H [ll?IJU1 ~Ur ~US~ U; 11lk? I ~LI H11- cal Information Center is to provide the broadest dissemination oossi- ble of information contain&ll in DOE’s Research and Development Reports to business, industry, the academir mmmunity, and federal, state ana .b~calgovernments. Although a small portion of this report is not reproducible, it is being made available to expedite the availability of information on the research discussed herein. *m-wn ------
LA-UJ?--83-257Q @/w -%&cc~Q’” 37 91?G4 001366
Loc AWW [email protected] oemtoo q MO Lfmvorskyof C.WOH fOrfh Wf.d 81OWO00P.fim.nl Of@WOY-f *IW! W’-74O5-EP4G+6
TITLE’ MATERIALS NEEDS FOR COMPACT FUSION REACTORS
.9-4.0 - . f Im’mE AUTHOW) Robert A. Krakowski ?QUTIOH$ OF,TWIS MPOR’7 AM ILM$IUIA 9t W been reproduced from ‘he best avallabla cow to permit tha broadest possible avdlabl~ll~. .*. A
SUIMf~TIED 70 Proceedings of the 3rd Topical Meeting on Fusion Reactors M8terhlS Albuquerque, New Mexico (September 19-22? 1983)
DISCLAIMER
This report was prcpurcdwan uccount of work qwraored by an rigencyofthc Unitd Statw Government. Ncilhcrthc United Stulcs Ciovcrnmcntnorwryagerrc ytherml,ouranyofthcdr cfrployccs, mukcri;my wurrunly,cxprcmor implied, or wau,mmnpy legal Iinbli(yor reaponsi. hility fortheaccur[lcy, c~)mplctcncss,or utufulrmnof uny information, rippartdoqproduct, or procasadinclod, or rcprcncntnIhul itn unc wou!d not in(ringo privrrtelyowmd rights, Refer- cncc herein to wry qwcific commcrciul product, pro w, or aarvicchy trade n~me, tr~demark, manufacturer, or nthcrwisc dom not ncccsr+anlyCOIMIiIUIeor imply iia endormment, rccom. mcndation, or fnvorinn o, the [Jnitcd Shrtcs (Jovcrnmcnt or ury agancy th!lron(,The viewI and opinions of uuthors caprcmcd herein do not ncmrmrily MtaIeor refhct Irma of the [Jnhf Slalcn (}ovcrnmcnt or nny HgcncyIhcrcof.
n nn LosAlarncwNationalLaborakm I.Ml!w!!kamosLOSAWTM3S,NWMexico 8754$
WVfllllIlllONw TN!!:IWIINI hl NATERIALSNSJUJSFOR COftPACTFUSION REACTORS
Sobert A. KRAKOWSKI
Los Uawo Naciorul laboratory, Los Ahmon, New Uexico, 8?545
TIIs ●conomic prosp+cta for rngnetic fution ●nergy cm be dramatically improved if for che same total powei output the fusion neutron first-wall (FW) loading ●nd the system power density can be Increassd by factorrn of 3-5 ●nd 1O-3O, respectively. A number of “compact” fumion reactor ●mbodiments have been proposed, ●ll of which would operate with increased FbI lomdings, would uae thin (0.5-0.6 m) blankets, and would confine qumsi-steady-ctst~ placm with reeittive, water- cooled copper or ●luminum coile. Increased ●yctem power dentlty (5-15 HWt/m3veroug—— 0.3-0.S NW/m3), considerably reduced phyeical size of the fusion power cora (FpC), •~ld spprociably reduced cconomlc leverage ●xerted by the FPC ●nd ●ssociated physics reoult. The unique Mteriala rcquiremento ●nticipated for theee compact reactors ●re outlined ●gainet the well documented bmckdrop provided by similar netds for the mclnline ●pproaches. Surprisingly, no single mmterials need that i. unique to the compscc systeme ie identified; crucial uncertainties for the compact ●pproaches mmt aleo be ●ddre~sed by the mainline ●pproach~a, particularly for in-vacuum component (FWs, limiters, divertora, ●tc.).
1. INTRODUCTION difftcult mmterlals cholcee, ●n ●xpauded Seth the technical ●nd co-rcial ●ucceso matcrlala data be-e, considerably more design of wsnetic fusion depend on ●dvancoo in detail, ●nd improved omtimmteo of ujor ●ub- ●ngineortng mmtcrialc operatin~ in ●n oyetem performance. Even ●t the conceptual
●nvironment of highly non-uniform surface ●nd desi:n level, however, the liet Jf msterial$ volumetric power denaitieo. Tlaeo@heat looda performance requirement. preeenta ● major will be sppliad under conditions where the challenge for the INTOR/i)EMO/COt4MSRCL+l. basic ●ngineering metarial propertied of development sequence. The more compact, stressed camponanta ●re being dramatically higher-power-density fusion ●pproached propose altered by ●n intenee neutron/8rammr4- ●mxller fueion power cores (ifPC, i.e., firmt- raylcharged-particle irradiation field. The wall/blanket/shield/coile ) opersting with in- intcrdopendence between phmae phyeLca/ cresoed puwer density ●nd FW neutron und enelnaaring, reactor desian, ●d materials hating losda. The degree to which meteriale mcience/enalneerin8 needed to ●chieve perforunce roquiromente ●re ●ltered by the economic, commercially ●ttractlvo fusion power needo of thoao compact fueion reactors ie ●d- IISO been hlghli~hted by ● number of ●xcellent dreooed qualitatively herein. Tho rationele, over’iew papers dealing with first Ualla] pathway, ●nd Seneric technology required fot (W), blanketoz (B), material. meede for the compact reactura have been deocrlbcd ●pacific deviceo, J*4 ●nd the worldkid~ recently. 700 wterialc pro~reme•ddroosin~ thaoe ne*de, $*6 After oummmricing the reaoone fo, con- Nygren3 pointe out that them ~tar?alo tiderin~ ●yeteu with met.erial requi, -menta needs have been identified primr~ly by con- that in ●ome caeeo mey .xce@d those prl~~cted ceptual daoign otudiee, with the more ●xactinu in Refo. 1-4, the Sanmric ne..de of [,,mpact “dtcisna to conotruct” ●ventually requiring deviceo ●rt described. Specific c~mpact reactm demigna heve been ●uggeeteda for the ●xtension of technology (e.g., reeietive Reversed-field Pinch (RFP), the Ohmically - rather then superconducting coile, ohmic tlested Toroidel Experiment (OliTE, ●n SPP with heeting rather then high-frequency rf ●uxiliary helical windi~o), end the high- huting or neutral-beam injectien, ●tc.). field tokemek. Other cendidstee for compect reeccora beve ●leo been identified. g$g This prescription for ●conomically Although the mzteriele ieeues ●nd neede competitive fmion ie not without rimke or ●ddreezed herein ●re generic, npecific trade-offe; “e potential for incrueed re- quantitative exemplee ●re referred to con- circulating pow-r, reducud thermal conversion ceptual deeign reaultc ●merging for the ●fficiency, ●nd reduced plent factor cculd compact RFP reactor (CT.FPR).10 Similerly, Iced to reduced plsnt ●fficiency, increaeed compariaone with th meinline development plent coet, ●nd increaeed COE. Hlnimization ●equence ●ro mede with the STARFISE1l ●nd of theoe rieke will depend on the ●vailability Culhem MkIlBA2 tokemek reector deslgno. ●nd use of mteriais ●tid mterial ●ngineering ●pproechee that differ ●omwhet frow thoee 2. COMPACTFUSION REA(XORS being suggeeted ●nd pursued by the winlime The dominance in uso ●nd coet of the FPC progcme. Theee difference mre highlighted for ucst approechee to w~netic fucion7 hee herein. created interest in wre compect, higher- Altnough heurietic ●~’8uemente can be mede powar-density ●yatemz. The following improvud to point the way toeardo imp:oved ●yetem cherscterietica ●re being pureued through the economics throu8h hisher ●ystem power deneity compect reactor option. ar lower ?PC meeo utlllzttlon, ultimately de- ● FPC we-s and VOIVIM compereb?e to tailed peremecric ●tudiee on opecific concepto ●lternative nucleer power ●yeteti (eystem mm t ●steblleh economically optimum, techno- power dcneity d 5-15 HWt/m3, 8eee logically feacible sycteme. 10 For the preeent
utilization of 0.3-0.5 tonne/lfWt), which purpoeem, however, Fi80 1 continuee with the are fee., a 01 1O-3Q tiwes becctr then heuristic ●pproech by diepleying the oyetem velues beins projected for moot megnetic power deneity versus the inveree of the WC fusion ●chemeo. ●aeo utllixation; linee of unit ●lope on ● Reduced neneitlvlty of unit direct caet ?18. 1 qive the ●verage FPC meea density, *PC (UDC, $/kWe) to the coat of the reector (tonne/mJ). The ●yotem power deneity for uost plent ●quipment (kPE/TDl: ~ 0.3 rether then of the “oup*rconductinS” fusion oyoteez di~- 0.5-0.8, whor? TDC io the totel dir~.ct pleyed on ?1s. 1 ●re ●t lee-t one order of coot). me:nitude below other nucleer powor syeteme. ● Cornpotltive nyotaD cocte and coot of Ln order to Jain ●n order of mest}itude in- ●lectricity (ax, nil la/kHeh ) uoln~ creaoo in thi(l importe it peregeter, an in- reeliotlc unit matorlala coete, febrl- craeoe in W neutron current by 3-5, mimll- cation/conot:uctlon ?Lteee, ●nd development tsn?ou~ly with ● docraaec by .2-3 in n ocheduleo/cneto. rediua, 8/S thickneoa$ end coil redius and ● bpid dtploymcnt of ●~ll ?PCe with the ●iae, ie required.7 Thc former chen~e meken potential for “block” lnet~llatlon ●nd ●tainlee- ●teel ●ven lee- ●ttractive from the wln~enence (i.e., ●inatc or few piece heat-trensfer viewpoimt, whereee the reduced FPC), unlng ●yatexe relyin~ on t minimum B/b thicknoce ●liminetee ●uperconductins coile principle is cepable of burn ●xtanaion by non- m .,1 alusurLiimo!i inducti?a mama. For thoaa compact reactora with plaexa cmfinemnt dapandimg in part I I (i.a., OHTE) or totally (i.a., Rigqatron) on I ●trong toroidal fialdo, tha ~gnat coils ruy ba highly ●treaaad as well ea praaanting ● potentially sarious drain on tha ovarall pbnt ●fficiancy (1.0., incraeaad recirculating pmiar, reduced tharmal racovary ●fficiancy, ●tc.) Genarally, tha high-hoot-flux FWs and othar in-vacuum coxponant (IVC) ●urtacaa, thin higt,-powar-daneity blenkate, ●nd raaiativa ● FIGURE 1 xo-blankat (CRPPR) or aaar-PW (OLTE, Riggatron) raoiotiva coil. largely defina the Comparison of syatcm power densitica being projcctcd for conceptual fusion reectrm with differancao in -tariala raquiremanta batwean ● STARFIRE a number of fi.sion reactor ywtema. ● tokamsk (hf. 11), Culham MkIIB tokamak (Ref. the compact nd tha other magnetic fucion 12), Superconducting Reveroed-field Ptnch ●pproacha$. fhactor RFPR (Ref. 13), Hodular Stellarator Reactor HSR (Ref. 14), ELMO Bumry Toruo Genarally, two crucial quaotiona mutt ba Reactor EBTR (Ref. 15), Magnox Gee-cooled ●nawarad befora tha ●conomic ●ttractivanaso of Reactor (hf. 16), Super Phenix Liquid-Metal to Faut-Brooder Fiooion Reector SP (Rd. 17), compact epproachao furion powar can be Advance CSD Reactor ACR (Ref. 18), *pact fully ●ubatantiatad. Reverfied-Field Pinch Reactor CRFPR(Raf. 10), e ● ● Ohmically+feat Toroldal Experment Reector OHTE can plasma confineaant chama baaad (Ref. 19), ifigh+ield Tokmmak Reactor, ●ithar on e xainline, alternative, or ● Riggatron (Ref. 20) , Preosurixed-Water fission Raactor PWR (Ref. 21), PWR Steam combination theraof be found ttat will Generator S1; (Raf. 21). stably confirm plaama of tha required powar density whila ~iving ●oma ●cauranca from consideration, since rmtron fluxes nnd of long-pulsad or ●taady-atata operation hemt deposition in the COILA cannot be kept with ● recirculating pouar fraction 1Ow in the specs avallabla. Iiance, the ~ 0.15-0.20? compact oysteme that ●merga (CRFPR, OiiTE, ● givan the pla$- physics infarrod from tha Riggatron) uoe reolotiv~ COpP@r-AllOY coils last lcoue, can ●ll ●ubelaxenta of the FPC with cer9mic ●lectrical inauletion mid (i.a., IVC, blankat./ahield, coils) ba made generally provide only ● thin (0.S-O.6m) to opareta with ●n ●ccartablt englnearad blanket botwem the FW ●nd th~ high-rsdiation- lifatime, both in tatma of raal time flux, rmolotive coil.. In certain Inatencea, (i.a., -intenanca pariod) ●nd flucnce FW (Riggstron) or near-FW (OHTE) actlvely- (i.e., total amount of ●.largy #aneratad driwn CO11OUy be necessary. par mono of fPC conoumed)? Tha compect ●ysteme depicted on Fis. 1 Tha first iaeue la not. u:thin the ●copa of would ●chiave DT ignition by Ohmic difisipation this papar, but ●acond-stabi lity-ragion of toroidel p14ma curreot.s. Inferrmd, tokexakm, RFP/OttTEm, ●nd ●pherosaks/fiald- thercfora, ia ●oma form of inductiva currant ravaraad conflgu:ationo provi d- ●xciting driw, ●t lmtt for ●tartup; ●ech ●yatem in p..entiel on both theoretical ●nd axpariaental ground.. The ●econd queetloo of FPC lifetime TABLS 1. SUFMARY OF FPC LIFSTIt4B DETBNmuNTs22 as ●arized in Table I, is complex, ●nd . &actor Operatimg Condition centers on the mterials the- of chin - FH oeutron loading overview. Four rnjor determ~nento of ?PL - Vohtmetric hUtit18 lifatime ●re identified in Table I: s ctot — damage ratee (dpa/yr, ~ ●PPm/Yr, operetitg condition.; FPC material propertied; E ●ppm/yr, bumup) compooent geometry ●nd consttainta; and design - Pleume ●mergy rejection ●nd failure criteria. By ●pplying similar — particle fluxes to IVC (DT, neutrals, desian ●nd feilure criteria to ●ll fusion Ue, impurities) ●pproached, ●nd ●emm.ing negligible influence - heat fluxes (conduction ●nd rediation) of rate on the effects of radiation tn - Duty cycle chsnging materials properties (i.e., ● fluence - Coolant (kind and temperature/pressure) ●ffect) the FPC lifetime ineue becomes one of ● kieterial Properties reactor operation ●nd component geometry. - therwil fheat apacity, conductivity, Operating in the compact re8ime ●xpsoeivity) significantly inf luenceo both reactor - mechanical (YounB’s modulus, ultimate ●nd operation ●nd geometry (i.e., sise). The yield ●trecsec, uniform ●longation, total major change in reactor operating conditions ●longation, fracture toughness, creep, ic the increaoed heat/particle fluxes, but fatigue, crack growth, swellimg) designing tc the came failure criteria ●hould - ●lectrical (conductivity) ●liminate theee differences, ●lbeit —— - nuclear (alloyi* constituents, crano- potentially e: ● hiuher coot. The reactor mutetiono, Seo production, dpm, redio- oparatiooel flexibility efforded by smeller ●ct~vlty, ●fterhut). FPCS, p~rticularly with respect to the la-c - surfaces (sputtering, ●dsorption, Sea point in Table I listed under component recycle, ●lectron ●miooion) georntry, potentially cen offeet the ●dded . Component Geometry ●nd Constraint coat of deslgnl~)s for a more highly ●tresoed - st.reso ●nd temperature distribution. reec -3.0 - liti~er .“ . - dlvertor -5.0 - coils “’4;0 6.0 8.0 1 .0’ 0.0 2.0 > h(n&-t)/. - ●ntennae - windows (rf) FIGURE2 ● BLank~t/Shield (B/S)2 Cross sectional comparison of ● compact fu>fon reactor daoign (CRFPR) with a fission rcsctor - brksder presoura voJael (PWR) snd the STARFIREtokamek - coolant raactor. - structure - ●ultiplier Although the rncope o? thic overview does - reflector/moderator not ●now ● comprehensive ●oseesment of the - tritium barrier “compsct” versus “conventional” symtema, Table .— - ducte (rf, beame, fueling, vacuum, 11 nevertheloo~ it included to give a coolantc) qwntitetive ●xample of the phynico, ● Magnet Coils (C) ●ngineering, ●nd economic difteren:ee between - conductor (wperconductor versus two comprehensive : okemak reactor reeistive) de@lgnall’12~23 tnd ● compact RFP re&ctor - inoulator (organic verew inorganic) daei~n. 10 Since the demands on ●ng~nee.lng - structure materiels perfor’.wnce ●re primarily generated - ~oolant (lie(g) vercue water) by the thermal radiation ●nd mechanical - kinda (TE, PF, Oti, EF, ●ctivs feedback, (streos; ●nvirotmant created by high-power- Passiva ●hell) dwnoity pl,sama, FU, and blanket operetion, the In ●ddition to comprehensive metarialm neutromicm re@ultaz4 from ● ●pecific hi&h- needr aeeecernnto for these ●ubeyotemo, i-q power-de,t~ity WC is Bivsn in Table 11A. Thie general reviewe of fusion materiale needo ●re deeign ●lso we ● ZO_-thick copper-alloy W, ●vailable.25 The technology needs for the uhlch ●hove come Infcrencas to be made for compact ●yeteme have ●leo baen euumarized thoca compact. reacrore requiring ?U reeiativo recently. e No sttempt is made here to repeat coil-. A-aIn, t h~ comptrisonc ●nd or to summarize theea reviawn ●nd etaeocment~. qwfitiralive lnformztion Sivew in Figo. 1-2 Inatesd, baaed on the general System ●nd Table, 11-111 era lntunded to demonatrcte difference ●nd goala ●e outlined in Sec. 2. the “order-of-magnitude” d:fforoncea betwoau ●nd Table 11, ditferencea in metarialr nmeds tht compact and more “conventional” .pproachas ... TABLEII. PLASNA, COSTINGANDPPC PARAMETERCOMPARISONBETUEPN Wslos-rowk- (m) ?U?oMAma~~~(.) munrm —.rmulw I I m,~,lx)aa CM. nwatl p-r, PmOWt) dooo 32*I SW 6.7 J.n U.*.t .mru mtltlpllutl-, ~ 1.14 1.14 I.1O us 9.3 Thtlul Cn”rolca *f flcl*wJ, ~ 0.54 0.3> 0.s5 !.75 I.0 Imlrculstlu *r frmcciom, c 0.147 O.oe O. lb o. 0. u.,. ●fIlci.me!, >- ~ (1-[) 0.20 0.54 0.50 8.s1 0.71 not ●l*etrlul POWr, ?*(W) 1200. 2200, moo. 04. 37.7 IlOm.nal 1/s tklickmto’ w(m) 1.3 0.40 0.W2 0.20 N Ilmimml coil Chicbnos, *(9) 1.4 0.45 4.0 o.le(:.2)@) P*CV91W,Vnc(mb IIIo(bbm) coal(ddol) 14a 2.9 e.oz ~1r8tw*ll ●r*e, %(.2) 740 ?16 112 10.2 :s.4 nc vc.1~1.vrt*c9, Vncl& 10.4(8.50) 11.2(6.15) 2.16 0.s1 11.1 SPIN ●inor r94iu*, Iz.o 20.0 r, - lV,,c/2t~l lii (m) 1.44( 6.”0) 7.?.(3.77) 1so 12.0 20.0 P1.9n clmtkr w1-, Vtc(m J) 1104(950) S70(U6) 4a. 1.50 3.24 ?irst+ll r.dl.e, rW(. ) 2.83 1.75 0.75 2?92. 3125. w rm”tron lw6tn’, %W ~utroalmt) 3.6 3.1 19,s S.do 83.2 Pm., &r,llt,, ?nlv, pc (lutl.1) O.so(o. kb) 0.41(0.74) 14. 1.2 1*. S ??CM**,I+pc(tome) 23174/14496 17WP 1140 20. . ● NIB 1374 4100 m ● lhlold 1s>60/6442 1690 — 9 COilm U240 9s40 917 mm mm mm am mmmsoe (mmu.mm m mm IU9* Utlllmtten +,clr~ (tmmlleft)>.7/4,1 5.3 0.40 F?c d.luitj, ~,~lv,pc (tawlmq 2.44/264 2,17(1.94) 5,6 20, 0.31 A,,, d.m,lty, qpclvrpc/qj(t_/m2; 1!.7 14.1 12.1 21. 11,40 19.n ?PcCenl (k$) 440.1/34).9 719.1[473.9] 4s.$ n. 7a,M 24.04 ● W/b 92.4 204.3[13. MI 14.0 *.44 1.71 9 lht.ld 184.1/109.3 157.2100,31 — 4.47 ● CO1lB 171.4 S71.4(24S.*1 50.0 12.W S,kd rrc Untt rwnt, c,pc(~lk, ) 19.0/23.0 41. $12?,1] S?,o Z3.43 9.27 Ftc .olwtrtc CW1, cppc(MOlm8) 0.053 /0.0>9 0.161LI,III O.ao 10.05 ZS.49 VW ●,,a ee,l, (Wc C991)IAJII$ 181) 0.44/0.51 I,oolo.kb] o.M J.w Ib.ol CO*I figur., 01 brlt 1.17 4.84 ● m?tllbc 0,>4 0.71 O.M 0.029 ● ?PCITDC o.26/11.21 0.23 O.w 100. 100. ● (rw/1)/loc 0.0s0 0.047 0.017 100.24 173.00 .. —.. ——— ns4114151(fi) It] 40.7 ‘“hlum 1. () baad en tomldal VOIUN, ●ttwmiaa wI- d emtral CIIIW. tW]Ud.d, t,l”v, IQ rich! d I 4. s01 i=l”d~ wt~ -Iw 1200 1000 ducts Srd perla. Valu** In II 8/ eem-folaa In 1!11 lol IMd by $ Intl. tlo. ftm 1911 10 1980! .IIWI’WIM the comwtmiullmllatlaa .rder 10 r* Wt, *d. ~b)~. “o, tr.c,ud, )5,0011loam Ircm cot.. (C),eln,d,l 11,14 ●t plaam ●48*. batwem the meinline ●nd tho compact 3.1. In-Vacuum Componantc fIVC) ●pproaches ● re highlight~d. Eech of tha three Tablo X11 ~iv~o tha noutronicc raoponoa of FPC msjor ouboystmos ii-ted ●bova 1s trcatad 9 “typical” high-hast-flux IVC (i.e., FU) to ● otparat81yo kat.arialo neadu for cubsystuaa fusion nmtroc PU loading, ~(NW/m2). Since outoid~ ~he FPC ●re ●xpacted to be similar for Iw typically will be 3-5 tlmeo 8reater for the all ●pproached ●nd, therofora, ●rc not compact reactor (~ ● 15-20 HU/a2, ●nd ● ven discussed. higher for the Riggatron), the radiative/ conductive/convective enercy fluxee emanetlng from the isnltcd DT phame, Xw ~ ~/6, will ba correepondinBly incremed for ●imilar TABLE III . NEUTRONICEESULTSFROM the ●pllt of ernch between FW, limlter, ●ndlor A “CANONICAL” C~ACT RzACTORFPC mm Fw NEUTRONLOADING~ (Nw/m2) diverter, rapreaents a crucial uncertainty for ●ll fusion devices. The majnr materiala ● First-wall (copper/33.@) questions for the IVCa are: 14.1-MeV neutron current, Jw (n/mzs) - * Removal of both surface (~ L*I4 MU/mz) 4.43(10) lpq ●nd vclumatric (-10~ NW/m3) heat loada Neutron flux, &(n/m2@) ‘4.43(10)1~ within ●ccept~ble temperature, strese, Total full power year fluence, &T (n/m2) - ●nd critical-heat-flux limits, (i.e., 1.40(lo)26~ need for materiala with high thermal Radiation dose rate, 3i(rad/s) conductivity ●nd high thermal etreaa Neutrons, ~(rads/e) = 8.2(10)4~ parameter, M). Gammarays, Ry(rcds/a) - 1.3(10)~ . Sputtar erosion and redeposition ratea dpalyr - 11% for FW●nd limiter surfaces. Helium appm/yr = 31% ● Long-term (swelling, creep, embrittle- iiydrogen appm/yr - 83~ rnent, ●lloy charges, ●tc.) and short-term Average transmutation rates (thermal conductivity changes, hydrogen Nickel (X/yr) - 0.13~ permeation and recycle, etc.) radiation Zinc (%/yr) - O.11~ effects. Heat flux, IQW (NW/m2) < IJ4 Average power density, Qw (NW/m3) - 10~ TWO limiting caaea of uniform heat dep~sition ● Blanket (Ab - 0.6 m, Li-Pb/B4C!W) onto IVCS can be envisaged: ●) all energy la Peak power density, QB(NW/m3) - 13% incidefit ● a radiation from a hi8h-Zeff plname Average power density, {6 = I 1 II 1 # I I , t 1 1 I ICQ 10’ FIRST-WALL THICKNESS, ll(mfn) “o Im 200 300 40C m TEMPERATURE (’C) FIGURE 4 Dependence ● ● FIGURE 3 llowed onto ‘f FU‘x’mmheatcoolant tubefl”x’lof Lh ckneaaFh’” b ●nd cooled with preaeurized water for ● given Thermal stress parameter ● s a function of primary plus secondary atreos level, o, for temperature for a range of potential IVC both ctainleaa steel ●nd copper ●lloy under metala. the conditirma indicated. limits, thermal ratchetting, &rid fatigue-creep reduction in UDC ●ccompanying the compact ● ● Iimita, can imilarly be pplied to Fig. 4. option reduceo the COE to ● n extent that The copper alloy ●chieves a superior exceedo the increaae aatiociated with a performance at a lower operating temperature, potentially lower ayetem performance (i.e., which will degrade somewhat the overall reduced plant ●fficiency, increased recir- theme’ performance to an ●xtent detemined by culating power fraction, ●nd decreased plant ● the fraction of the fusion energy ppearing in factor). the IVC coolant circuit. This importsnt If all the ene?gy rejacte!d by the plaema, tradeoff between high-heat-flux op8ration, on the other hand, ie depooited uniformly ● a decreaaed FPC ● ● ● ● ● coat, nd derated yatem ner8etic particlea with n nergy, TE , performance remaine to be comprehensively characteristic of the plaama edge, a particle ● ~seosed in termo of ● COE figure-of-merit. flux of 4.2(10)21/TEIW [-1.4(10)23 Indication are, however, that the ~ignificant particlea/m2 ● for 5 14W/m2 ●nd ‘w “ TE- 150 eV] would reeult. Por a DT “fluence” in ●n expected ehorter chronological ●puttering yield of -0.02 ●nd ● PU at-it lifetime, but only after Generating ● similar denetty of -43(10)28 stoma/ra3 (stainleen total quantity of fualon energy for nominally mteel), groin ●ronion retes of ~ 1 m/yr would ● ●imilar expenditure of PW/B mesa. Xaaues reeult, wen if self-eputtering and ion that relate ●pacifically to device compactness ●cceleration through electrostatic sheethm and the expee”zd higher erosion rates, were neglected. Thie problem ie worsened if hovever, ● re: particle ●nd energy fluxes ● re concentrated ● can the compact reactor plaama ●wvive a mto the IVC ●urfacea by limiter and I or potentially higher recycle rate and diverter ●ction. The degree to which this ●chieve andfor remain Ignfted? problem wilX hinder the development of fualon ● depending on the heat load under which dependa on poorly understood edge-plaama any IVC surface must function, the uee of proceegea that are generic to magnetic fueion thick-walled ‘ubee with an ●rosion margin and not uniquely ● compact reactor issue. de@igned to extend the sputtering life is Potential solutions to this problem ● re: generally leaa attractive for the compact ● Operate with edge-planma temperature ●7etems becauae of the higher heat fluxee below the sputtering threshold ($ 50 ●V). (Fig. 4). ● Operate with edge-plaama temperature that ● re well above the sputtering-yield An eatimete of the effectn of neutron maxfmum (~ 1000 eV). irradiation on a copper-clloy FW, und possibly ● Eetablish a high-Z radiating plaama on inorganic electrical insulation if FW coils mantle without having the PW supply the or electrical breaka ●re required, haa been high-Z material through la:ge sp~ttering ●ucmnerized in Ref. 8 and more recently for rates. the YWcopper-coil Insert proposed for !4ARS.26 o Design for large groee sputtering rates, Tranmmutetion-ioduced reeiativity increaaea in but aesure a nil net ●roeion rate through the PU copper conductor (Table III) and the careful control of redeposition distri- dimensional etability of both the copper alloy bution. ●nd the proposed MgO or t@1204 inaulation27 are key concerne for ● FU “coil”, whether From the viewpoint of PW ●urvivsbility, ●ctivaly driven (i.e., TF coil in Riggatron, theoe problem~ are not unique to or more R-coil in OHTE) or ● pasaive conducting Jhell ●evare for the compact raactora. Aside from needed to stabilized ehort-wave length plasma difference in basic plasma proceaees that may MID modes. Parkinn28 ●leo pointo out that for result when differences of -3-6 in average sufficiently high voltagen (~ 700 V) ●nd plaoma density (Table 11) ● re taken into Inatantaneoue radiation dose ratee (~ 104 Cy/a ●ccount, the ratio of particle flux to neutron - 106 rad/a), thenncl runawny through Joule current incident onto ● W from ● n ignited DT heating can be potentially destructive t.> planma ●hould b? ●imflar for both ●yeteme, electrical incubators; tk.nee conditions thereby decoupling ●omewhat the FW eronion generally apply near the FM and for relatively prublem from the iooue of dwice compactness; high-fle14, ●ctively driven coil.. the compact, FPC eimply ●chievee both ito neutron (dpa) ●nd erosion (mm) lifetime A increase of the electrical reniativ~ty by that uvsh ●lloys may play in ●heping the radiation ●nd tranmauration effects is ●lao fusion end product hea only recently been Accompanied by ● decr~aae in the thermal recognized. 33,34 conductivity in setals, since both current and 3.2. Blanket/Shield (B/S) heat are carried by ●lectrone. A high-heet- The B/S thickness for the compact reactor flux FW, therefore, must be demigned to ●pproached is reduced to the minimum required operate with increased thermal ● treasi towarda for ●dequate tritium breedins ●nd thermal the end of lifa, ●lthough thinning of the FW anergy racovery. The ‘Ainimun-thickneem by sputter erosion, if allowed, will tend to (optimized) B/S, when coupled with the counteract the effects of decreased thermal increaeed FW loading, ●chieves ● t laast ● n conductivity on the W stress. If the order of magnitude increaee in FPC power initially unirradiated material 10 a solution density, ●nd a conaidetable reduction in total strengthened copper alley, however, the coot, ● s well as providing options for decreaaed electrical ●nd thermal ●ppreciably different installation ●nd conductivitiee caused by alloy additiona can maintenance ●chemes because of reduced FPC mask the efiecte of transmutation product (Ni, mane (Table II). 14e?net ehtelding in the Zn) buildup. Nthough Borne information on usual ●enae ia not anvisaged; instaad a thin radiation-induced swelling ●xiata for (O.O5-O.1O m) outer region of the 0.5-0.6~- candidmte inorganic insulators, similar data thick blanket may contain a nixture of B4C ●nd for copper alloy are not available at present; a dense, high-Z @terlal operated at &he finsion reactor irradiations of relevant blanket tempnature and cooled by the primary ●lloys, however, are J.n progrean.29 Age- blanket ceolaat. hardened coppsr S11OYS, such as NZC may over- Yor W neutroc loadinga in the 15-20 HWlm2 age or the allaying element may diaaolve under range, the local blankat rower density becomes irradiation; generally,zg dispersion hardened comparat’e with that in the core Cf an LNR alloys may exhibit greater radiation stability (~ 200 Wt/m3), wi:h the ●verage blanmt power in this respect. It in noted that procedures density being in the range 36-50 31Ut/a3. At for radiation hardening againat high-energy the peak ●nd average power denaitieu anvienged neutronn of steering magnets for the LAMPF30 for the compact reactorn, ceramic breeders und the quadruple beam trannport mngneta for cooled by pressurized helium gas or water Y341T31have developed fabrication methode that become leas attractive. Brcauoe of the low are directly applicable to the ccmpact fusion lithium inventory, reduced fire hazard, and reactors (co-extruded Culngo co-axial unique combination of breeder/coolant/ conductor with Internal water cooling); the multiplier functions, the low-melting (235°C) radiation fi.eld~ ●nd lifetime fluence~ for lead-lithium eutectic, Pb83Li17 (referred to th~ue accelerator ●pplication fall ohort of hereinafter ● s PbLi), han become a popular fusion FU conditfone., however. Lxotly, the choice f~r high-power-density blank~te. 7,35-37 requirement of the W coil propomed for the Confinement ●y-”emo with magnetic MARS deoigntz will satitfy the needs for moot topologie8 that raquire liquld-metal coolant compact fusion ●yctema. Generally, the need to flew ● croez magnetic fields37j38 may be and potentially high payoff for high-heat..flux forced either to coat coolb?t ductn with alloyo in ❑ oot IVC application~ and the cole electrical inculctorm35 or to reduce the ~D pr.maure drop ●imply by limiti~ the coolant preernte come concern. The need to flow velocity ●nd thereby limit the YWneutron lr303ate/ineulate thermally the lover- loadimS.36 me high powar deneltY for tke temperature FW coolant circuit from the PbLi-cooled CRFPRblenket,7’37 bowevor, C*D be higher-temperature blanket coolant circuit In ●chieved with ●inimal pumping power without order to minimize the backflow of t.igh-quelity recouree to the uee of ●luctrically inculated blanket haat into the lower-quality PWhut, coolant ducts beceuse of the unique, low-field however, nmturally reeulte iti e double, if not poloidtl mmgnetic topology that characterizes triple, containment of the pressurized-water that. @yeCam. The materials problems relcted coolant circuit from the liquld-metel circuit. to corroeion (particularly for ceramic 3.3. Hegnet Coil- coatingn), tritium recovery, ●nd trltium Meet compact reector cmbodimentm conoiderad berriere for the compect reactorc remain to dete ●pecify water-cooled copper coile similar to Chose fo: other syeteme ucing locsted either ● t or neer the FW, outeide the similar blenkett. The ●cceleration of ctreec thin (0.5-0.6 m) hjgh-power-rlnnmity blanket, corronion ctecking by the ●ddition of ●mall or both (e.p., mein coile outsi~e the blenket, amounts of weter to theee liquid-metal ●yot~e feedback or ct.trent-drive coils within the remains ● s ● particularly critical concern. blanket or ●t the FW). In ejther caee, Although rf ●nd neutral-beam ducte ● re not radiation-resietmt inf genie ●lectrical in- ●nvisa~ed for the compact systome ● o far ●ulstlon wil~ be required. Either irmulator c.onsiJered, the taak of manifolding ●nd coatinun would be plemae-epreyed ont u (vscuum) ducting ●ppemrs to be moue ●xacting. preformed copper eonductore, or a powdered Since the Eaeeous (DT, He impurities) ●nd irmuletion (i.e ~ 3@0 or MuA1204) would be co- coolant throughput will in mngnitude remain ●x?ruded with conductor and coolsnt tube, the unchanged for eny fusion power plant of latter methnd being used in the fabrication of oimilsr power rating, the xeduction of the FPC radiation-ha~dqned coils for uoe in hlgh- volume by nt leaet en order of magnitude ●nergy perticle ●~celeratora. 30,31 Under more reeulte in ducting and menifdding to regione severe condition, the FW coil requirement outeide the FPC becoming h more dominant part shoul.8 be similar to the requirement of the FPC “real aetate”; FPC decign inte- ●nviea~ed for the MARS hybrid ●a87et -retion for the compact oyeteme becomes e more insert,26~32 or for tne lea. .Jvere ‘nkamak chellensing ●xerciee. 37 conditions ●nticipated ●t the in-blenket L<ly, ● ven for the topologirally ●quilibrium-fiald cojle. favorable RFF, the F(HDprea~ure drop needed to The ieeue of coil radiation lifa 10 poorly ‘,*ovidn •dequ~t~ coollns by ● liquid metal to resolved by the nxieting data baoe, but under the hi8h-heat-flux, high-power-danmlty FW the conditions lieted on Table III, a coil at re8ion csn ●enily require ●xcemoive mm the PWlocetion ●xposed to ● neutron loading pumping power. Eithtr ● cersaic coatins of af~- 20 ?M/m2 would ●uotein ● n MsA1204 the FW coolant chsnnele or ● ●eFarate ●welling rete of 11 volume percent per yeer preceuri;ed-wettr coolant circuit will bQ ●nd ● (peak) copper conductor reeintivity r?qulred. The probleme that ●ttend the uoe of increaee of 100-200% per yeer. Xt ie noted preeaurized-weter cooling, ev?n in conjunction that the owelline ●nd mechanical deRraJation with the ch~mlcelly leee reective PbLi, in cubic ceramice lika !4s0 or U&A1204 considerably 1*SC than ●ximym*tric caremics mu option ●vslleble only when thin-blemkated, (i.e.,hcxegonal A1203),27 and that the in- copper-coiled capact ●ysteme● re coneiderad. ~reeaed roslstivity in 300-400 K copper it related co the transmuted ●lloy ●dditions 4. SUUUMYMD @NCLUSIOhS rather than lnttincic point-defect.. Even Significant lmprovementm in both the under fresh stertup condition, ● SW soil em operatlomxl ●nd ●conomir protpect8 for fumion significantly reduce tha ovsrall plant pover at~ promi@od for cysteme with power ●fficiency for bth the 0RTE19 ●nd the denxitias ● n order of megnitude ●bove present Riggetron20 remctors; operational ltfetiaee of projection. These compact reactors will only ● few monthe ● re predicted for ~ - 20 ?equire wtertalc that in come cress differ t’fm(ln2. A strong incentive ●xicts, therefore, from the meinline ●pproaches. to locate theee coils outcide the YU cone ●nd The greatast need formeteriale development behind @t leant ~ O.1-m of blanket. Ax ●hovrr reets with the high-heat-flux IVCS (YW, Ir, Teble 111, interposition of ● 0.6-m-thtc3. limiters, divertorc). Clven that IVCS cen be PbLi blanket reducee the rate of inevletor dnoigned ●nd operated with 4-5 14W/ri2 heat ●well: ng ●ud conductor resistivity incaease by f lUXM , the critical ● rose raduce to the over two orders of maqnltude. Such ● CO*.1 partition of radiation veroua particle flux could possibly outliv* the YU/B ●nd =wIJ be incident upon IVC surfsces, the ●ssociated recyc: ●d. Generally, however, the Incevtiv? sputter ●rosion rate, the reposition proc~sw to move the coil outeide the blenk.et 10 not (location and integrity), ●nd the impect on driven by considerations nx lifetime ●nd the tha overall pleme performance of potantislly defiirti to reduce meou uoege (i.e., operatfrg large trmmfere nf impuritiam ●round tha coat), but ineteed by the nead to: a) imp~ove syetem. The ptoblcmc relatad to sputter the overall plant thermsl ●fficiency, since ●raeion, however, in u@tude ●nd kind, tre tha n coil uould operate ●t ● thet~c,- not unique to compact reactor.. Although dynemicelly unlrrtereeting ttmpereture, b) to sputtering rate- ● re ●xpected to be increaeed ● a@@ the breeding of tritium, ●lthough ● few for the compect cyotemo, Clvan cimilsr plaeme 10s of millimatero of copper has m net benefit cad ●dge-plaema phycico, the ●mounu of YW on tritium breeding btcauee of neutron multi- oputterod per neutron fluence [rn/(W Yr/m2)] plication, ●nd c) to relieve th~ overall YPC @hould be independent uf the concept ●nd @ongestion related to ●lectrical/hydraulic/ olmply becomae ● utter of “fluence”. thmmodyna~icftritium-recovery furrctiona. Oen- Ifenco, the potentially unique meterialc ●rtlly, the ●n~ineering development neede from problems for compact ●ytitemc are related to both e oyotema end ● materielo viwpoint, ● ven the need ta underetend ●nd contrnl the bulk for kho high-field YU megneto,i9120 ●hould be mechanical rediatlon dame~e properties of the ●enier ●nd lose costly than for th~ lar~e new Yk! matnriels (copper, vcnedium, ●olybdenum wperconductinp magnet Ae@i#rre. LeBtly, ● po- ●lloyo) required tn deal with the incrsaoed tcntia,’ly significant edvantege of compact heat fluxas. Bven then, ●uch meterlals meY be ●ystemo is the fecilitet~d uee of ●fficient uned in puapod limiters kndlor diverter pletee (i.e., reduced stored ener&y, eurrenhe, and for the larser supercot,ductin~ fuolon ●yetamn. forcee) ●egnetic dlvertora becauee of the close proximity of magnrt cone to the plame, The compect reactor option nerrowe the many REFERENCES B/S choicee lieted in Ref. 2 to ● few 1. R. W. Corm, J. Nucl. Ueter. 103-104 concepts thrt cen nperate st local ●nd ●verace (1961) 7. power dtnsit ieo cnnaidered ●conomically 2. D. L. Smith, ibid., p 19. ncce-eary fo~ other nuclo-r power sycteme 3. It. E. Nygren, ibid., p 31. (Fig. 1). The megnet development roquirod to prnduco relatively cmell, rediation-hardened 4. M. A. Abdou ● t ●l., ib4?., p 41. reoittive coile ●ppeare to be well 5. R. R. Neoiguti, ibid., p 51. ●dvenccd,S0$31 ●lbeit on ● reduced ●cale. 6. J. Nihoul, ibid., p 57. Hence, for both B/S mid megnet ●reeo, the meterialo requirenentn for the compact optione 7. R. A. Krakowski ●nd R. L. Psgeneon, ~tCmpact Fsleion Reactore~ “ Proc. 5th ANS ●ppear no more difficult, ●nd in meny rtepecte Top. Mtg. on the Tech. of Fus. Energy, ●eoier, than the meinline progrem neede. Knoxville, TN (April 26-28, 1983). In ●ucmry, all meteriale Ieeuez for 8. R. A. Krakowcki, J. E. Clancy, ●nd A. compact reectora are being or cen be ●ddreeoed E. Debiri, “The Technology of Comp*.ct within the mainline progrem. A new empheoie, Fueion Reactor Concepts,” Nucl . Tochnol./Fueion (to be published, 1983). however, ● ust be placed on underetendin~, 9. Cron9, ~lsuney af Reector Aopects of creep. fatisue, fmtigue-creep interaction, R. compact Fuoion Concepts,” Nuc1. alloy ●tability, coolhnt-alloy interaction, Technol./Fueion (to be publiehed, 1983). ● tc. for these new high-heat-flux ●yotezs. 10* R. L. Hegeneon ●nd R. A. Krekowoki, It i tr thio claaoical ● xea of meteriele nnd “Engineering Design of a Compact VP Remctor (CRYPR),” Proc. 5th ANSTop. ●ytitdma ●gineering, 80 applied to IVC Htg , on the Tech. of rue. I!norgy, ●urfeces, thet mejor mtridee cen be mede in Knoxville, TN (April 26-28, 1983). ●dv. .ng fueion ● e ● truly competitive ●nergy 11. c* c. Baker (principel inventigetor), ●ource. ● t ●l., “STARMRE - A Ceercisl Tokemak Fuoion Power Plent,” Argonnt Netionel Laboratory report ANIJFPP-80-1 ACRONYMS (September, 1980). F/s Bla.lkat end Shield 120 A. A. Hollie, “Am Anelyeia of the COE Coot nf Clurtricity ~mills/kUeh) Phtirneted Capitel Coot of ● ?ueion FPc Fusion Power Core (FW, B/S, ●nd coile) Reector,” UKAEA Herwell report ASRE-R 9933 (June, 1981). IVC In-Vacuum Compmenta (PW, limiter, ● divartnrm, ●te). 13* R. Hancox, R. A. Krekowoki, nd W. R. Bpeare, NUC1. EM. end Desi8n Q (1981) Yw Firet Wall 251. ?DC Totel Direct Coot 14. R. L. Niller, C. C, Bethke, R. A. RPE Reaator Plent Equiment (Account 72) co-t Krakoweki, ?, It. Neck, L. Gteen, R. ● al., “The UDC Unit Direct Cost ($/kWe) A. Deluce, t Hoduler Stellmwtor Reactorl A Fuoion Power TYc Toroidel-Fiald Coil Plent,” Loe Alemo@ Nationel Laboratory report LA-9737-MS (July, 1983). mc Idoidel-?i.ld Coil OHC Obic-HootinS Coil 15. C. C. Bethke, ● t cl., “EMO Bumpy Toru- ● CFC Equilibrium-Field Coil Reactor nd Power Plmnt Conceptual Dcotgn Study,” Loe A.lemoo Netionel Laboratory report LA-8882-M (Au@uet, 1981). 16. J. UXll, —na ~ ——of tha Commtructioa 27 ● ?. W. Cllmmrd, Jr., sod 0. P. Rurley, “ceramic ●nd organic bmuLatorc for go..%%% B%%LA.M%%%%% Fusion AppllcatloM,w J. IIW1. Hmtar. (1963). 103s 104 (1981) 705-716. 170 A. E. Ihltor ●nd A. B. Keymoldc, Past 28. LO Jo Perkins, Trans. Amr. Nwcl ● Brtedcr —.Raactoro— Porgmmon Press, - SOC.,44(A983) 128. m 29. ?. W. Cllttard, Jr., private e~ni- 18. G. C. Dxlc (od.) ●nd J. M. Bowemmnn, caticn, Loe Ahmos Rational Laboratory “Th@ Safay of tha AGR,” UK Centrsl (1983). Eloctriclty Generating Bomrd ●nd South of Scotland Eloctricitjf Board, (1982). 30. A. Harvey, ‘Rmdiotlon-Nardenod Mxgn*te using FltneralImxulated Conductors,” Loo 10~~E Ro~CtOr (hcaprs~” 19. R. ?. Bourque, Uamom National Laboratory report Proc. 9th SYMP. on Eng. Problomo of LA-5306-MS (June, 1973). Fus ● Romoarch, Chicago, IL Q, 1851 (October 26-29, 1981). 31. R. J. Grlogge, D. J. Lieka, ●nd A. Narvey, “Rmdiation-llardened Field Coils 20 ● R. U. Bucsard ●nd R. A. Shsnny, for YNIT Quadrupolea,” 1983 Particle “Conceptual Desigi. of a !fodular Throwway Accelerator con!., Santa Fe, MN (Nmrch Tok*mak Cmercial Fusion Power Plant,” 21-23, 19S3). Internml report INESCO Inc., (April 1978), c. A. Robinson, Aviat. Week ●nd 32. L. E1-Ouebaly, L. J. Porkific, ●nd C. w~r, ● Space Technol. —108 (June 1978) 61. Maynard, Axicell Damage nd Shi&ldins AMxlyais,” Proc. 5th MS ToP. 21. ~lA Technical Outline of Simwell ‘B’t me Mtgo on tho Tech. of Fus. Energy, British Proceuriced Water Reactor,” UK Knoxville, TN (April 26-X, 1983). Cantral Electricity Cenereting Board (1983). 33. O. K. RJ:lhB, G. P. Tu, .C ●i., J. Nucl. Nat@r. (1981) 103-104, 127. ”32. 229 R. F. Hettae, “FW1OU Component ● Lifetime ARAlycis,” ArRonne National 34 ● F. W. Wlffan, Workshop on Copper nd laboratory report AN./?PP/T?+l6o Copper Alloys for Fueion Reactor (Septembar, 1982). Appllcatiove, FEDC/Oak PAd~e Nat!onal Laboratory, Omk RidSe, TN (April 14-15, 23. J. T. P. Mitchell, IsUlenket RapJ.acemont 1983) . in Toroidsl ?u~ .n Roactoro,” rroc. 3rd ANs ToP . Mtg. on the Tcchnol. 35. R. F. Bourque, NUC1. Technol./Fuai..\ ~ Controlled Nucl. ?uaion, Sants ?., NN {1953) 493. (my 9-11, 1978). 36. L. J. Perkins ●nd C. L. Kulcinekt, 24 ● H. l!. Bettet, R. J. LMBMUVQ, ●nd R. “Economic Deci#n Optimisation of the LiPb A. Krakowoki, Trsne. Amer. Nucl. Sot. Blanket for the Nirror Advanced Reactor ~ (1983) 147. (MARS), ” Proc. 5th AM Top. Htg. on *ho Tech. of Fuk. Energy, Knoxville, TN 25* R. Gold, il. it. Bloom, F. U. Clinard, (April 26-28, 1983). Jr., ● t cl., Nucl. Technol./Fuaion ~ (1981) 169. 37. R. A. Krekowekl, R. L. NmBenoon, H. J. Embrochtc, N. III. Schnurr, G. 1!. 26. L. J. Perkins ●nd C. L. Kulcineki, Cort, M. E. saitat, ●nd R. J. “Naterialo Conelderationm for HiShly LeBauve, “Compect Reveroed-Fi@ld Pinch Irradiated Normal-Conductin8 )fmgnete in Reectoro (CRFPR)t Preliminary 5!nglnoorln~ the HAM Tandem Mirror Rgactor,” Sth Top. Coneidorotiont,” Loe A?●moe National Mtg* Roector Mmtarialo !~boratory report (to be published 1983). (Septemb~ 19%1 1983).