CO10-1

Activation Analysis for Soils of Hiroshima City and Gamma-ray Exposure due toNeutron-induced Radionuclides by Hiroshima Atom BombS. Endo, Y. Taguchi, T. Imanaka1, S. Fukutani1,M. Hoshi2 and K. Shizuma
Graduate School of Engineering, Hiroshima University
1
Research Reactor Institute, Kyoto University
2RIRBM, Hiroshima University
INTRODUCTION: For early entrance survivors inHiroshima and Nagasaki atomic bomb (A-bomb), radiation doses from activated materials induced by theA-bomb neutrons are dominant. For estimation of suchdoses, element compositions of environmental materialssuch as soil and rubbles are necessary. Especially Sc density in soil is important for estimating radiation doses at
the time of a few 10 days after explosion because 46Sc
has the half-life of 84 days. However, few data of Sc
density in soil are available in both of Hiroshima andNagasaki cities. Purpose of this study is evaluation of Sc
density in soil and the uncertainty using activation analysis.
EXPERIMENTS: Soil samples were taken from 11locations within 4 km from A-bomb hypocenter at Hiroshima city. The soil samples were dried by an oven at
120 degrees for over night. The dried samples weresieved through a 2-mm mesh to remove pebbles and plantremains. The sieved samples of about 10 g were grained
to fine mesh by a mortar for activation analysis. The
soil samples and reference rock sample of JA-11) wereactivated in Kyoto University Reactor (KUR). Element
compositions of soil samples were obtained by comparing counting rates of each identified radionuclide byGe-detectors with those from reference rock.
RESULTS: Twenty three element compositions including Al, Mn, Na and Sc are obtained by the activation
analysis as listed in Table 1. The obtained element
compositions are compared with values used in Dosimetric System 1986 (DS86) 2) and found roughly the same as
the reported values in DS86. Sc density in Hiroshimasoil was estimated to be 5.12±0.59 (ppm). It was foundthe unevenness of Sc density in soils for 11 location ofHiroshima city is about 12%.
Using element compositions by the activation analysis,time variation of the exposure rate by activated soil wasestimated. It was found that the exposure rate during afew minutes after the explosion is dominated by 28Al,
several days by 24Na, and in a few 10 days by 46Sc. Thisestimated result is compared with values of dose ratemeasured after a few months after explosion 3,4). It was
found that the estimated dose rate reproduces well themeasured ones.

REFERENCES:
1) Imai, N.et al. (1995) 1994 compilation of analytical
data for minor and trace elements in seventeen GSJ
geochemical reference samples, "igneous rock series",
Geostandards Newsletter 19: 135-213 .
2) Roesch, W. C., Eds. (1986) U. S.—Japan Joint Reassessment of Atomic Bomb Radiation Dosimetry in Hiroshima and Nagasaki. Vols. 1 and 2. Radiation Effects
Research Foundation.
3) Miyazaki Y, Masuda T (1953) Radioactivity in Hiroshima city and its suburbs caused by the atomic bomb
(II), vol 1. In: Collection of survey reports on theatomic bomb disasters, Japan Society for the Promotionof Science, Tokyo, pp 35–38 (in Japanese).
4) Pace N, Smith RE (1959) Measurement of the residual radiation intensity at the Hiroshima and Nagasaki
atomic bomb sites, ABCC TR 26–59. Radiation Effects
Research Foundation, Hiroshima.
5) K. Tanaka, et al., Skin dose from neutron-activated soilfor early entrants following the A-bomb detonation inHiroshima: contribution from  and  rays, Radiat Environ Biophys. 47, 331–336, 2008.
Table 1. Averaged values of element concentration insoil and DS86 values1)
element
Na
Al
Sc
VCr
Mn
FeCo
Rb
Sr
Zr
Nb
Sb
Cs
La
CeSm
Eu
GdLu
HfTh
UZ
1113
21
23
24
25
26
27
37
38
40
41
51
55
57
58
62
63
64
71
72
90
92

DS86 value (ppm)Concentration(ppm)
19300±
63300±
5.12±
21.4±20±517±
17100±
4.13±
137±
45±
105±2.0±
1.87±4.4±27.4±88±
3.7±
0.81±
2.23±
0.133±
4.17±
14.3±0.85±

Hiroshima

A-bombCastle

Dome

16000
71000
522.3
20.5
467
17700
3.7
23088
417
1.4
52340
3.4
0.9

12400
64900
525.3
27.3
587
20600
3.8
225
70
35
50.8
52136
3
0.9

4
13.3
2.8

49.9
2.6

20%
14%
12%
26%
65%
13%
16%
23%
12%
38%
40%
60%
11%
14%
23%
24%
27%
15%
44%
33%
19%
30%
18%

採択課題番号 23005 広島・長崎原爆中性子による誘導放射能評価のための組成分析（広大院・工）遠藤 暁、田口優太、静間 清（広大・原医研）星 正治（京大・原子炉）今中哲二、福谷 哲

共同通常CO10-2

Damage of USB Semiconductor Memory by Radiation Exposure

J. Takada, K. Tanaka and Y. Sakurai1
Center for Medical Education, Sapporo Medical University
1Research Reactor Institute, Kyoto University
INTRODUCTION: In estimating the damage of thenuclear disasters and planning how to defense the damage, quantitative evaluation of the radiation effect on thesemiconductor equipment is important [1]. Our group has
been working on evaluating this radiation effect [2]. In
2011, the radiation damage to condenser-resistor (CR)circuit was investigated.
EXPERIMENTS: The irradiation was performed with
Kyoto University Research Reactor Institute Heavy Water Neutron Irradiation Facility (KUR-HWNIF). The utilized modes were standard mixed neutron irradiation
mode (OO-0000-F), and standard epithermal neutron
irradiation mode (CO-0000-F). As semiconductor equipment, condenser-resistor (CR) circuit was utilized. The
condenser was metalized polyestel film type (Nissei corporation, MMX0630K474: 0.47 F) in irradiation #1, andceramic type (RS corporation, RS630-1646: 0.1 F) inirradiation #2. The register was ‘RS477-1964 by RS corporation, of 47 The CR circuit was connected with PC outside the irradiating room through the USB cable of 5m in length, theUSB hub, and the repeater cable of 5m in length. Thecircuit was tested as to its function by measuring the time
constant. The experimental setup is shown in Fig. 1 andPhoto 1.
Condenser
Function
generator

Register

VoltmeterPC
Irradiation roomFig. 1. View of irradiation port
RESULTS: Table 1 shows the dose irradiated. Thevalues correspond to the total dose (neutron + gammarays) to human tissue. The time constant () measured isalso shown. In both trials, the time constant was notchanged by the irradiation.
Table 1 Summary of irradiation
Irradiation

Mode

#1
#2

Mix + epi
Mix

Time(min)120
111

Dose(Gy)
2.6
2.7

(ms)
19.7
5.1

SUMMARY: The result obtained in 2011 indicates theCR circuit was not destroyed by the irradiations in thisstudy.
The circuit did not have influence by irradiations at about
1 Gy/h. The study on tolerance of the semiconductor is tobe continued. This includes the investigation of condenser structure, mode of function generator, and irradiation
conditions such as quality, dose, dose rate.
REFERENCES:[1] J.Takada, Nuclear hazards in the world, Kodansha(Tokyo) and Splinger (Berlin), (2005), 1-133.
[2] K.Tanaka, Y. Sakurai, S.Takatsuka, K.Kamo, J.Takada,
Radiation Protection Medicine 6 (2010), 41-44.

Operation room

Fig. 1. Experimental setup

採択課題番号 23062
核放射線照射による電子機器の誤作動の検証（札医大・医療人育成セ）高田純、田中憲一（札医大・総合情報セ）高塚伸太朗（京大・原子炉）櫻井良憲

共同通常

Evaluation of Gold in Melting Residue of the Municipal Wastewater Sludge

K. Oshita, M. Takaoka1, K. Shiota1, S. Fukutani2 andM. Sumi1
Department of Environmental Engineering, Graduate
School of Engineering, Kyoto University
1
Department of Environmental Engineering, Graduate
School of Engineering, Kyoto University
2
Research Reactor Institute, Kyoto University
INTRODUCTION: Noble and rare metals are common components of various electronic devices, and theirwidespread use is resulting in rapid depletion. In particular, noble metals such as Gold (Au) are becoming highly
depleted, which has a significant impact on the environment. Thus, there is an urgent need to develop substitutematerials and establish a material’s cycle system.
Au is found in municipal wastewater sludge. Lottermoser
reported high Au concentrations (56 mg/kg-dry) in dewatered sludge from the German jewelry industry [1].
Moreover, it was found that Au was abundant at 28.8 to
2,130 mg/kg in melting residue from a Toyota wastewater
treatment facility at Suwa, Japan [2]. However, little information is available regarding the Au concentration andbehavior in melting residue at other Japanese facilities.
Accordingly, the resource value of other melting residues
has not been determined.
In this study, Au concentrations in various melting residues and related municipal sewage sludge materials wereinvestigated using ICP-MS analysis after tellurium coprecipitation and INAA. Subsequently, the resource values of these residues were determined.
EXPERIMENTS: A total of 28 melting residues andrelated materials, including melting plant input sludge,
slag, melting fly ash and other dusts, were sampled atthree melting plants at municipal wastewater facilities.
The Au concentrations of these samples were analyzed
using ICP-MS after acid digestion with tellurium coprecipitation [3]. Moreover, Au concentrations werere-evaluated using INAA. All measurements were performed in duplicate.
RESULTS: The Au concentrations in the samples areshown in Table 1. Au concentrations in dust from air
pre-heaters, waste heat boilers, and suspended solids inwet-scrubbing wastewater ranged from 9.63 to 153
mg/kg, which is relatively high. Although the mass ofthese media is low, the Au quality was similar to ore.
Thus, these media may be a valuable resource.
Additionally, there was an increased Au concentration indust derived from lower points in the flue gas treatment
process. Au exists as a simple substance in sludge at
normal temperatures, and not as chemical compounds.
After treatment in the melting furnace, it could melt
(melting point: 1337 K) and react with other elements toform volatile compounds, e.g., gold chloride (gaseousphase).
A comparison of the Au concentrations determined using ICP-MS after tellurium coprecipitation and INAA isshown in Fig.1. The ICP-MS results are highly correlatedwith the INAA results. Thus, ICP-MS after acid digestion
with tellurium coprecipitation was validated. However,the slope of the regression line was 0.704. The analyticalresult using ICP-MS tended to be higher because Auconcentration in the standard sample; BCR-176 waslower than that of real samples. Thus, this point is currently being investigated.
Table 1 Au concentration in each media.
FacilityAA
A
A
A
A
A
A
A
A
A
B
B
B
B
B
BCCCCCCCCCCCClassItem
INPUT Dewatered sludge
INPUT Cokes
INPUT Lime
INPUT Clushed stoneOUTPUT SlagOUTPUT Dust from melting furnace
OUTPUT Dust before air preheater
OUTPUT Dust after air preheater
OUTPUT Dust from waste heat boiler
OUTPUT SS in wet scrubbing wastewater
OUTPUT Dust from wet electric precipitator
INPUT Dried sludge
INPUT Iron powder
INPUT LimeOUTPUT SlagOUTPUT Dust from waste heat boiler
OUTPUT SS in wet scrubbing wastewater
INPUT Dried sludge
INPUT Cokes
INPUT Lime
INPUT Clushed stone
OUTPUT SlagOUTPUT Dust from upper side of melting furnace
OUTPUT Dust from middle of melting furnace
OUTPUT Dust from lower side of melting furnace
OUTPUT Dust from air preheater
OUTPUT Dust from waste heat boiler
OUTPUT SS in wastewater for washing boiler

ICP-MS
0.330
0.02260.100
0.0592
0.428
0.344
9.63
13.6
35.8
9.8
92.4
0.122
0.0387
0.467
3.61
38.7
43.0
0.05990.02330.0729
0.139
2.37
0.573
0.426
7.67
9.44
49.8
153.0

INAA
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
8.53
16.0
36.2
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
29.1
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
0.788
1.01
9.76
9.74
22.3
N.A.

※Output samples in each facility were showed from upstream todownstream of flue gas treatment process.
※N.A. Not analyzed.

60y = 0.704 x
R = 0.837

50INAA (mg/kg)

CO10-34030201000

102030405060

ICP-MS (mg/kg)

Figure 1 Relationship of analytical result between ICP-MS and INAA.

REFERENCES:[1] B.G. Lottermoser, Inter. J. of Environ. Studies, 46(1994) 167-171.
[2] J. Shinoda, Kankyo Shisetsu, 118(2009), 45-50.(inJapanese)[3] E. Fujimori et al., Bull. Chem. Soc. Jpn., 78(2005)
1963-1969.

採択課題番号 2368 廃棄物焼却炉からの微小粒子の排出にともなう重金属の実態把握  ౒ห通常（京大院・工）高岡 昌輝、米田 稔、大下 和徹、松井 康人、塩田 憲司、今井 玄哉、角 壯志、山口 修史、劉 露、西岡 和久（京大・原子炉）福谷 哲