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Kamada, Masaki*; Yoshida, Takuma*; Sugita, Tsukasa*; Okumura, Keisuke
Nihon Genshiryoku Gakkai-Shi ATOMO
, 66(2), p.83 - 86, 2024/02
no abstracts in English
Furutaka, Kazuyoshi; Ozu, Akira; Toh, Yosuke
Nuclear Engineering and Technology, 55(11), p.4002 - 4018, 2023/11
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)Hironaka, Kota; Lee, J.; Koizumi, Mitsuo; Ito, Fumiaki*; Hori, Junichi*; Terada, Kazushi*; Sano, Tadafumi*
Nuclear Instruments and Methods in Physics Research A, 1054, p.168467_1 - 168467_5, 2023/09
Times Cited Count：0 Percentile：0.02(Instruments & Instrumentation)Rossi, F.; Koizumi, Mitsuo; Rodriguez, D.; Takahashi, Tone
Proceedings of INMM & ESARDA Joint Annual Meeting 2023 (Internet), 5 Pages, 2023/05
Rodriguez, D.; Abbas, K.*; Bertolotti, D.*; Bonaldi, C.*; Fontana, C.*; Fujimoto, Masami*; Geerts, W.*; Koizumi, Mitsuo; Macias, M.*; Nonneman, S.*; et al.
Proceedings of INMM & ESARDA Joint Annual Meeting 2023 (Internet), 8 Pages, 2023/05
Nagatani, Taketeru; Sagara, Hiroshi*; Kosuge, Yoshihiro*; Nomi, Takayoshi; Okumura, Keisuke
Journal of Nuclear Science and Technology, 60(4), p.460 - 472, 2023/04
Times Cited Count：1 Percentile：31.61(Nuclear Science & Technology)Rossi, F.; Koizumi, Mitsuo; Rodriguez, D.; Takahashi, Tone
Proceedings of INMM 63rd Annual Meeting (Internet), 5 Pages, 2022/07
Rossi, F.; Abbas, K.*; Koizumi, Mitsuo; Lee, H.-J.; Rodriguez, D.; Takahashi, Tone
Proceedings of INMM & ESARDA Joint Virtual Annual Meeting (Internet), 7 Pages, 2021/08
Rossi, F.; Koizumi, Mitsuo; Lee, H.-J.; Rodriguez, D.; Takahashi, Tone; Abbas, K.*; Bogucarska, T.*; Crochemore, J.-M.*; Pedersen, B.*; Varasano, G.*
61st Annual Meeting of the Institute of Nuclear Materials Management (INMM 2020), Vol.2, p.907 - 911, 2021/00
Koizumi, Mitsuo
Proceedings of 41st ESARDA Annual Meeting (Internet), p.260 - 267, 2019/05
Rodriguez, D.; Rossi, F.; Takahashi, Tone; Seya, Michio; Koizumi, Mitsuo; Crochemore, J. M.*; Varasano, G.*; Bogucarska, T.*; Abbas, K.*; Pedersen, B.*
Proceedings of INMM 59th Annual Meeting (Internet), 7 Pages, 2018/07
Komeda, Masao; Ozu, Akira; Mori, Takamasa; Nakatsuka, Yoshiaki; Maeda, Makoto; Kureta, Masatoshi; Toh, Yosuke
Journal of Nuclear Science and Technology, 54(11), p.1233 - 1239, 2017/11
Times Cited Count：8 Percentile：61.27(Nuclear Science & Technology)The previous active neutron method cannot remove the influence of the multiplication effect of neutrons produced by second- and subsequent fission reactions, and it might overestimate the amount of nuclear material if an item contains large amounts. In this paper, we discussed the correction method for the neutron multiplication effect on the measured data in the fast neutron direct interrogation (FNDI) method, one of the active neutron methods, supposing that the neutron multiplication effect is caused mainly by third-generation neutrons from the second-fission reactions under the condition that the forth-generation neutrons are much fewer. This paper proposed a correction method for the neutron multiplication effect in the measured data. Moreover we have shown a possibility that this correction method gives rough estimates of the effective neutron multiplication factor and the subcriticality.
Hosoma, Takashi
JAEA-Research 2016-019, 53 Pages, 2017/01
JAEA-Research-2016-019.pdf:5.71MB
Application of probability generating function for nondestructive nuclear materials assay system was studied. First, high-order neutron correlations were derived algebraically up to septuplet and basic characteristics of the correlations were investigated. It was found that higher-order correlation increases rapidly in response to the increase of leakage multiplication, crosses and leaves lower-order correlations behind, when leakage multiplication is 
1.3 that depends on detector efficiency and counter setting. Next, fission rates and doubles count rates by fast neutron and by thermal neutron in their coexisting system were derived algebraically. It was found that the number of induced fissions per unit time by fast neutron and by thermal neutron, the number of induced fissions (
1) by one source neutron, and individual doubles count rates were possible to be estimated from Rossi-alpha combined distribution and measured ratio of each area obtained by differential die-away self-interrogation and conventional assay data.
Naoi, Yosuke; Oda, Tetsuzo; Tomikawa, Hirofumi
Nihon Genshiryoku Gakkai-Shi ATOMO, 58(9), p.536 - 541, 2016/09
Japan has been promoting nuclear energy research and development, and the use of nuclear energy for only peaceful purposes in accordance with Atomic Energy Basic Acts enacted in 1955. In order to ensure limited to their peaceful utilization, it has been performing a nuclear material accountancy and reporting it based on bilateral nuclear agreement (Japan and the United States, Japan and France, Japan and Canada and so on) before concluding the comprehensive safeguards agreement with the IAEA. After the conclusion of that in 1977, the Japanese national law had been revised. The nuclear material accountancy and its reports to the IAEA have been implemented based on the revised law. In 1999, Japan ratified the additional protocol. Then it has been responding a new obligation in the additional protocol. The correctness and completeness of the declaration of nuclear activities in Japan have been verified by the IAEA, and then the "broader conclusion" was given to Japan in 2004. There indicates no diversion or undeclared nuclear activities in Japan. Since then Japan has been obtaining the "broader conclusion" every year. In this report we will report the JAEA's contribution to the IAEA safeguards on technical research and development and human resource development.
Bolind, A. M.*; Seya, Michio
JAEA-Review 2015-027, 233 Pages, 2015/12
JAEA-Review-2015-027.pdf:30.21MB
This report surveys the 14 advanced NDA techniques that were examined by the Spent Fuel NDA Project of the Next Generation Safeguards Initiative (NGSI) of the U.S. DOE-NNSA. It discusses and critique NDA techniques from a view point of obtaining higher accuracies. The report shows the main problem, large uncertainties in the assay results are caused primarily by using too few independent NDAs. In this report authors shows that at least three independent NDA techniques are required for obtaining better accuracies, since the physics of the NDA of SFAs is three dimensional.
Hosoma, Takashi
JAEA-Research 2015-009, 162 Pages, 2015/08
JAEA-Research-2015-009.pdf:22.3MB
Neutron coincidence counting assay systems have been developed in the last two decades. Objects would extend to high-mass uranium-plutonium dioxide containing other spontaneous fission nuclei, so essentials of neutron multiplicity counting were reconsidered and expanded: (a) Formulae of multiplicity distribution were algebraically derived up to septuplet using a probability generating function; (b) Leakage multiplication was evaluated not by Monte Carlo method but by an average length from an arbitrary point inside a sample to an arbitrary point on its surface and a probability of induced fission within the length; (c) Mechanism of coincidence counting was associated with a couple of different time axes in Poisson process, and consequently a pair of close-to-coincident neutrons from the process was derived. For the formulae, new expressions using combination were wrote down. For spectrum and mean free path, actually treated uranium-plutonium dioxide was selected as an example.
Tsuchiya, Harufumi; Koizumi, Mitsuo; Kitatani, Fumito; Kureta, Masatoshi; Harada, Hideo; Seya, Michio; Heyse, J.*; Kopecky, S.*; Mondelaers, W.*; Paradela, C.*; et al.
Proceedings of 37th ESARDA Annual Meeting (Internet), p.846 - 851, 2015/08
One of non-destructive techniques using neutron resonance reaction is neutron resonance transmission analysis (NRTA). We are presently developing a new active neutron non-destructive method including NRTA in order to detect and quantify special nuclear materials (SNMs) in nuclear fuels containing MA. We aim at applying the technique to not only particle-like debris but also other materials in high radiation field. For this aim, we make use of fruitful knowledge of neutron resonance densitometry (NRD) that was developed for particle-like debris in melted fuel. NRTA detects and quantifies SNMs by means of analyzing a neutron transmission spectrum via a resonance shape analysis. In this presentation, we explain the basic of NRTA and its role in the active neutron technique. Then, with knowledge obtained in the development of NRD, we discuss items to be investigated for NRTA in our active neutron technique.
Seya, Michio; Kureta, Masatoshi; Soyama, Kazuhiko; Nakamura, Hironobu; Harada, Hideo; Hajima, Ryoichi
Proceedings of INMM 55th Annual Meeting (Internet), 10 Pages, 2014/07
JAEA has been implementing development programs of basic technologies of the following advanced NDA (non-destructive assay) of nuclear material (NM) for nuclear safeguards and security. (1) Alternative to 
He neutron detection using ZnS/B
O
ceramic scintillator, (2) NRD (neutron resonance densitometry) using NRTA (neutron resonance transmission analysis) and NRCA (neutron resonance capture analysis), (3) NRF (nuclear resonance fluorescence)-NDA using laser Compton scattered (LCS) 
-rays (intense mono-energetic -rays). The development program (1) is for NDA systems that use ZnS/BO ceramic scintillator as alternative neutron detector to He for coming shortage of its supply. The program (2) is for a NDA system of isotopic composition measurement (non-destructive mass spectroscopy) in targets such as particle-like melted fuel debris using NRTA and NRCA. The program (3) is for NDA systems using a specific NRF reaction of certain Pu/U isotope caused by mono-energetic LCS -ray with energy tuned to the specific excited state of the isotope. This paper introduces above three programs.
Tsutsumi, Masahiro; Oishi, Tetsuya*; Yamasoto, Kotaro; Yoshida, Makoto
JAERI-Research 2004-021, 43 Pages, 2004/12
JAERI-Research-2004-021.pdf:8.55MB
We have designed and developed a measurement system to certify radioactive wastes below the clearance level. By advancing non-destructive -ray assay technology, it aims at quantitative determination of radionuclides contained in 200 litter drum/container wastes. Unlike the waste from a nuclear power plant, you have to assume that the waste originating from radioisotope usage and nuclear research laboratory have a variety of contents and a complex mixture of radionuclides, and furthermore the uniformity of activity concentration is unknown. To cope with the problems, we have developed the -ray measuring instruments (units) with effective improvement of capability against each problem. They are (1) germanium spectrometry unit for enhanced peak identification, (2) positioning detection unit for positioning of interactions and (3)high-efficiency detection unit for separation of low-energy component. This report summarizes the direction of the clearance level measuring system and the three developed measuring units with their performances.
Sonoda, Takashi; Togashi, Yoshihiro; Miyauchi, Masakatsu; Okazaki, Shuji*
JAERI-Tech 99-043, 16 Pages, 1999/05
no abstracts in English
