Activity report of JHPS Working Group on Accidental X-ray Exposures. Subcommittee 2: Dosimetric issues on X-ray exposure accidents

日本保健物理学会「エックス線被ばく事故検討WG」活動報告 ー第2分科会 エックス線被ばく事故における線量評価の課題 ー


Development of Convolutional Neural Networks to Estimate Depth Distribution of Radioisotope in Soil Layers


Development of a Low Radioactivity Detection System Using a Digital Intraoral Radiography Detector (Imaging Plate)

デジタル口内法X線撮影検出器(イメージングプレート)を応用した低放射能検出システムの開発


Dose Assessment on the Mean Absorbed Estimates Derived from the Simple Approach Method Applying Marinelli-Quimbys Formula for Ambient Risk Organs to Thyroid Uptake in the Administered 131I Radiopharmaceutical of Graves Disease Using PHITS and ICRP Reference Computational Voxel Phantom


Chemical Characterization of a Volatile Dubnium Compound, DbOCl3


Knowledge and risk perception of radiation for Japanese nursing students after the Fukushima Nuclear Power Plant disaster


Thermal neutron flux evaluation by a single crystal CVD diamond detector in LHD deuterium experiment


FEASIBILITY STUDY ON THE FUSION OF PHITS SIMULATIONS AND THE DLNN ALGORITHM FOR A NEW QUANTITATIVE METHOD OF IN-SITU MULTIPLE-CHANNEL DEPTH DISTRIBUTION SPECTROMETRY

We have recently have developed an in-situ multiple-channel depth distribution spectrometer (DDS) that can easily acquire on-site measurements of the depth distribution of specific radioactivities of Cs-134 and Cs-137 underground. Despite considerable improvements in the hardware developed for this device, the quantitative method for determining of radioactivities with this DDS device cannot yet achieve satisfactory performance for practical use. For example, this method cannot discriminate each γ-ray spectra of Cs-134 and Cs-137 acquired by the 20 thallium-doped caesium iodine CsI(Tl) scintillation crystal detectors of the DDS device from corresponding depth levels of underground soil. Therefore, we have applied deep learning neural network (DLNN) as a novel radiation measurement technique to discriminate the spectra and to determine the specific radioactivities of Cs-134 and Cs-137. We have developed model soil layers on a virtual space in Monte-Carlo based PHITS simulations and transported γ-ray radiation generated from a particular single soil layer or multiple layers as radiation sources; next, we performed PHITS calculations of those specific radioactivity measurements for each soil layer using DDS device based on machine learning via the DLNN algorithm. In this study, we obtained informative results regarding the feasibility of the proposal innovative radiation measurement method for further practical use in on-site applications.


First Ionization Potentials of Fm, Md, No, and Lr: Verification of Filling-Up of 5f Electrons and Confirmation of the Actinide Series

We report the first ionization potentials (IP) of the heavy actinides, fermium (Fm, atomic number Z = 100), mendelevium (Md, Z = 101), nobelium (No, Z = 102), and lawrencium (Lr, Z = 103), determined using a method based on a surface ionization process coupled to an online mass separation technique in an atom-at-a-time regime. The measured IP values agree well with those predicted by state-of-the-art relativistic calculations performed alongside the present measurements. Similar to the well-established behavior for the lanthanides, the IP values of the heavy actinides up to No increase with filling up the 5f orbital, while that of Lr is the lowest among the actinides. These results clearly demonstrate that the 5f orbital is fully filled at No with the [Rn]5f7s configuration and that Lr has a weakly bound electron outside the No core. In analogy to the lanthanide series, the present results unequivocally verify that the actinide series ends with Lr.

Journal of the American Chemical Society


Verification of the Thermal Neutron Shielding Effect of the Shielding Door of the LHD Experimental Hall


Availability of Japanese Government's supplemental texts on radiation reflecting the Fukushima Daiichi Nuclear Power Plant accident for elementary and secondary education from dental students' understanding

Following the Fukushima Nuclear Power Plant accident, the Japanese government created two supplemental texts about radiation reflecting the accident for elementary, middle school, and high school students. These texts were made to explain radiation and consequently to obtain public consent for the continuation of the nuclear program. The present study aimed to evaluate the appropriateness of the content of the texts and to collect the basic data on the level of understanding necessary to improve radiation education. Lectures on radiology including nuclear energy and the Fukushima accident were given to 44 fourth-year dental students in 2013. The questionnaire was administered in 2014 when these students were in their sixth-year. The survey was also administered to 40 first-year students and 41 fourth-year students who hadn't any radiology lectures. Students rated their level of understanding of 50 phrases used in the texts on a four-point scale (understanding = 3, a little knowledge = 2, having heard = 1, no knowledge = 0). Questions on taking an advanced physics course in high school and means of learning about radiation in daily life were also asked. The level of understanding of phrases in the supplemental text for middle and high school students was significantly higher among sixth-year students (mean = 1.43) than among first-year (mean = 1.12) or fourth-year (mean = 0.93) students (p < 0.05). Overall, the level of understanding was low, with scores indicating that most students knew only a little. First-year students learning about radiation from television but four-year and six-year students learning about radiation from newspaper scored significantly higher (p < 0.05). It was concluded that radiation education should be improved by using visual material and preparing educators to teach the material for improving the public's understanding of radiation use-especially nuclear power generation because the phrases used in the supplementary texts are very difficult for students to understand.


Infiltration of trace metal ions in the oral mucosa of a rat analyzed using SRXRF, XAFS, and ICP-MS

Although the accumulation and distribution of metals from metallic orthodontic appliances in the oral mucosa have been studied extensively, they remain unclear because their concentration is quite low. In this study, metal specimens (Ni, Ni-Ti, and Co-Cr) were sutured in the unilateral oral mucosa of rats, and the distribution of the eluted elements in the mucosal tissue was estimated using inductively coupled plasma mass spectrometry (ICP-MS) and synchrotron radiation X-ray fluorescence analysis (SR-XRF). While the infiltrations of Ni, Co, and Cr into the oral mucosal connective tissue were observed with SR-XRF, significant increases were only found in Ni from the pure Ni group and Cr from the Co-Cr group. Furthermore, Ni and Co were estimated as hydrated ions while Cr was estimated in oxide form through X-ray absorption fine structure (XAFS) analysis.


Manufacture and utilization of a low-level radioactive Ge-68/Ga-68 generator in a radiochemistry laboratory course

低レベル放射能のGe-68を用いたGe-68/Ga-68ジェネレータの作製と放射化学実習への応用

Japanese Journal of Radiological Technology


A Long-Term High-Fat Diet Changes Iron Distribution in Body, Increasing Iron Accumulation Specifically in the Mouse Spleen

Although iron is an essential trace metal, its presence in excess causes oxidative stress in the human body. Recent studies have indicated that iron storage is a risk factor for type 2 diabetes mellitus. Dietary iron restriction or iron chelation ameliorates symptoms of type 2 diabetes in mouse models. However, whether iron content in the body changes with the development of diabetes is unknown. Here, we investigated the dynamics of iron accumulation and changes in iron absorption-related genes in mice that developed obesity and diabetes by consuming a high-fat diet (HFD-fed mice). HFD-fed mice (18-20 wk) were compared with control mice for hematologic features, serum ferritin levels, and iron contents in the gastrocnemius muscle, heart, epididymal fat, testis, liver, duodenum, and spleen. In addition, the spleen was examined histologically. Iron absorption-related gene expression in the liver and duodenum was also examined. Hemoglobin and serum ferritin levels were increased in HFD-fed mice. The HFD-fed mice showed iron accumulation in the spleen, but not in the heart or liver. Increased percentages of the splenic red pulp and macrophages were observed in HFD-fed mice and iron accumulation in the spleen was found mainly in the splenic red pulp. The HFD-fed mice also showed decreased iron content in the duodenum. The mRNA expression of divalent metal transporter-1 (DMT-1), an iron absorption-related gene, was elevated in the duodenum of HFD-fed mice. These results indicate that iron accumulation (specifically accumulation in the spleen) is enhanced by the development of type 2 diabetes induced by HFD.

Journal of Nutritional Science and Vitaminology


Correlation between Asian Dust and Specific Radioactivities of Fission Products included in Airborne Samples in Tokushima, Shikoku Island, Japan


Simple Screening Method for Radioactive Concentration Using a Portable Dose Rate Meter

A new method was developed to estimate radioactive concentration [Bq/kg] using a portable dose rate meter [μSv/h] and a sample container surrounding the meter. It has been found that simple measurements can be performed for estimation of radioactive concentration. Lower limit of the detection (LOD) for the method was deduced to be 600 Bq under an environment of 0.057±0.005 μSv/h (3ς).


Decontamination of radioactivity from contaminated vegetables derived from the Fukushima nuclear accident


Evaluation of strontium introduced apatite cement as the injectable bone substitute developments.

We have developed bone cement introducing Strontium (Sr) to promote early bone regeneration. To prolong the release duration of Sr, we applied inorganic Sr filler for containing into the cement powder. The purpose of this study is to evaluate the mechanical properties, crystallinic properties, and ion release activities, especially Sr anion, of this cement. Alpha-TCP powder was mixed with Sr filler, with 0.1wt%, 0.5wt%, 1.0wt%, and 5.0wt%. These were mixed with mixing liquid and formed for each test. They were incubated and crystalized in 95% moisture for 1 week. The mechanical properties were studied by the compression, the diametral tensile strength and 4-point vending. Tested specimens were evaluated by X-ray diffraction(XRD) and scanning electron microscopic(SEM) imaging. The ion release behaviors were measured by inductively coupled plasma mass spectrometry(ICP-MS). The mechanical properties were increased in consistency of filler, but decreased in some samples because of declining the apatite matrix. And the Sr release showed interesting results as the sequential resource of Sr. By adjusting the mixing ratio or considering the application of these Sr releasable cements, this material would show good performance by its strength and longer Sr release for bone regeneration.

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society


Preliminary observation of dynamic changes in alcohol concentration in the human brain with proton magnetic resonance spectroscopy on a 3T MR instrument

Purpose: Our purposes were to establish suitable conditions for proton magnetic resonance spectroscopy (MRS) to measure dynamic changes in alcohol concentration in the human brain, to evaluate these changes, and to compare the findings with data from analysis of breath vapor and blood samples. Materials and Methods: We evaluated 4 healthy volunteers (mean age 26.5 years; 3 males, one female) with no neurological findings. All studies were performed with 3-tesla clinical equipment using an 8-channel head coil. We applied our modified single-voxel point-resolved spectroscopy (PRESS) sequence. Continuous measurements of MRS, breath vapor, and blood samples were conducted before and after the subjects drank alcohol with a light meal. The obtained spectra were quantified by LCModel Ver. 6.1, and the accuracy of the MRS measurements was estimated using the estimated standard deviation expressed in percentage (%SD) as a criterion. Results: Alcohol peaks after drinking were clearly detected at 1.2 ppm for all durations of measurement. Good correlations between breath vapor or blood sample and MRS were found by sub-minute MRS measurement. The continuous measurement showed time-dependent changes in alcohol in the brain and various patterns that differed among subjects. Conclusions: The clinical 3T equipment enables direct evaluation of sub-minute changes in alcohol metabolism in the human brain.


APPLICATION OF ICP-DRC-MS TO SCREENING TEST OF STRONTIUM AND PLUTONIUM IN ENVIRONMENTAL SAPMLES AT FUKUSHIMA

An application of sequential automated SPE separation equipment coupled to the quadrupole-based ICPMS instrumentation with a dynamic reaction cell such as a screening test system of (90)Sr and Pu isotopes in environmental samples was developed in this work. So far, during the course of a large number of reports as to various specific radioactivities in environmental samples surveyed at radioactive contaminated area around the Fukushima Daiichi Nuclear Power Plants (FDNPP), there is a much smaller number of reports on (90)Sr and Pu isotopes than that of (134)Cs and (137)Cs since the FDNPP accident, and then it would be expected to develop the simple analysis method of these isotopes instead of radiation measurements currently in use. In particular, a screening for (90)Sr in environmental samples has been accomplished using an isotopic ratio measurement mode in comparison with the characterization on the Solid Phase Elution (SPE) separation between strontium and zirconium isotopes around the mass-90 fraction. As a result, for a trial analysis of environmental samples of a muddy snow water and a soil which were collected at Fukushima, it was found that the present developed system makes it applicable for achieving up to the specific activity levels of several hundreds Bq/kg ((90)Sr) and about 1-2Bq/kg (Pu isotopes) as the screening test system.


走行サーベイによる徳島県の環境放射線調査

走行サーベイによる徳島県の環境放射線調査

福島第一原子力発電所の事故以降，徳島県下の線量率分布は不明であることから，走行サーベイの手法を用い，2010年5月から2012年6月にわたって線量率分布図を作成した．平野部では線量率が低く，山間部では高くなり，地質との関連では，四万十帯の線量率が高く，御荷鉾緑色岩類分布地の線量率が低くなり，和泉層群を通過するルートで高い線量率が見られた．地形や地質によって線量率が異なることを論じた．

Journal of Shikoku Public Health Society


Ground-state configuration of the N = 157 nucleus 259No


Measurement of airborne radioactivity from the Fukushima reactor accident in Tokushima, Japan


Development of elemental and isotopic analysis of uranium and thorium in material using an automatic SPE injection equipment coupled to ICP-DRC-MS

We have investigated to elucidate the relationship between specific activities of radionuclides and elemental concentrations of trace elements in environment and materials. In 2010 the funding for bigger equipment cost of ICPMS (Inductively Coupled Plasma Mass Spectrometry) and automated SPE (Solid Phase Elution) was allowed to insert it in the national revised budget for The University of Tokushima. In this paper, we have briefly introduced a new integrated instrumental system based on ICPMS and SPE for radiation measurement and multi trace elemental analysis.

International Journal of Modern Physics B


The Distribution of Thermal Neutron Flux into the Self-shielded Wall Equipped with a Medical Self-shielded PET Cyclotron

The Journal of the Korean Physical Society


医療用自己遮蔽型PETサイクロトロン及び電子リニアックにおける中性子束の箔放射化法による測定

Japanese Journal of Radiation Safety Management

日本放射線安全管理学会誌


Alpha-gamma coincidence spectroscopy of 259No


Evidence for charged-particle decay of dipole-excited 4H clusters embedded in 6He and 7He


Hexafluoro complex of rutherfordium in mixed HF/HNO3 solutions


Investigation of uranium and thorium activities and their isotopic ratios in environmental water samples in Tokushima, Japan, using extraction chromatography and samarium coprecipitation

Journal of Radioanalytical and Nuclear Chemistry


走行サーベイによる徳島県・三朝温泉(鳥取県)間の環境放射線の線量率調査

走行サーベイによる徳島県・三朝温泉(鳥取県)間の環境放射線の線量率調査


大気中の鉛(214Pb, 212Pb)とビスマス(214Bi)濃度の共沈分離による定量


α decay of 238Cm and the new isotope 237Cm


Experimental Identification of Spin-Parities and Single-Particle Configurations in 257No and Its -Decay Daughter 253Fm

alpha-gamma and alpha-electron coincidence spectroscopy for a short-lived heavy actinide nucleus (257)No (T(1/2) = 24.5 s) has been performed using a gas-jet transport system and an on-line isotope separator. Spin-parities of excited states in (253)Fm fed by the alpha decay of (257)No have been identified on the basis of the measured internal conversion coefficients. The nu3/2(+)[622] configuration has been assigned to the ground state of (257)No as well as to the 124.1 keV level in (253)Fm. It was found that the ground-state configuration of (257)No is different from that of lighter N = 155 isotones.


Chemical studies on rutherfordium (Rf) at JAERI


超重元素ラザホージウムの化学 -へキサフルオロ錯体[RfF6]-の形成-

超重元素ラザホージウムの化学 -へキサフルオロ錯体[RfF6]-の形成-


β-decay half-lives of new neutron-rich rare-earth isotopes 159Pm,162Sm, and 166Gd


Proton-neutron configurations in 236g, mAm and its EC-decay daughter 236Pu

The European Physical Journal A - Hadrons and Nuclei


環境中のラドン，トロン及びその子孫核種の動態調査研究

環境中のラドン，トロン及びその子孫核種の動態調査研究

Radiation Biology Research Communications


Fluoride complexation of element 104, rutherfordium (Rf), produced in the 248Cm(18O,5n)261Rf reaction has been studied by anion-exchange chromatography on an atom-at-a-time scale. The anion-exchange chromatographic behavior of Rf was investigated in 1.9-13.9 M hydrofluoric acid together with those of the group-4 elements Zr and Hf produced in the 18O-induced reactions on Ge and Gd targets, respectively. It was found that the adsorption behavior of Rf on anion-exchange resin is quite different from those of Zr and Hf, suggesting the influence of relativistic effects on the fluoride complexation of Rf.

Journal of the American Chemical Society


Chemical studies of the heaviest elements


6Heのt+tクラスター分子状態を(7Li,7Be)反応で励起された共鳴状態からのt粒子崩壊過程を測定して調べた．励起エネルギーEx=18 MeVにt+tと考えられる分子共鳴を見つけた．t粒子崩壊分岐比は90±10%で，tの2体崩壊していることが分かった．


α-decays of Neutron-deficient Americium Isotopes


野島断層500mボーリングコアの深度方向に対するガンマ線放出核種の放射能濃度分布


徳島県における大気·雨水中ラドン子孫核種及びBe-7の濃度

徳島県における大気·雨水中ラドン子孫核種及びBe-7の濃度


中性子不足アメリシウム·キュリウム核種のα/EC壊変特性

中性子不足アメリシウム·キュリウム核種のα/EC壊変特性


Reproducibility of Metabolite Concentration Evaluated by Intraclass Correlation Coefficient Using Clinical MR Apparatus.

The purpose of this study was to evaluate the reproducibility of in vivo quantitative proton MR spectroscopy (MRS) by repeated-measure analysis of variance and intraclass correlation coefficient (ICC) including assessment of both inter- and intrasubject variation. The concentration of metabolites was quantified using long-TR and short-TE stimulated-echo acquisition mode sequences with a quadrature head coil. All preparation procedures for MRS measurement except volume of interest determination were done by an automatic preparation scanning system equivalent to a clinical setting. Analyses were conducted by an LCModel running based on our original basis set by two different reference methods. The ICC showed a good correlation (r = 0.61-0.99) in any metabolite and almost the same value between the two different reference methods, but the concentration of myoinositol had a large intersubject variation. Our results suggest that the reproducibility of quantified metabolite concentration is acceptable in the clinical setting regardless of the reference method, although quantified values may have different intersubject variations.


Decay studies of neutron-deficient Am, Cm, and Bk nuclei using an on-line isotope separator

The EC and α decays of neutron-deficient Am and Cm nuclei have been studied using a gas-jet coupled on-line isotope separator. Decay schemes of the EC decay of 235, 236Am have been constructed, and weak α decays of 233, 235, 236Am and 237, 238Cm have been observed. The efficiency of the on-line mass separation of Bk nuclei was measured to be ∼1%. The Qα values, α-decay partial half-lives, and proton-neutron configurations are discussed.

Journal of Nuclear and Radiochemical Sciences


Performance of the multiple target He/PbI2 aerosol jet system for mass separation of neutron-deficient actinide isotopes

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms


Variation of 7Be concentration in Tokushima


Actinides Neutron-deficient the of Properties Decay Nuclear

Journal of Nuclear Science and Technology (Japan)


The European Physical Journal A - Hadrons and Nuclei


医療用理リニアックの中性子場を模擬した水晶体サイズでの中性子束密度及び線量評価(統計精度の拡充)

Annual Report of Cooperative Researches at Kindai University Reactor 2020

近畿大学原子炉等利用共同研究経過報告書2020


A Car-borne Survey of Environmental Radiation in Shikoku, Japan

走行サーベイによる四国の環境放射線調査

We investigated the environmental radiation in Shikoku area using a car-borne survey and obtained the change of dose rate by continuous survey. Dose rartes in Ozu city and its surrounding area, Ehime prefecture were the lowest in other areas of Shikoku. Dose rates obviously changed on the north side of it's low dose rates area but gradually changed on the south side. Dose rates in Ashizuri-misaki, Kochi prefecture were the highest in Shikoku and changed in accordance with the boundary of geological structure. Dose rate on the survey route, from Imabari city in Ehime prefecture to Shimanto city in Kochi prefecture, was the lowest at the surrounding area of the prefectural boundary. This lowest dose rate was considered to be caused by geological structure. The influence of altitued on dose rates was not observed in this survey route.The average dose rates of environmental radiation in Ehime prefecture and Kochi prefecture were almost the same and the lowest in Shikoku. Tokushima prefecture was the highest in the average dose rates of environmental radiation of other prefectures in Shikoku.

Natural Science Research, Faculty of Integrated Arts and Sciences, The University of Tokushima

徳島大学総合科学部自然科学研究


A car-borne measurement of environmental radiation in Kagawa Prefecture, Shikoku, Japan

走行サーベイによる香川県の環境放射線調査

After the accident of the Fukushima Daiichi nuclear power plant by the Great East Japan Earthquake on March 11, 2011, concern about radiation is increasing and monitoring of environmental radiation is performed even in Kagawa Prefecture. Then, we investigated for a short period of time for the purpose of creating the dose rate distribution map of Kagawa Prefecture while getting to know the dose rate of each municipality in Kagawa Prefecture in detail using a car-borne survey technique. As a result of measurement, the dose rates were low in the plain regions and those became high in the mountainous regions. Due to the average value of each municipality, the dose rates of municipalities in the southeastern prefecture, which contain Izumi Group and mountainous region affluent in granite, were high. The average dose rates of all municipalities in Kagawa Prefecture were obtained from this investigation, and the dose rate distribution map was created. From the tendency of the dose rate distribution in Kagawa, it has confirmed that a dose rate changed with geographical feature or geology.

走行サーベイによって香川県の環境放射線の線量率を調査し，各市町村の環境放射線の線量率分布図を作成した．地形的には環境中の放射線の線量率は平野部に比べ山間部で高くなった．山間部では走行路両側に近接する岩石や土壌に含まれる天然放射性核種からの放射線により線量率が高くなる．地質との関連では，和泉層群や花崗岩に富む県南東部の山間地域は高い線量率を示した．

徳島大学総合科学部自然科学研究