Analyses of Benchmark Experiments at FNS with Recent Nuclear Data Libraries
Kentaro Ochiai1, Satoshi Sato1, Masayuki Wada2 and Chikara Konno1
1Fusion Research and Development Directorate, Japan Atomic Energy Agency
Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 Japane-mail : ochiai.kentaro@jaea.go.jp
2Startcom Co., Ltd.
4-18-10, Hayamiya, Nerima-ku, Tokyo 179-0085 Japan

Integral benchmark experiments for nuclear data verification carried out at JAEA
FNS have been analyzed with MCNP-4C and the recent nuclear data libraries; JENDL-3.3,FENDL-2.1, JEFF-3.1 and ENDF/B-VII.0. In this paper the results for the experiments for
SiC and Iron were discussed and compared each other.

1. Introduction
For a few years several nuclear data libraries, JENDL-3.3 [1], FENDL-2.1 [2],JEFF-3.1 [3] and ENDF/B-VII.0 [4], have been newly released.
- JENDL-3.3 was released in May, 2002.
- FENDL-2.1 was released in December, 2004.
- JEFF-3.1 was released in May, 2005.
- ENDF/B-VII.0 was released in December, 2006.
It is essential to verify these libraries through analyses of integral benchmark experiments.
Many integral benchmark experiments for nuclear data verification have been carried out atJAEA/FNS [5-7]. Thus we analyzed these experiments with JENDL-3.3, FENDL-2.1,
JEFF-3.1 and ENDF/B-VII.0 and the results were compared each other.
2. Overview of integral benchmark experiments at JAEA/FNS
Two types of integral benchmark experiments for nuclear data verification with DT
neutrons have been performed for long time at JAEA/FNS. One is a Time-of-flight (TOF)
experiment, the other is an in-situ measurement experiment.
In the TOF experiments angular neutron spectra above ~ 50 keV leaking from slabs

2006 Symposium on Nuclear Data

SND2006-V.11-1

were measured at several angles. So far they were done for lithium oxide, beryllium,graphite, nitrogen, oxygen, iron, copper and lead slabs changing the slab thickness.
In the in-situ measurement experiments neutron spectra over almost the wholeenergy region, reaction rates for several dosimetry reactions, fission rates, gamma-rayspectra, gamma-ray heating, etc. were measured inside slabs. So far they were done forlithium oxide, lithum aluminate, lithium titanate, lithium zirconate, beryllium, graphite, SiC,vanadium, iron, SS316, copper, tungsten.
3. Calculation method
The Monte Carlo code MCNP-4C [8] was used for this analysis. The following
ACE files were adopted for the present analyses.
- JENDL-3.3 : ACE files supplied from JAEA Nuclear Data Center processed withNJOY99.67 [9] and local patch [10].
- FENDL-2.1 : ACE files supplied from IAEA Nuclear Data Services processedwith NJOY99.90 and local patch [11].
- JEFF-3.1 and ENDF/B-VII.0 : ACE files processed with NJOY99.161 forourselves.
4. Results and discussions
We have too many results of the analyses for integral benchmark experiments at
JAEA/FNS to show all of them in this symposium. The results of the in-situ measurement
experiments only for SiC and iron, where differences among the results with recent nuclear
data libraries are rather large, are described here. All the results will be published in
JAEA-Data/Code or so.
1) In-situ measurement experiment for SiC
Figure 1 shows ratios of calculation value to experimental one (C/E) for thereaction rate of 93Nb(n,2n)92mNb which is sensitive to neutrons above 10 MeV. The
calculations with JENDL-3.3 and ENDF/B-VII.0 agree with the measurement within 5 %,while that with JEFF-3.1 overestimates the measurement and that with FENDL-2.1 tends tounderestimate the measurement slightly. Figure 2 plots C/E distributions for the gamma-ray
heating rate. The calculation with FENDL-2.1 underestimates the measurement by around
30 %m while those with the other libraries overestimate by 20 – 30 %.
2) In-situ measurement experiment for ironFigures 3 and 4 show neutron spectra at the depths of 310 and 810 mm. Generally
all the calculations agree with the measurements well. The calculation with JENDL-3.3

2006 Symposium on Nuclear Data

SND2006-V.11-2

slightly overestimates the measurements below ~ 10 keV at the depth of 310 mm, if you
check them in detail. This is clearly indicated in Fig. 5, which plots C/E distributions for theneutron flux from 0.1 keV to 1 keV. Figure 6 shows the C/E distribution for the reaction rateof 115In(n,n’)115mIn, which is sensitive to neutrons above 300 keV. Note that the four
calculations show a different tendency each other, though the difference is not so large.
5. Concluding remarks
We analyzed integral benchmark experiments at JAEA FNS with the recent nuclear
data libraries (JENDL-3.3, FENDL-2.1, JEFF-3.1 and ENDF/B-VII.0) and MCNP-4C inorder to verify these libraries. The results of the in-situ measurement experiments only for
SiC and iron were discussed here. Differences among the results with recent nuclear datalibraries were rather large. In the future we will investigate origins of the differences among
the calculation results.
References[1] K. Shibata, et al. : J. Nucl. Sci. Tech. 39, 1125 (2002).
[2] D. Lopez Al-dama and A. Trokov : “FENDL-2.1Update of an evaluated nuclear datalibrary for fusion applications,” IAEA Report INDC(NDS)-467 (2004).
[3] A. Koning, et al. (Ed.) : “The JEFF-3.1 Nuclear Data Library,” JEFF Report 21, OECD
Nuclear Energy Agency (2006).
[4] M.B. Chadwick, et al. : Nuclear Data Sheets 107, 2931 (2006).
[5] Sub working group of fusion reactor physics subcommittee (Ed.) : “Collection ofExperimental Data for Fusion Neutronics Benchmark,” JAERI-M 94-014 (1994).
[6] F. Maekawa, et al. : “Data Collection of Fusion Neutronics Benchmark Experiment
Conducted at FNS/JAEA,” JAERI-Data/Code 98-021 (1998).
[7] F. Maekawa, et al. : “Benchmark Experments on Advanced Breeding Blanket Materials
and SiC with 14-MeV Neutrons, ” JAERI-Conf 2001-006, p.311 (2001).
[8] J.F. Briesmeister (Ed.) : “MCNP - A General Monte Carlo N-Particle Transport Code,
Version 4C,” LA-13709-M (2000).
[9] R.E. MacFarlane and D.W. Muir : “The NJOY Nuclear Data Processing System, Version91, ” LA-12740-M (1994).
[10] K. Kosako, et al. : “The libraries FSXLIB and MATXSLIB based on JENDL-3.3,”
JAERI-Data/Code 2003-011 (2003).
[11] http://www-nds.iaea.org/fendl21/index.html.

2006 Symposium on Nuclear Data

SND2006-V.11-3

1.3
SiC

2.093

Nb(n,2n) 92mNb

SiCγ-Ray Heating Rate

1.2Expt. Error

Calc. / Expt.

Calc. / Expt.

1.5
1.1
1.0
Expt. Error

0.9
ENDF/B-VII.0
JEFF-3.1
FENDL-2.1
JENDL-3.3

0.8
0.7

00.5

200
400
600
Depth in the assembly [mm]800Fig. 1 C/E for reaction rate of 93Nb(n,2n)92mNb.
in SiC experiment.

Flux / Lethargy / Source

Iron

10-5

1.0

ENDF/B-VII.0
JEFF-3.1
FENDL-2.1
JENDL-3.3

0.0

0200
400
600
Depth in the assembly [mm]800Fig. 2 C/E for gamma-heating ratein SiC experiment.

z = 310 mm
NE213
PRC
BF3ENDF/B-VII.0
JEFF-3.1
FENDL-2.1
JENDL-3.3

10-6

10-7
10-6

10-5

10-4

10-3

10-2

10-1

100101

Neutron Energy [MeV]Fig. 3 Measured and calculated neutron spectra at depth of 310 mm in iron experiment.

2006 Symposium on Nuclear Data

SND2006-V.11-4

10-5

Ironz = 810 mm

Flux / Lethargy / Source

10-6

10-7

10-8

NE213
PRC
BF3
ENDF/B-VII.0
JEFF-3.1
FENDL-2.1
JENDL-3.3

10-9

10-10
10-6

10-5

10-4

10-3

10-2

10-1

100101

Neutron Energy [MeV]Fig. 4 Measured and calculated neutron spectra at depth of 810 mm in iron experiment.

1.4

1.3
Iron 0.1 < En < 1 keV

1.2
1.1
1.0
0.9
0.8

Iron 115In(n,n')115mIn
1.2

Calc. / Expt.

Calc. / Expt.

1.3

ENDF/B-VII.0
JEFF-3.1
FENDL-2.1
JENDL-3.3

200
400
600
800
Depth in the assembly [mm]1000

Fig. 5 C/E for neutron flux from 0.1 keV
to 1 keV in iron experiment.

2006 Symposium on Nuclear Data

1.0Expt. Error

0.9
ENDF/B-VII.0
JEFF-3.1
FENDL-2.1
JENDL-3.3

0.8

Expt. Error

01.1

0.7

0200
400
600
Depth in the assembly [mm]800Fig. 6 C/E for reaction rate of115
In(n,n’)115mIn in iron experiment.

SND2006-V.11-5