caltheble

A major purpose of the Techni-Information Center is to providebroadest dissemination possi-of information contained in

DOE’S Research and DevelopmentReports to business, industry, theacademic community, and federal,state and local governments.

Although a small portion of thisreport is not reproducible, it isbeing made available to expeditethe availability of information on theresearch discussed herein.

L&LJR -83-930(Rev. )

TITLE cO?4PACT F1:SICN REACTORS . . .NOTICE

PORTIONS OF THIS REPORT ARE ILLEGIBLE.

It has been reproduced fr~~-=

available copy to permit the broadestpossible nvailatlliiy.

AuTPIOR(S) R, A. Krilkowskl1.0s /\lamOs National Latx)rdtorv, LOS Alamos, ?/:1 S75.’15

R, L. llil~c’nsonlecilnologv Inter: mtionil] inc. , Ames, IOWa 5091O

SUBMITTED 10 5th hNS ‘1’opicdl }lcctin~ cm the Technology of Fusion !:ncrxy

Knoxville, I’:1 (April 2h-2H, 1!483)

I.)ISCI.AIMER

Thisrcpurt was prcpurcdu tinWXJumr.rf work spjncurwjhy un ugcncycrf[he United SIIIICS

(iu~crnmenl. Neitherthe Unit4St{lt= (iovcrnn)cn[nr.wunynguncy[he~f, nornnyur[hcir

cmpluyccc,makes any wurrunty,cqwcsc or irnplial,or uuumcc any IegnlIitihilityur rcqronsi.

hililyhr Ihcuccuracy,~wmplacn-, or ucofulncuuf any inbrmatiun,~ppcru[us,prduct,ur

prows dicckd, or rcpr~ttlti(hutillucc wuuld not infringeprlvaialyuwncdrlghm,Refer.

cncc herein10wry spciiiccwmmerciul pIoducI,procac,or wvicc hy trhdcrmmc, trndcl,wrk.

murwrncturcr,ur othcrwi~ d~ not nccacurilyctmntilulcor imply illcndorccmcnt.rccom-

menr.hliun,or rnvoringhy ~hc UniM SIUICSGnvcrnmcnl or wry ugcncy lhcrcuf.TIc views

and opinium of ●ulhorn cxprcd hcr~IIdo nol ncccuorilyslme or Ale:{ (huw G! the

Unikl SMIM (iovernmcnlor ~ny agcrwy [hclwf,

~~~&~~~ LosAlamos,NewMexico87545LosAlamos NationalLaboratory

,. .1,. 1.,1,:r, ~.; /.1,, ... ,),,,,,!,!ll;:,1II.’ “.I,’~,![ !/.

COMPACT PUS ION REACTORS*

R. A. RRAKO!JSKI, Loo Alamoe Naciomal Laboratory R. L. RACZNSON, Technology International, Inc.P. O. BOX 1663 2515 Elwood DriveLoe tiamo.e, New !lexico 87545 Ames , Iowa 50010

(505) 667-5863 (515) 296-2233

ABSTRACT

Compact, high-power-density ●pp~oaches tofusion power are propooed to improve economicviability though the use of lese-advanced tech-nology ir, ayetems of considerably reducedocale. The rationale for and the meann bywhich these ny8tem8 can be achieved are die-cuased, as are unique technological problems.

I. INTRODU~ION

The engineering developmeltt neede for !hemainline tokamak have been quantified byde?ailed conceptual d.eeign atudiea of bothfirst-generation engineering3experiments 1‘2 andcommercial power react0r8 , while similarstudies of the Tandem Mirror Reactor (T?4R)Q”’6an well ae nearer-term ●nginaering devices”eare being conducted. The etatua of reactordeslgna for tokamaka, tandem mirrors, andalternative fo~lon

concev!o:~cs: ;::l~::summarized quantitatively,tive i+aeeaoment of the engineering and tech-nology rwedn of che major AFCS ham beenpree~nted recently, ll The ●saecam~nc ofeconomic viability for magnacic fucion energy(14FE) provided by these etudieu cat] becomeohncurcd by the interdependence of complex,phyaic#, engineering, ●nd coatin~faconomiceIn order to clrcomveot in pait thu ●mhiguitvchat unually accompanied ●tcemptu to combinefind interpret re~ults from n lar,te number ofrelatively lndepeodent ctudlea, this papev pro-c?edu Jn the harnie of onc atrnple oborrvatiouAnd O!]* ~trnightforvard remedy proponfid t[)r~duce the implication of that obaarvat 1oo,specifically:

● ol,nerv~tiofl: moat fualon power reacto. pro-jcctiorra, b? they mainline or AFC, indicatea watar-lloatin~ fualnn power cor~ 1’ C,1.*,, flrnt-wall/hlaokat/tliield/coi la (’ ./fl/S/C)l Llwrt in At lenmt finnrder of ma~nltudemtlrr man~lva alid vu]umioouu than ●l-t~rnativeeo

.. ..—---- ---- .hWork p~rf,~rm~d uodpr Lllr.’lUllplcellOf th@

IJSWE ,

Implication: chase WE ayotemn may be

appreciably more expensive than alternative,long-term energy aourcea in spite of anagllgible fuel charge,

Solution: FPCa of considerably hiRher powerGeneity that elmultaneoualy - ‘withoperateacceptably low recirculating power fraccions(~ 0.1-0.2) ●nd reasonable extra;,olartons ofpreoent tachno~ogy will he required,

Concern over this dominance in FOC nasfi●nd co8t for many f4TE approach esl-l O,therefore, haa led to consideration of morecompact oPtionaOIO-13 This generic cntef-ory

includes the Com act Reversed-Field PinchReactor (CRFPR) ,12-1 ! tha reactor ●mbodlaent ofthe Ohmlcally-Hearcd Toroidal Experiment(Ows),l’RiggatrOn~)lJ~~J~fi~~~ ‘okaMh’ ““”’:certain aube!emencs o.the Coa?act Toroids (CT, i.e., s heroma~s

1-and

field-reversed conflguratlono).2 27 Iha Word“compact” deacribee ●ppro?chea that WOO 1doperate with high ●ngineer. ng or oyete- pc,. dr

density (i.e.. total thermal power per uttit ofFPC volume) and doss not oece~sarlly in:ply-mall plAnt capacity. A180, “compact” does notneceooarlly refer to or limit a Hpecificconfinement echame: just 4s the lie,)ersed-Flel,i

::;:ji~:;i8’’’:o:p::: b::a::;:v:;:;:::1° “act”’fur thetokAmak15-]7; the atallarator/tor~atrot]/heliutron (S/T/it)29, ●nd ccrtnin CT eoofl~-uratioou can b~ envisaged. benv r~Icharacteriuticm bei!t~ nought hy the cuml ],$t

reactor optionA Are: power dennltles wit}~in tll~~

FPC approacllinR ‘hone cf ligllt-watur finpionretictoru (i.e., lo-l~ MJft/G3 or i!)-~~ Limt!!!Rreater than for other tiFE nyatem8); p-l~jc[to(ltotal coetu tlhtt are relatively illsooaitivt tolarR@ chanjj~n in unlc contn ($/kg) used ;,)eatirnAte WC ●od associated reACt Or p!nlltaquipmptlt (WK) [!onta, thereby reducink LIIV im-

Wct of ~lnc.ertaintl~d in the ●naociato:j phyki,:rnand technology 011 total co~t; conuldernblv ~~..

(l\lt!PdFPC mice And maom with potantldl f,,r

“block” (i.e., aloglu or fcu.piece) intitull-

ation and maintenance; and the potential forrapid, minimum-cost development a~d deployment.

The compact op:ion will require theextension of existing technologies to &ccomo-date higher heat and particle fluxee, higherpower densities, and, in some instances, highermagnetic fields required to operate FPCS withhigher syacem power densities. Both theadvantages and limitations of the compactOpt;o,,, as well as related technological needs,have recently been aummarlzed.30

II. S~AIWS

Although the achievement of physics energybreakeven and eventual deuteriuu-critiumignition represents major near-term andpractically achievable goals, these conditionsw!!] be demonstrated in devices containingtotal piasma kinetic energies that dtffer8ignificuntly from the reqtliremente projectedfor commercial uower reactors. This differenceis best illustrated on Fig. I by plotting theconfjt,ement parauecer against the total kineticenergy stored in the plasma. Civen steadyproRress towards achieving improved confinementat reactor-like plasma denaitiea and temper-atures, the gap ●xisting between ●xperimentand FED-like devices, as well aa between FED-like devices ar,d commercial reactors, trana-latcs into a need for uignlflcant technologydevalopmenc.

Key plasma, FPC, and power.p!antparameters emerging from recant reactor c~aignatudles are summarized on Table I. Civencontinued steady progress, improved plasmeconfinement lead.ng to plaema ignitior, nppearrias a reasonably attainable goal, Extenolon tothe additional 100-IOOO fold lncrenue in ntnredplnMma en~rgy required for the conmerclalr,:actoru @umm#rized in Table I and listed onFig. 1, however, will require wjortechnolo~ical devclopmerrt and attendant C06t8,Significant reduction in FPC miass utiiizatlon,stortd pl~ornn find magnetic-field Pnergies, and~~rojcc[ad unit Cr)ntn are potiaible for thec,~mptictnyntcmo. Thene smaller, rnnre cum~>Kct

alu!r lcl~en mi~y IQad to a le.es-costly conmwrci~lre~c..>r, uhi]~ conuidprtibly reducln~ dwrel Op-m~nt requlrtrmontm and cootu.

111. RATIONALE

AIcI1ouRI)th~ compact approached reduce thastored pl,l#m~ enerfly re(luired for cummorclulfulll>n hy 411 ord~r of ma~llltu(it!,whilvnihulc~tn*otj81y KiVillK enlialtcpd syntem powerdeunity and FP(:mans utilir,otlon, u!tlmi4t*ly,tllo doclaioll ol}411 optimal •ynt~m p[~wer dennitymust bu made on tllabaaia of ●coromicm, Thm

direct coeta of a fission or fusion reactor isd [vialed into the Reactor-Plant-Equipment (RF’E)and the Bmlance-of-Plant (BOP) costs. The BOPconsiate of all aubayatems outaide the second-ary containment. The RYE cost for fia~ion

reactors is approximately 25% of the ?lsnttots. direct coat (TDC). Heat of the #t,:diesc~rized on Tsble I, however, project RPC

costn that range from 50 to 75 percent of the

Toc . The BOP coata for a fission and fusionplant of th~ came electrical power output areexpected to be approximately the same, althoughthe reactor-building costs for tbe latter canbe greater. Hence, TDC eatim.ste9 for fusionreactore predict higher values than for fissionpower plante because of high R.PE costs related

primarily to expensive (i.e., massive, high-technology) FPCS. This simplified view must betempered with certain caveats. Fusion reactors

captrble of significant direct conversion attainhigher overall energy conversion efficienciesand, therefore, project smaller BOP costs; theTDC, however. wfll be smaller only if the coecof the direct energy convertors is aufficienclylow, Also, ayecem9 with high recirculatingpower fracti9na will require larger BOPS andassociated coste, even though the FPC mass

utilization MAY be low.

A correlation of the r~tio RPEI’TW withthe Unit Direct Cost9 (UDC) for a range ofconceptual fualon power plantn (Table I) isgiven in Fig, 2; chc dominance of the RPE costsfor both mainline and major alternative fusionconcepts i9 indicated, The UDC and the ratioRPE/TDC use nominal values of -- 900 S/kWe and0.25, respectively, in Fig. 2 to normaiizc t!,c

fualm projections to LIJW. The TDC for fueionrelative to fln.gion can then be determinedunder the aaaumption that the 40P costs forlike fubion and fission power plants arcnominally equivalent; thie curve of ~p~ -

~Y~~)\\s*OX!L~ql[Xs~l~l ;f,e;~;Yon~$l;~mc~~expend tucre on CAPICA; ln,~aucment becaus,, of nnegligible fuel co~t, thin tradeoff of fuel forcapital coac becomes rnargioal for R. valllc+ Inexeenn of -. 1.3 iftl,efuel co~t~orfissi,>,lnominally tomprlsetr l/G-l/3 of the energy co~t,Generfillyl operdt(nn 11.. ttle low-econo121c-”lev~ragc rugim~, whuru RPE/TI)C : O,), uiilrequiru Lhe Fl}C to hu a lCUS dominant compon[Inrof the TUC. For t~asot)ailo {Init co,]t~ ($/ky.!of ftthricat?d, htgh-tecl:nolugy component~, thivcriterion can h~ mvt only by decrnanvd F1’(:mm~s

utilization (tunnv/tWt) or increanct! syqtvmpower dpnnity; mvrv compact oyutemu will beruquirwd,

1

1

Z1—

102’

,02

0’r

0’8

017I

ST ARFIRE

I I I I 1 i i I ~MARS 1MSa(8U~~.CI MSR(4!4)

CTOR~ P ~RFPR“,;-”U’o ESTR

RIGGATRCX FED OCRFPR

AL C-C ~

● ~MFTF-BOTFTll

i

w-m4

FRx.~ ‘m,H-E

Ogln

P L?gATF-1

0u)

,~(0.f3 MA)

~ ,(.)10 ES&-S

a

r

●qml,’”

CTX~ TPE ~’

TMXm ● _’ZT-40M(0.2 MA)

,0151 NBT1 I I I I I ~ J

100 10’ ,02 103 ,04 105 106 10’ ,08 ,~o ,010

PLASMA ENERGY (J)

FIG. 1. achieved, projected, and reactor values of the confinement parameter,total

‘YE* plotted versuskinetic energy stored in the plasma, E . Solid points corresp>.ld to experimental achfev?men?s,

and open points are projections. Source@ of !nformntion: Alcator-C (Ret. 31): Oouble:-111 (Ref. 32);PLT (Ref. 33); Hcilotron-E (Ref. 34); Wendlgteln-VIIA (Ref. 33); ZT-40M (Ref. 36); ETA-BETA 11(Ref. 37); TPE-lP.M (Ref. 38); EBT-S (Ref, 39); NRT (Ref, 40); PRX-C (Ref, G!); C’TX (Ref, 42); TMX(Ref. 43).

The mass utillzntio,. for the LUR 1s computed aschc maos of L~e pllmary containment veenel(lCSS the fuel) divided by the total thermalpower. The masa utilization muet be usedcarefuiiy as a compara?!ve meaaure of ayetemperformance; clearly, ouch comparioona imply emonotonic relacionehip betwsen maas and coat.Syacem with a FPC comprioed of larRe maas($n oft[\.?xpenaive cool~lnt (L.C., PbLi) eho,~lJ urtemtt8s utllizationf4 Chnt are approplietelycomper,~lted (e.R. , masu of drained blanket),The mafiu of an cntiru fisnion power plant,

!XC1U91VC of concrete but lnc~udinR allre!nforcl(\W bar, iD ~()-~5 tot\t\e/hWt,WhiC\) for

by the FPCFPC Mot!rfinRe ofOhowfl in- 30 ~/kgCent of

) w1;) be

technology

uncertainties a8socisted with the 89.9unedplaama performance and WC operation; bo:;~oignlficantly ●ffect plar,t perfonmence endcoat, which in turn can lead to ippreclahlecoetinu uncertainty and eignific~nt under-●otlmacea.tig

The direct capital roat reprenent~ Olllvone cnmponenc used in estimating the cent 0:electricity (COE). ThtI annu!l fixed chorxcqwill be approximately pr~portional to thc TQCbecauee the indirect capi:al coat is nomin,lllvthe e~me percentage of the TDC for IIny fusioIIrenctor, Furtherrnoru, thp fixud chnrgv r<it(,will be the acme unlean , for example, thecorapect retctoro require lees tine to Congtrurtand dre more amenable to maen prOd~mtiOt\methodn . Ftle’,expelee~ will be equ~i for (l\(*came fueion power, ●nd operation And mail\to-nacce (06ti) coatn ●re axpected to h,,approximately equnl for the same :)1,11):●lectrical cup~city. The O&ii coetn w:lI vary

WSLSI -rwuvmauamas ma Au O?m Jvilmmurros Oma?Ts

oNfOmlmAL SsAcrOu_ —.~,..1**>(1 Or-a)

0.81(2.25)

11.O(al. *)

2**(21SS)

I. M(l. M)

1.0(1.0)

0.4(1.>)

1M(2S01

)..3(> .1.)

O.oa(o. m)

11.b(l.1)11.6(11.2>2.3(1.0>WI SICO)Irol(lbbo)O.bo(o,)ol&.*(I.&)o.l~(o.)~)0.07(0.01)0.11(0,11)II*$(Ibal)10(:0)1?90(I*9C)10(la)

1(SO

1.>*

1.0

11,

0.01

11

0.6161.

).0

0.C41

6.s

il.

].b

U31]

llIYI

0, 10

},>

0,13

0.167

0,10

!618

&

1W4

b)

I*W

1.0

1s.0

6*!

0.9$

2*

0.98

1]1.

1.7

0.11

6.!

10,

!.4

MIS

1216

0.26

19.8$

0.)3

0.1%

C.]o

11)1

>

1*1S

12

1919

1.1

12.1

MI

2.00

Ii

0.1:

:4.7

1,0

0.10

7.0

1.0

2.1

Mm

1!4

0.50

1.1

0.10

0.11

0.2$

1104

10

1*M

M

0.42

!so.(~~

b].

1.0

15

O.bh

e.b

G.*O

42.5

Is.o(bj

>.0

*$M

,,M(c)

—

,., (.)

O.&o

0.:6

O.*1

-Iw$

*,. O

, *kl

-.

—

90

la

-*II ml.198)

0.1!

).&

)4.

,,, (.)

*O(. )

0.!2

,., (1)

I,b

0.29

12.,

a.och~

19.>

)+00.

1000.

,9.8(,>).6) 13.0

0.11 O.lb

0.1) 0.1$

0.11

0. ]C

boo al>

a-lo \

t9a1 )981

@ 42.)

198)

O.bb

4 12

>4.,..(l)

,~.*,(~)

‘).16~[, )

l,>

0..

SI.o;,,,(b)

i.. o

11OQ.

,1,

1.1

-: .0

~.]>

0..,

0.:1

—

-.

41ccA1#w 1$,91>

3.>1

0.s0

1.

2-)4

11-2C0.01

0.61.,)

0.20

m.

;~.c{t)

64.6

Ill\.

]\)

>,1

0.18

O.* I

0.1)

0.21

. .

. .

———t.kmtr,l<.11.

~bh.k tl. td &c .1,,., throat.

(~):.cld;rq,,*” ‘,ml,, to,.01-,

(*)P1.,,m,,, t.,, p,dl t,. J I{*)4.-!1, Pte*l l*.o10,,0,, ,,, ‘ ,”,, * [,., ,,, ., l,., *,* . . 2 1,, 7(. ) 0. 0.2>1.1nit>.~Lth.,,m, u ,. OM.OII ~f.,, PI. - .t. rt.p. I.SW. A 10 - I u icmn) ●d -c~b,.,,,.;4 .6 w c, ,1 +,lq ,,,,1 .*, ,.d. <ti Q . IUIO1 of1-1 <Mr*atc*r.

[I)?.ti/1.14 ●t r?,01, , 1,.148 ,{ Ou ,*1I will ●**, **<h 10 r,

If the costs of replacing the FPC differ. Allfusion rcaccors, however, req~ire repiacersentof approximately equal ma~see of material perunit time (- 2,)0-LOO connc/yr) for the sameFW/B !ifetime (MWyr/m2). The annual generating

cost for o compact fusion reacror, thereforeis expected to be iower th,ln tor other

~PPruactles to fusion, Prtmarlly becaune of thelower RPE COBC.

compact fusion reactors clearly must behi~her performance. device$ reletivo to otnerfuelon npproachee becauee of higher potterdenuitlea, t ,ermal loads, neutron fluxes, andin JOme Ca.gc, higher magnetic ficldu at thecoil. Thene more “stressed” overattngcondltionn, ho.ever, ●r~ similar to Operatinxconditions cmcounterecl in fineion :yateme,AllJ9.!t !11 n more favorable coolant geometry,Furthermore, operntirtg in the comp3cc-reactorreglmv ehould nuc nacenaarlly redi~c(?the plant

c.apoclty fartor lf equal unKlnQeritg deuIRI)criteria nr+, uacd; s lli~l}erunit cunt for thucompnct approuchca, however, may reaul~ ,

>c.) (cam) th.t..lt, r.

Because of the signlflcantiy reduced massutilization, the compact eyetems con“block”

allowmaintefiance of the FPC, with the

attendant potent~al for relatively rapid FFC

change out, replacement , and reetart.Never theleee , a potential exists for .9 lowerplant faccor, perhupe diministt!ng tllc promlscof reduced COE relaccd to reduced TI)C nnd

construction time. Finally, the compact fusirmOptiorfi may offer coat and nchedul@ advancap,c~for Che ~verall devel::ment of a unable produrtfor fusion, theec aavantage9 a190 being rckatc,lto the leescr role played by che FPC ,Irdaaeociatcd eupport aystem~ in deviceu leading

tu the rciictor; b bolder remeorcl] and dl,vc lop-ment prcgrum may cnauc,

IV. PAT}IWAY

By focuei:lg on the nyerem power dunolts,

%’vc’~,,d “wheru 1’~{ im thQ total unuful thcrmolpowor 13 the FPC volume, the RunPt,tlchariictcrincism for {i compact fut4iol\ re~ctorcan be ●atim$ted, The ayotem power dennity,

r’* , I 1 ,

I

o’t

0.1 0.2 0.s 0.4 0.s 0.0 mKEACTOR PLANT EOUIPMEk T (RPE~‘TO TALDIHCCT COST (TOC)

FIG. 2. Plot of UDC vetdus RPE/TDC for a range—.of fualo,l reactor designs. Normalizing these

cost9 to the LUR (UDC = 90(J $/kWe, RPE/TDC .0.25), the curve of ‘DC - (UDC)FuSION/(UDC)F SSI() is aleo ehown as aPpE/d un]er che assumptionof~~~~~~o~q~~ROF cost fol comparable fuoion and flasion

power plants,

●xpressed in terms of the neutron first-wall

Io&ding, Iu(i4U/m2), blanket

cation, us* fir.9C-vailblanket/shield thickness, Ab,thickness, 6, 10 given by

‘TH 21,,(MN + l/4)rd

y“ (rti+ Ab + 4)2 “

Baaed ftolelv on F.uclidian

energy multipli.rsdiua , ~~1

and nominal coil

(1)

argumenta for a

toroid chat can be ●pproximated by acylindrical geometry, the naxtmum eyntcm power

density occurs for rw = Ab + 6 and equa19

($) -X~~~b~~~) “ (2)

c w*Iw,M~

In nrrivi::g ac r.hiaexprenrilon, ;$, Ab, and 6

are held conct?nt, lRnoring the rulaclvely we~kl;)terdupendtnce hetwaen Ab, Iw, rw, flN, atid Chcdesire to achieve ● given rafJiiitton/hcmtinglevel At tl’.e coil pon ition. Wlth[n these

limitatirma, Eq. (2) indicates chroe approached

(I I 1 1 1

180001 i

-)

I 1 , 1 1 Io a ● o 10 la

F:SION POWER COREMASS UTILIZATION, M/PTH (tonn@jMwl)

FIG. 3. Correlation of the UDC projected for anumber of fusion reactor deaigna on the FPC

mesa utilization. The small variations

res~lting from differences in total power out-put have been reduced by normalizing all

deeigns to 1000-t4We(net) plant capacity.

to increaaed eyetem power density and decr~naedFPC maaa utilization.

● Increaae blanket energy multiplication,

% “- reul increaae: in situ fission.—- virtual incraaae: in Situ flssile-fue!—-—-

breeding

● Increaae fusion ne,ltron first-wal!

current: Iw(FIU/m2) = C.S7r#.2B”.

● Decrease rainor syatea radius, r$ w rw + Ab+ 6, which is ae.hieved through a reduced

blari.et/shield thickneae.

Ueing Eq. (2) and requiring (PTH/vc)HAX ~

(pTN/VC)&, the latter being a reference or

decign value,

Pm—— —. > (pr}lil’c)~ , (3)

2(2m)2(Ab + 6)2% -

where rw s Ah + 6 and n con.gtraint u!) tot~!

power i~ implied. For tnotance, if I’Tl < LOOO

Mwt , raquirinF, that the major radiun 4 >ru+

bh+6* 2(Ah + 6), ar.4 opecifyin~- tt,at

(Pm/vc)~x -> 10 H%’/m3 together lead to the

following constraint

Pm(Ab+6)3<— * 2.5.4m3 ,(6)

(Pm/v:)* J4.)2

or that Ab +6( 1.36m. Clearly, only thin

tritiue-breedfng biankets (Ab ~ 0.6 m) andresist ve magnetd (6 $ 1.36 - Ab =’0.8 m) canmeet these constraint.

The compact reactor option withPwlvc ~ 10 !!wtlrc~, therefore , is available toK% approaches that: a) can operate with lon2-pulsed or 8teady-state reefaci.~e C0116 whileconsuming only a 8ma11 portion (~ 5-10%) of thefu8i0n power, and b) can operate with steady-atate first-wall neutron currents given by

vhere, again, . = 10 Kh’thj, Pm *4000 Wt, and(~~:vf!;~avebeenused. !ience.fu8!on neutton ~irsc-wall loadings chat are5-16 greater th8n those being projected forocher systems will be required . Furthermore,recalling that IW = 0.57 f32BQr and aa9uming rY rw, :he cJopacf. reactors ❑u~t be baaed ORplasmas that are capable of S82 ~ 5.1 T2, where3 :s evaluated at the plastna surface andtypically is Iess by a faccor of - 2 than theraagnetic field at the coil. Ceneraliy,lnproveme\lt9 in beta and/or coil technologieswfli be required for man; of the approacheslisted on Table 1 in order to significantlyenhance che system power density, decrease themass ~tillzation, and lower the T23C and COE,Simultaneously, these condtt ions muet beachieved In copper-coil ay9tem8 that do notrequire a large fractiun of the fuolon power torecircul~ted for makeup of Ohmic loe.ees, Chere-by aasuring the cent advantages of leas maa9!veFPC. are no: seriously eroded by nbnormnllylarge HOP coata.

v. OPTIONS

The survey uf compact fu~ion concept9given by Gro99 in the Ref. 30 workohopencompu#ae8 toroidnl devlcen Supporting largeplaamo current deuaity (RFPs, ONTES, high-field

tokam:!~s), a varle(y of field-reversed conf iK-uroit[onM nod npheromak~ , aud otliur Vciy JQIIIJC

and hi~hly pulsed confiiu-ationa (1.a,, denac

Z-pinch, imploding Iinera, wall-confined

systems). Only the fir8t grouping (RFP8,0RTE6, high-field tokamaks) is considered here,these devices sharing cccmon featurea of Ohmicheating co ignition in a re8ibtive copper-coilayatem, while focusing specifically on the r,eadfor high system power den8itiea. Typicalparameter for the CRFPR, OHTE, and Riggatronreactora are alao given in Tatle I.

A. Compact RFP Reactor (CRF?R)13The CT?FPR la a toroidal axisymmetric

4evice in which the primary confinement field

f8 poloidal being generated by a coroidalcurrent flowing in the plaama, Jlthough largewithin the plaama, the toroida! field passeathrough zero at the plaams edge, reversing

direction to a very low value at the magnetcoils. The resulting lar~e ma~netic shearallow8 high-6 operation and la mslr.caiaed byintTln8iC plaama processes that converr

poloida! to toroidal flux, thereby maincalni:,gthe reversal . All coils are po8iti0nedexternally to the bianket, enhancing the

ability to breed Lritium, providing radiationprotection of the exe-blanket coil, anddecreasing the recirculating power fraction.The high power density is attai.,ed withmoderate betza (0.1-0.2) without requiring highfields at Lhe COilS, which also sub8cantiallv

reduces the recirculating power fraccior..Significantly smaller plant-capacicy 9ystecls

than the 1000-HWe reported in Table I are alsopossible for the C’RFPR, although at a higher

unit coat. Centr81 to the achievement of hiflh

system power density is the reduction in

blanket/shield thickness accompanying the u8eof normal copper coils, For efficient hea”

recovery and for adequate tritium breeding,minimum blanket thicknesses of - 0.6 m will berequlrec!. Although designed for long-pulsedoperation, the potential exists for a uniqueand etflciant steady-state currant driveso for

the kFP.

B. Ohmlcally Keated Toroidal ~xperif$-nt(OHTL) Resctor’-Plore conservative assumptions with r<svccc

to the external control plasma energy l,SSCSthst ●ccompany the mdintenence of totfildal-

field reveraul near the RFP plasma edge lendsto the OHTE. The Field reversoI and associated

magnetic nhear at Che plasma edge 1s controlledby actively-driven helical coils po9i:!o11c!i

near the plasma edge. The high-power-densityopQracion is attained at moderate CO higli be:.1,but wit}l higher coil fields than for t!icRFPwithout helical win[!ings. TrI en~ura, prnpcrfield atructurc the~e helical coils fnrcl~ltirgcr a8pect ratio plahmns, lncrcnstny, tile

otored magnetic energy. In oddiclon, rhl’,

winding produces magnetic flux in opposition totile ohmic heating (OH) winding requiringincreaaed current @wings of - 252 in the OHact. Since the reaiative copper coils areoperated near room temperature and are

positioned near the first wall, the overallayacem per fonaance may be reduced in terms ofincreased recirculating power, reduced plantthermal efficiency, and increaeed sitoredenergy.

c. Riggatron High-Field Tokamaki5

The Riggatrcn 1s baaed on a high-field,

Ohmically-heated tokamak that uses a hightoroidal current density ar~ high torofdal -fleld copper coils poaitionei near the flratwall . Net energy productioti la possible in arelatively short burn period from a

moderate-beta, Ohmically-heated plasma. The‘evere thermal-mechanical and radiationenvironment in which the relatively inexpensiveplasma chaabe r and cots aet aus t operatedictates an approximately one-month life. Theoverall system performance in tetma of plantthermal efficiency and the ability to breedtritium la reduced, since the coils areposfc ioned near the ffrat wall. UnJike thecompact RFP and OHTE reactora, the fu8ionneutron power is recovered in a fixed lithiumblanket located outside of the p!asma chamberand magnet system. Recovery of Ohaic andneutron heating in the copper colia 18 also aneaaential element of the overall Riggatronpower balance, which like the OHTE reactorrequires a large recirculating power fract ior,.

D, Other Potential Ap proache8 to CompaccReactorsA m.tmber of reactor configurations based

on fie!d-reversed”i or spher~mak”2 plasmoldg❑ay qualify for the compact, high-power-density

option, as prevtoualy defined. These CompactToroicis (CT) are generally pulsed systems basedeither on a translating burning platrrcoidor aa:ationary plaamoid that 16 subjected co &situ magne:tc andlor liner compression. The~er a>proachec, as embodied in the TRACTZOor ~I~12i reactor9, offer .he potential for

system p-wer densities approachin~ the 5-10tiWc/m~ range; other CT reactor embodiments alsopromise significant Increaaes in .sy9tem powerdensity. The advantages and limitation of a

number of CT reactora have been reviewed inRefo. 9 and 25; no attempt la mt.de here toinclude unique engineering and technology needaof the CT reactors until reactor de9ign8 thatempha8ize the upecific ~oal of high systempowe 1 density and reduced coat become evail-nbie. Similar comment9 apply to the otherAFCLY.

VI. TECHNOLOGY

The technology requiremenca for thecompact approaches have been aummarized30

relatlve to the STARFIRE Lcbmak.3 This tech-nology assessment haa bee. presented according

to major uvatem~ that n ‘lY impact the FPC(Plaama Engi.ieering Sys iuclear Systems,and t%gnet Systeme); some A.. cations on RemoteMaintenance and Safety aystema are als9gfven.30

Compact reactors would op!rate at higher

plasma denaicies and, therefore , refueling,impurity con?rol, and aatl removal requirements

differ. The higher plasma density may alsolead to more difficult rf current-driverequirements for aceady-state operation. Thepotential for low-frequency (few kHz) “F-G

pumping”s” available to the RFP and OH~,however, represents an attractive mecns todrive steady-state piaams currents. ‘The f~rq~.

wal 1 power loadu for compact reactors arehigher than for other fuaicn ayatema, whichalao leads to higher blanket pousr densltfes.Al:hough the FW/B for the compact systems wouldoperate under ❑ ore highly atreaaed conditions,these conditions are considered scar.dard for

fiesion energy sources. The mag.~etic fieldrequirements for the RFPs can be iower than fcrmoat fusion reactor aystema, but th< fielde areconsiderably higher for the Riggacron.However, the primary difference in magnet tech-nology la reflected by the use of

reai9tive-copper rather that superconductingcr,ila for compact fusion reactors, giving thelatte; an enormous advantage in terms of de-

velopment and reliability requirements.

The requirement for the Plasma

Engineering Syatema should not significantlydiffer from other fusion 9yatems. Becauae ofthe higher first-wall thermal loadings, a heaC-flux-concentrating limi:er does not appear

feaaible, and a larger ‘raction of Ehe firstwall will have to serve the limiter function ifa dlvertor is not used. Therefore, the compact

option poses more difficult technologyrequirements related co the first-wail thermal/particle load and blanket (~r magnet forRiggatron) power density. A potenc!ally moredifficult safety requirement for tne compactayatem:l la related primarily to che need forincreaaed emergency-core-cooling capabilitybecause of the higher afterheat power densityin the iW/B or in the coils in the case of theRigRatron, this ●nhanced afterheat pUWer

deneity resultirrE from the higher overall

operatinE blanket power density. The magnettechnology requirements are significantly lessdifticult for the CRFPR and OHTE con.epts

because of the abeence of superconducting

magnets and, In the case of the CRFPR, thesteady-state. magnetic fields are low. Lastly,becauae of the physical alze and maaa, blockmaintenance ia possible for compact reactorn,

wherein the comolete FPC la removed external tothe rea:tor cavity, for maintenance and repairopera tiona , with a more rapid replacement by afresh, pre-tested unit, promising shorter dowrr-times and more reliable restarts.

VII. SUW4ARY ANT CONCLUSIONS

In sunmary, the followlng charac:eriacicsemerge for compact fusion sy9tems.

● The FPC is comparable in masa or volume to

comparable heat sources of alternativefission energy sources.- system power density: 10-15 !fdt/m3- mass utilization: 0.4-0.5 tonne/NWt

● LT)C ($/kWe) and COE (mills/kWeh) are lesssensitive to large changes in FPC unitcosts ($/kg) and related physics and tech-nology.

c Rapid development at reasonable cost maybc possible.- SZM1l system size, flexible (alterable)

deveiopmerst path, possible to ex-perfmenc with technology paths whileavoiding large cost and rime penalties.

- no need for long-lead development ite-s~~at are efficiently uncertain Inthemselves as to impact the overallapproach (..e., larg~ superconductingmagnets, high-frequency/large-power rf,large-power/ steady-sta!e neutral-beazinjectors, resioce maintenance ofmassive structures).

● “Blockr’ installation and maintenance

becomes a possibility.- off-site mass production of complete

FPc .

- shortened construction times.-complete pre-in~tallat:on thermo-

mechnlcailelectromechanicel lvac~?um teatof FPC.

- shortened schedule4/unscheduled down-time and higher plant availability.

Generally, the compact option~ require theextension ef existing technologies to accommod-ate the higher heat fluxes and power densitiesneeded to operate the FPC with enhanced systempower delsity and mass utilization, The majortechnological challenge, therefore, reets withachieving reliable reactor operation of a morehighly “stressed” FPC, In return, a powerayetem emerges in which baeic physics and tech-

nological unknmwoa related to the FPC exertconaiderqbly reduced ●conomic leveragea on thetotal plant and energy cos+a. Equally if notmore important are the benefits related to mererapid development, installation, and mainte-nance of FPCS chat are at lean- an order of

=wltude less ~ssive and complex than thosepresently being projected for other fGE ap-proaches.

Rl?.FsRIWcEs

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

C. A. FLANAGAAA,D. STEINER, and G. E.

SMITN , “Fusion Engineering Device OesignDescription,” ORN1.lT!l-7948, Oak RidgeNational Laboratory (December 1981).

“IhTOR, International Tokamak Reactor,Phase I,” IAEA repurt STI/PUB/619, Vienna,

(1982).

c. c. BAKER (Principai Investigator), ec

al., “STARFIRE - A Commercial Toka=~

fiaion ?ower !’ldnt Study,” ANL/?PP-80-1,Argon~\e National Laboratory (Septenber19BO).

C. A. cARLso!i , etg., “Tandem MirrorReactor with Thetmal Barriers,” UCRL-52836, ‘Lawrence Li\etmore National Labora-tory (September 1979).

B. BADCER, et al “kIITAMIR - I: 4 Uni-__ -’*versicy of Wisconsin Tandem Hirror ReaccorDesign,” UWFC!+400, University of

Wisconsin (September 1980).

c. 14EhWINC and B. G. LOGAN , “wirrorAdvauced Reactor Study (HAM),” Lawr6nceLivermore National Laboratory, \19B2).

B. BADGER, et al., “TASKA: A TandemMirror Fua io; ~gineering Facility, ”

LWFDt4->00, ‘University of Wisconsin (!4arch1982).

T. K. FOULER Gnd B. G. LOGA??, “TandemMirror Technology Demonstration Facility,”UCID-}9193, Lawrence Livesmore NationalLaboratory (September 1981).

c. c. BAKER, G. A. CARLSON, acd R. A.KRAKOWSKI, “Trends and Developments in!laRneti~ Confinement Fusion Reactr,rCoiicepts,” NucI. Technology/FuslonL ~,—.5-78 (January 1981).

Report o.) the Third IAEA Technical Coa-mittee Meeting and Workshop on FusionReactor Design-III, Tokyo, Japan, October5-16, 1981, !iUCi. FUS, Q, 671-7!9 (1982).— —.

11. R. A. KRAKOWSK 1, “Identlficatton of Fu-ture Engineering Development Ne~de ofAlternative Concepts for Magnetic Fu.si~nEnergy,” Nationnl Academy of Scienceiiorkohops on the Future EngineeringDevelopment Needs of Magretic F’ualou,Washington DC (August 3-4, 1982).

12. R. L. RACEtiSON and R. A. KMKOWSKI ,“Compact Reversed-Field Pinch Reactors(~?R) , Sensitivity Study and Deaign-Point Determination, ” LA-9389-?S, LosAlamos !iatlomal Laboratory (July 1982).

13. R. L. NACENSOti, R. A. KRAKOUSKI, etal., “compact Reversed-Field l’inz~actors (CRFPR): Preliminary EngineeringConsiderations,” to be published, LoaAlamos Ncclonal Laboratory (1983).

14. R. F. BOURQUE, “OHTE Reactor EmbodimentsBased on Pre!lmlnary RFP ExperimentalResult s,’r 5th TOP. Mtg. on the Tech. ofFus . Energy, Knoxville, TN (April i6-28,198?).

15. R. h’. BUIS~ and R. A. stLAm-Y , “Con-ceptual Design of a Ffodular ThrowawayTokamak Comer cial Fusion power Plant,”

Internal report, IhTSCJ, Inc., April 27,

1978, see also C. A. !(OB1!4SOii,

“Aerospace Aids Fusion Power Concept,”Avid:. Week and ~ Technol. ~, 61—— .(June 12, 1978).

16. C. E. WAGTLF. , “po69ibility of AchievingIgni:ion in a High-Field Otuaically-HeatedTokamak,” Rev. Lett. ~,U.— 654(1981).

17. “Compact High-Field Toroids: A Shortcut toIgnition?” m“ .~:’’’’’.~’o‘“-19! (Hayi98i).

18. ‘w. KOPPENDORFER, “The ZEPHYR Experiment,”’Fus . Technol ., 77 (1980), ?ergamon Press,ml~

19. 3. R. Cob.lq, et al “Near Term ?okamak——.*Reactor Designs t,:th Hif,h-PerformanceRes{st:ve Coils,” JA-81-20 MIT PlaamaFusion Center (1981).

20. H. .’ . WIL!,ENBERG , “Jefioltion and Con-ceptual Deeign of a $mall Fu@ion Remctor,”WShW-i 159, tiathematlcai Sciences !+olthweat

(February 1981).

2i. A. E. ROBSON, “A Conceptual Design foran Imploding-Liner FuJi O!I Reactor,”

@3a0a”sa w a“d Technol~., 415,

Pienum Publishing Co=, NY, (1980).

22.

23.

24.

25.

26.

27.

28.

29.

30.

31,

R. L. MILLER and F. A. K3L+KOWSKI, “Aaseasment of the Slowly-Imploding Liner(LIhTS) Fusion Reactor Concept,” Proc.bch ToP. Mtg. Technol. cf ControlledNuclear Fusion, CONF-30!Oli ~, 825, Kingof Pruaaia, PA (October 14-16, 1980).

R. E. OLSON, J. G. GILLICA?N, E.CRSENSPAN, and G. H. M7.LEY, “TheSpheromai. Approach to High Power DensityReactora,” Proc. 9th Symp. on Sng.Prob. Fusion Research ~, 1898, Chicago,IL (October 26-29, 1981).

R. L. HAGENSON and R. A. KRAKOKSKI, “ACompact-Torus Fusion Reaccor Baaed uponthe Field-Reversed Tl,eta Pinch,” Proc.4ch ~Op. !’ftg. ‘echnol . of Controlled%uclear Fu610n, CONF-8O1O11 x! li20,King of Prussia, PA (Occober 14-16, 1980).

R, L. HAGENSOS and R. A. KRAKOUSKI, “ACompact-Toroid Fusion Reactor Baaed on theField-Reversed Theta Pinch,” LA-8758-MS,Loa Alamos National Laboratory (Harch1981).

A. C. SMITN, et al., “The PrototypeMo. ing-Ring React=,’’~roc. 9:h SYMP. Ol!~i:g. Prob. of Fusion Research ~, i867,Chicago, IL (October 26-29, 1981).

J. G. GILLIGAN, G. Ii. !’!ILEY,and D.i3RIEMZYER, “Conceptual Design of a CompacLField Rcveraed !iirror Reactor - SAFFIRE,”Proc. 4th Top. Mtg. Technol. ofControlled Nuclear Fusion, CGN-801O1I ~,840, King of Prussia, PA (October 14-17,

1980).

!7. HA!!COX, R. A. KRAKOWSKI, and k. R.SPEARS . “The Reversed-Field ?inch Reactor(RF?R)” Concept,” Nucl. ~ anc Des=Q, 2, 251, (1981).—

——

R. 1. MILLEA, “General Reactor COnsic!er-ation~ for Stellarators,” LA-UR-U2-2667,Los Alamos National Laboratory 4C5

International SteliaratJr Workshop, I 337,Cape May, NJ (September 13-15, 1982)~

R. A. KRAKOwSKI. J. S. GL4NCY , and A.F. DABIRI, “The Techrto!ogy of CoapactFusion Reactor Concept,” ptesented at theUorkahop in Compact Fusion Reactors,Washington, DC (SeptembPr 31 - OccOber i,1982) LA-UR-82-299d, Loa Alamos !lationaiLaboratory.

Us. Department of Energy, “Summaryreport Toka~ak Conf inement Ex-periaents,RnDOL/ER-0i22, USDOE (1982).

32.

33.

36.

35.

36.

37.

38.

N . NACAHI ●rid D. OVERSKEI , “lJlgh-B In-jection Experiment with Shaperi Plaomea inLbublet-lll, ” 9th InL. Conf. on PianmaPhysics ●nd Controlled Nuclear PuaionResearch, Baltimore, KD, IAM-CW41fA-2(1982).

D. Q. RUAPC, H. BI~R, A. CAVALLO,R. CR3tIEN, and S. CO:[EN, “High Power ICRFand ICRF ?lUS MB Heating on PLT,” ~.,IAEA-cN-41/I-l (1982).

K. UO, A. II?OS141, T. OBLIKI O. HOTOJINA,and S. HORIHOTQ, “Part I Heating Experl-❑ erits on the Heliotron E Plaam,” g.,IAEA-CN-41/L-3 (:982).

W VII-A Team, “Neutral Injection HearCnpin the Wendelstefn VII-A Stellaracor,”ibid. , IAEA-CN-&l/’L5 (1982).

D. A. BAKER, M. D. BAUSHAN, C. J.BUCHENALTti, and L. C. BUKYHARDT, “Per-formance of the ZT-~OH Reversed-FieldPinch with an Inconel Liner, ” ~., IAEAC!l-61/rf-2-l (1982).

v. ANYoriI, H. BOCATIN, A. BVFFA, C.BLPITING, and s. COSTA, “Studiee on Highdensity RFP Plasmae in the Eta-Beta IIExperiment,” ibid., lAEA-CN-il/H-~ (1982)

K OCAkA, y. HAEJIMA, T. ,HI!!ADO. Y.!iIRANO, and P. C. CAROM, “Experimentaland Computational Studies of ReversedField Pinch on TPE-IR(9),” ~. ,IASA-CN-41/H-l (1982).

F. w. BAITY, et ~., “PIaama Propertiesand Ion Heac~g in ESIT-S ●nd Hot ElectronRings at TKW,” ~, , IAEA-CN-bl/L-l(1982).

M. WJJIWARA, et al. , “Experimental andNumerical Stud~e = Plaama Confinement InNagoya Bumpy Torus (NBT),” ~. ,IAEA-CS-Ll/L-2 (1962).

D, REJ and M. ~SZWSKY, “A Zero-Dimensional. !iode 1 for Field-ReverredConfigurations,” Proc. 5th Symp. onPhys:cs and Tech. of Cumpact Toioids inthe Yl&gnetic Fualon Program, Bellevue, WA(Novembqr 16-18, 1982).

42.

43.

44.

45.

f46.

50.

C. U. BARX~S, ● t al., “Current Results——from the Loa Ala-s ~ Sphere-k,” ~.,

T. C. SIUO?JEN, D. E. BALDWIN, S. L. ALLEN,and W. L. BARR. “m Tnndem rfirrorExperlmenta ●nd Thermal BarrierTheoretical Studlea,” ibid., IAEA-CN-kl/C-1 (1982).

R. L. MILLER and R. A. K2UKOWSKI, “TheModular S“.ellarator Fusion Reactor (HSR)Concept ,” 7A WR-81-2878, Laa AlamoaNational Laboratory, 3rd IASA Tech.C~ittae ●nd Workshop on Fusion ReactorDesign and Technology, Tokyo, Japan(October 5-16, 1981).

c. G. BATNfCE, et~., “ELNO Bumpy TorusReactor and Power Plant Conceptual DesignStudy,” U-8882-HS, LOIS Alamoa NationalLetaracory (August ]981).

R. L. WGENSON, R. A. XiAKOWSKI, andG, E. CORT, “The Reversed-Field PinchReactor (RFPR) Concept,” IA-7973-W, LOb

Alamoa Scientific Laboratory (AuguaL1979).

R. R. BORCHERS and C. M. V}.N ATTA (eds.),“The Narional Hirror Fualon Frogram Plac,”UCAR-10042-82, Uwrence Livermore Xat:onalbboratory (August 1982).

United Enginee.9 and Conacructors, Inc.,“1000-Mlie Central Station Power Plants[nvegtment Con: Study,” WASH-1230, U.S.AEC (June 1972).

E. U. KEhROL?, S. W. CHAPEL, and C.WOR~INC, “A Review of Coat Etsclmetlon InNew Technologies: Implications for EnergyProce9a Plants,” R-2&81-D9E, Rgnd

Corporation (July 1979).

K. F. SltOENBEI.G and R. F. GRIflBLE,“Osclllacing Field Current Orive fnrReversed-Field Pinch Discharges,” Pror,IEEE Htg. on Plaams Science, Ottawa (May17-19, 1982),