XA04N2806

NRSC/R-4.88INIS-XA-N-233

SAFETY REQUIREMENTSfor

A NUCLEAR POWER PLANT ELECTRICPOWER SYSTEM

Prepared byS L.F FOUAD & M.A.SHINAISHIN

Nuclear Regulatory and Safety CenterAtomic Energy Authority

Date Published I June 198ft

NRSC

Of CONTENTS

1. InTRoducTIon 1

2. SysTem DescRIpTIon 2

2. 1 ^oweR DIsTRIbuTIon sysTem ^

2.2 THe A.C. ^owER SysTem ^

2.^ The D.C. i oweR SysTem ^

2.4 NoN-lNTeRRupTabLe A.C. ^oweR SysTem ^

2.^ DIeseL GeNeRaTors ^

. INfoRmaTIoN RequIremenTs FoR SafeTy

ANaLysIs aNd Review 6

. 1 INfoRmaTIoN To be SuppLIed by The Licensee 6

^.1.1 I RefeRRed i oweR SysTem 6

^.1.2 STandby ^owER SysTem 6

^.1.^ D.C. oweR SysTems 8

^.1.4 FIRe ^RoTecTIon foR CabLe SysTems 8

^.2 Scope of review by THe reguLaToRy body 8

^.2.1 ^RefeRRed ^oweR SuppLy 9

^.2.2 STandby ^Ower SysTem 10

^.2.^ DC ^oweR SuppLIes 11

4. GeneRaL DesIgN CRITeRIa for ELecTRIc i oweR

SysTem 11

. MeaNS for ImpLemenTaTIoN/ReguLaToRy guides

aNd BRaNcH TecHNIcaL ^osITIoNS 14

. 1 INdepeNdeNce BeTween RedundanT STaNdby( ONsITe)

^oweR sources aNd THeIr DIsTRIbuTIoN SysTems. 14

^.2 SeLecTIon of DIeseL GeneRaToR SeT CapacITy foR

STandby ^ower SuppLIes 16

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TabLE of CoNTEnTs

I^eriodic TesTIng of ^RoTecTioN SysTem

AcTuaTIoN FuNcTIons 17

Seismic Design CLassificaTion 18

QuaLiTy AssuRance RequiRemenTs foR The

InsTaLLaTioN, INSpecTiN and TesTiNg of

InsTRuMenTaTIon and ELecTrIc EquIpmenT. 1^

CRITeRIa for SafeTy ReLeaTed ELecTrIc ^oweR

SysTem for NucLeaR ^oweR ^LanTs 18

QuaLIficaTioN TesTs of CoNTiNuous DuTy MoToRS

INSTaLLed INSide The ConTainmeNT of WaTeR

CooLed NucLeaR ^oweR ^LaNTs . 19

^ReopeRaTioNaL TesTiNg of ReduNdaNT ONSiTe

ELecTRicaL ^oweR SysTems To VeRify ^RopeR

Load GRoup AssignmeNTs 20

Bypassed aNd InopeRabLe sTaTus INdicaTion

for NucLeaR ^oweR ^LaNT SafeTy SysTems. 21

AppLicaTioN of THe SiNgLe FaiLure CRiTeRioN

To NucLeaR ^oweR ^LaNT ^RoTecTioN SysTems. 21

MaNuaL INiTiaTioN of I^RoTecTive AcTions 22

ELecTRicaL ^eneTRaTioN AssembLies in

ConTainmenT STRucTuRes for LigHT WaTer-

CooLed NucLeaR T oweR ^LanT. 2^

IniTiaL TesT ^RogRams for WaTeR CooLed

NucLeaR i oweR ^LanTs. 24

QuaLificaTion TesTs of ELecTRic VaLve

OpeRaToRs InsTaLLed Inside THe ConTainmenT

of NucLear I ower ^LaNTs. 26

of CONTENTS

^HysIcaL IndependeNce of ELecTRIc SysTem 27

ShaRed EmeRgeNcy aNd SHuTdown ELecTrIc

SysTems for MuLTI^UnIT NucLear ^oweR ^LanTs 27

QuaLIfIcaTIoN of CLass IE EquIpmeNT foR

NucLeaR i oweR I LanT. 28

AvaILabILITy of eLecTRIc power sources 29

Seismic QuaLIfIcaTIoN of ELecTRIc

EquIpmenT foR NucLeaR T ower F LaNTs ^0

THeRmaL OveRLoad ^RoTecTIoN foR ELecTRIc

MoToRs ON MoToR OpeRaTed VaLves ^0

^eRIodIc TesTINg of DIeseL GeNeRaToR UnITs

Used as ON-sITe ELecTRIc F oweR SysTems aT

NucLeaR ^oweR ^LaNTs 1

INSTaLLaTIoN DesIgN and INSTaLLaTIoN of

LaRge Load SToRage BaTTeRIes foR NucLeaR

MaINTeNaNce, TesTINg, aNd RepLacemeNT of

LaRge Lead SToRage BaTTeRIes for NucLeaR

DIeseL-GENeRaToR ReLIabILITy QuaLIf IcaTIoN

TesTIng

RequIRemeNTs on MoToR OpeRaTed VaLves 1 ^

THe EmeRgency CoRe CooLing SysTem AccumuLaToR

Lines

Use of DieseL-GeneRaToR SeTs f o r Load

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of

^.27 STabILITy of Off-SITe ^oweR SysTem

^.28 ReacToR CooLanT ^ump BReakeR QuaLIfIcaTIon

^.29 DIeseL-GeneRaToR F roTecTIve Trip CIRcuIT by

Masses

^ ^ 0 ^ AppLIcaTIon of THe sIngLe FaILuRe CRITeRIon

To MaNuaLLy ConTRoLLed ELecTRIcaLLy-OpeRaTed

VaLves

6. ConcLusIoNS

RefeRences

AbsTRacT

woRk alms at IdentifYINg THe safety RequIRemENTs foR THE eLEctric

power systEm In a typIcal NucleAR power plant, I n views of The USNRC aNd

THe IAEA. DescriptioN of a typical sysTem is pRovided^ followed by a

pReseNtatioN of ThE scopE of THE InfoRmatioN RequIRed for safEty EvaLuatioN

of The system desigN and perfoRmance^

The acceptance and desigN cRiteria ^ ^ i musT bE mET as being SpEeified

by boTh REgulaTory sysTems, aRe compared. Means of ImpLemeNTaTion of

Such criTeria as beiNg described i n ThE USNRC ReguLATory guIdes and bRanch

TEchnical p o s I t i ^ ^ on one haNd aNd In The IAEA safety gu ta^ ON The other

haNd arE investigated. IT is concludEd that ThE IAEA REgulations address

ThE pRobLems That may be faced with In countries having vaRying grid si^es

Ranging fRom LARge stabLe To Small potENtiaLLy unstaBLE oNes; and that

ThEy put Emphasis on ThE onsitE standby power Supply. Also, i n This RespeCT

The Americans ident i fy the gr id as ThE pREfERREd power supply to The plant

auxi l iar ies, whiLE The IAEA Leaves the possibiLity ThaT The pRefeRREd

power suppty couLd bE Either ThE gr id oR The uniT mrin geneRAToR depeNring

on The Rel iabi l i tY of Each. TH^EfoRE, it is found that it ^ paRticulaRly

NEcessary In Th^s aRea of clEcTric power supplies To dEal wiTh The IAEA

and The American SEti of REgulations as i f Each compLeMents and noT

SuppLEmEntS ThE other.

1 INTRODUCTION

T h ^ paper pResEnTs a compREhEnsivE coveRagE of The REgulaTory

REQuiREmEnts coNCERNIng ThE ELEcTric ^ower Supply (E^S) To a NuclEaR ^ower

^ ^ 1 (N^) i n gENERAL, and To EnginEered SafEty FEatuRes (ESFs) and Safety

RELated EQuipmEnt i n paRticuLaR. IT also aims at making a c r i t i cAL

comparison bEtwEEn ThoSE REQuIREmENts as being described by ThE United

States NuclEaR REgulaTory Commission USNRC, and by The InTeRnationAL Atomic

ENergY IAEA REguLations.

ThE scope of This woRk ExTEnds from out l in iNg ThE infoRmation nEcessary

To ENABLE foR maKing a SouNd ETS EvaluatioN, IdEnt i f y ing ThE GENERal DesigN

^ 1 -

- 2 -

CRiteria GDC THat muST be f u l l f l l e d in order To assurE a safe desIgN and

ReLIabLe perfoRmaNce, and ENds witH a descriptioN of THE methodoLogY ThaT

shouLd bE followed IN order To achieve a good impLementatioN of Thos

However, it SEEmed NEcessary To fiRST pRovidE a brief dEScription

of a typical E S foR a N^ , and THat wHat was donE THRough ThE following

SEction. ThE comparison paRAllELs EAch of The subJEcTs (infoRmation,

criTEria, and mCThodoLogy) iNcluded i n ThE Siudy. A gEneRal coNclusioN

is madE at The end; and REferENCes aRE LisTed.

2 SYSTEM

ThE ELEctrical power sysTems at a NucleAR power plant aRE designed

To providE diveRSE ReLtabLE powER souRces To plant componEntS and EquipmEnt

i n additioN to s^pty ing power fRom ThE plant To ThE of f -s t iE trAnsmissioN

neTwork. ThE stat ion power is supplied by Either The of f -s i tE mrin

disTribution grid oR by The unIT maIN gEneR^ToR. In CASE of Loss of o f fs i tE

power supplies, Including uniT gEneRAToR^ and the gr id, the power REquIreD

foR safE shutdown of THE ReaCToR is Supplied fRom diesEL gEneRatoRS Located

on-site and known as THe standby AC power Source.

ThE station cleCTrical system ^ designed to ensuRE ELECTrical

isolation and physicaL separation of The The Redundant power supplies

foR stat ion equipment REQuiRed for safeTy; and due to liMitations Imposed

by The power whicH can bE dElivered by thE dIeseL genEratoRS thE UN T

power suppty is spl lT beTwEEn ENgiNEered Safety FEatuRe^ (ESF) buses

which can bE SupptiEd by The diesELs, and non-ESF buses.

Redundant trAIns of EngineeRed Safety FEatuRes equipmEnt aRe maintained

ELEctrIcally SEpaR TE by having each TRain powered by I t s own diesEL.

This EnsuRes t^^T a sIngLE active faILuRe (e.g., Loss of a diescl) w i l l

noT JeopaRdi^e a Safe shutdown of The REacToR.

BaTtaries aRe pRovided as a source of power for vitaL instrumEntation,

bReaker contRolleRS, emergencY llghting, eTc. In ^SE of station blackoat,

i . e . TotaL Loss of plant o f f - s i t e and on-site AC-power, baitaries are

In view of ThE USNR unit gENERaToRS ARE considered parT of The of f -

SitE power supply bEcauSE Loss of ThE griD ^ assumed to automaticaLLy

Lead To Loss of The unit gEneRAToR

ESFs include eQuipmEnt REquiREd foR SafE ReacToR shut down, ResIduAL

hEat rEmoval, and Radiation coNfinEmEnt.

ThE oNty souRCE of power LefT^ They are maIntaInEd f u l l y chaRged by baTtary

chARgers fRom so- ca l led v i taL b u s ^ which arE fed fRom ThE ESF buses vta

FIguRE 1, bclow, shows a typIcal ELect r Ica l power SySTem of a NucleaR

power s ta t i oN , a descr ipt ioN of which is given

2^ 1

To The g r i d ^ Supplied fRom The mriN gENeratoR ThRough ThE

maiN power TRAnsfoRmer. THE s t a t i o n d i s t r i b u t i o n buses (1^.4^ ^v b u s ^

CAN REceivE power EitHer from THE mrin gEnEratoR ThRough ThE uniT

transfoRmer OR from ThE gRid through ThE s ta r i up transfoRmer.

2^2 THe ^ C ^

ThE s t a t i o n AC power system has four 4160 v o l l buses which REceivE

power fRom ThE two 1^.4^ ^v distrIbutioN b u ^ ^ vta two u n t i substat ion

transfoRmerS and individual bREakERS. Two of thesE buses aRE EnginEerED

SafEty FEataRE (ESF) buses, The other two cARRy servicE Loads wnich ARE

noT ReL^ed to emergencY safEguards. ThE two non ESF buses arE capable

of being cRoss coNnECTed. ThE ESF b u ^ ^ havE pREfERRed power coming fRom

The s ta r i up transfoRmeRS, w t ih The power coming fRom THe uNit TRAnsfoRmer

during NoRmal p lan t opeRatioN. A l l 4160 v o l l buses suppty a 4^0 voLT

d i s t r i b u t i o n system ThRough Load cEnter step-down TransfoRmers. THE 4^0

voLT system R e c c i n g power fRom tHe two ESF buses is compLeTeLY isolaTed

fRom that REceiving power fRom THe other two 4160 v o l l non-ESF buses^

ESF LoaDs are divided beTwEEn thE mrin 4160 v ^ T buses Such tHat ThoSE

The same funct ion are suppl ied fRom differEnt souRces.

The DC power supply system, shown i n F ig. 1, consists of onE ^ 0 voLt

DC and two 12^ voLT DC sysTems desigNed To pRovide an adequate and RELtabLE

SourcE of continuous DC p o w ^

ThE 2^0 voLT DC system Supplies power fo r LARgE DC motoR-drivEn pumps

such as THE EmergEncY bEaring o l l and emergency SEaL o l l pumps. This

system is not esSEntial foR a SafE shat-down of ThE p lant . IT has I t s

owN batTEry, batiERy chaRger and diStributioN bus, and is Located in I t s

own SEpARatE vEntiLated Room in THE Turbine buiLding.

The two 12^ voLT DC systems supply power foR emergency tighting,

DC contaoL funct ions foR ciRcuIT breakeRS^ various RELays, SoLEnoid valves^

NuclEar instrumEnTatioN, AC iNveriERS and smal l DC motoR drivEn Equipment.

THis equipment ^ pa r t of The ESFs, and ^ Located i n The auxiL iary

IT ^ comprised of two baTTEries, Each having two batiERy

cHaRgeRS powered fRom RedunDANT b u s ^ aNd The NEcesSARy disTribution

This portion of ThE sysTem is designed to pRovidE reLiabLE eLEctric

power foR conTroL and instrumentatioN. IT consists of 120 voLt InsTRumEnt

AC-aNd pREfERR^ AC SySTems ThE 120 vo l l Instrument AC sysTem contains

THREE buses aNd supplies contRoL and instrumENtatioN power foR EQaipmEnt

noT ReQuiRed foR The safE shutdown of The ReactoR.

ThE pREferred instruMEnt AC sysTem supplies continuous and RELtabLE

120 voLT AC power REquiRed foR safE shut-down of ThE REacToR

THE pREfErred instrumEnt AC system, compRised of fouR ESF-RELated

buses, supplies ReLiabLE 120 voLT AC singLe-phaSE power to ThE ESF channeL

EqaipmEnt and The ReactoR pRoTection chanNELs. Each pREfERRed instrumEnt

AC bus can be supplied from one of ThREe SouRces of power as sh^^n in

Fig. 1. ThE noRmaL SouRCE of power is I t s associated s ta t i c inveRTer wnicH

Receives i t s power from an ESF 4^0 voLT motoR center. THE backup pow^^

supply foR The inveRTERS is a connection to the 12^ voLT DC stat ion

batieries. I f it is necessary to take an invEnter ouT of servicE, i t s

pREfeRRed instrument Bus may be manuallY transfeRREd to ITs associated

1 0 vo l l InstrumEnt AC bus. THE two Incoming fEeder bReakeRS foR EacH

pREfERRed Instrument AC bus aRe manuaLLY opERated and mEchanicaLLY

InterLocked to pRevent boTH bReakeRS fRo^ being closed at THe same time.

In casE of Loss of o f f -s i tE power, ThE eQuipment esseNTIal to safe

shutdown of The pLAnt wiLL bE supplied by The diescl gEnERatoRS. DieseL

genERAToRS automaticAlly staRT and tiE i ^ the 4160 voLT vitaL b u ^

on a Loss of voLtage on The bus. Each diesEL ^ designed to REach Rated

spEed and voLtagE wi tn in Ten SEconds ^f Receiving the StaRT signal, and

to automaticallY accepT ESF LoAds i n a spEeified sequence^ To pREvEnt

oveRLoading and Tripping THE diesEL, ThE maJoR Loads aRE Tripped off bEfoRE

ThE diescl bREaker closes. The LaRgE Loads wILL then be seQuenced back

one at a time. The entiRe sequEncE takes about ^0 SEconds ANd ^accompLished by an automatic SEquEnc^ The seQuencer pRevents oveRLoading

by pErioRIti^ing vitaL EquipmEnt among thE^SELves.

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SAFETY

In THis sectioN we pResENT THE infoRmatioN wnicH sHouLd

concerning ThE eLEcTric poweR SY^Tem, by a licensEE of a nuclEAR power

p lan t as paRT of THE sa fe ty aNalysis RepoRTs. This sect ion s h a l l aLso

includE iaEntIfIcatioN of ThE scope of clEctric power systEm REview To

be perfoRmed by THE REgulaTory body^

HowEv^ bEfoRE going inTo thesE subjects we havE to cLar i f y the

dIf ferEnce beTwEEn thE American and THE IAEA ReguLAtions regaRDing THEIR

difIniti0N of ONE Of THE TERMS Wnich is COntiNUOUSly REfERRed To i n W^^T

fo l lows; nameLy ^thE pREfERRed power sysTEm^ ThE o f f - S i t e powER sysTem

is known i n ThE AmericAn INduSTry StandaRDs and NucleaR REgulaTory gaides

to be The pREferRed p o ^ ^ SysTem ^ 2 ^ IT includes two oR moRE i d E n t i f i e d

power souRces capabLE of opeRating idEpEndEnt of THE on-st iE (standby)

power sources; and Encompasses^ THE g r i d , transmission lines (overHEad

oR undergRound) , trAnsmission llnE toWERS, transfoRmeRS, switchyard

and contRoL systems, SwitcHyaRd battery systems, THE mrin

and d^sconneCT switches. In The IAEA REguLations REf. (^^, THE

pREfeRRed power system may be EitHer THE clEctric g r i d , oR The unIT mrin

gEnERatoR. ThE REiabiLi ty of Each SysTEm contRols ThE seLEction of The

pRefeRRed poweR suppty wr ich shouLd bE thE moRe RELiabLE of ThE two.

To be

In view of thE American ReguLAtions, infoRmation to be suppl ied by

licEnseE shouLd cover Those

1 ^REfERRed

ThE c t rcu i t s that suppty power fo r safCTy Loads fRom The TRansmission

network shouLd be i d e n t i f i e d and shown To meet voLtagE LEvcl and Length

of Each trAnsmission tinE from THE s i t E to ThE f i r s t major substa t ion

THat connects THe tine t o The grid^ Descr ipt ion and layout drawings of

The cIRcuITs T ^ T conneCT THE onsitE d i s t r i b u t i o n system to The pREfeRred

power suppty, incLuDing trAnsmissIoN Lines, switchyard arrangEmEnt, rights

of way CTc. shouLD also be provided^

The resuLTs of stEady s ta tE and t ransIEnt s t ab IL i t y analysis shouLD

be given. Information and discussion of g r i d ava ILabI l i t y , Inc lud ing the

frequency, Duration, and cAuses of o u t a ^ ^ must be provIded^

^^1^2 Standby ^ower

Descript ion of the on s i t e AC power systEms w i t h Emphasis placed

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on ThoSE poRtions of THE sysTem which arE safety RelaTed muST be

THose poRtions T^T are not RElaTed to safEty NEed oNLy to bE described

IN suff IeiEnt dEtaIL To pERmit an undERStanding of TheIR IntERActions

witH THE safEty ReLated p o R t i o ^ The description of The safety RelaTed

portion shouLd iNclude^

(I) 1 ^ ^ Suppty FeedeRS.

(^) Busing ARRANgemEntS.

(^) Loads Supplied from each bus^

(4) ManuaL and automatic IntercoNnEctions between buses

and Loads, and buses and S u p p l l ^

(^) InterconnEctions beTweEN safeTy RELated and NonsafEty RELated buses.

(6) ReDuNdAnt bus SEparatioN.

(7) EQuipmEnt CApacities.

(8) Automatic LoadiNg and Tripping of

(9) SafEty-RELated EQuipmEnt

(10) Instrumentation and contRoL systems for tHE appllcabLe power systems

wtih The assigNed power suppty idEnt i f i ca t ion .

( I I ) ELEcTric ciRcuit pRoTEction System neTwoRk.

(1^) ThE schemE foR TestiNg thesE systems during power opeRation.

(1^) Any systems and equipmEnt shARed bEtwEEn uni ts.

The basis foR thE power REQuiRed foR Each safety Load shouLd bE given.

The continuous and shoRt teRm Ratings foR thE on-stiE power SouRcE shouLd

bE given.

ThE following design aspecTs of thE onsitE EmergEncY eLEctric power

souRces (e.g. d iescl gENeRatoRS) shouLd be described i n tHE Safety Analysis

(1) StaRting i n i t i a t i n g ciRcuits.

(^) Starting mechanism and system.

( ^ ) Tripping dEvices .

(4) IntERLocks and pERmissives.

(^) Load sHEdding cIRcuits

(6) TestabiLitY

(7) FueL o l l stoRAgE and transfer systEm.

(8) Coollng and hEating systems^

(9) InstRumentation and contRoL systems, incluDIng status

aLaRms and indIcations wtih power

(10) Prototype QUALIfIcation

^ 8 ^

Any fEaTu^s or componenTs NoT pRevIousty used IN simILar applicAtions

In nucLeaR gENeRating stations sHouLd bE ideNTIfIe^ SIngLe Line diagRam

of The onsite AC disTributioN sysTems, IncLuding IdENtifIcatioN of a l l

safety Loads' shouLd bE pRov id^ ThE phYSIcal aRraNgEmEnt of ThE components

of The SysTEm shouLd be dEScribed I n suf f IcIEnt deTaIL to peRmit INdEpENdEnt

vErif icatioN That singLE EvEnTs aNd accidEntS w i l l not disabLE ReduNdant

fEatuRes. ^lant tayout dRawIngS shouLd bE suff ieiEnt To peRmti evaLuatioN

of ThE phYSical sepaRation and isolatioN of RedUNdant poRtions of The

SysTem. A tabLe That ILLusTRates The aatomatIc and manual Loading and

unLoading of Each standby power supply shouLd bE provided^ ANALYSis To

demonstratE compllance wtih REguLatory REQuIREmEnts Ident i f ied I n The

following SEctioNS shouLd bE made A l l Safety ReLaTed EquipmEnt which

is expECTed to operate i n a hoStiLE EnviRonmEnt due To RAdIation,

TempERaTuRE, pResSuRE, and humidity following a poSTuLated accident shouLd

bE Ident i f ied, a l l Such conditions shouLd be tabuLated, and The completion

of appllcabLe quaLIfication Tests OR plans and scheduLes foR perfoRming

incompLeTed Tests shouLd bE DocumEnted.

ThE mEa S proposeD to Distinguish betWEEn Redundant cLass IE sysiems

and iTs associaTed cIRcuITs on onE hand and The non-cLass IE system on

THE other hanD, shouLd bE described.

^. 1 ^ D.C. ^ower SysTems.

A description of The DC power SYSiems wnich cleaRLy dEfinE THE safety

RElaTed portion^ shouLd bE pRov id^ THE description shouLD includE

REquiRemEnts for SEpaRation, capacity, charging, vEntiLAtion, Loading

Redundancy, and Testing^ ThE Safety Loads shouLd be cleaRly ident i f ied

and The LengtH of time ThEy sHouLd be opeRabLE i n ThE EVEnt of Loss of

aLL AC power (i^e^ stat ion blackouT) shouLD bE s t a t ^

Analysis to demoNSTRatE comptiancE with safety ReQuiRements shouLd

be made.

^.1.4 FIRe ^RoTection foR CabLe

The mEaSuRes EmpLoyed foR THE pRevention of and pRoTEction againsT

f i res i n eLEcTrical cabLes shouLD bE REferEnced. however, The following

shouLd be Described^

a) CabLe deRating and cabLe TRAy f i l l , and

b) FIRe baRrieRS and SEpaRation bE^Een RedundAnt

^^2 Scope of Review by

The infoRmation to bE pResEnted in This SEction compLEmEnts (and

- 9 -

does NoT itERatE) t^^T gIveN in sec^ ^ 1 In deallng witH THe safety aspects

of a NUcleaR powER pLAnT eLecTric power supplies^ IT ideNt i f ies tHose

features T^^T sHouLd be emphasi^ed i n view of The AmeRican REgulaToRy

^RefERRed

ThE pRefERRed power sysTEm aRRANgEment ^ RevIEWed To dEteRmInE THat

ThE ReQuiRed minimum of two SEpaRatE ciRcuiTs fRom THat sysTEm To

THE standby power disTributioN system ^ p r o v i d e

ThE indepEndencE of THe pRefErred power system wi th respECT to ThE

standby power systEm is Evaluated^ The scope of REview ExTEnds to

The SafEty RelaTed disTributioN sysTem buses That aRe capabLe of

being powered by standby power souRces. IT does noT includE ThE supply

bReakeRS of The safety-RelaTed distr Ibut ion sysTem b u s ^ This

evaLuation wILL IncLude a Review of The clEctrical pRoTEctivE RELaying

and bREaker controL cIRcuITs and power supplies to assuRE that Loss

of ONE pReferRed systEm cIRcuit wILL not cause OR ResuLt i n Loss

of thE RedunDant par i noR any standby power system.

Design information and anaLysis dEmonstrating ThE su I t ab i l i t y of

thE power sources, trAnsmission lines, bREakeRS, and ^ ^ ^ 0 ^ ^ ^

used foR supptying pREfERRed power fRom a distant SOURCE aRE REviEWed

to asSuRE ThaT each path has SuffieiEnt capacity, capabILity and

RELiabILity To p^oRm I t s IntEnded function.

ThE InsTRumEntation REQuIRed foR monitoring and inDIcAting ThE status

of thE pRef eRREd powER system ^ REvIEWed to assuRE that any changE

I n thE pREfERRed powER system which wouLD pREvEnt ti from perfoRming

ITS IntEnded function w i l l bE ImmEdiatEly idEnt i f ied by thE contRoL

Room opERatoR. A l l inStrumEntation foR i n i t i a t i n g safeTy actions

associated wt ih the pRef ERRed power system aRE aLso REvIewed.

^REopERatIonal and 1 ^ ^ ^ ^ staRtup tests and pRogRams anD periodic

test ing CApabilitIes aRE REviewed.

The Review shouLd aLso incLudE.^

a-EnviRonmEntaL conditions foR thE pREfERRed power system To deteRmInE

any EffEct on function^.

b-QuaLity gRoup classif icAtioN of EQuipmEnt of thE pREfeRRed power

system, and

c-ThE EQuipmEnt and fuNctions of thE pREfeRRed powER systEms

ARE used as a basis foR assumptions i n tHE accIDEnt

Standby

The following fEaTuRes of THE standby power sysTem aRE To bE

1- ConfoRmancE witH THe SingLe FaILuRe CriTerIoN^ IN This REgaRd boTh

eLectrIcal isoLAtioN and physIcaL sepaRatioN of ReduNdant power sources

and associated disTributioN sysTems aRE Examined to assess THE

INdEpendEncE beTwEEN Redundant poRtions of ThE sysTEm.

2- Standby and ^REferred (o f f -s t ie ) ^ower SysTem Independence^ ThE

scopE of REvIEW shouLd covER ThE Station disTribution Load cEntERS

wnicH aRE powerEd fRom ThE uniT transfoRmer and ThE StaRTup

transfoRmer. IT shouLd aLso IncLudE THE Supply bReakERS connecting

The (Low) side of these trAnsfoRmeRS to The d is t r Ibu t ion buses

incluDiNg TheIR contRoL ciRcuITs and power suppty.

^- Standby ^ower S u p p ^ DiesEL gEnERatoRS capacity, and RELiabiLIty

to perfoRm ThEiR intended function sHouLd be dEmonsTRatEd. THis

includes an Examination of ThE charactEristics of Each Load and ThE

Length of ^ ^ each Load is RequiRed, THe combined Load dEmand

connECT^ to eacH diesEL gEnERatoR during THe woRST opeRating

conditions, automatic and manual Loaring and unLoading of EacH dieseL

gEneRatoR, voLtagE and fREQUEncy REcovery cHaRaCTeRIsticS of The

diescl generatoRS, continuous and sHori teRm Ratings foR THe aiesEL

gEneratoR Tests and aLLowabLE faiLuRes to demonsTRatE accEptabiLity,

and s ta r i ing and Load sHeDring ciRcuits. In addit ion, wHerE THe

pRopoSed Design provides fo r The connEction of non-safeTy Loads to

THE diesEL gEneratoRS OR sHaring of dieseL gENERAtoRS bEtwEEn nuclEaR

units at THE Si tE, EmphASis is To bE gIvEn To THe poss Ib i l i t y of

^RgInaL CApacity and degRAdation of ReLiabI l i ty that may Resuit,

and THE adeguacy of such design to mEET ThE singLE faILuRE cRiterioN.

4 VItaL SuppoRting SysTEms The InstrumEnTation, contaoL cIRcuITs,

and power connEctions of vItaL SuppoRting sysTEm aRE examined To

deTERmInE that ThEy are desIgned to The same cr iTer ia as ThoSE foR

The cLass IE Loads and power systems that ThEy SuppoRT. Th^s shouLd

includE examination of The vItaL Supporting sysTem compoNEntS^

Redundancy, power feed assIgNMEnt to InstrumEntation, conTRoLs and

L o a ^ I n i t i a t i n g ciRcuITs, Load chaRACTeRistics, And Equipment

iden t i f i ca t ion SchEmE and quALification. DesIgN cr iTEria and bases

foR The InstaLlat ion of Redundant cabLes shouLd be ver i f i ed , and

The means and scHEmes pRopoSed foR IdEnt i f Ica t ion of cabLes, RAceways,

and TeRMInal eQuipment shouLd be evaluated^

TestiNg and SuRveIllaNce^ ^REopERatioNal and INIt iaL startup

TesT pRogRamS aNd periodic 0N-sitE TestiNg capabILities aRE To be

Review^ The means pRoposed foR auTomaticAlly monitoRing ThE status

of system opeRAbility shouLd be evaLuated.

^ 2 ^ DC ^wer Supplies

DC SysTem RELEVAnt REvIew items simiLaR To ThoSE foR THe standby AC

power sysTem shouLD be consiDered^

ELEcTricaL drawings including voLtagE prof l lE curves^ dischARgE raTE

curves^ TempeRaTuRE effect cuRves, aNd ELEcTrical DIsTribution diAgRAmS

IncludiNg Load IdenTIfIcaTIon^ ShouLD be provided^ TabuLatioN of a l l safEty

RELated Loads To bE conNEcTed To Each DC Suppty, tHe chaRAcTERisties of

Each Load and ThE bases us Ed to establish ThE power REQuIRed To eacH Safety

Load sHouLd bE estabLisHed^ QuaLification TesT pRogRam, and TesT ResuLTs

demonStRating THE Sui tab i l i t y of the battaries and batTery cHaRger as

DC power supplies ShouLd bE described.

The IAEA REguLations (^ addresses this subJecT of The ELEcTric power

Suppty system infoRmatioN NEcessaRY foR SysTem SafeTy EvaLuation, by

indIcatiNg That a discuSsIon of the System ShouLd bE gIvEn. Emphasis ShouLd

be put on fEatuRes wnich aSSuRE continuity of power for safety nEeds.

REliabiLity anAlysis of The power souRces, THE distrIbutioN systems, and

EqaipmEnt sHouLd aLso bE givEn.

ThE dis t r ibut ion and intercoNNEctioN of clEctrical supplies witnin

THe nuclEAR poweR plant ShouLd bE shown. ThE aRRangEment of bus bars,

ThEiR switcniNg and Loading, and ThEiR physical SEpaRation, inDepEndEncE

and isolation wheRE appRopRiaTE, ShouLd bE discussed.

The ARRAngeMEnt of conNEctions to The mrin gr id, THe geNeRal

oRgari^ation of THE neTwoRk (grid) and The IndEpEndEncE of THe exTernal

souRces of power suppties to The NucleAR plant sHouLD bE shown^ ^RotEction

fEatuRes foR THe transmission lines and tRAnsfoRmERS, THe Local

ENviRONmenTaL factoRS T^T can affEct THe gr id RELiabilIty shouLd aLso

bE discussed. AliernatE ENergy souRc^ exTernal or inteRnal, shouLd be

described i n teRmS of the i r ReLiability, ThEiR indEpendEnce and adequacy

of thEiR capacity^

4^ GENERA DESIGN CRITERIA

FOR ELECTRIC ^ E ^ SYSTEM

AccEptancE c r i t e r i a foR eLEctric power system ^2,6^ aRE pResEnted

i n THis SEction. ImpLemEntation of t h ^ E c r i t e r ia w i l l provide asSuRAncE

safeTy RElated clEctrIc power systems w i l l perfoRm design safety

- 12 -

fUNCtions as REQUIRE

Off-s i te power sysTem pRovIded descriptioN Is consIDered acceptabLE

whEN it CAN bE coNcLuded That ThE InteRRELatioNShips betweEN ThE NuclEaR

unt i , and ThE interconnEcting gr id ARE clEaRly d e ^ ^ The Ident i f ica t ion

of safety Loads is acceptabLe whEn it can be concLuded t^^T a l l systems

and dEvIces That REquIRE clEcTric power (AC OR DC) to perfoRM safety

functions are desIgNated.

Acceptance of ThE pRoposed TEchNIcal spEeifications ^ based on THE

avaIlabiLity of SuffieiEnt EQuipmEnt To mEeT ThE sIngLE faILuRE criTeria

under The Limiting coNditions for opERation, and on That ThE pRovisIons

of ThE TEchnical speeifications ARE compatibLE w^th The safCTy analyses^

THe ELecTric power sysTEm ^ acccptabLE I f it satisfIes GEnERal Design

CriTERia GDC 17 and 18 ^ wnich aRE cITed bELow duE to theiR almost

importance. HowEv^ power sysTem sHaLL aLso satisfy GDC-1 concerniNg

The QuaLity assurance, TestiNg, and sysTem opERAbility SuRvEIllance.

GDC for pRoTEction againsT NaTuRal phEnomEna, GDC- foR fIRE pRoiEction,

GDC-4 foR pRoTEctioN agaInsT missiles, GDC- In case of sharing ThE onsitE

pOWer Supplies bEtWEEN twO (OR mORE) NUclEar UNitS ON ThE SamE SitE,

GDC 1 ^ 1 , ^ , ^ , ^ , ^ , ^ a^d ^4 with REgaRd to providing adequatE, capabLe,

and ReLIabLE power supplies to ReacToR pRoiEction, ReacToR makE up, Residual

hEat REmoval, EmergENCY coRE coollng, coNtainmEnt hEat REmov^ containment

atmosphere clEan up, and cootiNg water systems, RespectivEly. IN addition

The DC power system ShouLD Satisfy GDC- 2 wrich concerns REaCToR pRoiEction

SysTEm indEpendEncE.

Cri iErion 17 ELEctric Rower SysTem

An onsitE clEctrIc power sysTem and of fs i tE eLecTric power sysTem

shal l be pRovIded to pe^^T fuNctioning of sTRucTures^ sysTems, and

componenti impoRtant to safety^ ThE safety function for Each sysTem

(assuming The other sysTem is NoT fuNctioNing) shal l be to pRovide

SuffieiEnt capacity and capabiLITy To assuRE ThaT^

( 1 ) SpEcIfIed accEpTabLE f ueL desigN 1 1 ^ 1 ^ and design condItions of

The ReacToR cooLant pRessure boundary aRE not ExcEedEd as a ResuLT

of antieipated opeRatio^aL occuRences, and 1 ^ ^

(2) ThE coRE is cooLed, and contaiNmEnt InTegrity and other v i t a l functions

are maintaIned In ThE EVEnt of poSTuLated accIdEnts.

ThE onSitE clEcTric power supplies IncludI^^g ThE baTtaries and THe

onsite eLEctric disTribution sysTem sha l l havE suffIeiEnt independEnce,

and TestabILIty To perfoRm Their Safety functions assuming

a singLe faILure^

ELectric poweR fRom THe TRAnsmissIoN nE^oRk To the 0NSite eLecTric

disTributioN SysTem sHall be supplied by two pHysIcAlly INdEpENdEnt cIRcuITs

(noT Necessarily ON SEparaTE righTs of way) designEd and Located so as

To minimi^E To The exTenT pracTIcal The llkELihood of Their sImuLtaneous

faILuRE uNder opERating and poStuLated accIDent and enviRonmental

coNditions^ A switchYaRd commoN To both ciRcuits is acceptabLe. Each

of these ciRcuiTs sha l l bE desigNEd to bE avaILabLe in suf f Ie ient time

following a Loss of a l l onsitE aLTernating cuRREnt powER supplies and

The other o f fs i te eLectric power ciRcuits, To assuRe ThaT spEcif led

accpeTabLE f ueL desIgn LImITs and desIgN condItions of The^ ReACToR coolant

pRessuRE boundary aRE noT exceeded. One of thesE cIRcuITs shaLL bE designed

To bE avaiLabLE witniN a few SEcoNds following a Loss of coolaNT accidEnt

To assuRE that coRE cooting^ coNTaiNmEnt integRity^ and oTher vitaL Safety

fuNctions are maintaiNed^

^Rovisions shaLL be iNcluded To minimise The Loss of any of The two

(of f -s t ie and 0N-sitE) power systems as a ResuLt of Loss of The o T h ^

CritERion 1^ . InSpecti^N and TestiNg of ELectricAL ^ower

SysTEm

^ower sysTemS impoRtanT to safety shal l bE desigNed to pERmit

appRopRiaTE periodic InSpEction and TestiNg of impoRta^t aREaS and fEatuRes,

Such as wiring, Insulat ion, coNnEctions, and switcH boards To assess ihE

continuitY of THE systems and ThE condition of TheIR componenTs^ The system

shal l bE desigNed with a ^ p a b I ^ ^ y To periodicaLly Testi

1 ) The opERabiLity and f unCTionaL peRf oRma ce of The compoNEnts and

systems sucH as onsitE power sources, ReLays, switcHes, and buses,

and

2) ThE opERabiLity of THE sysTEmS as a wHoLe and under conDItions as

cLoSE to ThE desIgn as pRactical, ThE f u l l operation SEQUENCE T^T

brings The sysTEms into opEration iNcluding operation of appllcabLE

portions of ThE proTEction system, and The tRanSfer of power among

The nuclEar power unt i mrin gEnERatoR, The gr id , and THE onsitE power

system.

On the other haNd The IAEA CodE of DesigN ^ 7 ^^s indicATed The various

means of supplying emeRgENcy power incLuding watER, sTEam or gas TuRbines,

diescl Engines aNd baTtaries^ The criTerioN given by T^^s code StaTes

SELEcted combiNation of The means to suppty EmergEncy power

sHall have a REl iab i l i ty and foRm which aRE consisTEnt witH a l l The

ReQuiREmeNts of THe safety sysTems To be s u p p l l ^ and shal l meCT ITS

d u t i ^ ^ assumiNg a siNgLe fallure^ IT sha l l be possibLE to TesT The

fuNctioNal capabiLity of ThE EmergENCY power suppty^^

comparing ThE StaTmEnT aNd ThE iNTEnt of T h ^ critErioN to Those

of GDC 17, and 18, ONE can dRaw THE foLLowiNg REmaRks

1- The IAEA REfRatN fRom dEfining ThE eLecTric power sysTEm configuRation

and fRom specifying ThE NatuRe of The power supplies to be installed.

2- The IAEA criTErion, aLThough sTated i n bRoad tERmS is eQuivaLEnt

To THE AmERicAN CriTEria in w^^T coNCerns EmergEncy ^ower Supply

RELiAbILity, capabILIty, and Test ib i l i ty^ HowEver, i n This REgaRd

WE wouLd likE to point ouT ThaT^ aLthough ThE IAEA code of desigN

LimiTs ThE scopE of ThE eLEcTric emeRgenc power suppty to THE standby

AC poRtion, ThE IAEA SafEty gridE of Ref. ^ ExTends this ScopE to

incLude o f f -s i te gr id and uni t gEnERatoR, i n addition To the standby

on-SitE AC and DC power Supplies.

^- The IAEA-codE o ^ ^ not REfer ^ i n any way to ThE possibiLitY of using

ThE gr id as a power suppty ( i f it is avaiLabLE) i n CASE of EmergencY,

aLthough The AmEricans consider The gr id to be the pREfeRaBLe power

supply under noRmal and EmergEncY conditions.

GUIDES AND RANC TEC^NIC^^ POSITIONS

In Tris section WE put empHASis on THE methods RecommendEd, as the

mEans foR impLemEnting ThE acceptance cRitERia, by ThE USNRC and the IAEA.

THESE meThods aRE described i n ReguLatory and safeTy guides and bRAnch

Technical pos i t ions^ (9 - ^^.^

d b T d d T T d b ^ i t ) souRces

GenERal design criTErion 17 given befoRE REQuiRes That onsitE

eLEctrical power systems havE suf f ie ient indEpEndEncE to peRfoRm thEiR

safety fuNctions assuming a singLE faiLuRE. An accEptabLE dEgRee of

indepEnDEncE BetwEEn REduNdAnt standby (onsitE) power SouRces and theIR

distr ibut ion sysTEmS ^ asSuReD pRovIded That (9^

HowEver, mEntion of ThE gr id as a powER Suppty is pRovIded

In ^ ^ D ^ ^ ^ThesE aRe USNRC documenTs wnich take ThE RoLE of a REguLatory guidE

RG but foR pRobLEmS f OR which no RG has bEEn issued.

The eLEcTricallY powERed safety Loads ( C and DC) aRE bE sepaRATed

I^To ReduNdant Load groups such that Loss of any one gRoup w i l l noT

pREvEnt ThE miNimum safety functions fRom being perfoRmed^

Each AC Load gRoup have a connEction to The pRefERRed (off-sITe)

power source and to standby (oN-site) p^wer source (usually a singLe

diesEL gEVErator)^ ThE standby power source shouLd havE no automatic

connEction To any oTher Redundant Load group^ At muLtipLe NuclEaR

unt i s i tes, ThE standbY power Source ^or onE Load gRoup may have

an automatic connection To a Load gRoup of a differEnt unti^ A

pref erred powER souRcE bus, h ^ e v ^ may ^ervE ReduNdAnt Load groups^

Each DC Load gRoup ^ ENergi^ed by a batiaRy and baTtaRy chargEr.

ThE baTtary-chaRger combination sHouLd havE no automatic connEction

to any other Redundant DC Load gRoup.

Redundant Load gRoups and THE REdunda^T standby souRces aRE independEnT

of Each oTher whEn opeRating fRom The standby souRces

A single genERatoR driven by a sIngLe primE mover ^ acceptable as

The standby power source foR each AC Load gRoup of The sI^e and

chaRaCTERisties typical of RECEnt appticAtioN. I f other aRRangEmEnTs

such as muLtipLe dieseL gEnesatoRS opERated i n paRallEL OR muLtipLE

primE movers driving a singLe gEnEr ToR arE propose it shouLd be

dEmEnsTrated That The proposed arRANgEmEnt Has an EQuivalent

RELiabILity. Common modE failuRes as w^LL as Random singLE faiLuRes

shouLD be considered i n The analysis.

In The IAEA REguLations (sec. 6.1, 6.2 and A-^2 of Ref. ^ ) ) ,

THis tiem of Redundancy and indepEndEnce is expRessed by indicatiNg

THat The Emergency ^ower SysTem E S sha l l be divIdeD InTo DIvisIons,

each consisTEnt with THe sysTEm ti SERves; and as a minimum

shal l be two iNdependent divisions^ Automatic connections

REdundAnt divisions shouLD bE avoidEd, a nd i f any connection ^ made

ti sha l l bE shown That ThE REQuiremEnTs of ThE coNnEcTed safety Loads

arE mET taking into account ThE poTEntiaL for propagation of failuRes

and for overLoading The power s o u r c e S^feTy sysTemS suppori fEatures

shal l bE assigned to ThE SamE Division o^ The E S as The safety sysTem

ti ^ supporting^ Non-safety sysTems ^Hich are supplied from THe

sha l l be connEcTed to The E S ^ i t h safCTy grade isoLation

of DIeseL geneRaT^ s^T

This SEction describes an acceptabLE basis 10 foR ThE SELection

of diescl gEneRatoR seTs of sufficiEnT capacity and margin To ImpLEmEnt

gENERal desIgN criTErion 17. A diesEL genEratoR SET seLEcTed foR USE as

a standby power suppty shouLd havE The cApabILity to^

1 StaRT and accELeratE a Number of LaRgE matoR Loads i n rapid succession^

and be abLE to sustain The Loss of any such Loads.

2 Suppty continuousty The sum of The Loads nEeded to be powered at

any onE timE^

AT a time whEn ThE charAcTERisties of LoaDs are not accuRately known,

such as during ThE stage of desigN, each DEiseL genEratoR SET on a standby

(on-SitE) power Supply ShouLd bE SELECTed to havE a continuous Rating

EQual to oR gREater thaN ThE sum of The conservativEly estimated Loads

nEeded to bE powered CT any one timE^ In The abSEnce of f u l l y substantiated

perfoRmancE chaRacTeristics foR mEchanical EQuipmEnt such as pumps, ThE

eLEctiRc motoR drive Ratings shouLd bE calcuLated using conservativE

esTmates of thesE cHaRacTEristics (I^e. pump Ran out condItions and motoR

effEeiEneiES of 90^ oR Less^

^^ IdE The above REQuiREmEnTs, EacH diEdeL gEneratoR sCT sHouLd be

capabLE of start ing and accELeratiNg to RateD spEed, i n the REQuiRed

REQuEncE, a l l The nEeDed engineered safEty feaLuRe and EmergENcy shutdown

Loads. AT no timE during The Loading SEquEncE ThE fREQUEncy and voLtagE

dECREASE shouLd bE Less ThaN 9 ^ of nominal and 7^^ of nominal RespEctivEly.

During REcovery fRom TransiEnTs cauSeD by sTEp Load inerEases oR ResuLting

from THe des connection of LARgesT singLE Load, The spEed of ThE diesEL

geneRAToR SET shouLd noT excEed 7^^ of ThE differEncE betWEEn nominal

SpEed and ThE ovERSpEed Trip seT point oR 1 1 ^ of nomiNal wnich Ever is

Lower. VoLtagE shouLD be ResToRed To witnin 10^ of nominal and fREQuency

shouLd bE RestoRed to witnin ^ of nominal i n Less Than 4^^ of Each Load

SEQUENCE time interval . The su i tab iL i ty of Each diescl generaToR set of

The standby power Suppty shouLD bE ^ ^ 1 ^ ^ by pRoTotypE quaLIfIcAtion

TesT data and pREopERationaL Tests.

According to ThE IAEA, (SEC A 4 ^ 2 REf ^ ^ ) , ThE standby eLecTric

power sySTem sha l l have suf fIcienT capabILitY under antieipated operational

and accIdEnt conDitIons To StaRT and Suppty a l l Load as spEtifiEd i n ThE

design basis. Loads noT impoRtant To safety that arE not auTomatically

disconnEcTed shal l bE assumed connEcTed and shal l bE included i n THe

calculation of TotaL Loads. Load cApabiLity REQuiRes ThaT ThE standby

- 17 -

unIT sha l l maIntaiN voLtage aNd fREqueNcy wi th in time aNd LeveL Limits

That wILL noT dEgRAdE ThE perfoRmancE of any Load beL^w ITs minimum

ReQuiREmENTs EVEN duriNg TRAnsiEnTs caused by The LARgesT Load addition

oR Load REmoval

^ Periodic Testing of ^roTecTi^N SysTem

GeneraL desIgn cr i tEr ion ^0 REQuiRes That The pRoTection sysTem bE

desIgned to I n i t i a t E ThE opeRatioN of Systems and componEnti ImpoRtant

To safEty^ WhILe genERAL desIgN critErion ^1 REQuIRes That The pRoTEction

sysiEm bE desigNed To pERm T periodic Testing of ITS functioriNg when

ThE ReacToR is i n operation. In cuRREnt designs The ab i l i t y of The

pRoTection sysTem to IniTIate operation of safety sysTems depENds on The

pRoper perfoRmaNce of acTuation dEv i c ^ ThEREfoRE thesE dEvices aRE To

bE TesTed^ This section describes accEptabLE meThods ^11) of INcLuding

The aCTuatioN dEvices i n ThE periodic tests of ThE pRoTEction sysTem during

ReactoR opERation as follows^

1. THE pRoTEctioN sysTem shouLd bE desigNed To pERmti pErioric TestiNg

To exTEnd To and include The aCTuatioN dEvices and acTuated eQuipmEnt.

a. ThE pEriodic Tests shouLd dupLIcriE, as cloSEly as pRacticabLe,

thE peRfoRmancE that is REQuIRed of ThE aCTuation DEvices i n ThE

EvEnt of an a c t i d E ^

b.ThE pRoTEction sysTEm ANd ThE sysiems ti i n i t i a tes shouLd be designed

To peRmit TestiNg of aCTuation dEvices during REactoR operatioN.

^. AccEptabLE mEthods of including THE acTuation dEvIces In The perioric

Tests of ThE pRoTection systems ARE (11^

a. TestiNg sImuLTanEousLy a l l actuation dEvices and acTuated EQuipmEnt

asSocIated with each REduNdant pRoiection sysTem output s i g n ^

b.Testing a l l aCTuation dEvices and aCTuated EquipmEnT individuAllY

oR inJudieiously SclECTed gRoups.

c. REVEnting ThE opeRation of ceRtain aCTuated eQaipment during a

TesT of TheiR actuation dEvices.

d^Roviding ThE aCTuated equipmEnt wtih moRE ThaN one acTuation device

and TestiNg each dEvicE individually.

As REQai ed by ThE IAEA REguLation (SEC A ^.4 REf ^ ^ ) , automatic

contRoL sha l l bE pRovided uNLesS SafeiY actions witnin Each division of

THE E S can bE ReL^^Y perfoRmed maNuaLLY. THE functions of The contRollERS

includE The following^

Automatic dis connection of appRopRiaTE Loads (as specif ied i n design

basis) and a l l other power supplies fRom THE disTribution systEm

- 18 -

when The standby OR aLTeRNAtive po ER suppty is

^ Automatic staRT and connEction of ThE standby eLEcTric power sysTem

and The Loads To THE disTribution sysTem in THe pRoper sequEncE^

^ SyNchRoni^ation of ThE E S To thE noRmal supply whEn THE LAtter is

being Reinstated^

IsoLation dEvices foR inStrumEntatioN and contRoL cIRcuitS sha l l

be par i of The E ^ ThesE dEvices shal l bE such ThaT^

^ The maximum erEdibLE voLtagE OR cuRREnT ^ applied To The dEvice

output, and

^ ShoRTs, gRouNds, oR open cIRcuits occuring at The output w i l l noT

dEgRadE ThE ciRcuit coNnEcted to The device input To bclow an

accepiabLE LEveL^

^.4 Seismic Design

This guide describes a mCThod accpetabLe for iaEntifying and

ThoSE feaTuRes of lignt water cooLed nucleaR power plants

that shouLd be desIgned to withstand ThE effects of The safE shatdown

EaRThQuatE. The class IE clECTric system incluDIng The sppoRting systems

foR the on-stie AC and DC eLEctric power s u p p l l ^ tHat pRovIdE thE

emergency eLEctric poweR needed foR functioniNg of plant featuRes; shouLd

be desIgned to withstand thE effecTs of the safe shutdown EArihQuake and

functional^

Quality AssuR^ce ^e^uIre^^Ts for THe iNStaLLATIoN^ ins^ectiN

of insTRu^e^TaTIoN a^d eLecTric

safety guidE describes an accEptabLE method of emptying

the USNRC REgulations wt ih REgard to thE QuaLity asSuRancE REquiREmEntS

foR the instALlation, inspEction and testing of nuclEar power plaNT

instrumEntation and eLectric eQuipment.

The ReQuiRements foR tHe instaLLation, inspEction and testing of

nuclEaR power plant instRumEntation and clEctric equipment wnich aRe

included In ANSI N4^-2-4-19^2 I n conjunction w ^ ANSI N4^ ^ - ^^^ and

IEEE Std ^^6-1971 arE gEnerally acceptable^

AccoRding to IAEA, Sec 7 Ref. ^^ avaiLabiLity assurance LeveLs sHaLL

bE i n accoRdancE with No ^0-C-QA and RELated Safety guIDes.

^^6 CriTeria for safety relaTe^ eLecTRic ^o^eR sysTems for

FoR safety RELated eLEctric power systems Recommendations in IEEE

Std ^8-197^ aRE acceptabLE subJEct to thE following^

- 19 -

AvaILAbILIty of Off-SitE ^ower^ A pREfeRRed desIgN wouLd incLudE

two ImmEdIatE access cIRcuITs from THE TRAnsmissIon nEtwoRk AccEptabLE

desigN wouLd substitute a delayed Access cIRcuit foR one of THE

immEdiaTE access cIRcuITs pRovided ThE availabILitY of ThE dElayEd

access cIRcuit conforms to cRiteriAn 17.

The capacity of The b a t i ^ y chaRger suppty shouLd be based ON ThE

laRgesT combIned Demands of The various sTeaDy-StaTe Loads and THe

chaRgIng capacity To ResToRe The baTTa^ fRom The DesIgn minimum

chaRgE staTE to The fuLLy chaRged staTe iRrespectivE of THE staTus

of ThE plant during wnich these demanDs occuR.

The IAEA REf ^ , SEC A ^ 2 ^ HAS ExacTLy ThE SamE staTemEnt.

THE baTtaRy ServicE TesT described i n IEEE STd ^ ^ ^ 1 ^ ^ ^ shouLd bE

perfoRmed I n addition to ThE baTta^ perfoRmaNCE DischARge TesT^

The baTta^ servicE TesT sHouLd bE perfoRmed during REfuElling

operatioN or aT somE other outages wt ih intervaLs bEtwEEn Tests noT

to ExcEed 18 months.

IAEA reguLAtion, Ref ^ ^ Sec A - ^ ^ 2 Ref. addResses This

SubJeCT and has an EQaivalEnt meaning.

QuaLIficAtioN TesTs of ^ ^ 1 1 ^ 0 ^ duty motors

ofSEction iaENtifIes aN accEptabLE mCThod of complying wtih THE

USNRC REguLatIons wtih REgaRd To THE QUAlificAtioN Testing of pRoTotypE

continuous duty c^ss I motoRS insta l led insidE ThE containmEnt of water

cooLed nuclEaR power plaNTs^ THE meThod ^ described i n THE IEEE STd ^^4-

1971. IT delineates sper i f Ic pRocedures for THe QualifIcatIoN Testing

of class I motoRS to dEmonsTRatE adEquacy of desIgn foR ServIce witHIn

The containmEnts of nuclEaR power plaNts^ ThesE pRoceduRes pRovide foR

Testing uNder conditions simuLating ThoSE imposed During noRmal opeRation

In addition To ThoSE ResuLtiNg fRom a design basis Loss of coolant aceidENT^

ThE StanDArd aLso spEeifIes pRocEduRes foR accomplisning acceLerated

aging of componEnto to sIMUlaTe The effects of Long-TeRm opERation,

iNcluding Radiation effecTs^ and foR subjecting a pRototypE aged moToR

to combined (sTEam) pResSuRE, TempeRaTuRE, and chEmical EnviRonmENT

appRoximating ThoSE of ThE design bases Loss of coa^^t accidEnt^

ThesE pRocEduRes aRE gENERallY accEptabLE and pRovidE an adEquaTE

basis for complying wiTh The QuaLIfication Testing ReQuIREmenTs of c r i te r ion

^ of AppENdix B to 10 CFR pari ^0, to vErify adEQuancy of desIgn foR

servIcE under The most adverSE desIgn coNdItions, sub JecT To The followIng^

^ 20 -

To The ExTEnt pRActicabLe, ^ ^ ^ 1 ^ ^ eQuIpmEnt THat w i l l bE parT

of THe InsTalLed motoR asSEmbly sHouLd aLso be QualifIed i n accoRdance

w ^ IEEE STd ^4^ 1971^

THe qual i f icat ion Tests sHouLd simuLatE as cloSE as pRacticabLe a l l

design basis evEnTs wnich affEcT opERatioN of The moToRS auxiLIary

Equipment.

THesE REQuiRemEntS haVE no EQuiValENCE in THE IAEA rEguLations^

Testing of red^da^T o^sITe eLecTricaL power

verify proper Load

dEvIces ThaT aRE RequIRed To opERatE dEpendEnt EquipmEnt

bE supplied from a RELated bus SEctioN to pREvEnt thE Loss of clecTric

power In onE Load gRoup fRom causing THe Loss of EQuipmEnt I n aNother

Load gRoup. ThE IndependEncE amoNg ReduNdAnt 0N-sitE power souRcE and

ThEiR Load gRoups shouLd be Such T^^t The successfuL opERation of any

power SouRcE and ITS Load gRoup ^ i n no way affEcTed by ThE paRtial oR

compLeTE faILuRe of any other power SouRcE and iTs Load gRoup.

SincE ThE RELIabILity of an onsitE power sysiem is pRedicatEd on

ThE ExIsTencE of Thi^ IndepEndEncy a SuItabLE pREopeRational tes i to deTecT

any lack of indEpEndEncE shouLd be performEd. As a minimum a SuitabLE

TesT shouLd aSSuRE T^^T each RedundAnt on-site power SouRcE and ITS Load

gRoup can function wtihouT any dcpEndencE upon any other REdundant Load

gRoup oR poRtion therE of

To veri fy THE ExisTEncE of indEpEndence among Redundant on-sitE power

SouRces and ThEir Load gRoup, ThE on-sitE eLEctric power sysTem shouLd

be TesTed as follows^

1 . ThE plant clEctric power disTribution sysTem, noT nEcessarily incluDINg

ThE swtichyarD and ThE StaRTup and unti^ trAnsfoRmeRS, ShouLd bE

isolaTed from ThE of f -s i tE TRAnsmissIon nEtwoRk.

^. Under The condition mEntioned abovE, THE onsitE eLectric power sysTem

sHouLd be functionally TesTed successively in iHe various possibLe

combination of power souRces and LoaD groups wtih a l l dc and on-SitE

ac power souRces foR one Load gRoup at a timE compLeiEly disconnEcTed.

Each Tesi shouLd incluDE in jec t ion of simulaTEd acr i ^^T signaLs,

s t a r i up of on-SitE power souRces and Load gRoups under TesT,

SEQUEncing of L o a ^ and ThE functional perfoRmancE of The L o a ^

Each TesT shouLd be of SufficienT duration To achieve StabLe opeRAting

conditIons and THus pErmit ThE onsET and detEction of adveRSE

conDItions which couLd ResuLt from ImpropER assignmEnt of Loads.

- 21 -

During each TesT, The DC and onsite AC buses and rELATed Loads noT

uNder TesT should be monitoRed to veri fy abSEncE of voLtagE at ThESE

buses aNd Loads^

for

safety

CuRREnt desIgns of pRoTEctioN sysTEms aNd ENginEered safety featuRes

such ^ ^ i cERTAin safety RElaTed functions of NuclEAr power pLa^T

may bE bypassed or madE InoperabLe during ThE perfoRmaNce of periodic

Tests OR maInTenaNCE^ GEnERally^ The ptanTs adminisTRAtivE pRoceduRes

RequiRE That The operatoR^S permissioN bE obTaIned pr ior to i n i t i a t i ng

aNY ac t i v i t y that wouLd oR couLd aff ECT a safety ReLatEd sysTem^

Howev^ experiEncE fEedback indIcates T^^t wHen The mEasuRes used

To indicatE inopErabLE status consists SoLeLy of adminisTRAtive pRoceduRes,

ThE opER ToR is noT aLways f u l l y aware of ThE Ramification of Each by

pasSEd oR inoperabLe co^pone^ Thus, an accEptabLe way of riring THE

opERAtoR kNowLedgE of plant status is to suppLEment adminiStrativE

pRocedu^^ wt ih automatic indicAtion of ThE inopERAbiLity oR ThE bypass

of Each ReduNdAnt portion of a safCTy sysiem^ Automatic inaication of

a bYpasS OR induced inopERAbiLity ^ nEcesSary if.^

a. The bYPasS oR iNopeRabILity affects a SysTem that is desigNed to pERfoRm

auTomaticAlly a function wnich is impoRiant to publlc safety^

b^The bypass or iNopERAbILity is noRmaty REQuiRed to bE opeRabLe

c THe bypass or iNopeRabiLity ^ expEct^ to bE moRE fReQuent

The indication of The bypass condition shouLD be at The sysTem LEveL,

whETher oR NoT ti ^ aLso at ThE componEnT oR channeL LeveL^ For exampLe,

i n a design wnich u t i l i ^es A DC poweR to contaoL C^s, or DEENeRgi ing

a DC power JusT during maIntanancE shouLD ResuLT in indiREcT inopeRAbility

foR Each safety sysiem whoSE opERation is dEpEndEnt on That power sysTem.

BY-passing a pRoTective function of a shaRed SYSTem shouLD bE iNdicated

i n Each nuclEar uriT affECTed by The bypass.

of THe singLE f aILure criTerI^N to

THis SEction describes an acccptabLE method ^ 1 ^ of comptyIng

THe USNRC ReQuiREmEnts wtiH RespeCT to satisfying THe singLe-faiLuRe

criTerion^ THE guidance IN TRiaL use THE IEEE STd ^^9-1972, foR

apptyiNg The SingLE faILuRE criTErion To THe design and analysis of

nucLEaR power plant pRoTEction sysTem is gEneRally acceptabLe and

pRovides an Adequate inteRIm basis foR comptyIng with section 4^2

of IEEE STd 279-1971, subject To THE

1-IT mAy bE nEcessary IN spEeifIc InstaNCes To deparT from oNe OR

moRe of ITS pRovisions^

^E^TIoNS ^ 2 and 6^2 of IEEE STd ^79-1972 sHouLd bE SuppLEmEnted^

ThE detEctabILity of a SingLE faILuRE is pREdIcated on ThE assumption

That THE TesT ResuLTs IN ThE pResENCE of a faILure aRe ^I f f e^^^T

fRom ThE ResuLts THat wouLd bE obtaiNed i f no faILuRE is pResent

Thus, incoNclusIvE TestiNg pRoceduRes such as ^CoNtiNuIty checks^

of RElay cIRcuit coILs IN lleu of ReLay opERAtions shouLd noT bE

consideRed as adequAtE bases To cLASSify as dETEctabLE a l l poTEntiaL

faILuRes wnich couLd NEgatE ThE fuNctioNal capabiLity of ThE TesTed

In addition, where a sIngLE modE swtich supplies sIgNaLs To REdundAnt

channeLs, it shouLd bE consIdered thai sIngLefailuRe cr i ter ion wILL

noT be satis f ied i f either^

a. INdividual switch sections Suppty sIgnaLs to REDuNdant chaNnELs, OR

b. Redundant ciRcuitS contRollEd by ThE switch aRE SEpaRated by Less

Than s ix i n c h ^ without SuitabLE baRrieRS.

^ 1 1 MaNuaL INi t iAt ioN of ^RoTective Actions^

This section describes REQuiREmEnTs 19 for includiNg means i n ThE

pRoTection sysTems, for manuaL i n i t i a t i o n of pRoTEctivE a c t i o n as follows^

1. Manual i n i t i a t i o n of each pRoTEctivE action aT ThE systEm LEveL,

shouLd bE pRovided, REgaRDLess of whether means aRE aLso pRovided

to i n i t i a t E The pRoTEctive action at ThE componEnt oR channeL Levcl.

2 No singLe faiLuRe sha l l pREvent i n i t i a t i o n of pRoTEctivE action^

^. ManuAL I n i t i a t i o n of pRoTEctive action at ThE sysTem LEveL shouLD

perfoRm a l l actions perfoRmed by automatic iNI t iat ion^

4. ThE switches foR maNual i n i t i a t i o n of pRotEctivE actions at ThE sysTEm

LeveL shouLD bE LocATed in ThE coniRoL Room and bE Easily accessibLE

to ThE opERatoR.

^ ThE amount of EQuipmEnt common To both manual aNd automatic i n i t i a t i o n

sHouLd be kepT To minimum^

6. Manual I n i t i a t i o n of pRoTective actions shouLd depEnd on The operation

of a minimum equipmEnT^

7. Manual i n i t i a t i o n of a pRoTective action aT ThE sysTEm LEveL shouLd

be designed so That once in i t i a ted , it w i l l go on to completion.

AccoRding To ThE IAEA, SEc A ^ ^ , REf ^ ^ manual conTRoLs shal l

be pRovIded To peRmit SwitcHing The various avaiLabLe power supplies and

Loads To The disTribution SYSTem as reQuired^ ThEy aLso facILItatE THE

various plant mod^ 1^ e opeRation, TestiNg, maintEnaNCE, and E S

^12 ELecTricaL ^ENeTRATIoN ^SSe^bLIes IN

This SEctioN describes a meThod accEptabLe 20 to ThE NRC Staff

foR desigN quali f icatioN, construction, insTallAtion, aNd TestiNg of

clECTric pENEtRatioN assemblies iN coNtainmEnt structuRes of lighT-water

cooLed nuclEaR power plants^ ThE IEEE STd-^17, 1976, foR clectrIc assemblies

pENEtRatioN i n coNtaiNmEnt sTRucTuRes foR Nuclear power geneRatiNg statioN

is acceptabLE pRovided That ti is SuppLEmEnted by ThE following^

1. The clecTric peneTRatioN asSEmbly shouLd bE designed To withstand,

witHout Loss of mEchanical inTEgRity, ThE maximum shoRT cIRcuIT

cuRREntS vs. timE coNDitions That couLd occur givEN SingLE Random

faiLuRes of ciRcuit ovERLoad pRoiEction d e v i c e

^. The maximum shoRT ciRcuit cuRREnt asSesSEd CT ThE peneTRAtion asSEmbly

shouLd bE consisTEnt with ThE cRiteRia used In establisniNg The

intErrupting capabiLity of ThE pRoTEctive dEvicE associated witH

THE pEneTRAtion asSEmbly conduCToRS.

DiclEctric-StrENgth TesT shouLd bE SuppLemEnted foR QuaLification

TestiNg i n The following waY Each meDium-voLtagE power conduCToR shouLd

bE gIvEn an ImpuLSE withstaNd TesT by applyIng a I.^^^O us ImpuLse voLtage

TesT series consisting of Three posit ive and ThRee negative ImpuLse voLTAges

FLashover occuRS on onLy one TesT during any gRoup of Three consecutive

tests; three moRe Tests sha l l be madE I f no fLashover occurs I n ThE SEcond

group of t ^ t i , The flasHover I n ThE f i r s t group shouLD be consIdered

as a Random ftas Hover and The EQuipmEnt shouLd be consIdered as havINg

passed The TesT. The ^^^-hr aging timE at mIniMu^ aging TemperatuRe shouLd

be corrEcted to ^0^0-hr.

AccoRDing To THE IAEA, Sec A-4^4^ Ref. (^^, a l l cleCTric peneTration

asSEmblies I n contaInMeni StrucTuRes and passages pRovIded foR THe

conductoRS fRom circui ts originating In The E S shal l be REgaRded as Safety

system equipment; They shal l thereforE be Rated aNd QualIfIed for THE

expeCTed servIce and EnvIronmEntaL conDItions THat incLuDE THE cumuLativE

RAdiation EffECTs expecTed ThrougHout Their d^^gn llfE^ ContAinmEnt

penEtrAtions shal l havE a continous servicE voLtagE rat ing grEater Than

oR EQual To ThE voLtagE of THE system of wnich The conductors are part i

^ 24 -

They sHAll aLso have an ImpuLse RatiNg gReater ThaN oR EQual To THE maximum

cREdIbLE TRAnsIent voltage^ THe peNETRAtions shal l bE s i ^ To caRRy saf eLy

THe cuRReNTs that takE Into accounT voLtagE vaRiations and shori ciRcuITs,

as WEll as dEmaNds fRom Loads withouT ExcEEding allowabLe coNductoR

TEmpERatuRes OR dEgRaDing pResSuRE bouNdAries of ThE asSEmblies^ ThE

pENETRation asSEmbly shal l bE desigNed To withstand, witHouT Loss of

mEchanical intEgRity, THe max poSsIbLE ovERcurrEnt coNditIons THat couLd

occuR given a singLE Random falluRE of ciRcuit ovERLoad pRoTection d E v i c ^

THe pENEtratIoNS shal l be installed To meeT The same SEpaRation criTEria

as wel l as THE cabLes To which ThEy aRe

TesT Programs for

The SEctioN describes ThE gENERal scope and depTh of i n i t i a l TesT

pRogRams acceptable ^21^ to The USNRC sta f f for L^R-N^s^ design f e a ^ ^ s

and perfoRmance cApabILIty TesTs that shouLd be dEmonsTRated foR planT

ELecTric sysTems (among otHERS) during ThE I n i t i a l TesT pRogRam, shouLd

( 1 ) NoRmal AC ^ower ^ ^ ^ ^ ^ ^ 1 ^ ^ EmergEncY AC

DisTributioN SysiEms.

^Roper opeRAtion of pRoTEctivE dEvices^ i n i t i a t i ng dEvIces, RelayINg

and Logic, Transfer and Trip dEvIces, peRmissive and pRonibit intERLocks,

instrumEntation and aLaRmS, and Load sHeddiNg or stripping fEaTuRes, shouLd

bE demonstrated. Testing shouLd aLso be conducTed To demonsTRatE pRopER

opeRation and LoaD-caRrying capabilIty of bREakERS, moToR controllERS,

SwitchgeAR, TRAnsfoRmERS, and cabLes^ Th^s Testing shouLd simuLatE as

as pRActicaL, acTual SERvicE coNditIons. Redundancy and clEcTrical

sHouLd be dEmonstrated wheRe appropriaTE.

Tests of noRmaL AC power sHouLd demoNStratE THAT ThE intEgRated sysTem

shal l RespoNd as designed to a sImuLated paRT^L and f u l l Loss of o f f -

SitE power SouRces. Tests ShouLd aLso dEmonstratE ThE desIgn capabILIty

to transfer fRom on-sitE to of f - s i t e poweR souRces.

Tests of The Emergency AC power sysTem shouLD dEmonstratE

EmERgEncy OR v i t a l Loads w i l l StaRt I n THE pRoper SEquEncE and

unDer sImuLated aceident conditions wtiH boTH noRmaL (pREfeRRed) AC

souRces and The EmergEncy (standby) poweR SouRc^ EmergEncy Loads shouLd

aLso bE TesTed To dEmonsTRatE THat ThEy can staRT and opERatE wt ih ThE

maximum and minimum desIgn voLtagE AvaIlabLe^ To THe ExTEnt pRActical,

THE Testing of EmergEncY oR vItaL LoaDs sHouLd bE conducTed for a suf f ic iEnt

period of TimE To provide asSuRAncE T^^T EQuilIbrium conditions ARE

attained^ Loads such as motor gENERAToR (m-g) seTs witH fLYwhEELs, wnich

aRE supplied fRom The sysTem aNd wnich aRe desIgNed To pRovIde

NON-IntERRuptibLE power To plant LoaDs shouLd be TesTed To demonsTRate

proper operation. I f appllcabLE foR ThE facILitY d ^ g ^ Testing sHouLd

includE UNder-fREquENcy and UNdervoLtage ReLaYS associated witH sucH LoaDs

(m-g SEto^ Full-Load Tests for v i t a l buses shouLd bE coNducted uSiNg

NORMal and EmergEncY souRces of power supplies to ThE bus^ Tesing shouLd

aLSo dEmonsTrate ThE adEquacY of ThE plant EmergencY and esSEntial tighting

SysTEm^ Tests shouLd bE conduCT^ to dEmonsTRatE The pRoper opeRAtion

of Indicating and aLaRm devIces used To mo^^or The avaI lab i l I ty of The

emergENCY power sysTem iN THE conTroL room^

2 EmergENcy or StaNdby AC ^ o ^ ^ SuppLIs^

AppRopRtatE Tests sHouLd be conduCTed To dEmonsTraTE RELiabiLity,

and pRoper voLtagE and frequency REguLation undeR TRAnsient AND sTeadystatE

conditions. AuxILIary systems sucH as Those foR star t ing, cooting, heating,

vEntiLating, Lubricating, and fueting shouLd aLso be appRopriatEly tesTed

To dEmonstrate That Their peRformancE ^ INaccordance wt ih design. TestiNg

shouLd bE conducTed for a SuffieiEnt time To EnsuRE 1 ^ ^ EquILibrium ^

ReacHed TestiNg shouLd aLso dEmonsTRatE THE pRoper Logic, coRReCT SETpointS

for Trip dEvIces, and pRoper operatioN of In i t ia t iNg devices and permissives

and pronibit intERLocks and shouLd aLso demonsTRatE redundancy and

eLEctrical iNDEpendEncE^ Emergency Loads Supplied shouLd be confIrmed

to be i n agREement wtih Design s i t i ng assumptions used for The poweR

^ D.C^ System

^Roper CALIbRAtion and Trip seTtingS of pRoTEctivE DEvIces, including

ReLaying, and pRoper operation of permissivE and pRonibit inTeRLocks sHouLd

bE demonsTRated^ DeMOnstration sHouLd aLso incLudE design capabiLity

of baitery cHargers^ TRAnsfer devices and invERTERS, and THE EmergEncy

ligHting sysTemS. Testing sHouLd aLso bE conduCTed to demonstratE pRoper

operation of bReakeRS, transfer dEvices, inveriErs, and c a b L ^ This Testing

shouLd simulaTE, as cloSEly as prActical, actuaL service conditions.

DEmonstrate opeRation of instrumentation and aLarmS and ground deTection

instrumEntation^ DEmonsTratE redundAncY and clEctrical IndEpendence,

and T^^T acTual totaL sysTem Loads are In agrEEment witH desIgn Loads.

A discHargE TesT of each batieRy bank sHouLd be conduCTed AT f u l l Load

^ 26 -

and foR desIgN duRation To dEmoNSTRatE THAT The baTTEry baNk voLtagE

LImit aNd 1 ^ ^ ^ ^ ^ c e l l limits are NoT ExcEeded^

to IAEA, SEcs^(ii), aNd A- ^ of REf ^ Tests Shall

cARried out to vErify That each dIvisIoN of The E S perfoRmS as intENded

uNder coNditions as sImILaR as practicabLE To ThoSE ENcountered duriNg

opERAtioNal states aNd aceidEnt coNdItions^ poweR SouRces shal l be capacity

TesTed i f such Tests havE NOT bEEN caRried out bEfoRe^ Load Tests shal l

bE perfoRmed Either by paRaLLELINg The staNdby power suppty with The NORmal

suppty oR by using a substiTutE Load^ ARRANgEmENTs sHouLd bE such THat

dEmand foR Safety action ovERrides ThE TesT SEQUENCE Load SEQUEnriNg

and Load Tests utiLI^INg The aCTual LoaDs sha l l bE pERfoRmed whEn ThE

plant ^ shut down. Onty ONE gENERator shal l bE TesTed at A

TesTs of

of

section indicates a mEtHod accEptabtabLE To THE USNRC REguLatory

Staff ^22^ foR comptyIng witH REgulations coNcerNINg QualIfIcation t o t i n g

of cLASS I eLeCTric valvE opERatoRS foR servIce witniN The c^ntaiNmEnt

of lignt waTer cooLed NUclEaR power plants To aSSuRE ThaT ThE vaLvE opeRatoR

desIgn wILL mEeT ITS peRfoRmancE RequiRemEntS.

IEEE STd ^82 - 1972 spEcifies pRoceduRes foR accomplishing accclERated

agging of compoNEnTs to siMuLatE ThE EffECTs of Long-TeRm opE^^atioN under

noRmal opERating conditIons^ ThesE effects INcLude ExposuRe to nuclEAR

, TempERatuRE, pRessuRE, humiditY ^^d chEmical spRayS.

The pRoceduRes aLso pRovide foR coNducting QualificAtion TesTs of

clEctrical valvE opERatoR under conditions simuLating ThoSE that wouLd

bE imposed during aNd afTer a desigN basis Loss of coolant a c c I ^ e ^ subject

To The following^

1- To the ex te^ pRActicabLe, a^xiLIARy eQuipmENT (E.g. 1 1 ^ ^ switches)

ThaT ^ noT INTEgRal with ThE valvE operatoR mechanism but w i l l be

par i of THE installEd valve opeRatoR assEmbly shouLd bE ^ 1 ^ i n

accoRdancE with The SubJeCT standard.

2- The t ^ T SEQUENCE described i n The standard shouLd be used unLess ThE

antieipated aCTual SERvicE opERating SEquEncE for ThE vaLvE opERatoR

is ExpEcted To cReATE a moRE SEvere opeRating coNditions^ In such CASE,

THE actuaL service sequence sHouLd bE used i n ThE TesT.

^- TesT coNdItions shouLd bE based on conservativE calculations to assuRE

T^^T ThE valve opERaToR is TesTed uNder EnviRonmEnTaL coNditions ThaT

simuLatE The condItions To wnich The valvE opERatoR is ExpEcTed To

be exposed-to during and following a design basis

of

IEEE STd ^^^-^^^^ seTs foRTh cRitERia foR ThE SEpaRation of ciRcuITs

Equipment ThaT are RedundanT^ THE staNdaRd aLso seTs foRTh

rELatiNg To TesTs and aNaLYSis foR DetErmIniNg The f

chaRAcTeristies of pRopoSed cabLe INStaLlations^ ThE criTeria arE appllcabLE

pRovided such TesTs aNd aNaLY^is are based on REaListic pREmises aNd aRE

othERWisE f u l l y AppllcabLE To ThE acTual cabLE instaLLations^ AccEptancE

^ howEver, subJecT To ThE following ^ 2 ^

1- ThE standaRd defines ^isolatioN d e v i c ^ , of The noncLaSS IE ciRcuits

fRom cLASS IE or associaTed cIRcuITs, as Those preventing maLf unctions

In ONE section of a ciRcuiT fRom causing unaccEptabLe infLuEnces i n

other SEctions of That cIRcuit oR other ciRcuits^ This staTEment sHouLd

be suppLEmEntEd as follows ^InterRupting dEvIces aCTuated o ^ ^ by fauLt

cuRrEnt arE noT consIDeRed To bE isoLatIoN dEv ic^^

^- Locating RedundAnt cIRcuitS and EQuipmEnt i n SepaRatE safety-class

StrucTuRes^ This mEThod of SEpaRation shouLd bE used whEnEver practicabLE

and wh^e i t i USE does noT conftiCT with other Safety obJEctives.

^- Associated cIRcuits InstaLLEd shouLd bE SubJEct to a l l

placed on cLASS IE ciRcuITs.

and sHuTdown eLecTric sysTemS f ^R muLti-unit

This section poinTs out a mEThod accEptabLE to ThE USNRC staf f

RespECT to ThE sharing of onsitE EmergencY anD shutdown eLEcTric

foR muLti-unIT NUclEAR power plants.

Sharing of onsite power SYSTems at muLti-unit poweR plant s i tes

genERally ResuLts I n a Reduction In The numbeR and capacity of The onsitE

power SouRces to LEVELS bclow ThoSE RequiREd foR ThE SamE number of UNITS

Located at SEpaRaTe s i tes. The Reduced capacity couLd ResuLT i n undesIRabLe

IntERActions, ThuS^

1- DC sysTemS In muLti-UNit nuLcEAR pow^^ plants shouLD noT bE shaRed

2^ ThE desIgn of sHARed onsitE EmergencY and shutdown a. c. eLEcTric SysTEms

shouLd sat is fy ThE following^

a. THE sharing of onsitE AC clECtric systems shouLd bE limited to two

A sINgLE faILuRE shouLd NoT pREcludE The capabiLity to automaticAlly

minimum ENginEered Safety fEatuRes (ESF) Loads i n aNY onE

and To safeLy sHuT down The REmaining unit, assumiNg a Loss

of of fs i tE

- 28 -

c ONSite power cApacity shouLd be pRovta^ To energI^E seismic-CatEgory-

I EquipmENT To aTtaIN a Safe and oRdERLy coLd shuTdowN of a l l UNITS,

assumINg ThE Loss of o f f s t i e poweR and The moST SEverE design basis

EvEnt aNd a singLE faILure in The onsitE ELEctric sysTem^

d THE InteRActioN beTweeN eNgINEeRed safEty fEAtuRE ELecTric eiRcuits

of Each uriT shouLd bE 1 ^ ^ ^ That any allowabLe combINAtion of

maintENAncE IN The unITs w i l l NoT pREcludE ThE capabILIty To

auTomaticAlly Supplying power To minimum ESF Loads i n aN^ unt i ,

assumiNg a Loss of o f fs i te poweR^

e CompLeTe iNfoRmation REgaRding ThE StaTus of ThE sHARed sysTems

shouLd be provided for eacn unIT operator^

^- For muLti-uNit nucLEar poweR plaNTs each un^T shouLd have SEpaRatE

and indEpENdEnT 0N-site emergencY aNd shutdown eLectric sysTemS, boTh

AC and DC, capabLE of SupplyIng minimum ESF LoaDs and The Loads REquiRed

foR attaining a Safe and oRdeRLy cold shutdown of ThE unt i , asSumIng

a sIngLe faILuRe and Loss of of f -Si tE power.

AccoRdIng to IAEA, Ref. ( ^ , Sec. 6.9. each ReaCToR i n a muLti unIT

stat ion shouLd have a SEpaR TE And indEpEndEnt E^S. Howev^ i f poRtions

of ThE E S aRE shaRed ti sha l l bE shown that safety RequiREmEnts of each

ReaCToR individual ly, and of a l l REActoRS simuLtanEously, are

of cLass IE e^uI^eNT for

This section indicates a method acceptabLE To THE USNRC REgulatory

s ta f f for complyIng wtih THE commissIons^ REguLation wtih REgard To design

vEri f icat ion of cLass IE EQuipmEnT foR SERvicE i n lighT-watercooLed nuclEar

power plants ^2^^

ThE IEEE STd ^2^-1974^ describes basic pRocEduRes foR quaLifYing

cLass IE EQuipmEnt and Interfaces T^T aRE to ^ ^ ^ 1^ nuclEaR power

plants, and qualifYing componEnti OR EQuipment of any inteRfacE whoSE

faILuRE couLd adveRSeLy affEcT any class IE EQuipmEnt. The ReQuiremenTs

ouTlined Include pRineipLes, procEdur^ and mEthods of QuaLifIcation

wnich, when satis f i ^ wiLL confirm THE adeQuacy of The eQuipment desIgn

for The perfoRmancE of cLaSS IE funCTions under norm^ abNORmal design

basis EVEnt, post design basis EVEnt, and containmEnt TesT conditions^

AccoRding To The IAEA, REf ^ ^ , Sec.8, EQuipmEnt uSed in ThE E S

shaLL be quali f ied by confirming T^^t ti w i l l mEEt OR ExcEed i t s design

basis perfoRmancE REQuiRements wHILE subJeCTed To THe envIronmEntaL

conditions E x i t i n g at ThE timE of nEed. QuaLification may bE caRried

ouT by mEans of^

^ 29 ^

(a) type TestiNg of aN acTuaL EquIpment perfoRmaNce using s I ^ u L A ^ service

(b) consIdering opERAting Experience foR simILaR EquipmEnt ^nder compaRabLe

ServicE conditIons; oR bY

( c) aNAlySis, pRovided THat Just i f icat ioN of THE assumptions aNd valldatioN

of The mode's used ^ givEn^

of eLecTric

This section outlines oprating pRocEDuRes and ResTrictions, acceptable

To The USNRC REguLatory staf f , wnich shouLd be impLEmEnted i f ThE avaiLabLE

clEcTric power souRces do NOT mEET ThE Limiting Condition foR OpeRation

(LCO) ^26^ THEy aRE appllcAbLE to siNgLE and muLti unt i pLAnTs, incLuding

muLti un i i plants ThaT shARE ThE ELEcTric power sou rce

ELEcTric Loads impoRtant To SafEty of NuclEar power pLAnts aRE served

by an clECTric power system wnicH confoRms to GDC- 17. ^LAnTs with moRE

power souRces Than aRE REQuiRed by GDC 17 can toLERatE The Loss of one

OR moRE SouRces and s t i l l mEeT ThE LCO. During ThE noRmaL couRSE of

opeRAtion, hoWEver, any nucleAR power plant may LooSE p o ^ ^ souRces to

ThE ExtEnt that ThE LCO is noT mET Th^s SEction addResses Such CAS^

GDC 17 spEcifies design REquiRements, not opeRatin^ REQuiRemEnTs,

it therEfoRE does noT stipuLatE opERational Restrictions ^n ThE Loss of

power souRces^ NEvERtheLess, opERAtional ResTrictions based ON ThE Intent

of GDC- 17, on ThE Loss of power souRces, have been included I n The TEchnical

spEeifIcAtions of REcentLy constructed nuclEar power plants. Such

spEeifIcations are basEd on ThE following consiaERations^

^ ThE LCO of nuclEar power plaNts is meT when a l l ThE eLecTric power SouRces

RequiRed by GDC- 17 are avaIlabLE^

^ UndeR ceRtain conditions, it may be Safer to continue opeRation at f u l l

oR Reduced power foR a limiteD TimE than to affEct an im^edIAte shatdown

on The Loss of somE of The RequIRed eLeCTric power souRces^ Such dEcisIons

shouLd bE basEd on an EvaluatioN THat balances ThE Risk associated with

ImmEdiatE sHuTdown agaInSi ThAT asSociated with conti^ued opeRAtion^

I f ImmEdtaTE shutdown is thE Safer couRSE, ThE unit sh^uLD bE bRoughT

to an oRdeRLy sHutdown and to a coLd sHutdown statE as s^on as

I f continued power opERation is ThE safer couRSE, The period of

opeRation shouLd be u ^ to RestoRE ThE Lost SouRce. I f The LCO has

Noi bEEN achIEved during That pEriod The unt i shouLd bE ^RompTLy bRoughT

To an oRdERLy shutdown, and to a coLd shutdown StaTe as s^on as poSSIbLE,

THese ac t iv i t ies do noT Risk fuRTheR dEgRAdation of The

eLEcTric power sysTem OR i n any way JEopaRadi E plant safety^

of ELecTric E^I^e^T for

USNRC REguLatory posit ion about This SubJEct ENdorses ThE staTemEnt

coNfoRmance with THE REQuirEmEnts aNd REcommendatioNS spEeifIed

by THE IEEE Std ^44-197^, wILL coNfIrm THE adEquacy of THE EQuipmEnt desIgN

foR The perfoRmaNCE of cLASS IE functions, subJECT to The following ^27^

(1)A s ta t ic coEfficiEnt of 1 ^ Is used for EQuipmEnt SEismic aNalysis

to take InTo accounT The EffEcts of boTh muLtifREquEncy E^cItatioN

and muLtimode Response^ The use of This coeffIcienT is acceptabLe

foR verifying integRity of fRame-type structuRes^ FoR equipmEnt having

coNfIguRatIons other ThaN a fRame-typE, Just i f icat ion shouLd be pRovta^

foR ThE USE of a s ta t i c coef f ic ient

(2) For EQuipmEnt with moRE ThaN ONE pReDomInant fReQuency, The shakE tabLE

motion shouLd pRoducE a TesT R^on^e Spectrum (TRS) wnich closely

Env^p The appllcabLe poRtion of The REQuiRed ResponSE SpECTRum (RRS)

^ ^ THeRmaL OverLoad ^R^TecTIoN fo^ ELecTric ^ t o r s on Motor OpeRated

section ouTLInes a method accEptabLe To ThE USNRC staf f

coNCerning ThE appliCAtion of ThEmaL ovERLoad pRoTection dEvices that

aRE intEgRal wtiH The moToR StaRtaR foR ELEcTric motoRS on motoR

operated valves. This meThod wouLd EnsuRE ThaT ThE thERMal ovERLoad

pRoiEction DEvices w i l l not ^E^L^Sty pREVEnt ThE moTor fRom perfoRmIng

I t s SafEty RelaTed function^

TheRmaL ovERLoad dEvices aRE designed pRimariLY To pRoTEct continuous

dutY motoRS whllE ThEy aRE RunniNg Rather Than during starting^ HowEver

USE of ThesE ovERLoad dEvices To pRoieCT intERmittEnt duty motoRS

may TheREfoRE ResuLT I n undesiRed actuation of THE dEvices i f ThE

cumuLative EffEcT of hEating caused by successivE StaRTs aT shori

intervaLs is noT takEn into account i n dETERmIning ThE overLoaD Trip

IT is gEnERally vEry d i f f i c u l t for any theRmaLLY SEnsItivE

to adeQuatELy appRoxImatE The va^^ying ThERmal chaRActERisticS of an

IntERmitTEnT-duty moTor over i t s f u l l range of StaRtiNg aNd Loading

coNditions^ This is mrinty cauSEd by ThE wide variations In moToR

hEating cuRves for ThE various sI^es and desIgns and aLso by

di f f IcuLty i n obtaiNINg moTor heating data to an acceptabLE accuracy^

The accuracy obtaInabLe with thE ThERmal oveRLoad reLay Trip

gENERally varies f rom-^ To 0^ of Trip sCT p o I ^ SIncE thE pRImary

conceRn in THE appllcation of oveRLoad devIces is To pRoTecT THe motor

wInDings againsT excessive Heating, THe above negative ToLeRance in

Trip cHaracTeriStics of THe pRoTEctioN dEvicE is considered in THE

Safe dIREctioN for motoR pRoTection^ HowEver, The conseRvativE desigN

fEataRe buILt in to these ovERLoad dEvices foR moToR pRoTectioN couLd

interfacE wiTh ThE successfuL fuNctioniNg of a safEtyRElaTed sysTem;

i . E , ThE THERmal ovERLoad device couLd opEN To RemovE power fRom

a motoR bEfoRE THE safety function has bEEn compLeTed OR even 1 ^ 1 1 ^ ^

Thus, pRovIded That The compLetion of ThE safety fuNctioN is noT

JeopaRdI^ed oR That oTheR SafEty sysTEmS are noT degraded^ onE of

THE foLLowIng two aLTERNatives sHouLd bE impLemeNTed

a) TheRmal ovERLoad pRoTection devices shouLd be continously bypassed

and TempoRArIly placed In foRcE onLy wHEn ThE valve moTors ARE

undERgoIng pEriodic Testing maintENAncE, oR

b) THeRmal ovERLoad protection dEvices that aRE noRMaLLY 1^ foRcE

during plant opeRation shouLd be bypassed under aceidEnt

Another meThod of SoLution ^ estabLished i f a l l uncer^tainties i n

The Trip seTpoint of The ThermaL oveRLoad pRoTection devices aRe

compensated i n favoR of completing safety RELated actions^

1 Periodic Test i^^ of DIeseL GeneRATor ^nITs used as On-site ELecTric

aT NucLear

This section poinTs out a meThod accEptabLE to ThE USNRC staf f foR

complying witH The commission^s REgulations ^9^ witH regard to periodic

TestiNg of dieseL geneRator unITs to EnsuRE THat ThE diescl eLeCTric

power sysTemS w i l l meeT Their ava i lab i l i t y rEquiRements^ The dieseL

genE^^toR unt i consists of The EngInE, gEnEraTor, combustion rir sy^Tem,

coollng water sysTem up To ThE suppty, fuEL supply sysTem, Lubricating

sysTEm, s tar t ing EnergY SouRc^ auToStarT contaoLs^ manual

and dIescl gEnERatoR breaker^

Testing of dIesEL gEneratoR uniTs shouLd^

( 1 ) DEmonsTRatE pRoper startup opeRation bY simuLating Loss of a l l

AC voLtage and dEmonsTraTE THat THE dieseL gEnERATor uriT can

s ta r t aatomaticAllY And attain THe RequIRed voLtage and frequency

witHin acceptable LimiTs and time^

(2) DemoNSTRate proper opeRation foR desIgN accideNTLoadiNg SEquencE

and dEmonsTRATE f u l l Load CArRying capabiLITY, verifY That voLtage

and fREquEncy ARE maiNtaINed within THE rEQuiRed Limits; aNd

That THE cooll^g SYSTEm fuNctions within desigN LImITs^

(^) DemonsTRatE proper opeRatioN during diescl gEnEratoR Load

shEdding, iNcLuding a TesT of compLETE Loss of Load, and vErifY

ThaT thE voLtagE REQuiRemENTs are met and That ThE over-spEed

Limits aRE noT Exceeded^

(4) DEmonsTRate fuNctioNal cApAbiLity aT design basis TEmpeRaTuRe

cond i t i on

(^) DEmonsTRatE ThE abiLIty to^

(a) SyNchRoni e THE dIesEL geNeRatoR witH The

of f - s t i e power whILe coNNEcTed to THe emergENCY

Load,

(b) Trans fer laod to ThE o f f -s i tE power,

(c) IsoLATe ThE diesEL gENeRatoR unit , and

(d) RestoRE it to standby status^

(6) DEmonstRatE that THE ENginE w i l l pERfoRm pRopeRLy i f switched

from one fueL o l l suppty sysTem to anoTh^

(7) DEmonstratE REadiNesS foR supptying EMergENcy power whILE THE

dieseL gENERAToR unIT is undER TesT.

(8) DemonsTRatE The REQuIRed ReLiabi l i ty by RerunniNg consEcutivE

vaLid Tests ( 1 ^ with no faiLuRes) for 69/n times per

wHere n is THE numbeR of dieseLs of THE SamE desIgn and

InsTaLLATIo^ Design a^d INSTALLATION of ^arge ^oad

for NucLear

SEction descRIbes a mCThod acceptabLe^to The USNRC staf f foR

perfoRming THe inStallatIon desIgn and InstaLlatioN of LaRgE LEad StoragE

baTterIes foR nucleAR power plaNTs ^ 0 ^ THe IEEE Sid ^4-197^ REcommENded

pRacticE for inStaLlation desIgN and InstaLlatioN of LaRgE Lead StoragE

batiEries for gENerating stations and substiTutions, ^ suppLEmented with

The followiNg infoRmatioN ThaT takes inTo considERatioN ThE REcommEndations

on f i r e pREvEntioN by ThE NRC appoInted spEctaL REview gRoup following

ThE bRowns fERRy f i r e of march 1979^

( 1 ) The vENtiLLation sysTem sha l l limit HydRogen accumuLAtion To Less

than two percent by voLume aT any Location ^ 1 ^ ^ The baTTery AREA

(2) ResTRaIning chANneL bEams and tie Rods sHouLd be eLEctricallY InsuLated

fRom THE cells

statioNary water fac iL i t ies aRE pRovIded witnin

Room, Their desigN shouLd be such as to pRecLude aN

sp i l l i ng of water fRom THese fac iL i t ies on The batieRY Instal lAt ion

(4) Any ceLL ThaT Exnibits an ELEctrolyTE LEVEL of 1/2 an Inch oR moRE

bELow ThE Top of plates shouLd bE REplaced^

(^) CEllS shouLd noT bE Exposed To ExTREmeLy Low ambIEnt TEmpERatuRes

oR Locali^ed sources of heat during storage^

(6) HYdrogEN suRvEy shouLd bE perfomed to estabLish BaSELiNE data foR

LocatiNg HydRogEn dETEctoRS^

AccoRDing To THE IAEA, SEc A - ^ 2 ^ of REf ^ , ventI lat ion shal l

bE pRovided To avoid combuStibLe gas coNCEntRations i n baTTery Rooms,

a^d To maintaiN Such coNCENtration beLow an accEptabLe maximum^

ThE vEntiLation sysTem sha l l be powered by ThE E1^

of Large Lead storage

fsection points out a meThod accEptabLE to The USNRC staf f

foR perfoRming ThE maintEnancE, TestiNg, and REpLacemEnt of LaRgE LEad

stoRagE baitaries foR a l l types of nucleAR power plants.

IEEE Std 4 ^ - 1 9 ^ , Includes maintEnancE, iesT ScheduLes, i ^ t i n g

pRoceduRes, and REplacEmEnt criTeRiA foR LaRge LEad stoRAgE battaries.

ThE standard does not incLudE surveILLance and testing of The DC sysTem

EvEn Though ThE batieRy is paRT of ThaT sysTem.

The USNRC REguLatory posit ion IdEnt i f ied i n THIS SEction indicates

THat a l l RequiRemenTs as WEll as REcommEndations of that IEEE standard

consTitutE an aDEQuatE basis foR comptying witH THe RequIRmEnTS of ThE

comm^sIon REgulations with RespECT To maintEnancE, Testing, and ReplacEmEnt

of LaRgE LEad sToRagE baTtaries SubJECT to THE following.^

- ServIcE TesT DescriptioN, shouLD bE perfoRmed In addition to The b a t i ^ y

perfoRmancE dischaRgE TesT. ThE b a t i ^ y servIcE TesT shouLD be perfoRmed

during REfuEllng opERatIons or at somE other outagE, wt ih IntervaLs

bEt^EEn Tests noT to ExcEed 18 montHs^ In addition, I f THE sysTem desIgn

is chaNged so that ThE pREvIous ServIcE TesT is no Longer a vat id TesT

of ThE capabILIty of The baitEry to meCT The changed desIgn REQuIREmEnts

of The sysTem, ThE user shouLd conducT thE servicE TesT foR ThE new

sysTem design^

^^24 DIeseL-Ge^eRatoR ReLIAbILIty ^uALIfIcAtion Testing^

A staRT and Load ReLiabIl i ty TesT progRam is ReQuiRed ^2^ foR a l l

dieseL geNERatoR sets of a typE OR si^E noT pREviousty us Ed as a standby

emeRgency power s o u R ^ IN NucleAR power pLaNTs An acceptable TesT pRogRam

shouLd incLude The followINg^

(1) AT LEAST ^ o fuLL-Load Tests shouLd be perfoRmed on each

dIesEL-gENERatoR seT To demonsTRate THE staRT ANd Load capabILITy

of THe units witH some margIN i n Excess of THe perfoRmaNCE REquiREmENTs

Such TestiNg is Evaluated on a casE bY casE b^Is^

(2) ^rioR to 1 ^ ^ ^ fueL Loao^^, aT LEasT ^00 vaLId s t a r i and Load

TesTs sHouLd bE perfoRmed^ 90^ aT THE LeasT of these Tests shal l

be madE fRom desIgN coLd ambIEnt c o n d i t i o n and 10^ fRom desIgN

hoT EQuILibRium TempERaTuRE ThE ^00 vaLue incLudes a l l vaLid Tests

perfoRmed off-s i te^

(^) A faILuRe RatE I n Excess of 1^ LeaDs to ThE RequIRemeNT foR fuRTher

Testing as wel l as Review of The sysTEm desIgn adEquEcy^ A success

is dEfined as a s t a r i fRom ThE spEeifIed TempeRatuRe coNditions with

Loading To at LeAST ^0^ of continuous Rating ^ i ^ I n The REQui^d

time in terva l , and continued opeRation untiL Equilibrium is aitained.

on ^otor OperaTed VaLves I n T^e Emergency Core Coollng

This section gIves a guiDancE In mEeting The IEEE STD- 79 REQuiREmEnt

by ThE MotoR OpERated IsoLation Valves (MOIVs) on THE lines BeTweEn

ThE REaCToR Coolant SysTem (RCS) and ThE safety inJEction Tanks

( accumuLatoRS ) , foR TheiR being opeRating bypasses^ ThE following fEataRes

shouLd bE incoRpoRated^

1 ) Aatomatic opEring of The valves when Either ThE RCS pResSuRE is Reduced

To a seT valuE, oR a safety inject ion signal is pResent^

^) Visual indicat ion i n The conTRoL Room of The open oR closed SiaTus

of The v ^ ^

^) An audibLE aNd visual aLaRm, wnicH ^ acTuated by a SEnsoR ON THE vaLvE

whEn The valvE is noT In ThE fullyopEn posit ion.

4) UtiLI^ation of Safety Inac t ion sIgnal as an automatic ovERRIDing

signal To ThE MOIVs

of DIeseL^GENERatoR SeTs for Load

ALthough n e t i ^ ^ The GDC 1^, noR ThE IEEE STd ^08 pRonibit THE USE

of EmergnECY dIesEL foR non-Safety puRpoSes, THe USNRC staf f coNcLudes

^4^ That ThE poTEnTtaL foR common modE faiLuRes shouLd pREcLude

interconnEction of on-stie standby diesELs and o f f -s i tE power souRces

foR short pEriods foR ThE puRpoSE of Load Testing^ In particuLar,

EmergEncy power dIesEL geNeRatoR seTs shouLd noT be used foR Load peAking

servIces foR THe grid^

IT ^ obvious That isolaTed power SysTEmS aRE INhERenTLY Less StabLE

ThaN EQuivalEnt SYSTems with Supporting gRid intEries ANd aRE more

vuLNERabLE to NatuRal disasTERS^ Thus, as a conservativE appRoach, ThE

USNRC staff ExaminE The avaiLabLe gENERating capacity of such sysTems

to witHstaNd ThE outage of The laRgesT u r i ^ ^ ^ FoR such isoLated grids

mEasuRes foR additioNal capabiLIty and maRgin foR ThE 0N-sitE poweR sysTEm

beyond ThoSE noRmally used may bE REQuIR^ Other mEasuRes may bE moRe

appRopRtaTe based on 1

ThE IniEnt of This SEction is To explain how To meet ThE concern

ThE rEQuiRed disENgagemEnt of ThE ReacToR Coolant ump (RC ) motoR

fRom thE gr id whEN it ExpERIENces underfREQUENCY conditioN, mignt noT

occur. Thus ^ 6 ^

(1) Tripping of The RC^ bREakeRS is considered a REquired Safety action

u ^ ^ s it ^ demonsTrated (aNaLyticAlly) ThaT pump coasTDown is noT

pREVEnted at an uNderfREquEncy RatE of 1^ H /SEc

(^) I f crEdit is to be takEN foR RC coasTdown In THE accIdEnT aNalySes,

THe pump bREakers muST bE quaLifIEd i n accoRdancE with ThE REquIremEnTs

of IEEE STd ^79 and IEEE Std ^0^^ In addition, ThESe bREakERS shouLd

bE HouSEd I n a SEismIc category-I strucTuRe.

(^) RCR sysTEm Trip SEnsoRS associated with thesE bReakers shouLd meet

The reQuiRemEnts of The IEEE STd ^79, wheTher or noT creDit is taken

foR pump coastdown^

^.^9 DIeseL-GeneRATor ^RoTecti^e Trip CIRcuit By passes

Bypasses of The diesEL-gENERator Trips sHouLd be goveRNed by THe

following ^ ^

(1) THe desIgn of standby diescl geneRator shouLd be such T^T aLL Trip

sIgnaLs, excepT THose from ovERSpEed OR THE geNerator DIf ferEnt ia l ,

arE bypassed u ^ ^ acciaEnt coNdItions. HowEver, for routinE Tests

a l l Trips sHouLd bE retain ^

(^) I f other Trips^ i n addition to THe EnginE overSpEed and gEneRator

differENtial, aRE retained for accidEnt conditions, an acccptabLE

desing wouLd bE THat which pRovides two or moRe indepEndEnt

mEaSuREmentS of each of thesE Trip paramETers^

The bypass dRcuiTry shouLd be designed To meet THe RequiRemenTs

of THe IEEE STd 279; and abNORmal values of a l l THe bypass paRametERS

shouLd bE alaRmed in The co^R^L Room

of T^e siN^Le ^ I L ^ e CriTeRio^ To

section estabLisHes THe acceptabiLITy REQuriEmENts ^8^ foR

discoNNEcting power fRom eLEcTRIcally opERated valves of a fL r id SysTEm

as one meAns of guaRding againsT a SingLE FaILuRE (SF) That mIgnt cauSE

uNDesiRAbLE valvE actioN whicH iN-TuRn ResuLTs in Loss of a safeTy sysTEm

function^ THesE REQuiRemEnTs incLudE ThE following^

( 1 ) ^LanT TEchnical speeifIcations shouLd incLudE a LisT of a l l

clEctricaLLy opERated valves, and TheIR REQui^d p o s i t i o n

(2) THesE valves shouLd havE ReDuNdant position Indication I n The main

contRoL Room and The position Indication sysTem sHouLd ITseLf meCT

The sIngLe faiLure criTerion^

In T h ^ concERn, it ShouLd bE cLARified that ELEcTricallY opeRated

^ valves wnicH aRE classified as ^ active^ and wnich are manually

contRolled wouLd bE included among Those from wrich power is To bE

Removed i n oRDer To mEet ThE singLE faILuRE criTErion pRovided ThAti

(a) ELEctrical power can bE RestoRed to ThE vaLves fRom The mrin

contRoL Room,

(b) ValvE opERation (from ThE conTroL Room) is noT nEcessary for

aT Le^sT TEN minutes following occuRREnce of ThE EvEnt REQuiring

such opERAtion, and

(c) IT is dEmonsTRated ThAt a l l NEcesSary operatoR actions w i l l be

perf oRmed witnin THE timE shown to bE adeQuatE by The analysis^

Finally, it shouLd aLso bE pointed out That^ ^eLecTricAlly operated

valves^ incLude boTh valves opeRated dIRectLy by an eLEctrical device

(e.g., a motoR-operated vaLvE OR a soLEnota opERated valvE) and valves

opERated indIRecTly by an ELEcTrical dEvIcE (E. g ^ an atr-opERatEd valvE

whoSE a i r supply is controlled by an clEctrical SoLEnoid valvE) ^

^EfoRe WE StaRt ouR comparison beTweEn ThE American REgulatory Gaides

and ^Ranch TEchnical ^ositions on onE hand and ThE IAEA SafCTy Guides

on The other hand i n this arEa of eLeCTric power sysTemS we wouLd llke

To point out T^^t thE IAEA safety guidE SG-D7, is noT coNfiNed To describing

meThodoLogy but aLso pResENts cRITEriA^

MovIg THEN to ouR comparison we found

1) In boTh REgulaTory sysTems The E S shouLd at THe LeasT sa t is fy THe

S^gLe FaILuRe CRiterioN (SFC)^ However, we dRaw THE atiENtioN To

that i n THE USNRC REguLatioNS SFC is deTERministic w^l lE i n THe IAEA

viEW SFC sHouLd bE dictaTed by Random faiLuRE pRobabILIties^

2) THE IAEA sTResSes THe need for an eLectric gr id s tab IL i ty evaLuAtion

during The 1 ^ ^ ^ s i t e seLectioN phase of InsTallINg a NucleaR

power plant^ IT made The staTEmEnts THaT ^where TheRE is pooR gr id

stabILIty, mEasuRes foR ImpRovIng grid StabiLity at The s i t e may

be considered^

On The American side, we found That aLthough The SNRC s ta f f have

made ThE concLusIoN THat g r id avaIlabILity criTEria is met wi th SomE

margIn foR mosT plaNts ON The U S maInLaNd, ThEy as a consERvativE

approach ExamInE ThE avaILabLE geneRating capacity of an isolaTed

power sySTem on Loss of i t s LaRgesT unit , and indicat ioN was madE

T^^T pRovisions for addIt ioNal, bEyond noRmaLLy used on-stiE

cApabilit ies may be Required^

^) The IAEA indIcates T^^T The numbeR of connections to The clEcTric

gr id dEpENds on The desIgN CApabilities of The whoLe gr id , and on

ThE assign of ThE NuclEAR power plant ITseLf^ A sIngLe connEction

may bE accEptabLE I n s i tuat ions wherE ThE nuclEaR power plant

REpResEnts a LaRgE pRoportion of ge^ERatioN on THE eLECTric gr id

OR wherE ThE ELECTric gr id StabILi ty is Such T^^T ThE Loss of that

NuclEaR power plant w i l l LEad dIRecTly to The collapse of ThE gr id .

In Such situations ThE pRovision of a second TRansmissioN connection

adds LI t iLe To The ReLiabI l i ty of The E^S; other oN-site meASu^^

shouLd therE by be taken^ WHere THe geneRAtioN of The NuclEaR power

plant ^ a small pRopoRtion of ThE totaL geneRation and The gr id

is consIDered stabLe followiNg The Loss of The plaNT (or a ur iT of

it) The pRefErred appRoach is To pRovidE at LeasT two transmission

coNnEctions beTWEeN ThE pLaNT s i tE and ThE eLecTric grid^ These

trAnsmissioN llNES shouLd bE aDEQuatELy SEpaRated I n o r a ^ To avoid

common cauSE faILuRE^ An Indicat ion was aLso madE That THE uSE of

moRE ThaN two conNections to The grid may noT ResuLT i n incReased

RELiabiLity^ In This RegaRd The AmErican madE ThE clEaR cut ReQuiRment

T^^t two pHysically independEnT TraNSmission circuITs sha l l supply

power fRom ThE gr id To ThE onsite power disTribution sysTEm^

(4^ FoR a muLti-ReaCToR units NUclEAR power plant ThE IAEA and ThE USNRC

agREE That it is very ImportanT to fEed power To The emergency power

sysTem of any one reacToR u^T fRom The mri^ generAtoR of other REacToR

unITs iNdepeNdent of THe state of THE TRANSmissioN liNes fRom THe

eLecTric grid^

(^) In THE AmericAN sysTem there is No ReferEnce To aLTeRnativE on-stiE

oR of f -s i tE power souRces whllE, THE IAEA rEgulations IndIcatE THat

therE may bE aLtERNativE 0N-SitE or o f f -s i tE power SouRces That can

bE used To INcREasE ThE ReLiabiLIty of The emergeNc^ power sysTems,

buT which are noT To be consIDered thEmsclves as paRT of thesE systems;

e ^ , f oss i l fuEL gEneRatoRS NORmaLLy used fo r Load peakiNg duties

oR o f fs i te spEcIal purpose Locally ed gRid neTworks^

(6) WHILE ThE American sysTEm Takes ThE posit ion T^^t THE of f -st iE grid

power souRcE is the pREfERRed power suppty, THE IAEA indicates T^^t

ThE pRefeRRed power sysTem may be eITheR thE o f f - s i t e gRid oR The

main gene^^tor DEpENdiNg on ThE RELiAbILIty of each sysTem and

CApabILitY of ThE nuclEar plant conTroL and heat dissipatioN

systems To Reduce The power gEnERATed To THe House-Load i n a spEeifIed

period of time.

WHiLe The American rEgulaTory g r i ^ describE In-detaiLs THe bases,

Limitations, and mEans of impLEmEntatioN to acHieve a^ accpetabLe

ELEcTric power sysTem wnich satis f ies safety RequiRemenTs foR a nuclEar

power plant; THE IAEA safeTy guides; nameLy ThaT of REf ^ , speaks

i n gEneraL and sometimes i n brief Terms about The techniQues for

acnieving acceptabLE desigN and perfoRmancE of eLectric power sysTem

as a whoLE and ThE standby power supplies in particuLAR.

ThE accptaNCE cRitERia wrich musT bE applied f oR eLEcTric power sysTem,

as wel l as impLEmEntatioN methodoLogies of THesE cRiteRia as being described

In reLevanT safety guIdes are RevIEWed according To boTH THe USNRC and

THe IAEA REguLAtio^

THe pREfeRRed power sysTem seLECT^ for noRmaL pL^^t opERation may

be Either ThE eLectric gr id, or The uriT main gENERAtoR. The ReLiability

of Each sysTem conTroLs The sclEction. ReLiabi l i ty depEnds essentIally

on The east ing gr id, beiNg small or Large, stabLe oR poTENtiaLly u^stabLE^

and To SomE E^TEnt on thE typE of ThE Nuclear power plant^ where WR plants

are more stabLe ThaN BWRs and among The WR plaNTs T ^ E m S ^ ^ ThoSE

rEctrcuLAtion typE sTEam gENEratoRS are more StabLe Than oNes

onceTHrougH type STeam

Long TERm utiLI^aTIon of standby power souRces can decReASe TheiR

ReLiAbILity and incReasE Their maINTEnaNCE fREquency and outage timE in

a manNer That may noT bE compatibLE with The opeRating limits and

c o n d i t i o n FoR THese Reasons, THe standby souRces sHouLd NoT bE used

To suppty powER To The clectric emergencY power sysTem EE S ON a per ior i ty

basis but RatHer THe o f f - s i t e OR aLTerNativE power supplies aRE pREfERred

( in This RespEctivE oRdeR) whEN boTh oR one of Them is avaILabLe^

However, when The REl iabi l i ty of THe of f -s i tE souRcE is ReLativELy

L ^ ThE REliAbILitY of The 0N-sitE power supply sHal l bE inerEased so

That a l l safety sysTems wouLd have The necessary power foR Them to perfoRm

Their SafCTy functions when calLed upoN to do so^

A fInaL gENERaL coNcLusIoN wnich can bE made w^th Regard to

Regulations, out of This stady is T ^ ^ w^^E ThE American REguLatIons

describe ThE bITs of dEtaILs coNCerning design, pERfoRmance, mainTEnancE,

TestiNg, and a l l other aSpEcts of ThE ELEcTric poWER sysTEm compoNEnti

and equipmEnt, and of THe sysTEm as a whoLE, ThE IAEA REgulations address

ThE gEnERal pRobLEmS That may bE faced wtih I n countrIes havIng

grid sI^es RAnging fRom LARgE StabLE To small poTeNtiALLy unstabLE

As a ResuLT we fined that ti is paRticuLaRLy nEcessaRY i n This aREA

of ELEctric powER supplies to dEal wtih these iwo seTs of REgulations

as i f Each compLemenTs noT suppLemEnts The o T h ^ This sTems fRom The

faCT ^ ^ i clEctric power is mainLy a sTRong and ReveRSibLe link beTweEn

ThE nuclEAR plant and i t s ouTsIde^

REFERENCES

1. ^WR-InfoRmation M a n u ^ ^ WestingHouSE ELEcTric coRpoRation, NuclEAR

SeRvicE D i v i s i o n , OpeRation TRAiNing, Feb. 1979.

^ USNRC-SR^ ch^8^ ^ELECTric 1 ^ ^ , NUREG-7^/087^ REv^i, Nov^ 197^^

^ SafeTy SEries No^ ^0-SG-D7, ^EmergeNCY ^ower SysTemS at NuclEar ^ower

^^NT^^ IAEA, VienNA, 19^^

4. USNRC-RG 1^70, ^StaNdaRd FoRmat and ConteNT of SafeTy Analysis REpoRTs

foR NuclEaR ^oweR ^ lan ts^ , REv^, Nov^ 197^

^. SafEty S E R ^ No^ ^0-SG-G2, ^InfoRmation to be SubmIti^d I n Support

of licensINg Appl icat ions foR NuclEaR ^ower 1 ^ ^ ^ , IAEA, VIENNA,

10 CFR ART ^0, AppEndIx A, ^GEnERal DesIgN CrITeria foR NuclEAR

^, USNRC RuLes and REgulations^ ApriL

- 40 ^

SafeTy Series No^ ^0-C-D, ^DesIgN foR Safety of NuclEAr

IAEA, VIeNNa^ 1978^

Safety Series No. ^0-SG-D11, ^GENEraL DesIgN Safety ^r ineipLes foR

NuclEaR ^ e r ^AnTs, ^IAEA, Vienna, Rev^ 8, ^une 1^^^^

USNRC-RG 1^6, ^IndependeNce BeTwEEn ReduNdant Standby (oN-SitE) 1 ^ ^

SouRces aNd beTwEEn ThEIR DisTr ibut ion SysTems^, MaR ^ ^ ^ ^

USNRC-RG 1^9, ^E^E^TIo^ DesIgN, and Qua l i f I ca t ion of Diescl-GENERatoR

UnITs Used as on-SitE ELEctric F ^ ^ SysTEms aT NucleAR Rower ^ lanTs^

REv^i, Nov^ 1978^

USNRC-RG 1^22, ^ Per iodic Testing of ^RoTection SysTem Actuat ion

USNRC-RG 1^29, ^SEiSmic DesigN ClaSSif icat ioN^,

USNRC-RG 1^0, ^QuaLity ASSURANCE REquiRmEnTs fo r ThE Ins ta l lA t i oN ,

InspEction^ and Testing of InstrumEntAtion and ELEctric

USNRC-RG 1 . ^ , ^CriTERta fo r SafEty-RElaTed ELEcTric ^ower SysTemS

f o r NuclEaR ^ower ^LanTs^, ^ e v ^ FEb^ 19^7.

USNRC-RG 1^40, ^QuaLIficaTioN Tests of Continuous DuTy MotoRS InsTalLed

In sIdE ThE ContAinmEnt of Water CooLed NuclEar ^ower ^LANTs^, MaR.

USNRC-RG ^ ^ ^ ^^ReopeRatioNaL TestiNg of RedundAnt On-stiE ELEctric

^ower SysTEms to VErify ^Roper Load GRoup AssignmEnti, ^Mar^ 1^ ^

USNRC-RG ^ 4 7 , ^Bypassed and InopERabLE Statas INdiCAtion foR NuclEaR

1 ^ ^ ^ l an t Safety SysTems^^ May 197^

USNRC-RG 1 ^ ^ , ^Appl lcat ion of ThE SIngLE-FaILuRE CRitErion to NuclEar

^ower ^ l an t ^RotEction SysTems^, ^une 197^.

USNRC-RG 1^6^, ^ManuaL I N i t i a t i o n of T^RoiEctive ActionS^^ Oct. 197^^

USNRC-RG 1.6^, ^ELecTRic ^ENETRatioN AsSEmblies I n CoNTaiNmEnt

StrucTuRes f oR LIgnt-^aTer-CooLEd NucleaR ^ower ^LANTs^ Rev. 2, TuLy

1978.

USNRC-RG 1.68, ^ I n i t i a L TesT ^RogRamS f o r WaTeR^CooLed ReactoR ^ower

^LanTs^ Rev^ 2 Aug^ 1978^

USNRC-RG 1 ^ ^ ^ ^QuaLificatioN TesTs of ELecTric ValvE OpeRatoRS

Ins ta l l ed In-s IdE The ContaiNmEnt of NuclEar

1974^

^ USNRC-RG 1 ^ , ^ h ^ s i ^ INdependence of ELecTric

Sep^ 1978^

^ USNRC-RG ^ ^ ^ ^ ^SHaREd EmERgency and Shutdown ELecTric SysTems foR

MuLti-UNit NuclEAR ^ower ^LAnTs^ R e v ^ ^an^ ^^^^

^ USNRC-RG 1^89, ^QuaLifIc^TIoN of CLaSS IE EQuipmEnt foR NuclEaR F WER

^ N T s ^ Nov^ ^^^^

^ USNRC-RG 1.9^, ^ ^ I ^ I L I T ^ of ELecTric ^ E ^ ^o^c^S^^ Dec^ 1974.

^ USNRC-RG 7 ^ ^ ^ ^ ^Seismic QuaLifIcatioN of ELectr ic EQaipmEnt foR

NuclEar oWER ^LaNTs^^ REv^ 1, Aug^ 1977^

^ USNRC-RG ^ ^ ^ ^ ^THeRmaL OvERLoad ^RoTEctioN of ELEctric MoToR-OpERatEd

V a L v ^ , REv 1, Mar ^^^^

USNRC-RG 1^10^ ^^er IodIc TestiNg of DIescl GEneraToR UnITs UseD

as On-sitE ELEcTric ^owER SysTems aT Nuclear ^ower ^ lan ts^ , Rev^

1, Aug^ 1977^

^ USNRC-RG 1^128, ^InStaLLatioN DesigN and Ins ta l la t ioN of Large Lead

SToRage Bat ier ies foR NuclEaR ^ower ^ lants^ , REv 1,

^ USNRC-RG 1^129, ^MaInTENANCE^ Testing^ and REpLacEmEnt of

StoRagE BatiEries foR NuclEAR ^ower ^ lants^ , REv 1,

. BT^ ICSB-2, ^DIeseL GENERATOR REl iAbiLi ty Quallf i c a t i o n

USNRC-SR , Appendix-^, Rev^ 1^ OcT^ ^ ^ ^

. BTI ICSB-4, ^REQuiRemenTs on MoToR-OpERatED Valves I n THE ECCS

AccumulaToR LINes^, USNRC-S^^, A p p E n ^ ^ , REv. 1, OcT 197^^

BT^ ICS^-^, ^USE of DIeseL-GENERatoR SeTs f ^ ^E^^iN^^^ USNRC—SR ,

Appendix-8, Rev. 1, Oct^ 7^^^^

^. BT^ ICSB-11, ^STabILIty of O f f - s i t e F ^ ^ SysTems^, USNRC-SR , Appendix

8 Rev^i, OcT 1978^

ICSB-1^, ^^eacToR Coolant ^ump BREaker QuaLIf Icat ion^, USNRC

, AppeNdix-8, Rev^ 1, Octi 1978^

ICSB-17, ^^IeSEL GENeRatoR ^RoTective Tr ip CIRcuIT Bypasses^,

USNRC-SR , Appcnrix-^, REv 1, OCT 1978.

BT^ ICS^-18, ^AppLIcaTion of The SingLE FaiLuRE CRitErion To ManuaLLy

ContRolled ELEcTricaLLy OpeRated Valves^^ USNRC -SR^, Appendix^,