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. research discussed herein. ~

1

LA4JR -88-2 I 30

; ~)+ A1.+rn,,s Nal,ond Lmoram’y IS operated by !ne Umvnrwly of Cahlornm for lha Unmrd sldle~ DerMf Imenl 0! Emw under conl~acl w- 7405. ENri-36

TITLE THE STATUS OF NUCLEARDATAEVALUATIONSFOR VERS1ONW OF ENDF/B

LA-UR--88-213O

LIE88 014410

AUTHOR(S) P. G. YOUW, T-2

SUBMITTED TO Reactor Physics Conf.Jackson Hole, WSept. 18-22, 1988

DISCLAIMER

TIIb reporI wee ~paral M m eoxwnt of workIpomordby an qoncy of Ihe Unital StMaOovernmant. Nellhsr the Unitd SIateJ ~rnmont nor ●ny apncy hard, nor wry of theircm- makm any warranty, e~~ w implied, or uauma ●ry I@ Ilabillty or reepnrd-bilily for Ihe accuracy, com~to~ or umful~ d any informatti, ●ppwrelIu, prcwluct,or

_ dlmlod, w rqmerrta that ile um would ma Mringe pdvately ownul ri~hte, Refer.ence hernn 10 ●vy IpdfIC commerchl pmxhu-t, promaA or aervioe by trada name, trademmk,

manuktumr, or othwrwlm d- nd ~rily cunmtkuta or imply IIS cndtiment, reCOM.mendetion, or fmvoi+nsby the Unimd Steta (government or ●ny ●~ncy themr, The viowt●nd oplniom of suhre exprweeal herein do not n~dly Mate or reflect time of theUnited Slda Oovemrwem w ●y ~ncy thereof.

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IamimLos Alamos National LaboratoryLos Alamos,New Mexico 87545

I ,,..6 ,, .,, ‘,,

THE STATUS OF NUCLEAR DATA EVALUATIONS FOR VERSION VIOF ENDF’/B

Phillip G. Young

Los Alamos National LabomtoryLos Alamos, New Mexico, USA

ABs-rTL4cr

A new version of the United States national evaluated nuclear data file, ENDF/B-VI, isneruing corqlction. Majm emphasis is being placed on ccmecting some long-standing nucleardata problems that adversely affect a plied calculations for both fission and fusion reactors.

JThis paper reviews some of the ev uation activities of most relevance for fissicm reactorapplications, namely, those involving control, cooling, and shielding materials, structuralelements, and the major tides. Additionally, because of its impact on all the dam work onthe Standards Data F* for Version VI is also summarizd

INTRODUCTION

oversight and technical development of the United States national evaluated nucle~ database, ENDWB, is carried out by the Cross Section Evaluation Working Group (CSEWG),which is an indusrnaUgc’ ernmcnud cqwrative effort involving up to some 20 lakratories,Since its formation in 1966, CSEW(3 has systematically im vcd the evaluated data base as

rnew ex “ Yntal and tlmorcrical information bccauM ava.ila k, periodically issuing new ver-sions o the EN13F/B lihary, The last majcx revision of the data base occurred in 1979 withthe issuance of Version V of ENDFL3,~ followed by a significant up.1.ati.ngin 1981 that is rc-femc.d to as Revision 2 of ENDF/B-V.2 In the dmc period since ENDF/B-V.2 became avail-able, a number of important differential mcwreimnts have been completed+ and advances innuclear thcq and evaluation methods have axusrcd that * updating of the data base againdesimble, As a mult+ CSEVW is now working reward another major revision that is plannedfor issuance in the 1989-1990 titm franE M Version VI of ENDF/B.

Thorough reviews of the fissicm-rr~tor-related cross section data in ENDF/WV,2 werepublished in 1984.34 While Version V

Tsend a sigrdflcant improvement over pwious

versions, deficiencies are known to exist the data base, Time and space do not permit adetailing of all the problems we arc addressing. Lnveq general terms, we expect majorimprovements to be rcalimd in the EN’DF/B-VI standard cross section datm as well as otierreactions included in the simtdtaneous mmdarda analysis ( (SCCbelow), in the mcmance regionfor several key structural materials and the majm actinidcs, in the neutronics data for manymaterials due to impruvod rcpmsmations of emrgy-angie carcIattcms and improved theoreticalrndel calculations, and in the overah wmpleteness of the data base due to additions in tiegamma-ray production, covariance, yield, decay, ard delayed neuuon dma files. Finally, thereshould bc overall improvement in the entire evaluated dara file due to the mailability of moreaccurate and comprehensive cx@mentAI data with generally higher energy resolution.

In the merit paper the status of evaluations for ENDF/B-VI is reviewed with emphasisfon materia s of most interest for fission reactors, that is, contro~, cooling, and shielding

materials, structural elements, and the major actinides. Also, lxausc of its relevance to theevaluated data in each of these areas, work on the standards data file for ENDF/B-VI isdescribed. For reference, a master list of the isotopes and elements [hat are expected to beupdated for Version VI is included in Table I. It should be noted that at his writing many of[he ENDF/B-VI results refesmd to here are preliminary.

TABLE I

Status of Neutron Cross Section Evaluations for ENDFiB-Vl

wMar@al

lH Stand.,cmi.3* StarMl.% Stmui,T B-1~ T&d.%l%

l]B

&

v5Q,52,5354cr

55U,H,S637,58Fe

co58,60,61,62,64Ni

Shkld.mMulLStand,cono’olshieldStuuistiekl.shieldStrwastnJcLstrucLstnKLStnmsbUL

SUWL,=

Fhd%d.SmmAcdv.Activ.)D(m.Activ.Jkm,

m.ShiaklStand.?hmshiCkf-m~L

Fud Cyc.Fual Cyc.FI,@ Cye.FMICyc.Fti Cyc.Fml Cyc.Ful Cye.Ful Cyc.F@ CX.

TarguR&

9/887/087/88

9/887p38

11/889/887/88

7/889/887/831Q88

1MM

9/88

;Z9@l

Rcqmsble

MruaLax”

Mm

ORNLORNL

ORNLJAERIORNLAN.ORNLORNL

ORNL

ORNLORNL

ORNL

CNtx

FValIUKUS

D. Dodder.O. HaleG, HaleG. Hale, P. YoungP, yOun& T. BCyI~S, Perkins, E. Pkchaty, R. HmucrtcmG. I-We,P. YoungP. YoungC. Fw E. AxtcmC. Fu, D. Hari& D. ksonASml@ D. Smith, R. Howcrtcmet d.D. H-C. Fu, D. Laxm, K ShibataK. Sh.itamC. FtL C. -y, D. i-hick et al.A Smith, P. ChmmlWJ,R. HOWCIWI et al.D. I-ktr& C. -yp. IXUJCLC.Fu et d.D, Hatdck C. Fu+D. tiA Smih D, Smith, R. Roussctet d.ASmAth a&LA Smith, D. Smith. R. HowcrtcmP, YamgP, YcNm&E. ArthwE. Arthu, P. Young, D. Mu.&P, Young,E.ArLhlwC. Fuo,& SuJllm MMoweetd.A, Smih, W. Podk, M.Sow~y ti d,P, Young, L. Waum, H. IM’den ti d.L Wauon, E. ArthurLwelUon,li DarrbnataJ.D, bual.L. WaaaiD, Z30utid,D, ZhcuIUal.

STANDARDS DATA

Earlier ENDF/B standards evaluations generally followed a hiemchical procedure inwhich tie various sm.nda.rd reactions were analyzed scquenrially, with each new reactionevaluation depending on the previous results. The ENDF/B-VI evaluation, on the other hand,was performed by sirnulraneousty analyzing all the standard reactions that arc linked throughratio measurements, as well as scvem.1other non-standard reactions chat arc similarly linked tothe standards and for which absolute data exist. Although some of the details have changedslightly, the basic approach followed in the analysis is described in a 1985 paper,g and a moreup-to-date account was given rccendy at the Kim Conference.’O Starting from a very accuratelH(n,n)l H reference fdc, the light element standard reactions were analyzed in a coupled-channel R-matrix framework that pcmittcd inclusion of auxiliary information such as veryaccurate cha.rgcd-pa.rlick and neutron total cross section data. The heavier element standardcross sections, a potion of AC light element claw and the thermal constants were analyzedindependently using a generalized least squares program. The results of the R-matrix and leastsquares analyses were t-hencombined in a manner that took fulJ account of all correlations inthe cxpcrimcntal data as well as those introduced by the R-matrix analysis. The stmdards datafde fcuENDF/B-VI was compktcd ad mwlc availabk in the fall of 1987.

The ndmdology used in the simultaneous stadads evaluation is particularly appropriatefor fission rewtcw problems because it facilitates accumtc determination of cross sections forW&ml important axttroland M’tirMe matcriflk In additim todata fm the usual s- crosssection% which include t-he10B(n,a) and ~SU(nJ) dons, absolute moss section mcasurc-rncnts and coimcd.ng mao data for the 238U(n,y), ~au(mf), Md 239MnX) ~~tions W~

i~ in *C s~~~ ana.l@s. WC this tdm.iquc is expected to improve absolute cross scdcm, h should h cspcctally effective in chcminhg relative cross sections andcovarianccs, hopefully eliminating scmc of the Ma thm haa &n evident in the pmt txtwc.cnusan.ium and @utOtilt.mtiticd SYSUUM.

The results of the simultmwous standards evaluation fw the 23SU(n,f) and 239Pu(n,f)cross sections are C- to the EN’WB-V.2 values in Fig. 1. In ui.ditiom to tie ratios ofthe Version VI (prelimuuty to Version V ~5U and ~9Pu fission cross scction$ the Vemionv

Yratic is shown fcu the L $$fi(n@5U(n,f) -s section ratio, It is evident that both the

23(J~239pufj~$i~~~~ ~~~ mhtivc to ENDF/B-V.2 by of the orderof 1-2% in the flxsion spoctm.m range above 100 kcV, ●lthough their ratio has generallychanged less. The largest moss scctimt change cwum fcw~%%(n,f) near 16 MeV, where adecrease o!-13%isscen.

CONI’ROLCOOLANT, AND sHIELDINaM.AIHU.A.LS

WI isan importantmtml mamial inmany reactor systcma. l%e evaluation of che com-plete n+lOB dma fl.le, which includes the 10B(n,a) standard data to 250 keV, is being cticdout at Los Alatxw Additkml.ly, a new cvaltmtkm c4 n+l~B dm is being pmvidcd. AlthoughllBisna i&Uh~tti wwmd, itit~of Mti~tiisp~nt in me

Lquanti in =ta’s, and the cxisdng ENDF/B-V,2 evaluation is mm the ptorest in the datnbase. ccmtrol matutials suchasm Ag, (3d, andi-lfuage nmlf

3

y thought to be reason-ably dcscribal in ENDF/B-V.2, and u tes are not planned for the tit issue of Version VI.Thcimpvvermnts dwtarcncc&d6 ‘ b implcmntcd in ● futm imc of Version VI.

Iltc cd ENDF/B-VI mkity fw ccmlant materials arc the new stmida.rckevaluations forJIH and C. mm the point of view of ream cs.lculations, the changes in the evaluated data

fdes arc not great. Although existing data files for some other coolants (for example, 160)need updating, resources are not available to include them in this issue of Version VI.

Of the shielding materials that arc king updated some of the most signitlcant improve-ments arc being made for 9Be and 11B. In the case of ~Be, a complete new evaluation has &endone with special emphasis on accurately spccifjing the crmgy-angle ccmelated neufron emis-sion spectra from (n,2n) reactions. 11 The distributions were obtained usin a Monte Carlotechnique and recent new double differential experi.mentnl daa The new A B evaluation isprimarily based on improved experimental dat& supplemented with Hauser-Feshbach calcula-tions to extend the data to high= energies. llw rtmst signilkant improveunt fcx’ ~Boccurs inthe neutron total cress section, which in ENDF/B-V.2 is in error b as much as 40% near En =

1’1 and 2.3 McV. A comparison of the new evaluation of the I B total cross section withENDF/B-V.2 and with experi.amtal dam12 is given over this neutron energy range in Fig. 2.

NEUTRONENERGY(Mew

Fig. 1. Comparison of thereliminary EN DF/B-VI

FIssion cross sections o f239pu and 235u withENDF/B-V.2. The pointsindicate the VersionV4’Venion V (n, f’) cross-sccaon ratios and the curverepresents the tatio betweenVersions VI and V of the239pu/23SU cros~-section

ratio.

Fig. 2, The I IB neutron totalcross section from 0.1 to 3.2MeV. ‘T’hesolid curve is thepreliminary EN DF/B - VIevaluation, the dashed curveis ENDF/B-V.2, and the

are experimentalg:: i

STRUCKJIWL MATERIALS

Fe, Ni,and Cr arc among the most important structural materials for fissicin reactors.Separate evaluations are complete or in progress m Oak Ridge National Laboratory (ORNL) forall stable major isotopes of each of these elements. The evaluations are ba~ on analyses ofexpcrinxnta.1 cb and extensive new thorctical studies in the McV region. lJ-15 Additionally,new multichannel resonance parameter analyses are being performed for ~Fe and 58Ni (Ref.16) using recent high resolution ha.nsmission, capture, and scattering dau A similar anal sis

?for ~i transmission and capture already exists.17 New evaluations of Sshln, 6SCU,b CU.and ~~~Pb will d w be available. At &gonne National Labomtory (ANL). a wies ofnew neutron-inducd cmaa section measummnts ml thaxetkal analyses have been completedfor several structural matcrials,la and evaluations are &i.ng performed for V, Co, and Zr thatwill inccxporate the new rcsul~ ~ experirrmtal ad theoretical.

A sampk of results b the new Reich-Moore simultaneous analysis16 of transmission,capture, and scattering data for n+MNl reactions is shown in FI .3. These fits were made

f?with the SAMMY19 cock, which utilizes Bayes’ thccwem in its tting routines. In order forthis technique to be used most effectively, it is necessary that very high resolution data beavailable on an accumte ~ W Wh M h OMLA results shown in Fig. 3.

Ftg. 3. Simultaneous multi-channel Reich-Mcmre fitsfrom 116 to 132 keV ofn+58Ni ~smi~sion, radia.tive captute, and differentialelastic scatterin data at three

?an les. The qpre is pro-fvi cd courtesy of C. M.

Pemy.1~

NEUTRON ENERGY (koV)

To illustrate the capability of modern theoretical antdyses, a comparison is given in Fig. 4(left sick) of @Ni(n,n’) cross section measurements and a calculated cme using Hauser-Feshbach statistical thwry with comctions for width fluctuations and mchd.ing precquilibriumand direct reaction conmibutions. 14 In the right side of Fig, 4 the @Ni(n,n’) angular disrnbu-tion for the fmt excited state of @Ni wirh 6.S-MCVincident neutrons that is wediczed from theanalysis is compared to exprimntal data.lz

60NI(D,01)INELASTIC CROSS SECTION

JL____- 0.0 20 4.0 0.0 a.o 10.0 ILO la-o 10.0 19.0

NEUTRON ENERGY (MNm

60Ni(nmIJANGULAR D1STR1BUTIONEn . &5 meV, Ex w 1.333mt~

● PEREY, 197U— EN DP/B– V[

[

0.0 m.o 00.0 lmo I*.O 100.0

ANGL&)

Fig. 4. Calculated snd measured data for WNi(n,n’~ reactions. The solid cwcs werecalculated with the TNG codes14 and the pintfmnt expaimental data.lz Theenergy dependence of the *i total inelastic cfoss =fion is shown on the left side;the neutron an

Pdistrihtion from the 6@J(n#) resction to the 1.333-MeV state

in WI with 6. MeV inciclmt neuums is shown on the fight side of the figure.

MAJOR A~ES

New evaluations ofred WIremmce parammrs tin the Reich-Moore multilevel for-malism will be providui fa 3Su, 238u, 239~a ~ 2A ~. &h of ~ew ~mnmce

evaluations coven a considerably lsrger error7

range than dtm the current version ofENDF/B, and will thereby ruiucc difficulties an uruxmindes in calculating self-shield.in

::%”J!?*%that * ~Xl evaluation will extermiup to

‘rximuely 1-2 keV, 2388

tolkev. ofthese,ordythc~gwmld~l evahmtions sfe complete,the ~ucts of French/ORNL colldmmions. The ~5U snd ~8U sndyses are being canicdout m ORNULANLd oRNIJArwHMVellCousbmtiol’urespectively,

An example of the results of such a multilevel Reich-Mcmre/SAMMY analysis for the239~(n~ ~tim is hwn in Flg.S. Here the results of Denien et sl.,~ which will bC U-for ENDF/B-W, m tOtlM mmuemcnts of Weston ml Tc@l and to the existingENDF/lLv,2 evsluiued fcwneutron energies between 150 sd 2(K)eV. Again, tie avail-ability of high rcsoludon experhmntal dus is cm@al to such sn mslysis.

lm

104

1s

Fig. 5. Comparison of the 239Fu(o$) cross section between 150 and 2(N) CV from amultdevel Reich-Moore resonance analysis2~ with ENDF/B-V.2 and withexperimental daa21 The low= partof the figure shows the new analysis (cum)with the eqmimemal data and the uppr half compares ENDF/B-V.2 to the sameChatmthdlsphcedbyafacmoflo.

The Simuhneous Stdards evduaion should “ Sir “fictntly improved average(nJf) cross sections drove -“ 10 keV fm zss~ss ad 23& and improval (n,y) cross

%sections inthemmenngefix . “~y, it is eqected * new a Upd8tedthax’eticalanalyses of tne elastic smtcrin & (~a’). (n~n), ~ (n,3n) m+mns WN be available for themajor actini~ which should pruvade reproved &a fa Outgom$ neuawn cross sections an-gulsr distributicm& and emission

F“ ‘r_ M81ySWof this nature fm n#3SU

reactions wasmportedfor~=O.O to20Me attlMMito Gn.fcrence.~ Although ENDF/13-VI will rely on the simd~,us stanhfds results fm the (n@ cress section abve ~ -0.1MeV, itisnecemmy thacthetkwetkd Aysis fit the fis8ial ClOsssdcm reasonably well inorder to predict the neuuodcs dam F$

r6 shows ● comparison of the 23SU(n,f) cross

section calculated via the mukibarri~ ssion model used in the analysis with both theENDF/B-V.2 evduaticm and with the results from the Version VI simultaneous standardsanalysis. The fitted thaxcdcd curve genmlly ●grS with the evaluated data to better than*10%. In Fig. 7 the resulting theoretical calculations of 235U(n n) and (n,n’) angulardistributions at En=3.4 MeV sxe compared with experimentAI dataz~ and with the existingENDF/B-V.2 evsluatkm. At this energy the new calculations and data clearly show moreforward peaking of the angular distributions and probably will result in a somewhat harderspectrum.

In addition m Mter elastic, inelastic, and (n,xn) ~ ENDF/B-,VI will also provide im-proved evaluadcmsof~ (promptfisskxincutronmuhi lid

f &I&&:z”:F@~.:&”areawhere such@ ~ennmisnddisin E&) orMeV. Fi re 8 cmupucs the measurements of (lwln et al.~ (and older data)lz with the

rENDF/B- .2 CVdlldO!’1 and with ● nCW evahmtion?

LFrehaut.~ Current plans are to utilizethe Frchautevahmion Imlow 1(K)keV fm ENDF/B-V , perhapswith some tilcarions.

t’+ ENDF B-Vx END /B-W -D.

— PRESENT CAL

7’....,...,,........

- ‘“’”’””””“-. .,

----------

--------------

-------- .---

----

-.. ----

0:0 2.0 4.0 8.0 8.0 10.0 12.0 14.0 16.0 1S.0 i

NEUTRON ENERGY (MeV)Lo

Fig. 6. of* ~ O’& ~ -- frosn a new thcmctical analysis of~ (srxumthcurves) wnh results k k ENDFiB-W simultaneous

staadmds analyaia ad with ENDF/B-V.2 The dashed ad dotted cmvcs iIldiCtltC the

Camibutions from61’SLSccald-, ad thirkhalxc fhsion.

11/2- I#vdx 10

+ HAOUAT, 1901— Now Am Bh

v----- BNDfm- .2

\

ii

111..............................

Fig. 7. Cornpaxison of calculations22 of 23sU(nm)and (n,n’) augular dkibutions (solidcurves) with experimental data~3 and with the ENDF/B-V.2 evaluation (dashedcurves) at & = 3.4 McV. Bccmu it was not rmsibk to resolve all the 231J states inthe measur&ncnts, the calculated and eval~atcd angular distributions have beencombined fcx unresolved states to match tie cxpmimcng as indicatai

00m 1’ I

ti 1 I II I IllI 1

1 1 1I I II I [ i

‘ 10-4 10-3NEUTRON ENERGY (Me~

Fig, 8. The_ 6ssion ncutroa multi licity @ ) of 23f’Pufrom 103 eV to 100 keV. Thepoints are experimental -12 &&jthe so curve is ENDF/B-V.2, snd the dashed-ekmadtia@_~titih_fa~F~-~

Finally, it should be mentioned thnf the first actinide evaluation com let~ fully docu-mcnted~, and approved in initial CSEWG data testing for Version VI is tlatfor%. n.major neutron cross sections fm - in the ENDF/B-VI cvaluatim arc given as functions ofincident neutron energy in Fig. 9.

‘“: ~2:

i=u f“o

[%

5ulUY

2

‘1

~ -~1~~1~- __10- ~

s

2

K? 2 51&2 5d2 5 107

NEUTWY4 ENERGY (oV )

Fig. 9, Evaluated cross suxions~ fm n@@u reactions that will be used for ENDF/B-VI.This figure is provided courtesy of L W. Weston, Oak Ridge National Lalmatory.

.

YIELD, DECAY, AND DELAYED NEUTRON DATA

Substantial effcms arc underway to improve the fission-product yield data fdes for VersionVI of EN’DF/B. New or updated evaluations of independent, cumulative, and mass chainyields wi~ uncertainties will be given for 34 fissioning nuclides at one or more incidentneutron energies, as summarized in Table II. Evaluated yields for spontaneously fissioningnuclides are also incluc@ so that a total of 50 nuclide-energy combinations will be available,resulting in tic formation of approximately 1100 different fission products. Some 10 addi-tional yield evaluations arc in progress and might be completed for the initial release ofENDF/B-VI. Recent reviews of the status of fission yield data and evaluations are given inRefs. 27 and 28.

TABLE II

Evaluatd Ykld Dam Sets+ fm ENDWB-VI

%b (t)”

% (t)

2%’11 (fll)231~ (f)234J (t)233U (UN234U (fJO235u (LOO23du (fll)

(f)(s00(fJt)

(o

(f)

MO(f$)

(U)

(f)

~*b OLb)~%m(t)

243AM (f)‘*m (f)%m (s)

‘SCm (t)* (s)

(t)

*f251~

25~253~254&254Fm255Fm25~m

(s)(t)

(s)

(s)([)

(s)(1)

(s)

+ h progrus % (t),‘2Pu (LJO,‘7Np (t), ‘km (U), ‘Cm (f), ‘%m {s0, ‘km (f)●

s=spmmmusu t-thcam&f- fasLh=high(14Mcv)

‘he decay data (average dcca energies, decay specua @ to a lesser extent cross sec-tions) for many of the present - d fission pruiuct and 60 ~ nuclidcs in ENDF/B-V arcbeing improved fm Version VI. New experimental mcasurcmen U m being factored into theevaluatio~ and nuclear mdcl calculations arc bing usd to supplement the experimental database. The status of decay data for fission products, primrily those important for decay heatcalculad~ was rczxmtly reviewed.~

Delayed ncuuon data will be vastly improved for ENDF/B-VI as compared to ENDF/B-V.In particular, ~xi%idual ckay spectra and emission prob.sbilities will be included for some 271delayed neutron precursors. Addkiortally, tetrqmral six-bmup data (total ~d, group spectra,halflives, abundance) will be provided for most of the fissionable nuclides. A more detaileddiscussion of delayed neutron data is given in another paper at this conference.~

CONCLUDING REMARh“s

As indicated in Table 1, the time frame for completion of the various evaluations is Fall,1988. A meeting is planned by CSEWG in December, 1988, to continue reviewing and testingthe various evaluations for physics consistency, numerical errors, energy balance, and consis-tency with differential measurements. Such “differential” data testing will continue into thespring of 1989, when final testing of the major evaluations against integral data will begin.Concurrently, incorporation of the fission-product and decay data evaluations into the generalcross section fdes w-illbegin. It is hoped that the entire tested file will be available for issue inthe late 1989 time hame with documenmtion to contiuc in 1990.

To conclude, significant new experimental data and improved theoretical analyses arebeing included in evaluations for ENDF/B-VL Fm Version VI we have attempted to focus ourattention on tie most important data problems for applications, and the new information iscxpecd to result in a sigrd.kantly improved nuclear database for f~sion reactor applications.At the sar.m time, however, it should be recognized that there area number of important omis-sions flom the list in Table I of matmials being updated To cite s-c e

7!’s’uPsOrnew evaluations are not planned for N, O, N& Al, Cl, K, Tl, Mo, Re, or I, an generalupdating of fission-produc~ actinide, dosimetry and activation cross sections is not possiblefor this first issue of ENDF/B-VI. In soru cases signifkant deficiencies are known to exist inthese claw It is hoped thatthese omissions will lx corrected in a futureissue of the file.

ACKNOWLEDGMENTS

I wish to thank C. Rrey for provihg me with advance mpies of figures prior to publica-tion of the 58Ni multichannel resonance pammcter analysi$ld and T. Engls@ D. Larson, andL. Weston for several useful discussions.

This work was pcrfmned under the auspices of the U.S. Department of Energy.

REFERENCES

1. R. KINSEY, “ENDF-201: ENDF/B Summary Documentation,” BNL-NCS - 17541,Brookhaven National IAmratory (1979).

2. B. A. MAGURNO and P. 0. YOUNO, “ENDFI 201 Supplement 1: ENiiF/B-V.2 Sum-mary Documentation,” BNL-NCS-17541 (198S)

3. S. PEARLSTEIN, “Nuclear Data for Nuclear p actor Analyses - An OveMew,” Prog.Nucf, En. 13,75 (1984).

4. A. D. CARLSON, “Standard Cross-Section Dam” Prog, Nud, En. 13,79 (1984),

5. W. P. POENITZ and Cl.DE SAUSSURE, ‘The Nuclear Data of tie Major Actinide FuelMaterials,” Prog. Nud En. 13, 129 (1984).

6. P. G. YOUNO and L. STEWART, “Control Materials and Light Coolant Cross-SectionDat&” Prog. Nucl. En. 13, 193 (1984).

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9. A. D. CARLSON, W. P. POENITZ, G, M. HALE, and R. W. PEELLE, “The NeutronGoss Section Standards Evaluation for ENDF/B-VI,” Proc. Int. Conf. on Nud. Data forBasic and AppliedScience, Santa Fe, N. M., 13-17 May 1985, V2, p. 1429.

10. R PEELLE and FL CONDE’, “Neutron Standasd Reierence Dam” Proc. Int. Conf onNucl. Dau for Science and Tech., Mite, Japm, 30 May -3 June 1988, to be published,

11, S. T. PERKINS, E. F. PLECH.ATY, and R. J. HOWERTON, “A Reevaluation of the9Be(n,2n) Reaction and Its Effect on Neutron Multiplication in Fusion Blanket Applica-tions,” Nucl. Sci. Eng. 90, 83 (1985).

12. Experimental data obtained fkom the CSISRS com i.lation by the National Nuclear DataJCenter, Bmokhaven Nationai Lalnnatory, Upton, . Y.

13. C. Y. FU and D. M. HETIUC~ “Update of ENDF/B-V Mod-3 Iron: Neuuon-ProducingReaction Cross Sections and Energy-Angle Correlations,” ORNIJI’M-9964, Oak RidgeNafional IAmratury (1986).

14. D. M. I-ISTIUCK, C. Y. FU, and D. C. LARSON, “Calculated Neua’on-LnducedCrossSections for 58@Ni from 1 to 20 McV and Comptisons with Experiments,” ORNU’rM-10219, Oak Ridge National Labuatory (1987).

15. D. M. HETRICK, C. Y. FU, and D. C. LARSON, “Calculated Neutron-Induced CrossSections for Se from 1 to 20 McV am! Compssisons wkh Expemwnts,” 0RN4TM-10417, Oak Ridge National Labcmmy (1987).

16. C. hf. PEREY, F. G. PEREY, J. A. HARVEY, N. W. HILL, N. M. LARSON, and R,L, MACKLIN, “58Ni + n Transmission, DifFcrcntial Elastic Scattcrin , and Capture Mea-

8smcrnrnts and Analysis km 5 to 813 keV,” OR.NIJTM- 10841, d Ri3ge NationalLabmatory Report (1988).

17. C. M. PEREY, J. A. HARVEY, R L. MACKLIN, and F. (3. PEREY, “Resonance Pa-rameters of @Ni + n from Measurements of Transmission and Capture Yields from 1 to450 keV,” Phys, Rev. C27, 2556 (1983).

18. For exam le, see the following reference and the references cited therein: A. B. SMITH,U#P. T. G NTHER, J. F. WHALEN, and R. D. LAWSON, “CobalL Fast Neutrons and

P6ysical h4cdels,” ANIJNDM-101, kgonne National Lalmratory (1987).

19. N, M. LARSON and F. 0. PEREY, “Users (3uide for SAMMY: A Computer Model forMultilevel R-Matrix Fits !0 Neutmm Data Using tions,” ORNL/T’M-7485, OakRid e National Laboratory (1980); see also O

!-9179 (1984) and ORN4TM-

971 /Ill (1985).

20, H, DERRIEN, (3, DE! SAUSSURE, R, B. PEREZ, N, M, LARSON, and R. L,M.ACKLIN, “R-Matrix Analysis of the 23%%Cross Sections Up to 1 keV,” ORNL/TM-10098, Oak Ridge National Laboratory (1986).

21, L, W, WESTON and J, H. TODD, Nucl. Scf. Eng. 88, 37 (1984).

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.

22. P. G. YOUNG and E. D. ARTHUR, “Calculation of 2ssU(n,n’) Cross Sections forENDF/B-VI,” Proc. Int. Conf on Nucl. Datafor Science and Tech., Mite, Japan, 30May -3 June 1988, to be published,.

23. G. H.AXIAT, J. LACHKAR, CM LAGRANGE, J. JARY J, SIGAUD, and Y.PATLN, “Neutron Scattcting Cross Sections for zszlh, 233U, ~3sU, 238U, 23gPu, andZAZWBetw~n 0.6 Md 3,4 MeV,” Nucf. Sci. Eng. 81,491 (1982).

24. R. CWIN, R. R. SPENCER, d R. W. INGLE, “Mcasurcrneiits of tie Ener Depn-dencc of Prompt Neutron Rnissicm fkom 2S3U, 235U, and 2S9PUfor En = O.& 5 to 10McV Relative to Emission fkom Spontancaus Fission of ~S2Cf,”Nucf. Sci. Eng. 94,365(1986).

25. J. FREHAUT, “Coherent Evaluation of fip for 235U, 238U, and 2sgPu,” NE,4NDC(E)238/L, Ccntxe dEtdcs de Bruy&rcs-lc-Chhtel (1986).

26. L. W. WESTON and E. D. ARTHUR, “Evaluation of the Neutron Cross Sections for=,” ORNTX’M-10386, O@kRidge National Minatory (1987).

27. B. F. RIDER and T. R. ENGIAND, “Evaluation of Fission-Raduct Yields for the USANational Nuclear Data Files,” Proc. Spec. MtA.on Datafor Decay Heat Predictions,Studs@ ~WCdCIi, 7-10 Sep~ 1987 [~~-~5 ~’ (1987)] p. 21.

28. T, R. ENGLAND and J. BLACHOT, “Statusof Fwsion Yield Dam” Proc. ht. Co&. onNUCL Damfor Scknce and Tech., Mite, Japan, 30 May -3 June 1988, to be published.

29, C. W. REICH, “Reticw of Nuclear Data of Relevance for the 3ccay Heat Problem,”Proc. Spec. M . on Data for Dec~ Heat Pr~dfctiow, Smdsw Sweden, 7-10 Sept.1987 [NEAN & -245 ‘U’ (1987)] p. 107.

30. T. R. ENGLAND and M BRADY, “Delayed Neutron Da@” Proc. Int, Reactor Phys!c.sCoqf. , Jackson Hole, Wyoming, 18-21 SepL 1988, to be published.