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SG-40 10 May 2016

Evaluation of 238U+n in the resonance region

Peter Schillebeeckx

Evaluation of 238U+n in the resonance region

Contributing organisations and institutes

• Commissariat à l'Energie Atomique, Cadarache (France) P. Archier, C. De Saint Jean, G. Noguere

• European Commission, Joint Research Centre, Geel (Belgium) S. Kopecky, C. Paradela, P. Schillebeeckx

• Institute for Nuclear Research and Nuclear Energy, Sofia (Bulgaria) I. Sirakov

• Institute of Physics and Power Engineering, Obninsk (Russia) V. Pronyaev

• International Atomic Energy Agency, Vienna (Austria) R. Capote, A. Trkov

• Korea Atomic Energy Research Institute, Daejeon (Korea) D.H. Kim, H.I. Kim, Y.O. Lee

• OECD Nuclear Energy Agency, Issy-les-Moulineaux (France) E. Dupont, O. Cabellos

Papers & reports

Kopecky et al., "Status of evaluated data files for 238U in the resonance region", JRC Technical Report, Report EUR 27504 EN

H.I. Kime et al, "Neutron capture cross section measurements for 238U in the resonance region at GELINA"

Revised version submitted to Eur. Phys. J. A Sirakov et al., "Evaluation of cross sections for neutron induced reaction on 238U in the unresolved

resonance region" in preparation

Resolved resonance region

Evaluation in RRR based on Derrien et al., Problems:

– Transmission data of Olsen et al. were renormalised by Derrien et al. – Capture data included in evaluation, i.e. ORELA data of Macklin et al. and de Saussure et al.,

were renormalised by almost 10% and are not consistent with capture data in URR! ⇒ Additional transmission data to verify Olsen et al. data (basis of ENDF/B-VII.1)

– Measurements at 50 m station of GELINA to verify transmission data < 1000 eV – Data reduction (finalised), data analysis in progress

⇒ Improve capture data in resonance region: consistent in RRR and URR – Measurements 12.5 m and 60m at GELINA – Data reduction and analysis finalised (paper submitted to EPJA)

Resolved resonance region

Evaluation in RRR based on Derrien et al., Problems:

– Transmission data of Olsen et al. were renormalised by Derrien et al. – Capture data included in evaluation, i.e. ORELA data of Macklin et al. and de Saussure et al.,

were renormalised by almost 10% and are not consistent with capture data in URR! ⇒ Additional transmission data to verify Olsen et al. data (basis of ENDF/B-VII.1)

– Measurements at 50 m station of GELINA to verify transmission data < 1000 eV – Data reduction (finalised), data analysis in progress

⇒ Improve capture data in resonance region: consistent in RRR and URR – Measurements 12.5 m and 60m at GELINA – Data reduction and analysis finalised (paper submitted to EPJA)

RRR: transmission of Olsen et al.

Problem of transmission data of Olsen et al. <-> ENDF/B-VII.1 Can be solved by adjusting contribution of bound states

1 10 100

-100

10

resid

uals

Neutron energy / eV

0.2

0.4

0.6

Texp (Olsen et al. 1.475 in) TFIT (ENDF/B-VII.1)

Tran

smiss

ion

1 10 100

-100

10

resid

uals

Neutron energy / eV

0.2

0.4

0.6

Texp (Olsen et al. 1.475 in) TFIT (ENDF/B-VII.1, adjusted bound states)

Tran

smiss

ion

⇒ No impact on results of integral benchmark calculations : A. Trkov (IAEA) and D.H. Kim (KAERI)

1.425 inch 1.425 inch

Capture data at GELINA

• Same methodology as for 232Th(n,γ) & 197Au(n,γ) (see NDS 113, 3054 (2012)) − Flux: 10B(n,α) − C6D6: weighting function − Normalization to saturated resonance

• Measurements at 12.5 m and 60.0 m

• Measurements with 3 different samples: different thickness and geometry

⇒ Reduce bias effects due to resolution and sample properties

Normalisation

6.4 6.8 160 200 240 280-202

Resid

uals

Neutron energy / eV

0.0

0.2

0.4

0.6

0.8

1.0Yi

eld

0.00

0.05

0.10

0.15

0.20

0.25

Yexp 60 m Yexp 12.5 m YM 12.5 m

• 12.5 m data : saturated resonance • 60.0 m data : simultaneous RSA (transmission + capture data)

Results simultaneous RSA of transmission and capture data

capture and transmission data are fully consistent in RRR

Parameters in RRR (comparison with Derrien et al.)

0 500 1000 1500

0.6

0.8

1.0

1.2

1.4 l = 0 l = 1

gΓn,

GEL

INA /

gΓ n,

Derri

en

Neutron energy / eV

• gΓn − Consistent < 500 eV − Systematic difference > 500 eV

⇒ Additional transmission data required

• <Γγ>

− This work : 22.5 meV − Derrien et al. : 23.0 meV

Parameters in RRR (comparison with Derrien et al.)

• Parity assignment − Changed for 2 resonances

• Γf − Consistent with fission kernels

of Difilippo et al.

101 102 103

100

101

102

103

104

105

gΓ1 n /

meV

gΓ1n = 45 meV

= 0 = 1

Neutron energy / eV

RRR parameters for E < 1200 eV

• Introduced in IAEA file − Some minor problems…

• Introduced in JEFF-3.3T1 file

− No problems

⇒ Tests ongoing at KAERI

Capture data in URR

10 10050

60

70

80

90

100 12.5 m sample I 12.5 m sample III 60 m sample II

(σγ x

E1/

2 ) / (b

eV1/

2 )

Ullmann et al. Carlson et al.

Neutron energy / keV

• DANCE data − Large uncertainties − Not fully consistent with GMA data of Carlson et

al.

• GELINA data (3 data sets) − Fully consistent within uncorrelated

uncertainties due to counting statistics − Fully consistent with GMA data of Carlson et al.

⇒ GELINA capture data are fully consistent with

transmission data in RRR and GMA data in URR

GELINA capture data in URR

GELINA 238U/197Au(n,γ) cross section ratio: fully consistent with GMA data of Carlson et al.

Neutron energy (MeV)0,001 0,01 0,1

Rti

f

U(

) t A

()

ti

1

DS346, L. Kazakov, 1986 DS441, K. Rimawi, 1975 DS461, W. Poenitz, 1979 DS419, H. Menlove, 1968 DS437, N. Buleeva, 1988 DS412, W. Poenitz, 1975 DS430, K. Wisshak-1, 1978 DS431, K. Wisshak-2, 1978 DS470, R. Block, 1972 DS457, R. Spencer, 1975, shape Standards 2006Geel measurements, 2014-2016 Standards Apr2016

σ(n,γ)

ratio

: 23

8 U/1

97Au

New GMA evaluation + parameterisation (HW+WF)

10 10050

60

70

80

90 JEF-2.2 JEFF-3.2 ENDF/B-VII.1 Carlson et al.

(σγ x

E1/

2 ) / (b

eV1/

2 )

GELINA (this work) GMA (GELINA + Ref. 20) HF + WF

Neutron energy / keV

⇒ Production of ENDF-6 compatible evaluation for URR in progress

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