2006Symposium on Nuclear Data
25 January, 2007

Recent Activities
ofMA Cross-Section Measurements
JAEA

S. Nakamura, M. OHTA, and H. Harada

Kyoto Univ. T. Fujii and H. Yamana

2006 Symposium on Nuclear Data

SND2006-V.01-1

High Level Waste (HLW)
Fission Products（FP)
99Tc, 129I,137Cs, 90Sr, 129I….
Minor Actinides（MA)237Np, 241Am, 243Am, 244Cm….
Public Acceptabilityof Nuclear Power Reactors
Waste Management
Environment
Cross Section Measur.

Nuclear Transmutation
2006 Symposium on Nuclear Data

・Activation Method・Time-Of-Flight・Prompt -rays……. etc.
SND2006-V.01-2

Chart of the nuclides
Basic Reaction
for FBR

237U

238U

237Np

238Np

239Np

238Pu

239Pu

240Pu

239U

The build-up of these nuclides
is important for waste management,for decay-heat studies,and for the fuel cycle.
241Pu

242Pu

242mAm
241Am

Decay-heat2006 Symposium on Nuclear Data

242Cm

242gAm

243Cm

243Am

244Cm

244Cm

SND2006-V.01-3
Higher Cm isotopes

Motivation
243Am

244m,gAm

244Cm

245Cm, 246Cm,…

7370yr18yr
8500yr 4730yr
・Long-half life 7370yr.
・Production of long-lived Cm isotopes
・Discrepancies among the cross section data〜about 10%m(b)g(b)

JENDL-3.3ーー

Mughabghab

71.3±1.8

3.8±0.475.1±1.8

Letourneauー

5.2±1.781.8±3.9

Schumanー

5.9ー

4.3

84.3

Ice

80

Street50

2006 Symposium on Nuclear Dataーm+g(b)

76.7

ー
SND2006-V.01-4

Partial Decay Scheme of 243Am
Im=1820±70 (b)m=75.1±1.8 (b)243Am244mAmE.C.

7370 yr5275.3 (87.4%)~26min244Pu-99.9639 %5233.3 (11.0%)
g=3.8±0.4 (b)Ig=94±9 (b)244gAm10.1 h-244Cm

18.10 yr
5804.82 (76.4%)
2006 Symposium on Nuclear Data

5762.70 (23.6%)

SND2006-V.01-5

243Am Sample for irradiation @KUR
243Am 1Ci

High purity quartz tube
7mmφ 25mm
Au/Al wire
Co/Al wire

0.5mm
1.mm

KUR @Hyd.
10H Irrad.

ネジ式のアルミ容器

2006 Symposium on Nuclear Data

Irradiation capsule for Hyd.

SND2006-V.01-6

-ray spectrum of irradiated 243Am sample
8000
243Am

5.3MeVCounts

6000

244Cm

5.8MeV4000〜1 month cooling
30 min measur.

2000

0600

700

800

900

1000

1100

1200

Channel2006 Symposium on Nuclear Data

SND2006-V.01-7

Analysis of effective cross-section
Tirr

thm243Amgm

AmYAmYAm244mAm-〜26min
244Cm

g244gAm-10.1 hReaction Rate:

RAmCm

Effective Cross Section:

2006 Symposium on Nuclear Data

effCm

YCm

YCm 1YAm Tirr

Rth

SND2006-V.01-8

Results of effective cross section
for the 243Am(n, )244m+gAm reaction

ˆm gThis Work*JENDL-3.3

174.0±5.3(2002)

Mughabghab (1984)

150
158±7

*M.Ohta et al.: J.Nucl.Sci.Technol.,43, 1441, (2006).

2006 Symposium on Nuclear Data

SND2006-V.01-9

Motivation
241Am

242m,gAm

242Cm

238Pu

・Related to production of 239Pu・Production of long-lived Cm isotopes
・Problem of decay heat 242Cm (163 day)・Discrepancies among the reported data: 0〜more than 20%0 (b)I0 (b)

ReferncesYear

Maidana et al.

(2001)

602±9

1665±91

Fioni et al.

(2001)

636±46------

Shinohara et al. (1997)768±581694±146

Gavrulov et al. (1977)

780±50------

Harbour et al.

(1973)

748±201330±117

Bak et al.

(1967)

670±602100

Deal et al.

(1964)

770

2006 Symposium on Nuclear Data------SND2006-V.01-10

0.308 eV 0.573 eV

JENDL-3.3 300k
639.4 bat 0.0253eVThis Work
Cut-off Energy
0.1 eV

2006 Symposium on Nuclear Data

Cut-off Energy
0.5 eV

SND2006-V.01-11

Partial Decay Scheme of 241Am
m241Am

141 yr432.2 yr5.4856 MeV
5.4429 MeV

242mAm

238Np

IT
99.541%

243Amg

7370 yr
242gAm

EC=17.3%
242Pu

16.02 h-=82.7%242Cm

162.8 d238Pu
2006 Symposium on Nuclear Data

6.11272 MeV
6.06942 MeV

SND2006-V.01-12

241Am Samples for irradiation @KUR

Am-241 100Bq
2.5 l solution
Co/Al 1 mm
Au/Al 0.5 mm

High purity quartz tube
8mmf, 50mm in length

KUR@Long-Irrad. Plug
1week (68H) Irrad.
Two folds ofAl enclosure rods

Am-241 500Bq

20mm in length12.5 l solution
Co/Al 1 mm
Au/Al 0.5 mm

2006 Symposium on Nuclear Data

Gadolinium capsule
10mmf, 30mm in length
25 m in thickness
SND2006-V.01-13

Measurement of sample
20 Days Cooling after Irrad.
flux monitors
Irradiated241Am sample

ray measurementwith a Ge detector
flux information
3M HNO3
Add 50 l solution

241Am242Cm

ray measurement
EG&G ORTECSOLOIST
2006 Symposium on Nuclear Data

SND2006-V.01-14

-ray spectrum of irradiated 241Am sample
5000242Cma) bare4000

6.1MeV

3000

241Am
2000

5.5MeV

1000

50000b) with Gd

4000

3000

2000

1000

0800
2006 Symposium on Nuclear Data

850

900

950

1000

Channel

1050

1100

1150

1200
SND2006-V.01-15

Modifying the Westcott’s convention
R01

G th

2s G epi

50for irradiation without a Cd shield,

01Gth

2s G epi
0for irradiation with a Cd shield.
where04I00I0’ is the resonance integral
after subtracting the 1/ component

R/ 0 (×1013 n/cm2・sec)

Rsbare4198Au

360Co

2with Gd1

Resonance Integral I0

I0=I0’ + 1.006 0
for cut-off energy of 0.1 eV2006 Symposium on Nuclear Data

005

1015

20

parameter s0
SND2006-V.01-16

Results of 0 and I0
for the 241Am(n, )242gAm reaction
This WorktanTe!
etiv 0 (b)628±22I0 (b)

Cut-off E

3.5±0.3 k

0.1eV

JENDL-3.3 (2002)

639.4

1456

Maidana et al. (2001)602±9

1665±91

Fioni et al. (2001)

636±46----

Shinohara et al(1997)768±581694±146

Gavrulov et al. (1977)

780±50---

Harbour et al. (1973)

748±201330±117

Bak et al.

(1967)

670±602100

Deal et al.

(1964)

770

2006 Symposium on Nuclear Data

0.5eV

0.5eV
0.369eV---

SND2006-V.01-17

Summary
・241Am(n, )242gAm Reaction:
0g = 628±22(b), I0g = 3.5±0.3(kb)Ec=0.107eV・243Am(n, )244m+gAm Reaction:
in Hyd.＠KUR
eff = 174.0±5.3(b)・Evaluated data for 243Am is 13% smaller
than the present result.

2006 Symposium on Nuclear Data

SND2006-V.01-18

JAEA’s Data for MA Cross-Sections
Nuclide

237Np

238Np

241Am

Half-life

2.14×106ｙ

2.1 d432 y

Past Data（Author, Year）
0＝158±3ｂI0＝652±24ｂ（Kobayashi 1994）

No Data !

0ｇ＝ 768±58ｂ

I0ｇ＝1694±146ｂ（Shinohara 1997）
0m＝80ｂ,

243Am

7370ｙ

2006 Symposium on Nuclear Data

0g＝4.30m+g＝84.3ｂ（Ice 1966）

JAEA Data
0＝141.7±5.4ｂ

I0＝ 862±51ｂ（2003）
0＝169±6ｂ(2006)
eff＝479±24ｂ(2004)

References
Katoh et al., JNST, 40(2003)
Harada et al.,JNST,43,No11(2006)
Harada et al., JNST,
41(2004)

0ｇ＝628±22ｂ

Nakamura et al.,JNST, to be submitted

eff＝174.0±5.3ｂ

Ohta et al.,JNST,43,No.12(2006)

I0ｇ＝3.5±0.3kｂ(2006)

SND2006-V.01-19