwater system control ofreactor reci rculaticn systemrunback circuitry - recircu-lation flow loop A:a. Feed«ster low flow:

1. PSL-10604A12. FSL-10604813. PS I -10604C1

b.

Peed�«a

to r high le vs 1:l. LSHU-10317A22. LSUU-10317823. LSUII-10317C24. LSUll-10305A25. LSNN-10305826 ~ LSUII-10305C2

c. Condensate pump low dis-charge pressures1. PSL-10507A2. PSL-1050783. FSL-10507C4. FSL-10507D

Off

Off

Failure of the tempera-ture switch has no localeffects

Loss of bus voltage ispredominant

Loss of bus voltage.causes:

, - Low flow runback signaltransmitted to auxiliarycircuits A and 8

Circulating ~ater pumptrip signal transmitted Ito auxiliary circuitsA and 8

Oenerator field breakerfor loop A will open andtrip the H-0 set (re-circulation pump)

Scoop tube for loop AH-0 set will lock inposition at the instantthe bus voltage is lost

Redundant lube oil tem-perature indicators anda temperature switch-alarm combination provideadditional monitoring

No inherent compensatingprovision for loop A

Compensation of loop 8is limited to a flowreduction via recircula"tion pump 8

Loss of automatic com-pensation for high lubeoil temperature

Por recirculation loopA, the H-0 set must berestarted after the busis recovered

. Control of loop A is re"established after therestart procedure

For recirculation loop8, control may still beexercised over the re-circulation pump

. Operation of the recir-culation pump in loop 8must be governed by thecriteria for single loopoperation

Loss of recirculationflow is, caused by theloss of flow in loop A

A coro flux differencowill result from theflow imbalance

d. Circulating water pumptrip circuits1 ~ COIL 52XI-101US

- In loop A, speed controlcircuitry speed limiterNo. 2 is enabled

13. Loop A circuitsca. Under-voltage relayb. Lockoutc. Pump vibration resetd. Scoop tube power failure

lock and resete. Auxiliary circuitsf. Uenerator field breaker

Off Loop 8 controller ad-)usts the scoop tube toreduce H-0 set speed

FacilityaDockotc

Susquoimuna Steam Electric Station50-307, 50-3SB

PAIIURE HODES AND EFFECTS AHAIYSIS Sheot 3s of 3

Comaon Power Supply or Sensors

Control Systoa Affected:

1D615 125 VDC

p ~Rl to ~dT A Co It *1

CSID: 0160-004-001

CDx 0160-004-011

Job Ho e

Prepared byeDatesChecked by:Approved by>

0160-004-671

RovDate:Dates

Component IIamesnd Humbor

PailuroHodo

Symptoms and LocalEffects IncludingDopondont Failures

System InhorontCompensating Provision

Summary:Effect Upon

Control System

SumaarysEffect Upon

Plant Performance

2. Sequential trips I Ia. ZS-I Ol GOA2-F2, AS-PS/ I Fa i 1 Off I

Position switchos onlntorcopt and intormodistostop valves-servo valves

b. ZS-1014IA2-D2/Position . I Fail Offswitchos on aain stopvalve-servo valves

c. 52XT1-IR101/A-C circuit I Ps i 1 Offbreaker

All contacts aust closo tocomplete tho sequentialtrip

Pails to energize andopen contactsa- Causing an interruption

in tho gonorator so-quontial trip

d. 33Xl-10141/Positionswitch relay - main stopvs 1 vo

IFail Off I Coil fails to energizeand chango stato of con-tacts in tho anti-aotoringcircuit

Anti-motoring circuit inunit protection is alsoon 1D615. primary lock-out relays on unit pro-tection bus are disabled

Power directional relayfails to energize andcoaplete circuit thatcontains contacts fromsequential trip - there-fore, any adverse offoctsfrom the iapropor con-figuration of sequential Itrip contacts is elim-inated

3. Prlaary unit protectiona. 060C/Primary lockout I Fail Of

f'elays-unit protectionCoils do not onorgizo toclose contacts in EIIC andinitiate a tripPrimary unit protectioonis disablod

Facility: Susquehanna Stean Electric StetionDocket: 50-387, 50-388

FAILURE NODES AND EFFECTS ANALYSIS Sheet 1 of 4

Couson Power Supply or Sensors

IControl Systen Affected<

1D625 125 VDC

Reactor Feedwater Control S sten

CSID$ 0160-004-001

CDa 0160-004-012

Job No.Prepared byeDatesChecked by:Approved bye

,v4 gn ')Il~ /r

0160-004-671

Rev 0Date: 7Dates

Component Naeeand Nunber

I

Failure I

Mode

Sywptoes and LocalEffects IncludingDependent Failures

'ysten InherentConpensating Provision

SusearyxEffect Upon

Control Systen

SunmaryxEffect Upon

Plant Perfornance

ll. Reactor feed pusp turbine 8I trip circuit - Level 8 trip

contacts

De-ener-gized

Trip circuit is de-ener-giredLevel 8 trip signal cannotbe processed

Trip circuits for reactorfeed punp turbines A andC are powered by otherDC power supplies

Loss of ability to tripturbine B on a Level 8trip signal

There is no affect onplant perforsance unless I

a Level 8 trip condition Iexists

Pacility:Docket!

Susquehanna Steam Electric Station50-387, 50-388

P*ILURE NODES AND EPFECTS ANALTSIS Sheet 2 of 4

Common Power Supply or Sensor:

IControl System Affected:

1DG25 125 VDC

Recirculation Plow Control

CSID'160 004-001

CD: 0160-004-012

Job No.Prepared bysDate!Checked by:Approved by:

0160-004-671


Pai lureNode

Symptoms and Local-Effects IncludingDependent Failures


Summary:Effect Upon

Control System

Summary!Effect Upon

Plant Performance

I 1. Temperature swi tch:I TSB-1402182

l2. Circuits - recirculationflow loop 8:a. Under-voltage relay

b- Lockout

c. Pump vibration reset

d. Scoop tube power failurelock and reset

e. Auxiliary circuitsf. Bonerator field breaker

IOffI

Off

Pa i lure of the tempera-ture switch has no localeffectsThere are no dependentfailures associated withthe switch failureLoss of bus voltage ispredominant

Loss of bus voltage willcause the following:- Uenerator field breaker

for loop 8 will open

— The scoop tube for H-0set, loop 8 will lock in I

position at the instantbus voltage is lost

- The H-0 set and recir-cu lat ion pump for loop8 will trip and coast'to a stop

Redundant lube oil tem-perature indicators anda temperature switch-alarm combination pro-vide additional moni-toring

Recirculation loop Awill continue to oper-ate normally

Reactor runback signalswill be processed inthe auxiliary and speedcontrol circuitry forloop A

No compensation effectfor the loss of flow inloop 8

Loss of automatic com-pensation for high lubeoil temperature

. Operation of the recir- .

culat!on pump in loop Amust be governed by theflow criteria for singlepump operation

Control of loop 8 recir-culation is lost andcannot be re-establisheduntil the bus voltage isrecovered

Control of recirculationloop A may be exercisedvia the master control-ler, H/A transfer stationand speed control cir-cuitry

Recirculation flow isreduced due to the lossof flow in loop 8

A core flux differencewill result from theflow imbalance

Pacilitys Susquehanna Steam L'lactric StationDocket: 50-387, 50-388

PAILURE HODES AND EPPE~ ANALXSIS Shoot 3 of 4

I

IIICommon Powor Supply or SensorsIIControl System Affoctods

10625 125 VDC CSIDs 0160-004-001

CDs 0160-004"012

Job No.Prepared byDatesChecked by:Approved bys

0160-004-671

Ro v.Dates ~~@Date's ~+fr

Componont Nameand Number

Pa i lureNod o

Symptoms and LocalEffocts IncludingDopendent Pailuros

System InherentComponsating Provision

SummarysEffect Upon

Control System

SummarysEffect Upon

Plant Performance

1. Unit protectionsa. 1R101/Oonorator oil

circuit breaker-230kvponos

2. Trip ansi alarm switchossa. PSL-11981A2, 82/Thrust

boaring uoar detector andlow bearing oil pressure

b. PSL-101808/Low hydraulicfluid pressure

c. PSL-119328/Shaft pumpdischargo-low pressure

d. TSUN-1011SA2-C2/Exhausthood high temperaturegenerator ond trip

e. LSll-101278s -288, -298/Hoisturo soparatorroheatar drain tank 18high water lovel

Il"ail Off I

Pail llighl

IPail Nigls

Pail Nigh

Pail tow I

Pail tow

52X coil in 1R101 controlsystom fails to remainonorgizad

Contacts in breaker aux-iliary SNS2-1 will close{normally closed statewhen da-energized)

Closed contacts initiatean ENC trip

PSLX-10112A2-82 will notenergizes- Contacts remain un-

changed in logic circuitlPSLX10180B will notenergize s- Contacts remain un-

changed in logic circultlPSl.X11932B wtll notonorgizas- Contacts remain un-, changod in logic circuit

TSNNX-10118A2-C2 will notenergizes- Contacts remain un-

changed in logic circuitLSNX101278 will notona rg iza s- Contacts remain un-

changed in logic circuit

Circuit logic (2/3) pro-vonts inadvertent tripvia the instrumentationcircuits

Initiates tho T/0 tripsignal in the EHC system- no noad for furtherturbine relay circuitryAny two energized tripand alarm switchos .registering a transientsuffictent to changetheir associated contactswill cause a T/0 tripRemaining relays bocomaarranged in a 2/2 logic

The generator sequontialtrip becomes disabled

There are no furthor ac-tions or trips tnvolvodwhon the soquontial tripis lost

Tha main generator1R101'ilcircuit breaker do"

anorgizos and trips thoT/8

Pacility: Susquehanna Steam Electric StationDocket: 50-387, 50-388

PAILURE HODL'S AND EPPBCYS ANALTSIS sheet 3a of 4

Common Power Supply or SensorsIIControl System Affectdd:I


1D625 125 VDC

e„„,~n,> c*, - roc,c o>

I I Symptoms and LocalI Pailure I ''ffects Including

Dependent Pailures

CSIDc 0160-004-001

CDs 0160-004-012

System InherentCompedsating Provision

Job No.Prepared by:DateaChecked bysApproved bye

SummaryaEffect Upon

Control System

0160-004-671

RevDate R

Date:

Summary I~ Effect Upon

Plant Performance

3. Sequential trip instrumenta-tion:a. ZS-10160A2-P2, A5-P5/

Position transducers-intercept and intermediatestop valves-servo valves

b. ZS-10141A2-D2/Positiontransducers - main stopvalves-servo valves

Pail Of f

Pail Of f

~ Sequential trip disabledby the failure to energize33X2-10141

Contact 5X2T2-1R101 failsto open due to the ina-bility to energize thecorresponding coil inthe auxiliary circuitSame as ZS-10160

c. 52XT2-1R101 IPail Off52XTI-IRIOI/Hain generatorlauxiliary relay

Pails to energize andopen contact in generatorsequential trip

Facility: Susquohassna Steom Electric StationDockots 50-387, 50-388

PAIl UEE NODES AND EFFECTS Al|ALYSIS Shoot 4 of 4

ICommoss Power Supply or SensorsI

IControl System Affoctods

10625 125 VDS CSIDs 0160-004-001

CDs 0160-004 012

Job No.Prepared bysDatesChecked bysApproved bys

0160-004-671

R ~ 0D0%,, /.D t

Componont Nameand Number

Pai lureHodo

Syssptoms and LocalEffects IncludingDependent Pailures

Systom InherentCompensating Provision

SummarysEffect Upon

Control System

SummarysEffect Upon

Plant Porformanco

1. Volvo control monitor Off Shear valve is inoperative

Dry gas purgo circuit isinoperative

~ On loss of 125 VDC, TIPis automatically with-drawn

Control system returnsTIP probo to normallyhoused positionPurther system operationis not possible until DCpower is restored

Unable to perform TIPoperation

Unablo to obtain coreflux readings throughTIP probe

Facility: Sus<lucl!anna Steam Bloctric StationDocket! 50-387, 50-388

PAILURB HODL'S AND BFPBCTS ANAfYSIS Shoot 1 of 2

Common Power Supply or Sensors

Control System Affected!

10635 125 VDC

Roactor Pecdwater Flow Control

CSIDs 0160-004-001

CDs 0160-004-013

Job" No.Prepared bysDatesChecked bysApproved bys

7/ )» ~l

Rov. oDatesDates

0160-004-671

Component Nemoand Number

IFailure I

Hode

Symptoms and LocalLffccts IncludingDependent Failures

System InhorentComponsating Provision

SummarysBffoct Upon

Control System

Su!sclary s

Bffoct UponPlant Performance

ll. Puodwator flow instrumcnta-I tions

a. Pocdwator flow sensortrain 8/C32-N002

2. Foodwator lovel instrumonta-tionsa. Reactor vessel lovel

sonsor C/C32-N004C

b. Reactor vessel l!igh levelalarm train C/C32-K624C

3. Reactor feed pump turbinetrip (RPPT) circuit train C

Off

Off

AlarmArmed

Off

Plow signal from sensor 0goos to zero for flowsignal processing circuit

Lose C train reactor waterlevel signal

High lovel alarm is armed I

for Level 8 tripLe ve1 8 contact in t ripcircuit not processed

Lovel 8 trip logic isroducod from 2/3 to 1/2and provonts an inad-vertent trip causod bya powor failure

In the 3 element modes- A zero flow input sig-nal to the flow controlcircuit causes an in-crease in spood forreactor food pump tur-bine A, 8, and C

In start-up mode thorois no affectReactor vessel high lovol(Level 8) trip is armedin train C

Circuits are in 1/2 logicThoro is no affect on thocontrol system, providingthe trip condition is notpresent

If Level 8 trip isrcachod, RPPT C will nottrip duo to tho disablinglof tho trip circuitA Levol 8 trip is possi-ble due to the zero flowinput signal to the flow Icontrol circuit I

Pacilitys Susguehnnna Stuns Electric StationDocket: 50-387, 50-300

PAILUIM llODES AHD EPPECTS ANALySIS Shoot 2 of 2


Control System Affected<

1D635 125 VDC

P ~81 to dT/AC t*iCSID4 0160-004"001

CDR 0160"004-013

Job No.Prepared byeDatesChockod byeApproved bya

0160-004-671

ev ODatesDates


Pa i lureHode

Symptoms and LocalEffects IncludingDopondont Pailuros


SummaryaEffect Upon

Control System

SummarysEffect Upon

Plant Performance

1. Trip and Alarm switchosaa. PSL-11901A3, 83/Thrust

bearing wear detector andlow bearing oil pressure

b. PS1.-10100C/Low hydraulicfluid prossure

c. PSL-110132C/Shaft pumpdischarge low pressure

d. rSHH-1019A3-C3/High ex-haust hood temperaturegenerator end

o. Lovel 8 reactor highwator lovel trip. train C

2. Back-up unit protectionBGODBack-up lockout relay unitprotection

I pail HighI

I pail Highl

1'ail High

Pail Low I

Armed

Off

Coil doss not energizeand fails to chango stateof contacts in EHC logiccircuit

One third of Lovel 0 tripcircuit armed

Loss of redundant unitprotection system

Ci rcu i t log ic ( 2/3) p re-vents inadvertent EHCtrip

Lovel 8 trip can stilltrip T/0

Primary unit protectionremains activnted

Control logic circuitreduces to a 2/2 logicsystem

Lovol 8 trip logic isreduced from 2/3 to 1/2

Loss of back-up unitprotection

No trip of EHC occurswhen powor supply'lost

No impact to overallplant performamcowill occur

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FacilityiDocket'usquehanna Stcam Electric Station50-387, 50-388

PAII.URE WODES ARD EPPEefs ANAl.ySIS Shoot la

Control System Affected: P ~ll 1 t* iTn carolCommon Power Supply or Sensors 1D645 125 VDC

CDg 0160"004-014

CSIDx 0160-004-001

Job Ho.Prepared byeDatosChecked by:Approved bye

0160-004-671

Rov ODatesDatex

Component liameand Wuml>or

Pai lureHode

Symptoms and LocalEffects IncludingDopcndont Pailuros

System InhorcntCompensating Provision

Summa ry s

Effect UponControl System

SummnrycEffect Upon

Plant Performance

5 ~ ZS-IOIGOAI-PI, A7, C7, E7/Open switchos, closeswitches, rospcctivoly

Off Switches aro disabled nnd Iintercept valves l. 3,and 5 cannot bo proporlypositioned

k. ZS-i0140AI-EI, A2-E2/ IPosition switches

Off All position switcheson bypass valves arodisnbleds

~ - Bypass valve cannot bopositioned

Al1 va 1 ves thn t a ro'oporated by positionare disabled

1. Valve test logic circuits Off Ho toots on valvos can boconducted whilo customerDC is not functioning

Tho Emergency Tripsystem will close valves,if activated

m. Lcvol 8 reactor high waterlovel t r ip, train 8

Armed One third of Lovel 8 tripcircui't armed

Lovel 8 trip can stilltrip T/0 on high level

Pacilitya Susquehanna Steam Blectric StationDocket: 50-387, 50-388

PAILURV HODBS AND EPPECYS ANAfYSIS Sheet 2 of 2

I

I

I

ICommon Power Supply or Sensor:

Control System Affcctcds

1DG45 125 VDC


CSIDx 0160"004-001

CD: 0160-004-014

Job No.Prepared byeDatesChecked byaApproved bye

3~ nY PPI'1GO-004-671

Re v.Datea

IDates


II Failure

Hode



A

Summary:Effect Upon

Control System

Summary:Effect Upon

Plant Performance

l. Peedwater level instrumenta-tionsa. Reactor vessel level I

sensor train 8/C32-N0040

b. Reactor vessel high levelalarm/C32-K6240

Off

Armed

If 8 is selected, thelevel signal input to theflow control circuit goesto zero

Level signal input toflow control circuit be-comes zero

Loss of power to alarmenables 1/3 logic ofthe Level 8 trip circuit

If level A is selectedas input to flow controlcircuit, there is noeffect on the resultingcontrol signalA and C train input sig-nals to Level 8 trip cir"cuit are not enabled

If level A is selectedas input to the controlsystem, there will be noaffect on the controlsystem

If level 8 is selectedas the input signal tothe control system, azero level signal resultsinc-Reactor feed pump tur-bine speed will increasecausing a high steadystate reactor vessellevel to compensate forthe low level signal

Level 8 trip logic (2/3)is reduced to 1/2 logicdue to arming of the8 train portion of theLevel 8 trip circuit

For level A selected,there is no affect onplant performance

For level 8 selected,the higher steady statereactor vessel waterlevel may result inLevel 8 trip of reactorfeed pump tu'rbtnes A, 8,and C

Pacilitys Susquehanna Stoam Electric StationDockots 50-387, 50-388

PAILURE NODES AND EPPECTS ANALYSIS Shoot 1 of 17

IIICommon Power Supply or SensorsIIControl System Affoctods

1Y218 120 VAC

Nuclear Pressure Relief

CSIDs 0160-004 001

CD: 0160-004-015

Job No.Prepared bysDatesChecked bysApprovod bys

0160-004-671

RovDates I-'I 5Dates i

Componont Nanoand Number

PaiiufoNode

Symptoms and LocalEffects IncludingDopondant Pailures


SummarysEffect Upon

Control System

Summa ry'ffact Upon

Plant Performanco

1. Temperature monitoring/leakdetection subsystemsa. Thormocouple/1N004 0, N,

K, H, N, A, 8, C, 0, E,P, N, P, R, S

b. Temperature recorder/R614 I

As Is

Off

Loss of signal to s~itchin RG14

~ Loss of high temperaturealarm indication

There are no inherentcompensating provisions

Loss of safety reliefvolvo leakage detection

Loss of high temparaturosignal to annunciatorcircuitLoss of tomporature in-dication/leak detection

Loss of ability to moni-tor for downstream leak-age from safety reliefvalve

Loss of temperature in-dication downstraass ofsafety raliof valvo

Pacilitys Susqueha»na Steam Electric StationDocket! 50-387, 50-388

PAILURE NODES AND EFPECTS ANAlYSIS Sheet 2 of 17

Common Power Supply or Sensor<

Control System Affected!

1Y218 120 VAC

Pressure Be<iulator - T 0 Control

CS ID! 0160-004 001

CD! 0160-004-015

Job No.Prepared by!Date!Checked by<Approved by:

/~ a.

01GO-004 G71

Date;Date!


Pai lureHo<le

Symptoms an<i LocalEf facts I»eludingDependent Failures


Summary!Effect Upon

Control System

Summary:Effect Upon

Plant Performance

I I. Level 8 trip circuit forI T/0 train A

One third of Level 8 tripcircuit armed

Level 8 trip logic re-duced from 2/3 to 1/2

No affect on plantperformance

Facilityc Susqucha»na Stcam Electric StationDockot: 50-387, 50-388

PAILURE NODES AND EPFECTS ANAIYSIS Sheet 3 oE 17

ICommon Power Supply or Sensor:IIControl System Affected:

1Y218 120 VAC

Reactor Paedwater Flow Control

CSID$ 0160-004-001

CD) 0160-004-015

Job Ho.Prepared by>DatoaChecked byeApproved bye

0160-004-671? „r e~ )j~

RovDatetDatos


Pa i1uroHode


System InherentComponsating Provision

SummarysEffect Upon

Control System

Summary\Effect Upon

Plant Porformanco

l. Fcadwater Elow control in-strumantationca. Paedwator flow sensor

C32-N002A, C

b. Steam flow sensorC32-H003A, 8, C, D

IOffIII Off

Zoro output trains A, C

Zero output all trains

Loss of fcedwator flowsignals and automaticcontrol in 1 or 3 elementmode

Loss of steam flowsignals

In start up or at power,tho RPPT H/A controlsare disabled

Foedwater flow remainsinvariant duo to a"Speod Froozo"

d. Reactor prcssure levolC32-H005

Off

e. Hain turbine first stageprcssuro. stoam flowC32-N007

Off

f. Roactor pressure sensor IOffC32-H008

g. Square rootorC32-K605C32-K606

Off

h. Oain and bias control

i. Dias/gain stcam flow sig-nal/C32-K603

5. Hain and bias inputs/C32-K602

Off

OEE

Off

k. Proportional ampl ifier/C32-K616 (summer)

Off

c. Reactor water level sensor OffC32-H004A

Zero output train A

Zero output

Zero output

Zero output

Zero output

Zero output

Zoro output

Zero output

Zero output

Two lovel sonsors remainon 2/3 logic for reactorwater level (lovol 8)trip

Loss of entire instru-mentation loop connected Ito SRUs 1, 4, and 5 I

IAt low flow, control Isystem fails to regulate I.flow

H/A control of RPPTs viaa single control signalis lostAll control of individual!RFPTs within tho feed-wator control system isdisablod

Active trip system isreduced to 1/2 logicAny additional alarmwill trip tho system

"Spood Praozo" initiated Ivia tho I C-12730/electricautomatic positionor oneach RFPT

Peedwatcr flow regulationis unavailablo duo to tholloss of tho start-upvalve control stationReactor runback signaltransmitted to tho ro-circulation system

Prior to tho Lovol 8trip. tho RPPTs may boterminatod only via anoperator-initiated tripSoo sheet 16 for theoffccts on tho recircu-lation system

Reactor vossol highwater lovel ( La vol 8)trip is possible if"Speed Proozo" occurs atmaximum demand. Reactorvassal low lavol (iovol2) trip is possible if"Speed Frooro" occurs atminimum demand

1. Dynamic Couponsator/C32-K649

IOfE

IZoro output

m. Punction generator/C32-K630

OEE Zoro output

Pacilitys Susquehanna Steam Electric StationDocket s 50-387, 50-388

PAILURE MODES AHD EPPECTS AHALYSIS Shoot 3a of 17


Control SystemAffected'Y218 120 VAC

Reactor Paodwator Control S stem

CSIDs 0160-004-001

CD) 0160-004-015

Job Ho.Prepared byeDatesChecked by<Approved bya

0160-004-671

Rove 0Dates

~ Dntea

Component Haseand Number

I PailureModo

Symptoms and LocalEffects IncludingDopendent Pailures


SummarycEffect Upon

Control System

SummarysEffect Upon

Plant Performance

2. 24V 08 power supply:a. C32-K611b. C32-K612c. C32-K613

Off Zero output power to theindividual instrumentloops

3. Control stationsxa. Low flow demand signal

logic/C32-K645, K646

b. Paadwatar demand signal(I or 3 element levolcontrol)/C-32-K633, K634,K653

Off

Off

Loss of auto/annual con-trol of the foedwatarstart-up control valve

Loss of all auto/manualcontrol of feadwatercontrol system

"Speed Freeze" is ini-tiatod when tho controlsignal is lost

c. RPPT logic control/C32-K637, K638A, 8, C

d. A/A transfer station/C32-R600, R601A, 8, C, R602

Off

Off

Loss of auto/manual con-trol associated with each

~ RPPT - Ho speed freezeoverride availablo infaadwater system

Loss of transfer stationdue to failure of asso-ciated devices poweredby 1Y218

4. Alarmssn. Recirculation loop pump

cavitation interlock/C32-K618

b. Peodwater pump interlock/recirculation loop flowreduction alarm/C32-K628

Pal 1 Low

Pail Low

Transmits a low-low run-back signal to the re-circulation system

Transmits n trip signal totho recirculation system

c. Steam flow lovel/C32-K608 Pail Low Transmits a low flow sig-nal to the computer


FAILURH HODBS AHD BPPBCTS ANALYSIS Sheet 3b . of 17

IIIICommon Power Supply or Sensor:IIControl System Affected:I


I IPailure I

Hode

IY218 120 VAC

Symptoms and LocalBffects IncludingDependent Failures

CHID: 0160-004-001

CD: 0160"004-015


Job Ho.Prepared by:Date:Checked by:Approved by:

Summary:effect Upon

Control System

0160-004-671

Rev ~

Date: ~-II~.lDate: ~ .I

I

Summa lyBffect Upon

Plant Performance

d. Bi-level alarm/C32-K635

e. High reactor water levelturbine trip/C32-K624A

f RPpT control signal loss/C32-K607

IPail Highl.land Low I

IIII

I Fail Highl .-I

III

IPail Dif-l.IferenceI

High and low level annun-ciators for reactor waterlevel are energized on.the control room displaypanel

Train h alarm indicateshigh reactor water level

The alarm for the lossof contiol signal isarmed

. High water level logic(2/3) prevents inad-vertent trip with arming Iof train h alarm

. A 'Speed Freeze isinitiated


PAILURE KODES AND EPPECTS ANALYSIS Sheet 4 ot 17

IIIICommon Power Supply or Sensor:IIControl System Affected: erector r *teeter Control ~s er.en

CSID: 0160-004-001

CD; 0160-004-015

Job No.Prepared by:DateChecked by:Approved by:

0160-004-671

Rev. D .IDate: 'j'Q21fpi.lDate: r~Pgg/..


I II Failure II Node II



Summary:-Effect Upon

Control System

SummdryeEffect Upon

plant Performance

Il. a. K6058/Steam signal squareI rooterI

b: K6068/Feedwater flowsignal square rooter

l2. K6078/Peed pump 8 speedI control signal lossIIl3. a. K6188/Recirculation loopI pump cavitation interlock

alarm

b. K6288/Peedwater pump tripinterlock/runback signalto recirculation system

l4. K6308, C/Function generatorIIS. K6378 & C, K6388 6 CiI K6388-1 6 c-l, R6018 rr c/

Peed pump manual/auto trans-fer control station

IOffIIIIOffIIIPail Lossl.lof SignallI II IIPail Low I.I II II IIPai1 Low I

Loss of signal input, zeroloutput from 8 train to Icontroller

Loss of automatic signalinput to the auto posi-tioner for feed pump 8

Speed Freeze'n train8 initiated

IOffIIOffI

. Zero output signal

. Loss of all automatic and I. 'Speed Preeze'n feedmanual control of reactor I pumps 8 6 C initiatedfeed pump turbines 8 and Cl

Runback signal transmittedl. Ho compensating devicesto recirculation system

Loss of signals will in-duce feed pumps to in-crease flow in 3 elementcontrol

. Automatic control fortrain 8 and C feed pumpis lost

. Trip signals transmittedto recirculation system

. Ho manual override of'Speed Freeze'ircuitis available on RPPT 8and C

. RPPT speed is increaseddue to the loss of train8 signal

. Runback sit3nals sent torecirculation system

. Optimum water level maynot be maintailwu byautomatic control

Initiation of a 'SpeedPreeze't high pump

I speed may result in a.I high level (Level 8)I tripII Initiation of a 'SpeedI Freeze't low pumpI speed may result in uI low level (level 2) trip II I

I I

I II I

I I

I II I

IIIIIIIII

I I

I I

I I


PAILURE HODES AHD LPPECTS AHALYSIS Sheet 5 of 17

III[rosooo possr soppiy or ssosor: ~1Y218 lyo Y~AQ ro ory-rory yrvooLIIControl System Affected: Reactor Peedwater Control S stem

CSID: 0160-004-001

CD: 0160-004-015

Job HoPrepared by:Date:Checked by:Approved by:

0160-UU4-671

-ry Hev ~-/ y P~Date;Date:

Component Hameand Humber

I II Pailure

Hode



Summary:Effect Upon

Control System

Summary:Effect Upon

Plant Performance

Ill. a. K606A/Peedwater flow hsquare rooter

. Ho compensating devicesControl signals are lostfrom train A,

)Off

Offb. K616/Proportional ampli-fier

Input signals to the levellcontroller are lost I

IInput signals to each feed)pump control station arereduced to zero

c. K630A/Punction generatortrain h

Off

d. K605A/Steam flow h squarerooter

IOffIIIPail Highl Trip logic I2/3) pre-

vents an inadvertentLevel 8 trip resultingfrom a power failure

I2. K624A/High level turbinetrip alarm

Pails in high water level I.mode II

II ~

II

IPail Loss).lof Signall

Level 8 trip logic Il/3)is armed

IPails in 'Speed

Preeze'rientation

I3. K607A/Alarm for feed pumpI control signal lossIII4. K633, 634, 634-1, 653, R-600/

Ievel controller

Ho compensating deviceneeded

IIIOff . Each pump can be con-

trolled by separatemanual control stations

. Since input signals arereduced to zero, allautomatic control is lost

Auto mode is disabledfor all pumps

. Hanual control of all 3feed pumps from a singlecontrol station is un-available

'Speed preeze's ini-tiated)5. K637Ap 638A, 638A-1, R-601A/ )Off

I Peed pump A manual/automatic II transfer control station I

Ile K645 ~ 646 '46 1 ~ R602/ OffI Start-up, low flow control

station

. All automatic/manualcontrol of feed pump Ais lost

Low flow conditions will Ibe altered by manualcontrol of feed pumpturbines

. Por low feedwater flow,manual/automatic controlof the start-up valve islost

Input signals via auto-matic monitoring of thereactor water level arelost - level controllercannot be operated inthe auto mode

Initiates a 'SpeedPreeze'n trains A, B,and C

. Loss of all 1 or 3 modelevel control

. Hanual or automatic con-trol of all 3 feed pumps Ifrom a single stationcannot be exercised I

. Loss of manual overrideof feed pump h

~ Por conditions of lowfeedwater flow demand,control of feedwaterflow cannot be performedvia the start-up valve

Hanual override of'Speed Preeze'or RPPT8 and C is available

Low flow runback signaltransmitted to the re-circulation system

Pacility: Susquehanna Steam Electric Station.Docket: 50-387, 50-388

PAILURE HODES AND EPPECTS ANALYSIS Sheet ba of 1'/ 4

!

IIIICommon Power Supply or Sensor:I[Control System Affected:

lY218 120 VAC to C32-K612 24VDC


CSID: 0160-004-001

CD: 0160-004-015

Job No.Prepared by:Date:Checked by:Approved by:

0160-OU4-671III

Hev. oDate: ~3~g ~~IDate: /> pg


I I

I, PailureI Hode


II

System Inherent ICompensating Provision

Summary:Effect Upon

Control System

Summary;Lffect Vpou

Plant Performance

l7. a. K618A/Recirculation looppump cavitation interlock

b. K628A/Peedwater pump tripinterlock/runback signalto recirculation system

IPail Low I. Runback signal is trans-l I mitted to the recircula-I I tion systemI IIPail Low )

IIIII

2

I


PAILURE HODES AHD EPPECTS AHALYSIS Sheet 6 of 17

IIIICommon Power Supply or Sensor:IIControl System Affected:

1Y218 120 VAC to C32-K613 24VDC

Reactor Peeduater Control S stem

CSID: 0160-004-001

CD: 0160-004-015


016U-UU4-6/1

o I

LY. 2 &..~I

Component Sameand Humber

IPailure I

Hode



Summary:Effect Upon

Control System

Summary;Eftect Upon

Plant PerformanceI

Ill. a. K602/Steam and feedwaterI signals gain and biasI

b. K603/Steam flow signalgain and bias

c. K615/Peedwater signalgain and bias

d. K605 CED/Steam flow C andD square rooter

e. K606C/Peeduater to trainC square rooter

)OffIIlOffIIlOffIIlOff

Off

. All output signals yo tozero

Ho compensation is avail-I. In 1 element mode, aable or necessary I loss of bias and gain

has no consequence

In 3 element mode, the .

level controller output Iwill initiate a speedincrease of all 3 feedpumps

. Automatic control forfeed pump C is I.ost

. Recirculation systemreceives a lou flourunback signal due tothe loss of the feeduaterlflow siynal

Level 8 trip may be ini-tiated as the result ofspeed increase of feed-water pumps

. Tl)e speed of pump C can-not be increased due tothe 'Speed

Preeze'.

K649/Dynamic compensator

12. K635/Bi-level trip alarmIIIIl3. K636/High pressure alarmIIl4. K608/Steam level alarmIIIS. K607C/Peed pump speed signalI loss alarm unitII

I

IOffII IPail Lou

I Pail High I .I II IIPail Low I.I II I(Pail Loss(.lof SignallI I

III

Annunciators for high and I.lou reactor water levelare energized in the con-trol room

same as item 1

Low flow signal is trans-mitted to computer

'Speed Preeze'ignal istransmitted to the elec-tric automatic positioner

. Same as item 1

Speed Preeze'ircuitis available for train Cwhen in the auto mode- Hanual override of

'Speed Preeze'vaila-ble

Annunciator for reactor . Same as item 1high pressure is energizedl


4

FAILURE HODES AND EPPECTS ANALYSIS Sheet 7 ot 17

IIIICommon Power Supply or Sensor"rIIControl System Affected:

1Y218 120 VAC

Reactor Hanual Control S stem RHCS

CSID: 0160-004-001

CD: 0160-004-015

Job No. 016U-UU4-671Prepared by:Date: ''t l. Rev.Checked by: ~ Date:Approved by: Date:


I I

I Failure IHode

Symptoms and Local IEffects IncludingDependent Pailures


I Summary:I Effect Upon

Control System

Summary:hffect Upon

Plant Performance

SUHHARY REACTOR NAHUATL CONTROL SYSTEH

ll. Rod control unit operating IOffI benchboardI12. Rod position information Of fI system ~

I13. Rod sequence control system IOffI Il4. Trip unit, turbine pressure IOffI IIS. Scram time test panel IOffI I

l6. Control rod drive hydraulic IOffcontrol I

. See sheet 9

See sheet 10

. See sheet 8

. See sheet 12

. See sheet ll

. See sheets 13, 14

. Control rods cannot beoperated due to a lossof pouer to these sub-systems

Pull core display is notavailable

. Operator signals-cannotbe transmitted to roddrive control

. Rod ppsition informationis not available I

IRod sequence control isde-energized

. Rod movement limitationassociated with RCS arestill imposed

. Scram timing test cannotbe operated

Control rod movement isnot possible:

Power changes cannotbe made

Rod testing cannot be Iaccomplished (if in I

progress) IIIII


PAILVRE RODES ARD EPPEerS ARALYSIS Sheet 8 of 17

IIIICommon Power Supply or Sensor:IlControl System Affected:

IY218 120 VAC

Reactor Iraaaal C trot ~s stea~RHCS

CSID: 0160-004-001

CD: 0160-004-015

Job Ho.Prepared by:Date:Checked byeApproved by:

0160-Ou4-671

Ruv. D

. Date: /ATE P

Component Rameand Rumber

I

Pailure IRode I

symptoms and LocalEffects Including IDependent Pailures


Summary:Effect Opon

Control System

SummaryeLfrect Upon I

Plant Performance I,I

1. Rod sequence control system/p659:a. RSCS page lOff

IIII

b. Rod pattern controller lOff

. Loss of timing and gating lsignals

. Loss of test signals

. Loss of memory circuitryprocessing

. Rod block contacts openif closed and remainopen if already open

. See summary sheet page 1 lI

. Rod block function with-draw and insert signalsto input isolation ofRDCC are activated

I. RsCS rod movement limita-l

tions are invoked: I1. Prevents out-of-

sequence rods frombeing moved

2. Limits movement otout-of-sequence rod

III


PAILURE HODES AUD EPPECYS AUAIYSIS Sheet 9 of x I

IIIICommon Po~er Supply or Sensor:IIControl System Affected:

1Y218 120 VAC

a actor nannal control a~stem anon

CSID: 0160-004-001

CD 0160-004-015

Job Uo.Prepared by:Date:Checked by:Approved by:

U160-U04-671

RuvoDate:Date:

I.I

Component Nameand Uumber

II Pailure

Node



SummaryrEffect Upon

Control System

ISummary:

Effect UponPlant Performance

1. Rod control unit operatingbenchboard/P6804a. Pull core display module IOff

Ib. Rod select switch assemblylOff

II

c. Rod select and transmitterIOffmodule

. Loss of full core display I

. Switch assembly inopera-tive

. Signals cannot be trans-mitted to rod drive con-trol

. See summary sheet page 1 I . Lose full core displaymodule

Lose rod select switchassembly

. Lose rod select andtransmitter module-cannot transmit to roddrive control system .

. Lose rod worth minimizeroperator panel - initia-tion

Loss of ability to selectland move control rods I

IIIIIIIIII

Facility: Susquehanna steam Electric StationDocket: 50-387, 50-388

FAILURE NODES AND EFFECTS ANALYSIS Sheet 1 u of 17

III)Common Power Supply or Sensor:I(Control System Affected:

1Y218 120 VAC

«*a«««««a «al C««««1 ~St* R«jCS

CSID: 0160-004-001

CD 0160-004-015

Job No.prepared by:Date:Checked by:Approved by:

«««. «

I'omponent

Nameand Number

I ) Symptoms and Local.I Failure ) Effects Including

Dependent PailuresNodeSystem Inherent

Compensating Provision

Summary:Effect Upon

Control System

SummaryrEffect Upon

Plant Performance

Ill. Rod position informationsystem/P615:a. Control module - control )Off

file, multiplex file III

IIII(offb. Nultiplex module (2)

. All electrical controlsignals are de-energized(control file)

I. Rod position indicator

probe signals are not pro-(cessed I

I. Rod position indicator I

probe signals are not pro-)cessed

See summary sheet page 1 I . Lose rod position outputto scram time test panel

. Lose rod position outputto 4 rod control file

. Control rod positionI cannot be monitored

i,ose 'Rods In'ignal to Irefueling hoist controI

. Lose rod position in-dication

Facility: Susquehanna Steam Electric StationDocket: 50-387, 50-388

PAILORE HODES AHD EFFECTS ANALYSIS Sheet li of


1Y218 120 VAC

Reactor Hanual Control S stem RHCS

CSID 0160-004-001

CD: 0160-004-015


016U-UU4-671

Hev ~

Date:Date;


'I I

i Pal lureI Hode II



Summary:Effect Upon

Control System

Summary;Lffec.t Upon

Plant Performance

l. Scram time test panel/P610 I Off . Loss of rod position/movement signal from therod position informationsystem

Loss of input from themaster clock from RDCCP616

See summary sheet page 1 I. Loss of ability to meas-ure scram time for con-trol rods

Hormal operation of Icontrol rods is not Iaffected - scram testing I

function is lost II

Loss of scram test signalfrom the output isolationof RDCC F616

~ Loss the of scram signalprocessing input to scramtime test panel fromreactor protection

Pacility: Susquehanna Steam Llectric StationDocket: 50-387, 50-388

PAILURE HODES AHD EPPECTS AHALYSIS Sheet 12 of 17

IIIICommon Power Supply or Sensor:IIControl.System Affected:

1Y218 120 VAC

Reactor nan at Control ~Sstes ~Rs~CS CD 0160-004-015

CSZDr 0160-004-001

Job Ho.Prepared „by:Date:Checked by:Approved by:


I II Pailure I

Hode

b. Press indicating switch/ IOffPIE-1B654hc 8 I

Ic. Pressure transmitter/ IOff

PT-18054hc 8

Ill. Trip unit first stage turbineIpress/P613a. SRU-1 Off

Symptoms and LocalEffects Including IDependent Pailures

instrument loop is de-energised

. Contacts in switch remain Iopen I

I. Signal from transmitter isI

not processed


. See summary sheet page 1 II

SummaryeEffect Upon

Control System

pressure transmittersignals are not processed

. Trip unit signal is notbypassed when low powerset-point is reached-signal is not sent toRSCS P659

ISummary: I


II

Hod movemeut limitations Iof HSCS are still presuntleven atter low power set-Ipoint is reached: Il. Cannot move out-ot- I

sequence rod II

2. Limits movement of Iin-sequence rod

Pacility: Susquehanna Steam Electric StationDocket 50 387s 50 388

PhILURE NODES hND EPPECTS hNhLYSIS Shout 13 of 17

IIIICommon Power Supply or Sensor:IIControl System hffected:

1Y218 120 VAC

Reactor Hanoal Cont~col S t~RH~CS

CSIDx 0160 004 001

CD: 0160-004-015

Job No.Prepared by:Date:Checked byrhpproved by:

I

.I.I


I I Symptoms and LocalI Pailure I Effects Including

Dependent PailuresNodeSystem Inherent


Summary:Effect Upon

Control System

SummaryaEffect Upon

Plant Performance

IIl. Control rod drive (CRD)hydraulic control:

a. Plow control station I10-009h/0:1. PE-1N003/Plow element

2. PC-1R600/Controller

3. PY-IK001/Converter

4. FT-1N004/Plow trans-mitter

5. 18600/Power supply

Off

. Loss of power does noteffect flow element

. Controller does not sendsignals to converter

. Converter does not re-position to allow control Iair to reposition air-operated valve

Plow signal is not trans-mitted to controller

Loss of power (hC to DCconversion) to control/instrument loop

. See summary sheet page 1 I Loss of automatic flowcontrol capability.

. Loss of system flow in-dication

. Differential pressureindication required toproperly ad)ust drivewater pressure controlvalve is not available

. Cannot maintain properdifferential pressurebetween reactor .vesseland drive water header

Loss of alarm indication I

for high charging waterheader pressure

. Normal control rod move-ment cannot be accom-plished due to loss ofnormal control rod drive Ihydraulic control in- Istrumentation I

IIIIII

b. Drive/cooling water pres- Isure control:1. PDT-lN011/Differential

pressure

Off

Loss of transmitteddifferential pressure(reactor coolant/drivewater header) downstreamof pressure controlstation

2. PDT-1N008/Differential Ipressure

~ Loss of transmitteddifferential pressureupstream of pressurecontrol station

Facility: Susguehanna Steam Electric StationDocket: 50-387, 50-388

FAILURE HODES AHD EPFECTS AHALYSIS Sheet <4 or 17

IIIICommon Power Supply or Sensor:1

(Control System Affected:

1Y218 120 VAC

R a t*r Ran al Co carol ~Sstew~RN~CS CD 0160-004-015

CHID: 0160-004-U01


0160-OU4-671

Hev ~~

rDate: ~g~/~Date:


IFailure

Hbde



Summary:Effect Upon

Control System

Summ4TY'ftect

UponPlant Performance

3. PE-1H010, FT-IH009/Cooling water flow

4. IK600/Power supply

5. FE-lH006, FE-1H007/Drive header flow

c. Charging water header lOffpressure instrumentation:

1. PT-1H005/Pressuretransmitter

2. PISH-1H600/Pressure Iswitch

3. PAH-14604/Chargingwater high pressurealarm

. Loss of cooling waterflow indication

. Loss of instrumentation/control loop for pressure Icontrol I

I. Loss of drive water headers

flow indication

. Loss of charging water Ipressure signal to switch I

. Loss of high pressuresignal to alarm

. Loss of alarm signalindication


PAILURE NODES AND EPPECTS htthLYSIS Sheet lb ot 17

IIIICommon Power Supply or Sensor:


1Y218 120 VAC

Reenter Mater ~cl an ~ate ~Race

CEIL 0160-004-001

CD: 0160-U04-015


0160-UU4-671

IRj R~IRR R 'r.'ate:Date:

Component Nameand tlumber

II II Pailure I

Node



SummaryEffect Upon

Control System

II Summaryr

Efrect UponPlant Performance

1. Differential flow instrumen-tation:a. PT-1N036-RHCS inlet flow IOff

PT-1N012-RWCS blowdown Iflow IPT-lt(041-RWCS return flow ISRV1

. Instrument loops de-ener-gized

, RHCS Leak DetectionSystem

I

. Signal processing lost II

. Signal to isolation valvesINV-lP001, NV-1P004 lost

. RHCS system isolationprotection (in event ofhigh differential flowdue to RHCS systemleakage) is lost

I. RHCS system will continue l

to operate normally - If Isystem leakage is preseutlisolation will be pro-vided by the RHCS LeakDetection System

Fhcility: Susquehanna Steam Electric StationDocket: 50-387, 50-388

PAILURE HODES AND EFFECTS ANALYSIS Sheet re of I I


1Y218 120 VAC

Recirculation Flow Control

CSID: 0160-004-001

CD: 0160-004-015


6U-004-671

DateDate:


II Pailure

Hode



Summary:Effect Upon

Control System

Summary:Effect Upon

Plant Performince

1. Recirculation flow controlsystem:

a. H/A transfer station and IOffspeed control for Loop h I

IH/h transfer station and IOffspeed control for Loop 8 I

IHaster Controller IOff

Loss of the bus voltage I.causes the following to Ibecome inoperative: I

— Haster Controller— H/h Transfer Stations

A and 8- Speed Control Circuitry Ifor Loops h and B I

I. The fallowing reactor run-I

back signals are trans-mitted to auxiliary cir-cuits h and 0:

Scoop tube locking cir-cuitry permits recircu-lation pumps h and 8 tomaintain the flovs priorto loss of bus voltage

Hanual adjustment of the I.recirculation pump speed Ican be performed at the IH-G sets through posit-ioning of the scoop tubesI

Speed controls for bothrecirculation pumps arelost until:- Hanual speed ad)ust- .

ments are made

- Bus voltaye isrecovered

Reactor runback signalscannot be processed

. Recirculation flow ratemaintained at the valueprior to lose of busvoltaye I

I. Variation of the reactor I

power Level cannot beperformed unless the re-circulation flow ratesare altered via manualpositioniny of the scoop Itubes

- Lov flow from feedwatersystem alarm/relay- Low NPSH from feedwatersystem alarm/relay

~ Runback signals cannot be Iprocessed because of theloss of the above compo-nents

. Scoop tubes on the H-Gsets A and 0 vill lock in Itheir last positions priorIto the bus failure- Recirculation pumps

maintain previous speedI

Indicators for speed andspeed set point indicatezero


FAILURE MODES AHD BPPECTS AHALYSIS Sheet 17 of 17

I

II(Common Power Supply or Sensor:IIControl System Affected:

1Y218 120 VAC CSID: 0160-004-001

CD: 0160-004-015


016u-004-671

S>l 1 yl.gfl"

Date:

I.II


I IFailure

Mode


I I

I I

I System InherentCompensating Provision

Summary:Effect Upon

Control System

III

Summary:Effect Upon

Plant performance

I l. TIP control and monitor:

b. X-Y recorder/J600-1 I OffIIlOffIIII

d. Valve Control Monitor- 10f f

c. Drive control unit/J600-A-B

Purge circuit

a. Plux probe monitor/J600-2 lOff . Plux detection processingcircuit is de-energized-Ho signal input to X-Yrecorder

. Plotter drive circuit isde-energized

. Control circuit for pro-cessing signals to thedrive mechanism and in-dexing is de-energized

. Mechanism, computer andX-Y recorder pen lift

. TIP can be isolatedthrough either of thefollowing:— Isolation signal from

primary containmentreactor vessel iso-lation system

- Manual isolationthrough shear valveoperation powered offDC

. Cannot record TIP fluxsignals vs detection .

position

Loss of flux signals toprocess computer

. Loss of control capabil-.ity to successfully pro-cess signals to the driveland indexing mechanisms

I. Loss of ability to I

operate TIP - Core fluxlevels cannot be obtainedl

I


PAILURE MODES AMD BPPECTS AMALYSIS Sheet 1 of 2


IY219 120 VAC

Reactor a naal Con~trol a at n

CSID: 0160«004-001

CD: 0160"004-016

Job Mo.Prepared by:Date:Checked by:Approved by:

U160-004-671I

.I

Component Hameand Number

PailureMode



Summary:Effect Upon

Control System

Summary:Bftect Upon

Plant Performance

Ill. Control Rod Drive TemperI Monitoring:II a. Thermocouple TC-(185)I

b. Recorder R018

aturelIII IU'AIIIOff

. Thermocouple signals arenot processed

. Recorder is de-energized

. There are no inherentcompensating provisions

. Temperature signal fromthe thermocouple is notprocessed through thetemperature circuitry

. CRD temperature monitor-ing/recording is notavailable

. CRD temperature infOrma-tion is not available

. Potential CRD high temp-erature condition cannotbe detected


FAILURE HODBS AHD EFPFCTS ANALISIS Sheet 2 of 2

IIIICommon Power Supply or Sensor:

lControl System Affected:I

ly219 120 VAC

Reactor water clean~us~stem {Rw~cs

CSIDl 0160-004-001

CD: 0160-004-016

Job Ho.Prepared by:Date:Checked by:Approved by: Datet

D~z J~:::


II PailureI Hode

Symptoms and I,ocalEffects IncludingDependent Failures

Systeta Inherent ICompensating Provision

Summary:Effect upon

Control System

III

Summary:.Effect Upon

Plant Performance lI

1. Liquid radwaste/main conden-ser flow control instrumentslla. PSL-ltl013, PSH-1N014 IOff

SV-14438 I

. Plow control solenoidvalve SV-14438 de-ener-gizes 'shutting flow con-trol valve to condenser/liquid radwaste system

. Normal system flow returnlto feedwater system is Istill available

Nortaal operation of theRWCS is not effected

. Automatic operation ofisolation valve to thecondenser or liquid rad-waste system is notavailable

ILoss ot ability to uirecc IRWCS liquid to either Imain condenser or liquid Iradwaste system I

I

2. RWCS pump cooling water high Itemperature shutoff: Ia. TE-lH001A, B, IOff

TISH-lt{002hiB

3. RWCS temperature monitoring: Ia. TE-1N004/Inlet, tempera- IOff

tureTE-ltl015/Outlet, tempera-

tureT8-1tl019/Non-r e gene rat ivs- heat exchange

effluentTE-1N006/Regenerative-

heat exchangeseffluent

TB-1N043/Reactor bot tomhead drain

TT-ltl045/Temperaturetransmitter

. Pressure switch signals Ihigh or low have no affectlon solenoid valve since Iit is already closed on Iloss of power

Instrument loop de-ener-gized

. High temperature annun-ciators are inoperative

Instrument loop is de-energized

. No inherent compensating Ieffect I

. No inherent compensating Ieffect I

. High temp. shutoff pro-tection for RWCS pump is Ilost I

I. Ability to monitor key I

RWCS temperatures is lostlI


PAILURE NODES AND EPPECTS ANALYSIS Sheet 1, of 2 ..

IIIICommon Power Supply or Sensor: 1Y226 120 VAC CSID: 0160-004-001

Job No. 0160-OU4-I'llPrepared by:

Nev..4'ontrol

system Affected: Nuclear Pressure Relief CD: 0160-004-017


I I Symptoms and Local I+I Pailure I Effects Including

Dependent Pa i luresI NodeI


Summary:Effect Upon

Control System

SummaryEffect Upon

Plant Performance

IIl. SRV flow monitoring/DIV.

a. Vibration transmitterVT-14180 81-88

b. Vibration indicatingswitch (high)

II: IIIOffI

I(OffI

II

. Transmitter unable totransmit flow information

. Switch unable to indicate I

high flow condition I

IIIII

. Division I Safety Reliefvalve flow monitoringsystem is still available)(powered by a differentpower supply)

. Loss of Division II . Operator is unable toSafety Relief Valve flow I monitor safety reliefmonitoring capability valve flow for 8

Division II SRV's

I

I

Facility: Susquehanna Steam Electric StationDocket: 50-387, 50-388

FAILURE NODES AND EFFECTS ANALYSIS Sheet 2 of 2

IIIICommon paver Supply or Sensor:


1Y226 120 VAC

Reactor Mater Cleanu S stem RWCS

CSID: 0160-004-001

CD: 0160-004-017


0160-004-671

Nev. bDate: i'~Date: n


I I

I Failure INode



Summary:Effect Upon

Control System

SummaryrEftect Upon

Plant Performance

Il. Filter demineralizer tempera-II ture instrumentation: II a. TE-lN007, TE-1N008 IOff Filter demineralizer in-

strument loop is de-energized

. Alternate system hightemperature availablethrough TSH-1N020/TAH-14420 at the inletfilter demineralizer

. Automatic RMCS systemI shutdown Ipump andI valves) is disabledII

toIq Yprotection I

IIIIIIIIIII

. RMCS system will stillI operate normallyII. Operator action is re-I uired to ensure s stem I

Pacility: Susquehanna Steam Electric StationDocket: 50-'387S 50-388

PAILVRB HODBS AND EPPECTS ANALYSIS Sheet 1 of 3

I

IIICommon Power Supply or Sensor: IY629 120 VAC

I!cont!a! sYstem Affected: . Reantot manna! cont a~is t m JBa~cs CD; 0160-004-018

CSID: 0160-004-001

Job No.Prepared by:Date:Checked by:APProvef) bye

U16U-UU4-6 IlHev.i Zl ... ~

Date'ate:


IIl. Rod Drive Control Cabinet/P616:

a. Power Section

b..Activity Control

I II Pailure I

Hode

IOffI

)Off


. Loss of power to branch5unction modules

. Loss of power to logicpower supply IRDCC elec.)

. Loss of power to contactpower supply (externalcontacts to RDCC)

. Loss of input processingand isolation

. Loss of rod motion signalprocessing

. Loss of rod motionsequence timing signal


Can disconnect power tothe system if the selftest sub-system in theanalyzer determines amalfunction has occurred

. affect of loss of powerI in 1-a. is the overridingII factorI

. Loss of the activitycontrol is enveloped bythe loss of power

Summary:Effect Upon

Control System

. The ma5or effect on theRHCS is the loss of powerlto operate the HCU'sgtherefore, no rod move-ment is possible

. Command signals cannotbe processed

. The solenoid valves ifin operation will failshut) therefore, rodmovement will stop atthe nearest mechanicallatch position

. All modes of operationare lost — operatorcontrol, scan, and selftest

SummaryEffect Upon

Plant Performance

ILoss ot reactor power Icontrol through the RHcs I

. Loss of rod movementcapability during rodtesting

fI

c. Analyzer IOff

d. Branch Junction Nodule IOff

Loss of system signalcomparison device

. Loss of fault mappingcircuitry

. Loss ofCOHHAND'ord'ignal

processing tovalves

. Loss of power to trans-porter

. Effect of loss of powerin 1-a. is the overridingIfactor

Loss of the analyzer isenveloped by the loss ofpo'wer

Effect of loss of powerin 1-a. is the overridingIfactor I

ILoss of the transporteris enveloped by the loss Iof power

. There is also a loss ofelectrical output fromthe accumulator pressure/Ilevel limit switches,scram valve position,scram testNOTE: The loss of the

RHCS does notimpact on thescram function


PAILURE MODES AND EPPECTS ANALYSIS Sheet la of 3

I

II(Common Power Supply or Sensor:IIControl System Affected:

1Y629 120 VAC

R a tor Rannal a*astrol R taa~llllCS CD: 0160-004-018

CSID: 0160-004-001

Job No.Prepared by: (Date:Checked by:Approved by:

0160-OU4-671

Bev ~

Date;Date:


e. Transponder

I I) Pailure (

Mode

)Off


. Loss of command signalprocessing from the trans-Iponder to the directional Icontrol valves (HCU) I

I. Loss of power to the

directional control valves((HCU)

Loss of accumulator pre-ssure and the level limitswitch circuit

. Loss of the scram valveposition switch circuit

. Loss of the scram testswitch circuit

System InherentCompensating Provision j

IDirectional controlvalves fail shut on loss (

of power III

I

Summary:Effect Upon

Control System

Summary:Effect Upon

Plant Performance


FAILURE HODES AHD EPPECTS AHALYSIS Sheet 2 of 3

IIIICommon Power Supply or Sensor:IIcontrol system Affected:

1Y629 120 VAC

Recirculation Plow Control

CSID: 0160-004-001

CD: 0160-004-018


ig i''f:::Date.~ .+'lf


I II Pailure I

Hode



Summary:Effect Upon

Control System

Summary:Efrect Upon

1'lant Performance

Off

Peedwater system train B: IOff1. PT-10604812. PY-10604813. PSL-10604B1

Peedwater system train Cr IOff1. PT-10604C1 I2. PY-10604Cl3. PSL-10604C1

II l. Reactor runback instrumenta-

tion:a. Peedwater system train A:,I

1. PT-10604Al2. PY-10604Al3. PSL-10604A1

I. Low flow signal trans-

mitt

ted from the feedwate rsystem control of reactorrecirculation system run-back circuitry to aux-iliary circuits A and 8

. Relay contacts in theauxiliary circuitry logic Iare activated as part ofthe runback signal pro-cessing

. Bus failure will notsystem to react to therunback signal withoutthe following inputs toauxiliary circuits A and IB: I— Low flow input from I

feedwater system alarm Irelay I

I— Circulating water pump I

— Low HPSH input fromthe feedwater system

Reactor runback circuitryIis partially armed

. Plant performance is notaffected

. Recirculation flow isidentical to the flowprior to the loss ofpower

Pacility: Susquehanna Steam Electric StationDocket:

PAII URE HODBS AND BPPECTS ANALYSIS Sheet 3 of 3

IIIIComaon Power Supply or Sensor:IIControl System Affected:

IY629 120 VAC

Pressure Re ulator and T G Control

CSID 01'60-004-001

CD: 0160-004-018

Job NoPrepared by: ~Dater L. c.

Checked by:Approved by:

0160-004-671

Nev. O


PailureHode



Summary:Effect Upon

SummaryEffect Upon

Plant Performance

1. Non-redundant power supplieddevices

a. pirst stage pressurefeedback potentiometer

II

IIIIAs Is

b. PA/PA Cransfer potentio-meter

IAs IsI

c. Load reference motor lhs IsI

e. Pressure reference signal IOffmotor

f. Past-acting solenoidvalve - intermediatevalve/SV-10160A2 - P2

IAs Is

d. Bypass valve jack motor I Off

. Gain is not applied tothe signal which operates Ithe control valves at Istart-up

I. Hodulating control is not

transferred from the stop Ivalves to the controlvalves

. Automatic modulation ofthe load reference signal Ican not be conducted I-The power/land unbalance Icircuit cannot reset Iload signal automaticallyl

I

. Disable manual position-ing of the bypass valvesduring start-up and cool-down

Hanual control of pressurelset-point is disabled-No variable set-pointpressure for pressurecontrol unit's primarypressure amplifier

IIntermediate valve failshs Is

Inherent compensatingdevices unnecessary fornon-redundant powersupplied devices

The solenoid valves thatfail 'as is'ill beclosed by ETS only ifloss of load occurssimultaneously with loss Iof power supply I

. Loss of the AC bus vol-tage without PHG results Iin: I

Loss of 24, -22, 30 VDCII

— Blectrical trip system Idisabled I ~

I— Both master trip pilot I

solenoid valves of the IHaster Trip Solenoid Ibecome de-energized I

I. The Haster Trip Solenoid I

valve will close and Iresults in: I- Emergency Trip System I

actuates to trip T/G I

. At speeds sufficient to.operate the permanentmagnet generator IPHG),redundant power foressential devices issupplied— All 24, -22, 30 VDC

operated devices

. Although several regu-laCing control featureswill be unavailable, atrip will not occur when Ithe PHG is supplying Iredundant power I

I

ht operating speeds, de- Ivices without redundantpower supply either:— hre not required at

operating speeds

T/G trip is actuatedwhen pHG is not providinglredundant electricl Ipower - otherwise no Itrip will o««ur I

IReactor scram will occur Ifollowing T/G trip only Iif. reactor po~er is Igreater than 30% I

I

I

Pacility: Susquehanna Steam Electric StationDocket:

PAILURE HODES AHD EPPECTS AHALYSIS Sheet 3a of 3

II

Common PoMer Supply or Sensor:

Control System Affected:

1Y629 120 VAC

Pressure~Re ulator and~TG Control.

CSID: 0160-004-001

0160-004-018

Job Ho.prepared by:Date:Checked by:Approved by:

0160-004-6yl

Rev'Date:Date:


PailureHode



Summary:Pffect upon

Control System

Summary:Effect Upon

Plant Performance

h. Solenoid valve - bypassvalve/SV-1014A — E

i. Solenoid test valve-stop valve/SV-10142

IClosedIII(off

j. Reset oil valve solenoid/ lOffSV-10123 I

I

Ik. Lockout valve solenoid/ lOff

SV-10124

1. Oil trip valve solenoid/ lOffSV-10122 I

IIIIAs IsII

In. 'Closing solenoid - controllAs Is

m. Closing solenoid valveintercept valve/SV-10160C1 - Pl

valve/SV-10150A - D

g. Past-acting solenoid lAs Isvalve - intercept valve/SV-10160A1 — Bl

Intercept valve failsAs Is

. Bypass valves will failclosed - the bypass sys«tern is disabled

Inability to energizeprevents valve position-ing by chest/shell Marminglstop valve

Cannot be energized toreset mechanical tripvalve

. Prevents lockout valvefrom bypassing mechanicaltrip valve, whereby themechanical trip valveremains effective

. Valve closes and prevents Iacceptable hydraulicpressure by closing mech-anical trip valve

Intercept valve failsAs Is'

II

. The control valves millfail 'As Is'

fail as is and have ahydraulic backup systeml

I- 'Preeze'n its last Iconfiguration prior to Ithe failure of the ACbus

o. Past-acting solenoidvalve - stop valve/SV-10141A - D

As Is . Stop valve fails 'As Is'

pacility: Susquehanna Steam Electric StationDocket:

PAILURE HODES AllD EPPECTS ANALYSIS Sheet 3b of


1Y629 120 VAC

Sr ss ra Separator d~TG Co ntrolCSID: 0160»U04-001

CD: 0160-004-018


U16U-004-671

Rev. 0

Date;

Component Hameand llumber

I I

I Pailure IHode



Summary:Effect Upon

Control System

Summary:Effect Upon

Plant Performance

p. Solenoid test valve-stop valve g3/SV-10143

Solenoid test valve-stop valve l4/SV-10144

Solenoid test valve-intermediate valve/SV-10160A3 - P3

Il2. Redundant power-supplied

devices:.

IOffII

II

I

a. Speed control

b. Pressure control

c. Load control

d. Bypass control unit

IOffIIOffIloffIIIOff

e. Automatic pressure set- IOffpoint adjustment I

If. Hain steam sensor/PT-10101IOffIIIOffIII

h. Electronic pressure trans-IOffmitter in steam chest/ IPT-10102

Inability to energizeprevents opening andclosing of valve when Icontrolled by positioning Iunit in shell/chest warm-ing stop valve

. Loss of speed signals

. Loss of pressure control

Loss of power-load match-ing

. Loss of bypass system, to Idirect steam to condenser.lRequired system at low Ispeeds I

ILoss of pressure set-pointlsignal to other systems

. Loss of main steam pres-sure signals

. Loss of intermediatesteam pressure signal(power-level signal)

loss of steam chest pres-sure signal

At operating speeds, re-dundant power is availa-ble from the permanentmagnet generator IPHG)

Several devices areessential at low speedswithout redundant power-the emergency trip isactivated

rPacility: Susquehanna Steam Electric StationDocket:

PAILURE NODES AND EPPECTS ANALYSIS Sheet 3c of 3


1Y629 120 VAC

PCeSSue R~ ~latae ad T G Cantral

CSID: 0160-004-001

CD: 0160-004-018

Job No,Prepared by:Date:Checked by:Approved by:

0160-004-671

Hev.LDate: i7 2%1Date; m+/


I Symptoms and LocalPailure I Effects Including

Node Dependent PailuresSystem Inherent


SummdryrEffect Upon

Control System

Summary:Effect Upon

Plant Performance

Offi. Servo valve - controlvalve/XV-10148A - D

. Loss of control valvepositioning

$ . Servo valve — main stopvalve/XV-10141

Off Loss of stop valve 42positioning for chest/chell warming

k. Servo valve - intercept Ivalve/XV-10161A, C, E

Servo valve - bypassvalve/XV-10139A - E

l. Auto load following unit

Off

Off

Loss of intercept valvepositioning

. Loss of tracking signals

II

II

m. Prequency-voltage con- lOffverter I

In. Line speed matcher lOff

II

o. Chest/shell warming (Offcircuit and logic

p. Current/voltage converter lOffI

q. Rate-sensitive power-load lOffunbalance circuit I

Ir. Valve positioning units lOff

Is. Haster trip bus lOff

I

t. Position transducer - con-lOfftrol valve/ZT-10150A - D I

IPosition transducer — main lOffstop valve/ZT-10141A - D

. Unnecessary at low speeds I

. Loss of chest/shell warm-ing circuit. Requiredin start-up mode (lowspeeds)

Loss of converter

Loss of rate-sensitiveload control

. Loss of flow control

. Pails to energize

. Loss of position feedback Isignal to the positionunit in flow control

II

Ii

Pacility: 'Susquehanna Steam Electric StationDocket:

PAILURE NODES AND EFEECTS ANALYSIS Sheet 3d . of 3

III(Common Power Supply or Sensor:

(Control System Affected:

IY629 120 VAC

Pressure Re ulator and ~T G Control

CSID: 0160-004-001

CD: 0160-004-018

Job No.Prepared by:Date;Checked by:Approved by:

P. I Nev ~'ate:nate:


I IPa ilure

Hode II



Summary,Effect Upon

Control System

SummaryJEffect Upon

Plant Performance

Position transducer - lOffintercept valves/ IZT10160A1 - El I

IPosition transducer - lOffintermediate stop valve/ZT-10160A2 - P2

u. Haster trip solenoids Off . Doth solenoids de-ener-gized actuates EmergencyTrip System


PAILURE NODES AND EPPECTS ANALTSIS Sheet 1 of 2


PE-1N001A 8 C - Plow Elements


CSID: 0160-004-001

CD: 0160-004-020

Job No.

Date:Checked by:Approved by:

0160-004-671

~. s" Rev.

Date:


II l. Peedwater flow signal in-

strumentation:

I II Pailure I

Node



Summary:Effect Upon

Control System

Summary:Effect Upon

Plant Performance

Plow element/FE-1NOOIA> 0, C ~ IIPail Nighl.

IIIIII

Nigh flow level signalfrom 1 of 3 sensors willbe transmitted to levelcontroller


. Upon failing high, thefeedwater signals aresummed together and fedinto the control system

. The sensed floW rate willibe too high ta maintainthe desired level I

I

, The feed pumps will re-ceive a speed runbackcontrol signal from thelevel controller

There will be no atfecton plant performanceunless Lqvel 2 and 3'trips ale reached

. The reactor water levelsignal will in turncounteract the flow sig-nal and attempt tostabilize the water levell

Pail low II

Low flow level signalfrom 1 of 3 sensors willbe transmitted to levelcontroller

. There are no inherentsystem compensatingprovisions

I ~ Level 2 and 3 tripsmay occur in dynamictransient

. Upon failing low, thecontrol signal speeds up Ithe reactor feed pumps tolcounter lower feedwaterflow rates.

. There will be no affecton plant performanceunless Level 8 trip isreached

. The reactor level willrise and in turn attemptto counteract low flowsignal Level 8 tripmay occur in dynamictransient

~ Assumes failure of one element only, PNEA is the same for any one element failure.


PAILURE MODES AND BPPECTS ANALYSIS Shoot 2 of 2

IIIICommon Power Supply or Sensor:I(Control System Affected:


I IPailure I

Mode

Symptoms and LocalEffects IncludingDopendent Pailures

PE-1NOOlh 8 C - Flou Elements

~ Recirculation Plow Control

CSID: 0160-004-001

CD: 0160-004-020

II

System Inherent ICompensating Provision

+


SummarytEffect Upon

Control System

ISummary:


0160-004-671

kev. Dp~aJ ~ Date: ~. r-

Date t W P/

I

1. Reactor Runback SignalInstrumentation-FeedwaterSystem:a. Plov element,

PE-1HOOlh, 8 CIPail Night. Ho low flow runback

I signal associated withI instrument failureII

IPails Loul. Low flov signal trans-mitted from the feedvatersystem control of reactorrecirculation system run-back circuitry to auxil-iary circuits A and 8

. Relay contacts in theauxiliary circuitry logic Iare activated as part oftho reactor runback signallprocessing I


Recirculation controlsystem vill not reactto the runback signalwithout the followinginputs to the auxiliarycircuits:— iow flou input from

feedwater systemblare/Relay

— Circulating water pumptrip input

- Low HPSN input fromfeoduater system

Loss of ability to moni-tor actual low flow con-ditions from the failedinstruments

. Reactor runback circuitrylis partially armed

. Plant performance isnot affected

Plant pertormance isnot affected.

. Recirculation flow isidentical to the flowprior to instrument'sfailure

Assumes failure of one element only, PMEA is the same for any one failure.

Paciltiy: Susquehanna Steam Electric StationDocket: 50-387, 50-388

PAILURB NODES AHD EPPECTS ANALYSIS Sheet 1 of 1


Cascading Power Supply Effect1Y218 and 1Y219 120 VAC

See Note

CSID: 0160-004-001

CD: 0160-004-019

Job No.Prepared by: ~Date:Checked by:Approved by:

0160-004-671

Hev, O

Date:


I II Pailure I

Hode



SummaryEffect Upon

Control System

Summary:Effect Upon

Plant Performance

Note: Th e PHEAs for these power supplies are ad dressed individually under 1Y218 and 1Y219, respectively.I

Documents

FAILURE MODES ANALYSIS - nrc.gov · Summaryx Effect Upon Control System Summarya Effect Upon Plant Performance 1. Reactor feed pump turbine Ac I a. Trip circuit-Level 8 I trip contacts