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(cr) at 318 K in the presence of ironYoshida, Yasushi*; Kitamura, Akira; Shibutani, Sanae*
Journal of Nuclear Science and Technology, 60(8), p.900 - 910, 2023/08
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)Saito, Tatsuo; Yamazawa, Hiromi*; Mochizuki, Akihito
Journal of Environmental Radioactivity, 255, p.107035_1 - 107035_14, 2022/12
Times Cited Count：0 Percentile：0(Environmental Sciences)The seasonal variation of dissolved U (DU) in Lake Biwa was reproduced by the following model and parameter research. The introduced models are the water-DU mass balance, and the ion exchange between UO
and H
on the lakeshore soil. The optimized parameters were the CEC of the lakeshore, TU as the sum of DU and AU (soil adsorbed U), kads and kdes as the first order reaction rate coefficients during rapid soil adsorption and desorption of U, respectively. Tabulated by the chemical equilibria constituting DU and analyzed the contribution of each chemical species, it is shown that the seasonal variation of DU is caused by the seasonal variation of pH. A correction to the ion-exchange equilibrium to shift to first order rate reaction only when the daily AU ratio increased above kads or decreased below kdes, improved the reproducibility of DU measurements and reproduced the delay of the DU peak from the pH peak.
Nakamura, Shoji; Shibahara, Yuji*; Endo, Shunsuke; Kimura, Atsushi
Journal of Nuclear Science and Technology, 59(11), p.1388 - 1398, 2022/11
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)The present study selected 
Np among radioactive nuclides and aimed to measure the thermal-neutron capture cross-section for Np in a well-thermalized neutron field by an activation method. A Np standard solution was used for irradiation samples. A thermal-neutron flux at an irradiation position was measured with neutron flux monitors: 
Sc, 
Co, 
Mo, 
Ta and 
Au. The Np sample and flux monitors were irradiated together for 30 minutes in the graphite thermal column equipped with the Kyoto University Research Reactor. The similar irradiation was carried out twice. After the irradiations, the Np samples were quantified using 312-keV gamma ray emitted from 
Pa in a radiation equilibrium with Np. The reaction rates of Np were obtained from gamma-ray peak net counts given by 
Np, and then the thermal-neutron capture cross-section of Np was found to be 173.8
4.4 barn by averaging the results obtained by the two irradiations. The present result was in agreement with the reported data given by a time-of-flight method within the limit of uncertainty.
Np(n, 
) reaction with TC-Pn in KURNakamura, Shoji; Endo, Shunsuke; Kimura, Atsushi; Shibahara, Yuji*
KURNS Progress Report 2021, P. 93, 2022/07
In terms of nuclear transmutation studies of minor actinides in nuclear wastes, the present work selected Np among them and aimed to measure the thermal-neutron capture cross-section of Np using a well-thermalized neutron field by a neutron activation method because there have been discrepancies among reported cross-section data. A Np standard solution was used for irradiation samples. The thermal-neutron flux at an irradiation position was measured with flux monitors: Sc, Co, Mo, Ta and Au. The Np sample was irradiated together with the flux monitors for 30 minutes in the graphite thermal column equipped in the Kyoto University Research Reactor. The similar irradiation was repeated once more to confirm the reproducibility of the results. After irradiation, the Np samples were quantified using 312-keV gamma-ray emitted from Pa in radiation equilibrium with Np. The reaction rates of Np were obtained from the peak net counts of gamma-rays emitted from generated Np, and then the thermal-neutron capture cross-section of Np was found to be 173.84.7 barn by averaging the results obtained by the two irradiations. The present result was in agreement with the reported data given by a time-of-flight method within a limit of uncertainty.
Shiotsu, Hiroyuki; Ito, Hiroto*; Sugiyama, Tomoyuki; Maruyama, Yu
Annals of Nuclear Energy, 163, p.108587_1 - 108587_9, 2021/12
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)Sugiyama, Daisuke*; Nakabayashi, Ryo*; Koma, Yoshikazu; Takahatake, Yoko; Tsukamoto, Masaki*
Journal of Nuclear Science and Technology, 56(9-10), p.881 - 890, 2019/09
Times Cited Count：4 Percentile：41.24(Nuclear Science & Technology)
Am-Li sourcesHoshi, Katsuya; Nishino, Sho; Yoshida, Tadayoshi; Tsujimura, Norio
JPS Conference Proceedings (Internet), 24, p.011020_1 - 011020_6, 2019/01
We studied the application of AmLi interrogation neutron sources, which originally deployed in non-destructive assay apparatus for nuclear safeguard, to calibration work. To determine the emission rate, the angular distribution of neutron fluence was measured by a potable long counter. The emission rate at the date of measurement (October 23rd, 2015) was determined to be 1.00
10
n/s (4.1% (
= 2)).
Matsuda, Norihiro; Kunieda, Satoshi; Okamoto, Tsutomu*; Tada, Kenichi; Konno, Chikara
Progress in Nuclear Science and Technology (Internet), 6, p.225 - 229, 2019/01
Chadwick, M. B.*; Capote, R.*; Trkov, A.*; Herman, M. W.*; Brown, D. A.*; Hale, G. M.*; Kahler, A. C.*; Talou, P.*; Plompen, A. J.*; Schillebeeckx, P.*; et al.
Nuclear Data Sheets, 148, p.189 - 213, 2018/02
Times Cited Count：67 Percentile：98.06(Physics, Nuclear)The CIELO collaboration has studied neutron cross sections on nuclides that significantly impact criticality in nuclear facilities - 
U, U, 
Pu, 
Fe, 
O and 
H - with the aim of improving the accuracy of the data and resolving previous discrepancies in our understanding. This multi-laboratory pilot project, coordinated via the OECD/NEA Working Party on Evaluation Cooperation (WPEC) Subgroup 40 with support also from the IAEA, has motivated experimental and theoretical work and led to suites of new evaluated libraries that accurately reflect measured data and also perform well in integral simulations of criticality. This report summarizes our results and outlines plans for the next phase of this collaboration.
Rai, D.*; Kitamura, Akira
Journal of Chemical Thermodynamics, 114, p.135 - 143, 2017/11
Times Cited Count：9 Percentile：19.61(Thermodynamics)Isosaccharinic acid is a cellulose degradation product that can form in low-level nuclear waste repositories and is known to form strong complexes with many elements, including actinides, disposed of in these repositories. We (1) reviewed the available data for deprotonation and lactonisation constants of isosaccharinic acid, and the isosaccharinate binding constants for Ca, Fe(III), Th, U(IV), U(VI), Np(IV), Pu(IV), and Am(III), (2) summarized complexation constant values for predicting actinide behavior in geologic repositories in the presence of isosaccharinate, and (3) outlined additional studies to acquire reliable thermodynamic data where the available data are inadequate.
Di Lemma, F. G.; Yamashita, Shinichiro; Miwa, Shuhei; Nakajima, Kunihisa; Osaka, Masahiko
Energy Procedia, 127, p.29 - 34, 2017/09
Times Cited Count：4 Percentile：90.81(Energy & Fuels)Chemical effects of molybdenum (Mo) and boron (B), which were considered to form compounds with Cs, on the Cs chemisorption were predicted using a chemical equilibrium calculation. It is seen that CsMoO
were formed in the chemisorbed compounds. On the other hand, little effects were observed for B. The results suggest that the effects of Mo should be considered for further experimental investigation.
Nakamura, Shoji
Kaku Deta Nyusu (Internet), (115), p.18 - 23, 2016/10
This is a summary report on the planning joint session entitled by "Decommissioning of reactor and accelerator facilities and present status of activation nuclear data libraries".
Okumura, Keisuke; Kojima, Kensuke; Tanaka, Kenichi*
JAEA-Conf 2015-003, p.43 - 47, 2016/03
In the safety assessment concerning disposal of radioactive wastes generated in the decommissioning of nuclear facilities, it is necessary to evaluate the radionuclide inventory produced by the activation of structured materials. For this purpose, we have to pay much attention to the activation of many impurities irradiated in various neutron spectra depending on their positions and materials. Therefore, accurate activation cross-section data are necessary for many nuclides and reactions. A new multi-group neutron activation cross-section library (MAXS) was developed based on the recent nuclear data JENDL-4.0 and JEFF-3.0/A to apply it to the activation calculations for the decommissioning of nuclear facilities. The library contains cross-sections and isomeric ratios for many reactions such as (n,), (n,f), (n,2n), (n,3n), (n,p), (n,
), (n,d), (n,t), (n,n), (n,np), and so on, for 779 nuclides, in the 199-energy group structure of VITAMIN-B6.
Simanullang, I. L.*; Honda, Yuki; Fukaya, Yuji; Goto, Minoru; Shimazaki, Yosuke; Fujimoto, Nozomu*; Takada, Shoji
JAEA-Technology 2015-032, 26 Pages, 2016/01
JAEA-Technology-2015-032.pdf:2.07MB
Decay heat of the High Temperature Engineering Test Reactor had been evaluated by the Shure Equation and/or ORIGEN code based on the LWR's data. However, to evaluate more accurately, a suitable method must be considered because of the differences neutron spectrums from the LWRs. Therefore, the decay heat and the generated nuclides for the neutron spectrums of the core with different graphite moderator amount were calculated by the ORIGEN2 code. As a result, it is clear that the calculated decay heats are similar value with LWRs for about one year after the reactor shutdown, and that the significant differences are observed on the longer period affected by the generated nuclides such as 
Y, 
Cs, 
Pr, 
Rh, Am etc. It is also clear that the dose is affected by Pu on the initial stage after the reactor shutdown.
Imai, Makoto*; Sataka, Masao*; Matsuda, Makoto; Okayasu, Satoru; Kawatsura, Kiyoshi*; Takahiro, Katsumi*; Komaki, Kenichiro*; Shibata, Hiromi*; Nishio, Katsuhisa
Nuclear Instruments and Methods in Physics Research B, 354, p.172 - 176, 2015/07
Times Cited Count：14 Percentile：75.5(Instruments & Instrumentation)Both equilibrium and non-equilibrium charge-state distributions were studied experimentally for 2.0 MeV/u carbon ions after passing through carbon foils. Measured charge-state distribution established the equilibrium at a target thickness of 10 
g/cm
and this remained unchanged until a maximum target thickness of 98 g/cm. The equilibrium charge-state distribution, the equilibrium mean charge-state, and the width and skewness of the equilibrium distribution were compared with predictions using existing semi-empirical formulae as well as simulation results, including the ETACHA code. It was found that charge-state distributions, mean charge states, and distribution widths for C, C
, and C
incident ions merged into quasi-equilibrium values at a target thickness of 5.7 g/cm in the pre-equilibrium region and evolved simultaneously to the "real equilibrium" values for all of the initial charge states, including C
and C
ions. Two kinds of simulation, ETACHA and solution of rate equations taking only single electron transfers into account, were used, and both of them reproduced the measured charge evolution qualitatively. The quasi-equilibrium behavior could be reproduced with the ETACHA code, but not with solution of elementary rate equations.
Takai, Toshihide; Nakajima, Kunihisa; Furukawa, Tomohiro
JAEA-Technology 2015-002, 20 Pages, 2015/03
JAEA-Technology-2015-002.pdf:3.46MB
To improve the evaluation technique of source term, the measurement technique of the equilibrium vapor pressure using a high temperature mass spectrometer is required to expand the thermodynamic database of the simulated FPs. Existing test apparatus was adapted for this purpose. A mass spectrometer capable of measuring a wide mass number range and glove box for handling simulated FPs were installed for analyzing heavy FPs and preventing deterioration of simulated FPs in an air atmosphere, respectively. Function verification using standard sample and precision investigation using simulated FP sample were carried out. The oxygen dissociation pressure and standard enthalpy of formation of RuO(s) were evaluated, and it was confirmed these evaluated values were agreed with the calculated value from existing thermodynamic data and evaluation value written in the literature. Consequently, it was proven that high precision thermodynamic data was able to obtain by using this apparatus.
Okubo, Ayako; Kimura, Yoshiki; Shinohara, Nobuo; Toda, Nobufumi; Funatake, Yoshio; Watahiki, Masaru; Sakurai, Satoshi; Kuno, Yusuke
JAEA-Technology 2015-001, 185 Pages, 2015/03
JAEA-Technology-2015-001.pdf:56.65MB
Nuclear forensics is the analysis of intercepted illicit nuclear or radioactive material and any associated material to provide evidence for nuclear attribution by determining origin, history, transit routes and purpose involving such material. Nuclear forensics activity includes sampling of the illicit material, analysis of the samples and evaluation of the attribution by comparing the analyzed data with database or numerical simulation. Because the nuclear forensics technologies specify the origin of the nuclear materials used illegal dealings or nuclear terrorism, it becomes possible to identify and indict offenders, hence to enhance deterrent effect against such terrorism. Worldwide network on nuclear forensics can contribute to strengthen global nuclear security regime. In this paper, the results of research and development of fundamental nuclear forensics technologies performed in Japan Atomic Energy Agency during the fiscal term of 2011-2013 were reported.
Sasaki, Ichiro; Hanaoka, Hirofumi*; Yamada, Keiichi*; Watanabe, Shigeki; Sugo, Yumi; Ohshima, Yasuhiro; Suzuki, Hiroyuki; Ishioka, Noriko
Peptide Science 2014, p.257 - 260, 2015/03
Ikeda, Kiyoshi; Gonda, Mayuki; Nagaya, Shun; Hayakawa, Misa; Kunii, Katsuhiko; Mineo, Yukinobu; Yonezawa, Minoru; Itabashi, Keizo
Proceedings of 16th International Conference on Grey Literature (GL-16), p.139 - 145, 2015/03
The Japan Atomic Energy Agency (JAEA) Library has collected Internet information related the Fukushima Accident. We previously reported the development of the Fukushima Accident Archive using the DSpace in 15th International Conference on Grey Literature. We have encountered a new challenging issue grey literature. In many cases, Internet information contains valuable numerical data. However, it is difficult to identify the existence of numerical data in the Internet sites because numerical data is not often organized in a systematic manner on the web sites. We considered such method as to identify numerical data and attempted to introduce "data flagging" system, which was previously used in the International Atomic Energy Agency's International Nuclear Information System (INIS). In this presentation, we will introduce our "data flagging" system for numerical data on the Internet and how we apply the system to our Fukushima Accident Archive.
Akaoka, Katsuaki; Miyabe, Masabumi; Otobe, Haruyoshi; Wakaida, Ikuo
Reza Kenkyu, 42(12), p.918 - 922, 2014/12
For the remote analysis of the next generation nuclear fuel material containing minor actinide (MA), Laser Induced Breakdown Spectroscopy (LIBS) was applied to uranium oxide (U
O
) including a small amount of neodymium oxide (NdO) as a simulated sample of MA. By using deconvolution technique for the spectra of Nd in U, the complex, overlapped and confused spectra were separated and their actual intensities were determined. As a result, the calibration curve with good linearity and the detection limit of less than 700 ppm were demonstrated.
