ENDF/B-VIII: What has changed so far? · NUCLEAR DATA SHEETS M.B. Chadwick et al. agreement. (n,n’) inelastic scattering Add. Although we have not made many changes here, include

ENDF/B-VIII: What has changed so far?

D. Brown, National Nuclear Data Center, BNL

Critical assembly performance

Plot curtesy A. Trkov

So, what has changed and what hasn’t?

§ CIELO evaluations§ TSL evaluations§ Many other ENDF

evaluations§ V&V, QA§ New format

This is what gets us the amazing performance




But many other applications need these




This is how we insure good performance




This is how we prepare for the future

Fraction of evaluations provided for ENDF/B-VIII

CSEWG is a long standing collaboration between data users who, incidentally, are also the biggest content providers

ENDF/B-VIII highlights§ CIELO:

• 16O• 56Fe• 235U• 238U• 239Pu

§ Neutron standards§ 1H§ 6Li§ 10B§ 197Au

§ Structural materials:§ 12,13C§ 40Ca• 54Fe, 57Fe, 58Fe• 58-61Ni• Yb, Dy, Os

(JENDL4)• 63,65Cu• 182,183,184,186W• 174,176,178,179,180Hf• 132Te

§ Other non-CIELO:• n• 7Be• 18O (RUSFOND)• 35,37Cl• 59Co• 73,74As• 78Kr• 124Xe• RQ Wright’s nubars• 40Ar• 236m1Np• 240Pu• EGAF gammas• Bug fixes


• 16O• 56Fe• 235U• 238U• 239Pu



(JENDL4)• 63,65Cu• 182,183,184,186W• 174,176,178,179,180Hf• 132Te



• 16O• 56Fe• 235U• 238U• 239Pu



(JENDL4)• 63,65Cu• 182,183,184,186W• 174,176,178,179,180Hf• 132Te


Bug fixes

§ Beta4 • 35,37Cl• 74As• 241Am

§ Beta5 (ENDF/A)• 48Ti• 10Be• 180,181Ta• 185,187Re

Serious changes

§ Beta4• 63,65Cu Covariances• 240Pu• Standards• CIELO

§ Beta5 ??• Standards• CIELO• 53Cr?

240Pu§ Resonances

• 2010 ORNL evaluation did not perform well, was rejected, but minor fix to bound level needed, V. Sobes made correction

§ Fast Region• Fission cross section updated: Replaced by Tovesson 2009 data from

5.7keV to 40 keV (URR), Weston 40keV - 190keV.• Capture cross section taken from ENDF/B-VII.0 (=ENDF-B/VI.8), with

an additional 2% reduction above 42 keV to improve• Elastic cross section taken from ENDF/B-VII.0 (=ENDF-B/VI.8).IAEA

noted problem in URR, ave. capture restored to VI.1

Capture in URR94-Pu-240(N,G),SIG

Incident Energy (keV)

Cro

ss S

ectio

n (b

arns

)

10 20 30 40 50 600.4

0.5

0.6

0.7

0.8

0.9

1.0

0.4

0.5

0.6

0.7

0.8

0.9

1.010 20 30 40 50 60

ENDF/B-VII.1:PU-240ENDF/B-VI:PU-240Pu240-beta4-Sobes

1977 Weston1972 Hockenbury1979 Wisshak1978 Wisshak

Final thermal constants; validation covered later in meeting

Neutron Reactions on XXX . . . NUCLEAR DATA SHEETS M.B. Chadwick et al.

agreement.(n,n’) inelastic scatteringAdd. Although we have not made many changes here,include plots of inelastic scattering compared to dataand other evaluations. Include key angular distributions,as in Ref.[92].

(n,2n)Only a modest change to the (n, 2n) cross section hasbeen made for ENDF/B-VIII.0 – the rise from thresholdhas been increased, in the 6.5 to 8 MeV incident energy,after which the cross section follows ENDF/B-VII.1.

The previous ENDF/B-VII.1 evaluation came from theGEANIE-project evaluation by LLNL and LANL [100].In the late 1990s and early 2000s, the GEANIE detectorat Los Alamos measured gamma-ray decays contribut-ing to the (n, 2n) reactions, and these data were aug-mented by GNASH model calculations for unmeasuredcomponents to infer the (n, 2n) cross section. The finalevaluation, used in ENDF/B-VII, was based on a least-squares (covariance) analysis of these data together withthe 1980s 14 MeV Lougheed [101] radiochemical data, asshown in Fig. ??. Other data such as those from Frehaut,and from Mather, were not used in the analysis becausetheir uncertainties were felt to be too high.

Some integral feedback on the production of 238Pu ina fission spectrum has suggested that this cross sectionshould rise from its threshold somewhat faster. For ex-ample the PROFIL experiment suggested the need fora 25% higher cross section [81], in the threshold region,though internal LANL studies indicate the need for amuch smaller increase. Therefore the evaluation has beenmodified in ENDF/B-VIII.0 to follow the upper errorbars on the 7 – 7.5 MeV GEANIE data, as shown inFig. ??.(n,xn) secondary neutron spectraAdd. Include 14 MeV and other (n,xn) plots.

Gamma production and (n,f) PFGSAdd TK’s work with Ionel’s fission PFGS.

Future workIn the coming years we expect to see new plutoniumprompt fission spectra (PFNS) and fission cross sectiondata from the Los Alamos Chi-nu and TPC experiments,and these will influence future standards and ENDF eval-uations. These data, together with the DANCE detectorneutron capture measurements, will be used in evalua-tion updates in the resonance region as well as the fastregion. The thermal plutonium PFNS clearly needs moreattention. The spectrum we have adopted is very similarto that in ENDF/B-VII, and – together with Subgroup34 resonances – allows an improved prediction of thermalsolution plutonium criticality relative to previous evalu-ations. However, it is not consistent with the somewhatsofter thermal spectra adopted for 235U and the recom-mendations of Ref. [10], nor with the trends seen in thesomewhat softer PFNS adopted for ENDF/B-VIII.0 for

fast energies in the 0.5-5 MeV region, as seen in Fig.??Neutron inelastic scattering has not been changed in

this latest revision of ENDF. More work will be done toassess the accuracy of the current evaluation; in partic-ular, the semi-integral scattering technique pioneered byRPI, which have provided useful data for 238U, C, Fe, willbe applied to plutonium and uranium, at the LANSCEfacility. Such future data should provide a useful valaida-tion check on the database, and point to improvementsthat may be needed in the magnitude and the angulardistributions of inelastic and elastic scattering processes.

6. 240Pu

Lead: BNL, ORNL, LANL Lead: BNL, ORNL,LANLBackground & Previous Evaluationstmp

Resonance RegionThe negative (bound) levels of the Derrien, et al. [121]RRR evaluation were adjusted with the evaluation codeSAMMY to better match the thermal cross section val-ues found in the Atlas of Neutron Resonances (Table IV).The resonance parameter covariance matrix was adjustedaccordingly to preserve the relative uncertainty of thecross section in the original evaluation of Derrien etal. [121]

TABLE IV. Thermal quantities for 240Pu at293.6 K = 0.0253 eV

Quantity Atlas ENDF/B-VIII.0 ENDF/B-VII.1�� 289.5 ± 1.4 b 289.4 b 287.5 b�s 1.73 ± 0.10 b 1.73 b 0.95 b�f 0.056 ± 0.030 b 0.056 b 0.064 b�B 18.8 b 17.96 b 3.02Wescott’sg-factor 1.0264 1.0259 1.0278

7. 241Am

Lead: LANL

8. 243Am

Lead: LANL

E. Primary gammas

Lead: LLNL

42

ENDF/B-VIII highlights, continued§ Charged

particles:• p+d, p+7Li, p+a,

p+13C, p+207Pb• d+7Li• t+a, t+7Li• 3He+a, 3He+3He• a+a

§ EPICS2014:§ photoat§ electrons§ atomic_relax

§ Decay data:• 93,95,96Rb• 95Sr• 82,83Ge• 95,98,98m,99Y• 88,89,90,91Br• 90Kr• 140,141Cs• 143Ba• 143,144,145La• 134Sb• 138I

§ Thermal Scattering:• Be(metal)• UO2 (x2)• Regular & reactor

graphite• BeO (x2)• Polyethylene• SiO2 (x2)• SiC• Lucite• UN• Water: H2O & D2O

(x2)• Water Ice Ih (x2)• YH2 (x2)

















Also, added LEAPR inputs for all TSL evaluations except the General Atomics benzene evaluation from 1969

Bug fixes

§ Beta4• Be(metal)

§ Beta5 (ENDF/A)• p+2H• D2O (D, O)• H2O (H)

Serious changes

§ Beta4• Light charged particles• UN

§ Beta5 ??• nothing planned

UN: New TSL evaluation from NCSU§ LEAPR from NJOY99.396§ 7 temps. (296K-120K)§ Inelastic uses Incoherent approx. § Elastic uses generalized coherent

approx. with modified LEAPR

10-2 10-1 10010-3

10-2

10-1

100

10-2 10-1 100 10110-3

10-2

10-1

100

= 0.5409

= 5

.134

= 3

.941

= 3

.025

= 1.8

93 = 1.00

5

SS(,)

= 0

(a) U(UN)

= 0.5409

= 5

.134 = 3.

941

= 3

.025

= 1.893

= 1.0

05

SS(,)

= 0

(b) N(UN)

10-5 10-4 10-3 10-2 10-1 10010-1

100

101

102 ENDF/B-VIII: total ENDF/B-VIII: inelastic ENDF/B-VIII: coherent elastic ENDF/B-VIII: incoherent elastic

1200 K800 K600 K400 K

Cro

ss S

ectio

n (b

)

Energy (eV)

296 K

Light charged particle evaluationsp td h 6Lia 7Li

p

d

t

h

a

RecommendECPLinfuture

KeepENDF/B-VII.0

Target: Projectile:

HereECPLtoENDF/B-VIII.0

p+7Li

0 4 8 12Incident proton energy (MeV)

0

0.02

0.04

0.06

0.08

Cro

ss s

ectio

n (b

)

Abramovitch, 19840.5x Spinka, 19710.5x Mani, 1964Sarma, 19630.5x Cassagnou, 1963Lee, 1969Rolfs, 1986Gibbons, 19990.5x Sawyer, 1957Gibbons, 19990.5x Ciric, 1976ENDF/B-VII.0ENDF/B-VIII.0

7Li(p,a)4He

0 5 10 15Incident proton energy (MeV)

0

0.1

0.2

0.3

0.4

0.5

0.6

Cro

ss s

ectio

n (b

)

Abramovitch, 1964Abramovitch, 1964Presser, 1972Burke, 1974Newsom, 1957Poppe, 1976Bevington, 1961Borchers, 1963Schery, 1977Sekharan, 1976Sekharan, 1976Burke, 1974Liskien, 1975Liskien, 1975Sekharan, 1976Gibbons, 1959ENDF/B-VII.0ENDF/B-VIII.0 : gsENDF/B-VIII.0 : exENDF/B-VIII.0 total

7Li(p,n)7Be

P. Navratil merged ECPL cross sections with fits in literature; D. Brown added outgoing distributions from ECPL using inverse kinematics when needed

d+7Li

5 10 15 20Incident Deuteron Energy (MeV)

0

0.02

0.04

0.06

0.08

0.1

Cro

ss s

ectio

n (b

)

Vysotskij, 1990Guzhovskij, 1980ENDF/B-VIII.0

7Li(d,2n)7Be

1 10Incident Deuteron Energy (MeV)

0

0.05

0.1

0.15

0.2

0.25

Cro

ss s

ectio

n (b

)

Weissman 1998Filipone, 1982Kavanagh, 1960Schilling, 1976Filippone, 1982Elwyn, 1982Schilling, 1976Mingay, 1979Parker, 1966ENDF/B-VIII.0

7Li(d,p)8Li

1 10Incident Deuteron Energy (MeV)

0

0.05

0.1

0.15

0.2

Cro

ss s

ectio

n (b

)

Macklin, 1955ENDF/B-VII.1ENDF/B-VIII.0

7Li(d,t)6Li

0 5 10 15 20Incident Deuteron Energy (MeV)

0

0.2

0.4

0.6

0.8

Cro

ss s

ectio

n (b

)

Ma Weiyi, 1980ENDF/B-VII.1ENDF/B-VIII.0

7Li(d,n+α)4He

t+7Li & 3He+3He

0.01 0.1 1 10Incident 3He Energy (MeV)

0

2

4

6

8

10

S-fa

ctor

(MeV

.b)

WA66BA67DW71DW74KR87BR87AR97BO99ENDF/B-VII.1ENDF/B-VIII.0

3He(3He,2p)4He

0 5 10 15 20 25 30

Incident Triton Energy (MeV)

0

0.5

1

Cro

ss s

ecti

on

(b

)

ENDF/B−VIII.0

7Li(t,2nα)α

10−1

100

101

Incident Triton energy (MeV)

0

0.02

0.04

0.06

Cro

ss s

ect

ion

(b

)

Brune, 1991ENDF/B−VIII.0

7Li(t,n)

9Begs

Elastic scattering on 4He

0 2 4 6 8 10 12 14 16 18 20

Incident projectile energy (MeV)

0

1

2

3E

ffe

ctiv

e c

ross

se

ctio

n (

b)

0 2 4 6 8 10 12 14 16 18 200

2

p−4He MT=2 MF=3

t−4He MT=2 MF=3

h−4He MT=2 MF=3

α−4He MT=2 MF=3

More to come

§ 235,238U§ 239Pu § 54,56,57,58Fe§ Covariances§ C

ENDF/B-VIII planned for late FY17

6 year timeline not to scale

CSEWG Nov. 2016

WPEC May. 2016

ND2016 Sep. 2016

Mini CSEWG Apr. 2016

rev. 8108 Apr. 2016

rev. 82525 Apr. 2016

rev. 91919 Aug. 2016

rev. 10182 Nov. 2016

rev. 58622 Dec. 2011

rev. 108928 Feb. 2017

beta5: covariancelate spring 2017

beta6: release candidatesummer 2017

ENDF/B-VIII.0 latesummer 2017

Mini-CSEWG 4-5 May 2017

WPEC 15-19 May 2017

ENDF Hackathon©

2016

rev. 105119 Jan. 2017 ENDF/B-VII.0 contains 393

neutron evaluations; 1644 citations since 2006 (Google Scholar)ENDF/B-VII.1 contains 423 neutron evaluations; 945 citations since 2011 (Google Scholar)

Documents

ENDF/B-VIII: What has changed so far? · NUCLEAR DATA SHEETS M.B. Chadwick et al. agreement. (n,n’) inelastic scattering Add. Although we have not made many changes here, include