LEGAL NOTICE

Neither the Organisation for Economic Co-operation and Development, any of its Xember Countries, or their agencies, nor any person or organisation acting either on behalf of any of them or otherwise in the development, compilation, publication or distribution of the information in this report :

1. makes any warranty or representation, expressed or implied, with respect to the accuracy, completeness, or usefulness of the information which it contains, or that the use of any information, apparatus, method, or process disclosed may not infringe privately-owned rights; or

2. assumes any liabilities with respect to the use of, or for damage resulting from the use of, any information, apparatus, method or process disclosed.

AVERTISSEMENT

L'Organisation de Cooperation et de D6veloppement Economiques, ses pays membres, ou leurs agences, les personnes ou organisation agissant en leurs noms ou pour le dgveloppement, la compilation, la publication ou la distribution de l 'infor- mation dans ce rapport :

1. Ne garantissent, express6ment ou imp1 ici tement ni que les informations ci-jointes sont exactes et completes, ni que l'utilisation de ces informations, ainsi que des appareils, methodes ou proc6d6s d6crits ne portent pas atteinte 2 des droits acquis ; ou

2. N'assument aucune responsabilite en ce qui concerne l'utilisation des di tes informations, apparei l S, methodes ou procedes ainsi que les consequences pouvant en r6sul ter.

The N.E.A. Data Bank i s p a r t of t h e Organisation f o r Economic Co-operation and Development and i s financed by t h e fol lowing s ix - t een Member countr ies :

Aust r ia , Belgium, Denmark, Finland, France, Germany, I t a l y , Japan, the Netherlands, Norway, Por tugal , Spain, Sweden, Switzerland, Turkey, and the United Kingdom.

La Banque de Donnges de 1'AEN f a i t p a r t i e de l ' o r g a n i s a t i o n de Coopgration e t de Developpement Economiques e t e s t financc5 par l e s s e i z e pays Membres su ivants :

Allemagne, Autriche, Belgique, Danemark, Espaqne, ~ i n l a n d e , France, I t a l i e , Japon, Norvsge, Pays-Bas, Por tugal , Royaume-Uni, Susde, Suisse e t Turquie.

NEUTRON NUCLEAR DATA EVBLLIATION VENSLETTER

NNDEN/3P

This Newsletter summarises eva lua t i on a c t i v i t y i n the OECD area. I t should be noted t h a t work i n proqress and f u t u r e p lans c i t e d i n t h i s document may be chanped wi thout no t i ce : consequent.ly, the Newsletter should n e i t h e r be quoted as a reference i n p u h l i c a t i o n s nor be l i s t e d i n an abs t rac t journa l .

The i n fo rma t i on contained i n t h i s news le t te r concerns:

1. Eva lua t ion work on p a r t i c u l a r nuc l ides;

2. Development o f codes f o r the manipulat ion o f data and f o r the c a l c u l a t i o n o f cross sect ions;

3. Pub l i ca t i ons re levan t t o the neutron data f i e l d .

Cont r ibu t ions on eva lua t i on a c t i v i t i e s have been rece ived from:

Paoe L

FRPNCE CEN, RruyEres-le-Chatel CEN, Cadarache

GERI'ANY KFK, Kar l sruhe

ITALY CNEN, Roloqna

JAPAN Japanese Nuclear Data Committee 7

NETHERLANDS ECN, Petten 1Ci

UNITED KINGDOtf AEE, W i n f r i t h 11

UNITED STATES Na t i ona l Nuclear Data Center 14

Other i n fo rma t i on inc luded i n t h i s issue:

I. J o i n t European-Japanese evaluated data f i l e p r o j e c t 16

11. Intercomparison o f methods used t o determine average resonance 16

111. I n t e r n a t i o n a l nuc lear model code comparison 17

1 . NEW E V A L U A T I O N S R E C E N T L Y COMPLETED a ) , I N PROGRESS h ) , OR PLANNED I N THE NEAR F U T U R E c )

Service de Physique Neutronique e t NuclEaire

Centre d'Etudes de BruyPres-le-Chztel

France

Names : 0. BERSILLON, M. COLLIN, J .P. DELAROCHE, J . JAW, Ch. LAGRANGE,

R. PERRIER, C. PHILIS, J. SALVY, N . VERGES .

Address : Service de Physique Neutronique e t Nuclgaire

Centre dlEtudes de BruySres-le-Chztel

B.P. no 561, 92542 Montrouge Cedex, France

- Pub l i ca t ion

- "Progress Report of recent works on a c t i n i d e nuclear d a t a a t BruyPres-le-

ChZtel", NEANDC (E) 211 "L", I N D C (FR) 41/L (1981) .

- Work i n progress

- Coherent o p t i c a l and s t a t i s t i c a l model ca l cu la t ions of neutron cross sec-

t i o n s f o r Gd i so topes (J.P. DELAI:dC:IE, Ch. LAGRANGE).

- Calcula t ion of neutron cross sec t ions f o r some P t i so topes (J .P. DELAROCHE)

- Evaluat ion of neutron cross sec t ions f o r 2 4 1 ~ ~ i n the energy range 10 -5

4 eV - 20 MeV (0. BERSILLON, Ch. LAGRANGE, D. MADLAND ) .

- Calcula t ion of neutron s p e c t r a from a c t i n i d e (n,xn) reac t ions . Applica-

t i o n s t o 2 3 5 ~ and 2 3 9 ~ ~ ( J . JARY) . - Evaluat ion of -5 2 3 7 ' 2 3 9 ~ neutron cross sec t ions from 10 eV t o 20 Me"

(C. PHILIS , J. JARY, Ch. LAGRANGE) o

- Evaluat ion of neutron cross sec t ions and 7 - ray production da ta f o r W * i so topes i n the energy range 500 keV - 20 MeV (E. ARTHUR , C . PHILIS,

A.B. SMITH**) - ... I . .

- Complete e v a l u a t i o n of n e u t r o n c r o s s s e c t i o n s and Y-ray p r o d u c t i o n from -5

10 eV t o 20 MeV f o r '09L3i (0 . BERSILLON, C . PHILIS, N . VERGES).

-5 - Complete r e - e v a l u a t i o n of 16'Tm from 10 eV t o 20 MeV (E. ARTHUR* , M. COLLIN, D. GARDNER *** , M. GARDNER**; P . NAGEL, C . PHILIS, P .G. YOUNG*).

- P l a n s f o r t h e n e a r f u t u r e

- Complete e v a l u a t i o n of t h e n e u t r o n c r o s s s e c t i o n s of u n s t a b l e Tm i s o t o p e s .

* Los Alarnos S c i e n t i f i c Labora to ry (USA)

** Argonne Ivat ional Laboratory (USA)

'** Lawrence Livermore Laboratory (USA)

SECTION DE PHYSIQUE DES NEGTRONS RAPIDES CENTRE D'ETUDES NUCLEAIRES DE C A D A R A C H E

NAMES : H. DERRIEN, E. FORT, D. LAFOND, P. LONG, J.P. DOAT

ADDRESS : S e c t i o n de Phys ique des Neut rons Rapides (S.P.N.R.) - - Cent re d lEtudes N u c l e a i r e s de CADARACHE

B o i t e P o s t a l e NO1

13115 - SAINT-PAUL-LEZ-DURANCE - (France)

WORK RECENTLY COMPLETED :

R e e v a l u a t i o n o f t h e 237~p(n,2n) c r o s s - s e c t i o n w i t h emphasis

on 2 3 6 ~ u f o r m a t i o n c ross -sec t ion . (E. FORT).

WORK I N PROGRESS :

. E v a l u a t i o n o f a comple te s e t o f n e u t r o n c r o s s - s e c t i o n s f o r

2 3 8 ~ u . Present extensi ,on up t o 3 Me" (H. DERRIEN).

. E v a l u a t i o n o f a comple te s e t o f n e u t r o n c r o s s - s e c t i o n s f o r

58~i, ON^, 62~i. P r e s e n t e x t e n s i o n f o r 58~i and ON^ : 6 Me"

(H. DERRIEN, D. LAFOND), f o r " ~ i : r e s o l v e d resonance r e g i o n (H. DERRIEN).

WORK PLANNED FOR THE NEAR FUTURE :

Complet ion o f t h e work on N i c k e l i s o t o p e s i n o r d e r t o o b t a i n

a complete s e t o f d a t a f o r n a t u r a l N i c k e l .

Contr ibut ion t o NNDEN-30

KFK-KARLSRUHE

GERMANY

Names : F.H. Friihner , B. Goel, H. Jahn, B. Krieg

Address : I n s t i t u t fi ir Neutronenphysik und Reaktortechnik Kernforschungszentrum Karlsruhe Postfach 3640 D-7500 Karlsruhe, West Germany

Work r e c e n t l y completed

24 1 - The KECAK evalua t ions of Am+n c ross sec t ions i s now completed and a f i r s t d r a f t of t h e documentation was wr i t t en . A l l resonance parameters were newly evaluated, and unknown f i s s i o n widths were sampled from t h e i r estimated d i s t r i b u t i o n . The l a s t e s t RfK f i s s i o n da ta i n t h e subthreshold region were used together with information from s t a t i s t i c a l a n a l y s i s of t h e resolved resonances t o c a l c u l a t e a l l c r o s s sec t ions up t o 200 keV with a s t r eng th funct ion model (code FITACS). Above 200 keV a global sphe r i ca l optical. p o t e n t i a l f o r a c t i n i d e s was used, together with a g lobal giant-dipole model fo r r a d i a t i v e t r a n s i t i o n s and a double-humped f i s s i o n b a r r i e r f i t t e d t o recent f i s s i o n d a t a , i n a Lauser-Feshbach c a l c u l a t i o n (code AAUSER-4) of a l l c r o s s sec t ions . (U.Fischer, F.H. Friihner, B. Goel, E. .Tahn, B. Krieg)

Work i n progress

- Evaluation of 242mh 244 , 243Am and Cm neutron c ross sec t ions : This work i s i n i t s f i n a l s t age , with some c a l c u l a t i o n s t o be redone i n t h e unresolved resonance range. (U. Fischer , F.H. Fr8hner, B. Goel, H. Jahn, B. Krieg)

- Assessment of t h e outcome of t h e l e v e l spacing benchmark es t imat ion i n i t i a t e d by P. Ribon (NEANDC(E) 213-AL): This very worthwhile exerc ise indica ted c l e a r l y t h e need t o account not only f o r l e v e l s below some obse rvab i l i t y threshold hut a l s o f o r unrecognised m u l t i p l e t s . The STAR. code was modified correspon- d ingly and t h e new vers ion i s being t e s t e d . (F.h. FrGlmer)

- Study of combinatorial methods f o r l e v e l dens i ty i a l c u l a t i o n s : The mathematical theory of p a r t i t i o n s was used t o de r ive q u i t e r igorous leve l -dens i ty formulae. Their r e l a t i o n s h i p t o cur rent approximations i s under s tudy. (A. Anzaldo, H. Jahn)

C.N.E.N. - DIVISIONE FISICA - LABORATORIO DATI NUCLEAR1

Via ~azzini, 2 - 40138 BOLOGNA, ITALY - tel. 307562 - telex 610167 CNENRO I

Names: F. Fabbri, G. Maino, T. Martinelli, E. Menapace, M. Motta,

G.C. Panini, G. Reffo, M. Vaccari, A. Ventura.

Publications

1) T. Martinelli, E. Menapace, M. Motta, M. Vaccari

valuation of Cm-247 neutron cross sections in the resonance region,

Proceedings of the Second Technical Meeting on the Nuclear Transmutation

of Actinides, Ispra, 21-24 April 1980, EUR 6929.

2) T. Martinelli, E. Menapace, PI. Motta, M. Vaccari, A. Ventura

Evaluation of Cm-246 neutron cross sections in the resonance region,

CNEN Report, RT/FI(80)7, 1980.

3) T. Martinelli, E. Menapace, M. Motta, M. Vaccari, A. Ventura

Evaluation of Cm-248 neutron cross sections in the resonance region,

CNEN Report, RT/FI(80)10, 1980.

Work in progress

1. Theoretical methods for nuclear data evaluation

The statistical method developed in ref. (1) for the calculation of

thermodynamic functions, level densities in particular, of nuclei with

an odd number of protons andjor neutrons is being extensively applied

in order to deduce the trend of neutron (proton) ground state gap

parameters, An (Ap) , versus neutron (proton) number for both odd and even systems.

(V. Benzi, G. Maino, A. Vcntura).

2. Actinide data - - - The evaluatiorsof the Curium isotopes Cm-246, 247, 248 under IAEA

research agreement No. 2114jCF are in progress with the extension of

the capture and fission cross section calculations in the continuum

region (beyond 10 keV).

(1) G. Maino, E. Menapace, A. Ventura, Nuovo Cimento 57A, 427 (1980) -

The following parameters were selected for calculations:

- - - Dobs, r y . I'f' So , at neutron binding energy from analysis of

resonances ;

- Optical model parameters and those concerning fission barriers, giant resonances, etc. from local systematics LL~d comparison with experimental

data.

(G. Maino, T. Martinelli, E. Menapace, M. Motta, M. Vaccari, A. Ventura).

3. Structural material data - - - - - - - - - - - - - For the selection of a recommend file of Fe-56 a comparison is in progress

among the results of capture integral data measured at fast critical

facility R3-2 in Bologna and calculated ones, obtained using different

files which were prepared with resonance data of different laboratories

(Oak Ridge, Geel) . (E. Menapace, M . Motta, G.C. Panini, M. Vaccari).

Work planned for the next future --.p- -- -

- A new evaluation of structural materials Cr-52 and Cr-53 is planned,

followed by a comparison with integral capture data obtained in RB2 fast

facility.

- A revision of the evaluations of Pd-l05 and -107, starting from new

resonance data, will be performed.

(G. Bonifazzi, E. Menapace, M. Motta, G.C. Panini, M. Vaccari).

Contr ibut ion t o Neutron Nuclear Data Evaluation Newsletter-30

Japanese Nuclear Data Committee (Nuclear Data Center, JAERI)

1.

Work Recently Completed and Publ ica t ions :

( i ) Neutron Cross Sect ions of 28 Fiss ion Product Nuclides Adopted i n JENDL-1

Yasuyuki Kikuchi, Tsuneo Nakagawa, Hiroyuki Matsunobu, Masayoshi Kawai, S i n - i t i I g a r a s i and Shungo I i j i m a

JAERI 1268 (1981)

This i s t h e f i n a l r e p o r t concerning t h e evaluated neutron c ross s e c t i o n s of 28 f i s s i o n product nucl ides adopted i n t h e . f i r s t ve r s ion of Japanese Evaluated Nuclear Data Library (JENDL-1). These 28 nucl ides were se l ec t ed as being most important f o r f a s t r e a c t o r ca l cu la t ions , and a r e 9 0 ~ r , 93zr , 9 5 ~ o , 9 7 ~ 0 , 9 9 ~ c , ~ O ~ R U , 1 0 2 ~ ~ , 1 0 3 ~ h , ~ O ~ R U , 1 0 5 ~ d , ~ O ~ R U , 1O7pd, 1 0 9 ~ g , 1291, 131xe, 1 3 3 ~ 8 , 135cs, 1 3 7 ~ s , 143Nd, 144ce, 1 4 4 ~ d , 145Nd, 1 4 7 ~ m , 147~m, 149sm, 151sm, 1 5 3 ~ u and 1 5 5 ~ u . The s t a t u s of the experimental da t a was reviewed over t h e whole energy range. The present eva lua t ion was performed on t h e b a s i s of t h e measured da ta with the a i d of t h e o r e t i c a l ca l cua l t ions . The o p t i c a l and s t a t i s t i c a l models were used f o r eva lua t ion of t h e smooth cross s e c t i o n s . An improved method was developed i n t r e a t i n g the mul t i l eve l Breit-Wigner formula f o r t h e resonance region.

( i i ) Evaluation of Neutron Nuclear Data f o r 2 3 3 ~ i n Thermal and Resonance Regions

Yasuyuki Kikuchi

JAERI-M 9318 (1981)

The thermal and resonance cross sec t ions of 23317 were evaluated f o r JENDL-2. The cross s e c t i o n s below 1 eV were evaluated by the use of t h e measured f i s s i o n and capture c ross s e c t i o n s . The resolved resonance parameters were obtained so a s t o reproduce t h e measured t o t a l and f i s s i o n c ross s e c t i o n s . The c ross sec t ions from 100 eV t o 30 keV a r e represented by t h e unresolved resonance parameters.

( i i i ) Decay Heat Calcula t ions Based on Theore t ica l Estimation of Average Beta- and Gamma-Energies Released

from Short-Lived Fiss ion Products

Tadashi Yoshida and Ryuzo Nakasima

(To be published i n J. Nucl. Sc i . Tech. Vol. 18 , No. 5)

F iss ion product decay hea t of 2 3 5 ~ was ca l cu la t ed f o r s h o r t cooling-time on t h e b a s i s of a prel iminary vers ion of a new decay da ta l i b r a r y r ecen t ly completed by the Japanese Nuclear Data Committee. It was shown t h a t a f u l l adoption of recent pub l i ca t ions of-decay schemes t o de r ive the average energ ies of beta- and gamma-rays, E6 and ET, l eads t o a l a r g e underestimation of t h e gamma-ray component of t h e decay hea t and t o an overest imation of t h e beta-ray component. I n o rde r t o remedy t h i s , t h e o r e t i c a l va lues of Eg and - Ey were introduced f o r high Q-value decays, which were obtained with a gross theory of beta-decay. It improved remarkably t h e agreement between ca l cu la t ion and experiment not only f o r t h e 2351~ decay hea t but f o r 2 3 9 ~ u and 2 4 1 ~ u a s wel l .

( i v ) Evaluation of Neutron Nuclear Data f o r 243Cm

Tsuneo Makagawa and S i n - i t i I g a r a s i

(To be submitted t o JAERI-M r epor t )

The neutron nuclear d a t a of 2 4 3 C m were evaluated i n t h e energy region of 10-' eV t o 20 MeV. The evaluated q u a n t i t i e s a r e resonance parameters up t o 27 eV, t h e t o t a l , f i s s i o n , c a p t u r e , e l a s t i c and i n e l a s t i c s c a t t e r i n g , (n ,2n) , (n,3n) and (n,4n) r eac t ion c ross sec t ions , angular d i s t r i b u t i o n s of emit ted neutrons and t h e number of neutrons per f i s s i o n .

(v) Evaluation of 238U resolved resonance parameters

Tsuneo Nakagawa

(To be submitted t o J A E R I r epor t )

Evaluation of 238U resonance parameters has been made f o r JENDL-2. A l l t h e a v a i l a b l e resonance parameters were compiled i n a t ab le . The sys temat ic d iscrepancies among resonance energ ies were inves t iga ted . The neutron and cap- t u r e widths were evaluated by the simultaneous eva lua t ion s i m i l a r t o t h e a rea method.

Work i n Progress:

( i ) Reevaluaion of neutron cross sec t ions f o r about 80 FP nucl ides i s i n progress i n t h e energy region from thermal t o 15 MeV.

(from M. Kawai, NAIG)

( i i ) The gamma-ray production c ross sec t ions assoc ia ted with neutron induced r eac t ions f o r n a t u r a l molybdenum a r e evaluated i n t h e energy region from thermal t o 20 MeV. The gamma-ray spectrum i n t h e low energy neutron capture is ca lcula ted on t h e b a s i s of s t a t i s t i c a l model tak ing i n t o account t h e d i s c r e t e l e v e l s and El , M 1 , E2 t r a n s i t i o n s . (from M. Mizumoto, JAERI)

( i i i ) A s reported by M. Kawai i n the NNDEN-29, gamma-ray production c ross sec t ion f o r A l , S i , , Ca, Fe, N i , Cu, Nb, Ta, Au and Pb have been analysed i n t h e energy range from 1 t o 20 MeV with t h e spin- dependent and mult i -s tep evaporation model. The present model was use fu l f o r ca l cu la t ions of average energ ies and production c ross s e c t i o n s of secondary gamma-rays from medium weight nuc le i i n t h e neutron energy region where the ( n , n t ) r eac t ions a r e dominant.

(from Y. Harima, TIT)

Work about codes and da ta f i l e s :

( f ) A computer code GROGI-IV was developed i n order t o c a l c u l a t e gamma-ray production c ross sec t ion and nucleon s p e c t r a wi th t h e mult i -s tep evaporation model taking y r a s t l e v e l i n t o cons idera t ion . This i s a rev ised vers ion of GROGI-3 developed by Takahashi, BNL.

(from M. Kawai, NAIG)

( i i ) The decay da ta f i l e f o r f i s s i o n product nucl ides (FP DECAY DATA FILE) has been prepared f o r summation ca l cu la t ion of t h e decay hea t of f i s s i o n products. The average energ ies re leased i n 8- and y - t r ans i t i ons and necessary information have been arranged i n t abu la r form together wi th t h e est imated r e s u l t s f o r 470 nucl ides of which decay d a t a a r e not a v a i l a b l e experimental ly. This has been published i n JAERI-M 9357. (from Z. Matumoto, JAERI)

Work Planned f o r t h e Near Future:

( i ) Reevaluations of neutron nuclear d a t a f o r 2 4 1 ~ m and 2 4 3 ~ m a r e planned below 20 MeV. (from S. I g a r a s i , JAERI)

( i i ) Reevaluation work w i l l be made on t h e i n e l a s t i c s c a t t e r i n g cross s e c t i o n s of C r , Fe and N i by tak ing account of t h e d i r e c t process wi th t h e coupled channel o p t i c a l model and DWBA.

(from Y. Kikuchi, JAERI)

S. I g a r a s i Nuclear Data Center Tokai Research Establishment Japan Atomic Energy Research I n s t i t u t e Tokai-mura, Naka-gun, Ibaraki-ken 319-11 Japan

May 10, 1981

NEUTRON NUCLEAR DATA EVALUATION NEWSLETTER-30

ECN-Petten - The Netherlands

1. Names

H. Gruppelaar, H.A.J. van der Kamp, R.J. Heijboer and D. Nierop, Netherlands Energy Research Foundation (ECN), P.O. Box I, 1755 ZG Petten, The Netherlands. Telephone: (02246)-6262, telex: 57211 reacp nl.

2. Recent publications and preprints (available upon request)

( I I Gruppelaar, H. and J.M. Akkermans, Comparison of experimental and calculated neutron emission spectra and angular distributions, Paper contributed to the Symposium on Neutron Cross Sections from 10 to 50 MeV, Brookhaven, May 12-14, 1980, BNL-NCS-51245, Vol. - 2 (1980) 711 (also ECN-80-071).

121 Gruppelaar, H. and J.B. Dragt, Cross section adjustments using in- tegral data, Review paper Conference on Nuclear Data Evaluation Methods and Procedures, Brookhaven, September 22-25, 1980 (ECN-80-159).

131 Akkermans, J.M. and H. Gruppelaar, Random-walk model of precompound decay: dynamics and multiparticle emission, to be publ. in Z. fiir Physik A (ECN-81-027).

141 Gruppelaar, H. and R.J. Heijboer, Dutch request list for fission product capture cross sections, Contr. to NEANDC-meeting, Aix-en- Provence, 6-10 April 1981 (STEK-Memo-90).

3. Work recently completed

. Part 1 of the revised and adjusted RCN-3 evaluation of neutron cross sections for fission products (KEDAK format) has been forwarded to the NEA Data Bank. The present library contains 29 materials.

. A short intercomparison of recent fission-product libraries (including ENDFIB-V) was made. . The evaluations of neutron cross sections for the radioactive cor- rosion products 58g~o and 58m~o have been completed.

4. Work in progress

. Re-evaluation of neutron cross sections for the stable Pd-isotopes and 107pd. . Work on precompound models 1 l, 31 .

5. Work planned for the near future

. Continuation of efforts in evaluation and adjustment of capture cross sections for about 20 fission-product nuclides (RCN-3 evaluation). . Evaluation of neutron cross sections for nuclides in the primary cooling circuit of a LMFBR, i.e. for 22~a, 38940~r, Il2sn. . Evaluation of neutron cross sections for fusion-design studies.

6. Computer codes

. Contributions have been prepared for the international comparisons of model codes for average resonance parameters and optical- and statistical-model calculations. . A new code system has been developed to calculate multi-particle pre- compound emission with an arbitrary number of outgoing particles 131.

NUCLEAR DATA EVALUATION NEWSLETTER

The United Kingdom

1 PERSONNEL

The following graduate personnel a r e c u r r e n t l y working on nuclear da ta evaluat ion: - UK Atomic Energy Authori t? -

i ) Winfr i th , Nuclear Data Group J S Story - M F James - R W Smith

Address: Building B21, Atomic Energy Establishment, Winfr i th , Dorchester, Dorset . Telephone Dorchester 311 1 , Telex No 41231

Winfrith Technology Branch - A L Nichols

Address: Building A50, Atomic Energy Research Establishment, Winfr i t h , Dorchester, Dorset. Telephone Dorchester 3 l I 1 , Telex No 41 23 1

i i ) Harwell, ELectron Accelerator Group (Building 418)

J E Lynn - M C Moxon - M G Sowerby - C A U t t l e y

Address: Atomic Energy Research Establishment, Harwell, OxEordshirt, OX11 ORA. Telephone Abingdon 24141: Telex No 83135

Harwell Chemistry Divis ion (Building 220)

J G Cuninghame - E A C Crouch - Katherine M Glover - M King

Address: Atomic Energy Establishment, Harwell, Oxfordshire, OX1 1 ORA. Telephone Abingdon 24141 : Telex No 83135

i i i ) Cent ra l E l e c t r i c i t y Generating Board

Berkeley Nuclear Laboratory - B S J Davies - A Tobias

Address: Berkeley Nuclear Laboratories , CEGB Berkeley, Gloucestershire , GL13 9PB. Telephone Berkeley 451.

i v ) B r i t i s h Nuclear Fue l s Limited

Windscale and Calder Works - V Barnes

Address: Windscale and Calder Works, S e l l a f i e l d , Seascale , Cumbria. Telephone Seascale 333.

2 WORK COMPLETED

A r e p o r t has been produced by Tobias & Davies (CEGB) on the new l i b r a r y of f i ss ion-product decay d a t a (UKFPDD-2) mentioned i n NNDEN-29. These d a t a have been used, together with the CROUCH-3 f i s s i o n y i e l d s , f o r summation c a l c u l a t i o n s of decay hea t , and show improved agreement with i n t e g r a l measurements, e s p e c i a l l y a t sho r t cool ing times, a s compared with c a l c u l a t i o n s based on UKFPDD-I; see the paper of Tobias (1 980).

An extens ive eva lua t ion of t h e ha l f -1if e of 239-Pu has been under taken, r equ i r ing d e t a i l e d s tudy of over 30 references ; ser ious d iscrepancies between d i f f e r e n t measurements made dur ing the p a s t h0 years were c r i t i c a l l y examined. The, recomnerded v a l u e of 24113 +_ 45y has been incorporated i n t o the heavy element decay d a t a l i b r a r y , UKHEDD-I. A r e p o r t on t h i s work i s i n d r a f t .

Evaluat ion of the neutron c r o s s s e c t i o n d a t a f o r 243-Am was completed and a d a t a f i l e compiled i n the UKNDL format i n Dec 1980 by Bowey, P a t r i c k & Sowerby (AERE). Documentation w i l l be s t a r t e d shor t ly .

As p a r t of a programme of work t o produce a j o i n t European-Japanese evaluated nuclear d a t a l i b r a r y , a review of Fe eva lua t ions has been c a r r i e d out, by Moxon & Sowerby (AERE) and Story (AEEW), t o de f ine t h e composition of t h e f i l e t o be used i n the i n i t i a l ve r s ion of the l i b r a r y .

3 WORK I N PROGRESS -

Evaluat ion of spontaneous f i s s i o n da ta , prompt gamma and neutron spec t ra , f o r t h e heavy element decay d a t a l i b r a r y (UKHEDD-I), which i s i n the ENDFIB5 f o r v V, i s nea r ly complete; James (AEEW) . Further s t u 6 i e s a r e i n progress on the d iscrepancies , f o r 239-Pu f i s s i o n , between i n t e g r a l measurements of f ission-produc t decay heat, a d ca l cu la t ed va lues using the summation method; James (AEEW) . Work has been s t a r t e d t o e x t e d and improve the UK f i l e of decay da ta f o r a c t i v a t i o n products. A l i s t of over 380 nucl ides has been drawn up f o r i nc lus ion i n t h i s f i l e , a s compared with the c u r r e n t f i l e of 91 nucl ides which was completed i n 1977; however 158 of these nucl ides a r e a l r eady l i s t e d ill the f i ss ion-product decay d a t a f i l e UKFPDD-2, and 15 appear i n the heavy element decay d a t a f i l e UKHEDD-I; consequently 211 nucl ides remain t o be evaluated f o r the a c t i v a t i o n product f i l e .

Work has continued on evalua t ion of t h e resonance parameter d a t a fo r 58-Fe and 56-Fe. With the help of the programmes LJPROB and DEEBAR it has been found poss ib l e t o make r a t i o n a l assignments of sp in and p a r i t y t o almost a l l observed resonances, i n keeping with the s t a t i s t i c a l p red ic t ions of t h e Fermi gas-mcdel. The expected weak energy dependence of mean spacings has been taken i n t o account; t h i s implies a f a c t o r 2 r educ t ion i n the mean spacing of S-wave resonances over a range of about 1 MeV.

The programme LJPROB has been developed f o r examining the poss ib le (1,J) assignments of resonances. For each resonance i t computes the neutron s t rength

f o r each of a range of poss ib le (1,J) assignments, where i s the number of channel sp in s t a t e s . Using input va lues fo r the s t r eng th func t ions ( ~ n ( 1 ) ) , f o r each resonance the p r o b a b i l i t y per cen t i s ca lcu la ted of f ind ing resonances of the same (1 , J ) wi th la rger va lues of Sn(1,J;E).

5 PAPERS

Tobias A & Davies B S J (Nov 1980). CEGB Report RD/B/N4942; 'UKFPDD-2; a Revised T i s s i o n Product Decay Data F i l e i n ENDFIB4 Format'

Tobias A (Nov 1980). CEGB Report RD/B/4949; - 'Decay Heat Sumat ion Calcula t ions Using UKFPDD-2 '

J S STORY

Reactor Physics Division AEE Winfr i th

USA CONTRIBUTION TO NNDEN-30

Via the National Nuclear Data Center

Recent Publications

BNL-NCS-28933 1980 September "Evaluation Methods for Neutron Cross Section Standards ," M.R. Bhat.

LA-8626-MS 1980 December "Evaluated Neutron-Induced Cross Sections for 54, 56-Fe to 40 MeV," P.G. Young.

ORNL-5662 1980 September "An Evaluation of Cross Sections for Neutron- Induced Reactions in Sodium," D.C. Larson.

ORNLITM-6405 1980 September "Evaluation of Resonance Parameters for Neutron Interaction with Iron Isotopes for Energies up to 400 keV. C.M. Perey, E.G. Perey . ORNLITM-7341 1980 October "GLUCS: A Generalized Least-Squares Program for Updating Cross Section Evaluations with Correlated Data Sets," D.M. Hetrick, C.Y. Fu.

ORNLfTM-7485 1980 November "User's Guide for SAMMY - A Computer Model for Multilevel R-matrix Fits to Neutron Data Using Bayes' Equations," N.M. Larson, E.G. Perey, J.A. Harvey.

ORNLITM-7523 1980 November "Evaluation of Neutron and Gamma Ray Production Cross Sections for Natural Iron (ENDFIB-V Mat 1326)," C.Y. Fu, E.G. Perey.

Evaluations Recently Completed or In Progress

Material

85 ,87Rb

107, logAg

W isotopes

Natural IJ

Laboratory

LANL

LANL

ORNL

BNL

ORNL

BNL

BNL

BNL

LANL, ANL

LANL

LANL

BNL

BNL

Status

In Progress

In Progress

Extension up to 40 MeV in is progress

Extension up to 50 MeV is in Progress

Contribution to Natural Iron is in progress

Extension up to 50 MeV is in progress.

Complete, Being Reviewed

Complete, Being Reviewed

Complete

Summing of W isotopes is in progress

In Progress

Resolved resonance region revision to agree with ENDB-V standards is in progress.

Thermal Parameters Evaluations is in progress

Norman E. Holden National Nuclear Data Center Brookhaven National Laboratory Upton, New York 11973 May 1981

I. J o i n t European-Japanese e v a l u a t e d d a t a f i l e p r o j c c t

A second mceting of t h e NE4CRP ad-hoc working qroup on c o o r d i n a t i o n of evaluations was he ld d u r i n g t h e A p r i l 1981 meeting of NEANDC a t Aix-en- Provence. The meeting i n c l u d e d r e p r e s e n t a t i v e s of NEACRP, t h e Chairman of t h e NEA Oata Rank Committee, and a number of e v a l u a t o r s . R e s p o n s i b i l i t ) was a s s i o n e d t o d i f f e r e n t members of t h e qroup f o r s e l e c t i n g t h e e v a l u a . t i o n s ne'ded t o qake up a f i r s t r e f e r e n c e f i l e . S u b j e c t t o t h e approva l o t h e Data Rank Committee, i t was aorced t h a t t h e Data Bank would t a k e on t h s e c r e t a r i a t and t e c h n i c a l work needed t o c o o r d i n a t e members' c o n t r i b u t i o n and t o assemble t h e c o n p o s i t e f i l e . A d e t a i l e d p roposa l was agreed on, t be cons ide red by t h e Data Dank Committee f o r submiss ion t o t h e S t a c r i r Committee f o r Nuclear Encrqy, which would g i v e t h ~ : p r o j e c t o f f i c i a l t e r r of r e f e r e n c e and an i n i t i a l oroTram of work. Followinq t h e Data Oar Committee 's d e c i s i o n taken at. i ts May 1981 meet ino, a modif ied p roposa l h: been "repared f o r c o n s i d e r a t i o n by t h e ~ t e e r i n ~ ~ ~ o r n m i t t e e a t i t s Octobt l7n1 meeting.

\',anwhile, work has s t a r t e d on s e l e c t i o n of e v a l u a t i o n s and t r a n s l ; t i o n of d a t a f o r an l n i t i a l f i l e t o c o n t a i n d a t a f o r :

Standard r e f e r e n c e m a t e r i a l s : He, L i , B, C , Au, U-235. S t r u c t u r a l m a t e r i 8 l s : Fe, C r , N i , T i . Fuel m a t e r i a l s : U-235, ll-23P, Pu-239, Pu-24C, Pu-241, Iliqh mass a c t i n i d e s : Cm i s o t o p e s F i s s i o n p roduc t s .

A number of r e c e n t European and Japanese e v a l u a t i o n s f o r o t h e r mat€ r i a l s were noted t o be cons ide red f o r p o s s i b l e i n c o r p o r a t i o n i n an ex tende f i l e . The Oata 3ank is p r e p a r i n g r e p o r t s on ENDF/R V d a t a p r o c e s s i n g an v e r i f i c a t i o n codes , and on codes f o r g e n e r a t i n q rnult iqroup c r o s s - s e c t i o s e t s , which can be made a v a i l a b l e t o Data Pank customers .

The prooram w i l l be reviewed a t a meeting of t h e workina group t o bt h e l d a t Gl infr i th i n conjunction with t h e NEACRP meet inq, 1 4 t h t o 1 8 t t September, 19P1.

11. I n t c r c o m p a r i s o n o f met.hods u s e d t o d e t e r m i n e a v e r a q e r e s o n a n c e p a r a m e t e r s ( c o o r d i n a t e d by Dr. P. Ribon, CEN S a c l a y )

The 1979 meetinq of NEA Nuclear Data Committee endorsed a p roposa l t o c a r r y o u t a henchmark in te rcompar i son s t u d y of methods used t.o de te rmine average parameters from r e s o l v e d resonance pa ramete r s . The r e p o r t NEANDC- (E)213"AL", s e n t ou t i n September 19eO ( F i r s t o a r t : g e n e r a t i o n of t e s t d a t a ) and ).'arch l981 (Second p a r t : r e s u l t s and t h e i r i n t e r p r e t a t i o n ) showed impor tan t s y s t e m a t i c d i s c r e p a n c i e s between t h e s e t s of s o l u t i o n s o b t a i n e d hy p h y s i c i s t s u s i n g e s s e n t i a l l y t h e same approach t o t h e c a l c u l a t i o n of averaoe l e v e l s p a c i n g s , s t r e n g t h f u n c t i o n s and r a d i a t i o n w i d t h s i n t h e two h y p o t h e t i c a l n u c l e i f o r which a r t i f i c a l l y g e n e r a t e d resonance pa ramete r s were s u p p l i e d .

A workshop w i l l be he ld a t t h e NEA Data 9ank i n October 1981 f o r p a r t i c i p a n t s i n t h i s e x e r c i s e . The aim of t h e workshop is t o i d e n t i f y t h e o r i g i n of t h e d i s c r e p a n c i e s between d i f f e r e n t s o l u t i o n s ; i n o r d e r t o pro- v i d e a c l e a r e r b a s i s f o r d i s c u s s i o n , a second e x e r c i s e has been d i s t r i b u t e d t o t h e o r i g i n a l p a r t i c i p a n t s , and t o a smal l number of o t h e r p h y s i c i s t s who

d i d n o t s u b m i t s o l u t i o n s b u t who r e g u l a r l y c a r r y o u t c a l c u l a t i o n s o f t h i s k i n d . Da t a h a s heen s e n t f o r c a l c u l a t i n q two c a s e s e a c h , a t t h r e e l e v e l s o f c o m p l e x i t y i n c a l c u l a t i o n :

( a ) two c a s e s o f p u r e r e d u c e d n e u t r o n w i d t h d i s t r i b u t i o n s ( t h e 0

o n l y q u a n t i t y t o be d e t e r m i n e d is <c >).

( h ) two c a s e s o f r e s o l v e d r c s o n a n c e p a r a m e t e r s , w i t h o u t any e x n e r i - men ta l e f f e c t .

( c ) t w ~ c a s e s o f p s e u d o - e x p e r i m e n t a l r e s o n a n c e o a r a m e t e r s s e t s , s i m i l a r t o case l o f t h e p r e v i o u s e x e r c i s e , b u t w i t h o u t t h e c o r r e l a t i o n s i n t r o d u c e d by a prooramminq e r r o r i n t o t h e d a t a f o r t h e p r e v i o u s e x e r c i s e .

I t was c l e a r f rom d i s c u s s i o n s du r in ; t h e a n a l y s i s of t h e p r e v i o u s e x e r c i s e t h a t t h e me thods u s e d a r e n o t a l l f u l l y prescribed, and t h a t r e s u l t s may depend on t h e way i n which p h y s i c i s t s apf l ly t h e i r judflement, f o r example i n d e f i n i n g t h e neut.ron w i d t h t h r e s h o l d t o e x c l u d e p-wave r e s o n a n c e s . D e t a i l e d comments w i t h s o l u t i o n s s h o u l d make it p o s s i b l e t o d e t e r m i n e t h e i m p o r t a n c e o f s u c h d i f f e r e n c e s .

111. I n t e r n a t i o n a l n u c l e a r model c o d e compar i son ( c o o r d i n a t e d 5y Dr. E. S a r t o r i , IAEA and NEA-DD)

T h i s compar i son is b e i n g c a r r i e d o u t i n t h r e e s t a q e s :

- c o u p l e d c h a n n e l c a l c u l a t i o n f o r e l a s t i c and i n e l a s t i c n e u t r o n s c a t - t e r i n o c r o s s - s e c t i o n s on U-73A;

- s p h e r i c a l o p t i c a l model and s t a t i s t i c a l model c n l c u l a t i o n s of a wide r a n n e o f r e a c t i o n s f o r To-59;

- p r e - e q u i l i b r i u m e f f e c t s a t h i p h e r n e u t r o n e n e r q i e s i n t h e c o n t e x t o f t h e CO-59 problem above ,

R e s u l t s f o r t h e c o u p l e d c h a n n e l c a l c u l a t i o n , u s i n g , i n t h e main , d i f f e r e n t v e r s i o n s o f t h e code JL!PITOR have been r e c e i v e d and a n a l y s e d . The r e s u l t s of a f i r s t compar i son of r e s u l t s were i s s u e d i n t h e document NEANDC-A-136 p r e s e n t e d a t t h e A p r i l 1.981 m e e t i n q o f NEANDC. Subsequen t i n v e s t i g a t i o n s by P r . S a r t o r i showed t h a t d i s c r e p a n c i e s be tween i n t e g r a l v a l u e s of c r o s s - s e c t i o n s a t d i f f e r e n t e n e r g i e s were due t o t h e methods u s e d f n r i n t e q r a t i n n a n g u l a r d i s t i b u t i o n s .

Only a few of t h e c o n t r i h u t i o n s e x p e c t e d f o r t h e s c c o n d e x e r c i s e on CO-59 have y e t r e a c h e d t h e R a t a Rank. A f u r t h e r r e n o r t w i l l be i s s u e d l a t e r .

A p r e l i m i n a r y set o f s p e c i f i c a t i o n s f o r t h e t h i r ? s t a q e h a s heen p r e p a r e d and w i l l be s e n t o u t when n e c e s s a r y c h e c k s have heen made.

GENERAL RECOMllENDiiTIONS TO CONTRIBUTORS

Contents and P r e s e n t a t i o n

These n e w s l e t t e r s a r e r e a n t t o be i n f o r m a l : n e v e r t h e l e s s , we t h i n k i t u s e f u l t o g i v e some recommecdations concern ing t h e con ten ts , p r e s e n t a t i o n , d i s t r i b u t i o n , e t c .

The idews le t te rs a r e concerned w i t h e v a l u a t i o n a c t i v i t i e s - w i t h e v a l u a t i o n work i t s e l f and w i t h computer programs u s e f u l f o r

e v a l u a t i o n .

Exper imenters shou ld be c a r e f u l t o d i s t i n g u i s h betweep " e v a l u a t i n g " a l l t h e good d a t a and t h e rrore customary p r 0 c e . s o f s imp ly a n a l y s i n g t h e i r own seasuremects.

When c o m p i l i n g y o u r c o n t r i b u t i o n , t h e f o l l o w i n g hezdings say s e r v e as a g u i d e :

1. Names, address, te lephone number, t e l e x code.

2. Work r e c e n t l y completed an$. p u b l i c a t i o n s .

3. Work i n p r o g r e s s - p l e a s e g i v e names o f p h y s i c i s t s do ing each e v a l u a t i o n .

4 . Work p lanned f o r n e z r f u t u r e , i e., work expected t o s t a r t w i t h i n s i x lnonths ( b e f o r e pub1 i c a t i o n o f t h e n e x t n e w s l e t t e r ) .

5. Computer ?rograms f o r : n u c l e a r d a t a f i l e c p e r a t i o n s - n u c l e a r d a t a a n a l y s i s - n u c l e a r model c a l c u l a t i o n s .

Any n o t e c r r e p o r t ment ioned shou ld be a v a i l a b l e on r e q u e s t t o ano the r e v a l u a t o r f o r h i s own use b u t n o t n e c e s s a r i l y f o r w idespread copy ing and r e - d i s t r i b u t i o n . The c l i s t r i b u t i o n l i s t o f each n e v r l e t t e r w i l l be a t t a c h e d t o i t.

C o n t r i b u t i o n s shou ld be forwarded t y p e w r i t t e n i n s i n g l e spac ing, as

t h e n e w s l e t t ~ r s w i l l be produced d i r e c t l y f rom t h i s t y p e s c r i p t . -

IMPORTANT NOTE

F u t u r e Neut ron Nuc lea r Data E v a l u a t i o n N e w s l e t t e r s w i l l be d i s t r i b u t e d on 1 s t June and 1 s t December each year .

E v a l u a t o r s a r e reques ted t o send t h e i r c o n t r i b u t i o n s by :

1 5 t h May and 1 5 t h November

NEA DATA BANK 91191 GIF SUR YVETTE CEDEX

DISTRIBUTION LIST

AUSTRALIA W. Gemel l

AUSTRIA F. Putz

BELGIUM H. Ceulemans, F. Motte

CANADA G.C. Hanna, C. Keating, W.B. Lewis, W.H. Walker

DENMAR K N. Neltrup

EURATOM K.H. Boeckhoff, H. L isk ien, H. Rief , G. Rohr, E. Wattecamps, H. Weigmann

FINLAND P. Silvennoinen

FRANCE J.C. Bluet, J. Bouchard, C. Cardot, C. Dev i l l e rs , E. Fort, P. Harmer, R. Joly, J. Legrand, A. Michaudon, V.C. Ph i l i s , P. Ribon, M. Salvatores, J. Salvy, H. T e l l i e r , R. Vidal

GERMANY S. C ie r jacks , F.H. Froehner, B. Goel, E. K ie fhaber , H. Kuesters, M. Mattes, M. R i t tberger

GREECE M. Dr i t sa

ICELAND M. Magnusson

IRELAND T.A. Nevin

ITALY V. Benzi, U. F a r i n e l l i

JAPAN N. Yamamuro, S. I ga ras i , S. I i j i m a , Y. Kanda, I. Kimura, H. Matsunobu, K. Sugiyama, R. Nakasima, M. Yamamoto, Y. Seki

NEA L. Garcia de Viedma, N. Tubbs, J.A.G. Rosen

NETHERLANDS M. Bustraan, H. Gruppelaar, H. Van Dam

NORWAY E. Andersen, J.O. Berg

PORTUGAL F. Gama Carvalho

SPAIN A. Carbo, G. Manero, C. Sanchez de l Rio, G. Velarde

SWEDEN G. Apelquist, H. Conde, E. Hel ls t rand, L. Wall in, T. Wiedling

SWITZERLAND J. Hadermann, R. Richmond, W. S e i f r i t z , F. Widder

TURKEY c. Ertek

UNITED J.R. Askew, C.G. Campbell, P. Christmas, J.C. Cuninghame, A.C. KINGDOM Douglas, C . Moxon, A.L. N i c h o l s , B.H. P a t r i c k , E.D.

Pendlebury, J.L. Rowlands, M.G. Sowerby, 3.5. Story, J.C. Tyror, C.A. u t t l e y

UNITED R. Benjamin, R.C. B lock, C. Bowman, C.L. Cowan, H. Goldstein, STATES J. Hardy, C.R. Head, P. Hemmig, W.B. Henderson, N. Holden, R.

Howerton, B.R. Leonard, C.R. Lub i tz , D. Mathews, C.W. Maynard, H. Motz, NNCSC L ib ra ry , E.H. Ot tew i t te , 0. Dzer, N.G. Paik, R.W. Peelle, E.R. Pennington, F.G. Perey, RSIC, G.L. Rogosa, R.E. Schenter, A.B. Smith, N. Steen, W.A. Wittkopf, P. Young