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Lee, J.; Kodama, Yu; Rossi, F.; Hironaka, Kota; Koizumi, Mitsuo; Hori, Junichi*; Sano, Tadafumi*
Dai-44-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2023/11
no abstracts in English
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)Kageyama, Tomio; Denuma, Akio; Koizumi, Jin*; Odakura, Manabu*; Haginoya, Masahiro*; Isaka, Shinichi*; Kadowaki, Hiroyuki*; Kobayashi, Shingo*; Morimoto, Taisei*; Kato, Yoshiaki*; et al.
JAEA-Technology 2022-033, 130 Pages, 2023/03
JAEA-Technology-2022-033.pdf:9.87MB
Uranium handling facility for development of nuclear fuel manufacturing equipment (Mockup room) was constructed in 1972. The Mockup room has a weak seismic resistance and is deteriorating with age. Also, the original purpose with this facility have been achieved and there are no new development plans using this facility. Therefore, interior equipment installed in this facility had been dismantled and removed since March 2019. After that, the Mockup room was inspected for contamination, and then controlled area in the Mockup room was cancelled on March 29th 2022. A total of 6,549 workers (not including security witnesses) were required for this work. The amount of non-radioactive waste generated by this work was 31,300 kg. The amount of radioactive waste generated by this work was 3,734 kg of combustible waste (103 drums), 4,393 kg of flame resistance waste (61 drums), 37,790 kg of non-combustible waste (124 drums, 19 containers). This report describes about the dismantling and removing the interior equipment in the Mockup room, the amount of waste generated by this work, and procedure for cancellation the controlled area in the facility.
Lee, J.; Hironaka, Kota; Ito, Fumiaki*; Koizumi, Mitsuo; Hori, Junichi*; Sano, Tadafumi*
Journal of Nuclear Science and Technology, 8 Pages, 2023/00
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)Lee, J.; Ito, Fumiaki*; Hironaka, Kota; Takahashi, Tone; Suzuki, Satoshi*; Koizumi, Mitsuo; Hori, Junichi*; Terada, Kazushi*
Dai-43-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2022/11
no abstracts in English
Lee, J.; Hironaka, Kota; Ito, Fumiaki*; Takahashi, Tone; Koizumi, Mitsuo; Hori, Junichi*; Terada, Kazushi*
KURNS Progress Report 2021, P. 97, 2022/07
no abstracts in English
Al
Koizumi, Takatsugu*; Honda, Fuminori*; Sato, Yoshiki*; Li, D.*; Aoki, Dai*; Haga, Yoshinori; Gochi, Jun*; Nagasaki, Shoko*; Uwatoko, Yoshiya*; Kaneko, Yoshio*; et al.
Journal of the Physical Society of Japan, 91(4), p.043704_1 - 043704_5, 2022/04
Times Cited Count：2 Percentile：44.06(Physics, Multidisciplinary)Ito, Fumiaki*; Lee, J.; Hironaka, Kota; Takahashi, Tone; Suzuki, Satoshi*; Hori, Junichi*; Terada, Kazushi*; Koizumi, Mitsuo
KURNS Progress Report 2020, P. 98, 2021/08
A compact Nuclear Resonance Transmission Analysis (NRTA) system using a Laser Driven Neutron Source (LDNS) has been developed as a part of the development of nuclear non-proliferation technology supported by the MEXT. In NRTA, the neutron energy emitted from a pulsed neutron source is measured using the time-of-flight (TOF) method. LDNS is of interest because of its short pulse width, which is necessary for accurate TOF measurements over short flight distances. In the short-distance TOF measurement, there will be a large gamma-ray background event due to the coincidence of the timing of the arrival of 2.2 MeV gamma-rays due to neutron capture on hydrogen in the moderator and the timing of the arrival of neutrons around the resonance energy. Since the LDNS is still under development, the neutron flux is not sufficient and it is desirable to use a detector with high detection efficiency. For these reasons, we have developed a detector with low efficiency to gamma-rays and high efficiency to neutrons (multilayer neutron detector). As one of the results of this year's experiments, we confirmed that the multilayer neutron detector have low sensitivity to gamma-rays.
Rodriguez, D.; Koizumi, Mitsuo; Rossi, F.; Seya, Michio; Takahashi, Tone; Bogucarska, T.*; Crochemore, J.-M.*; Pedersen, B.*; Takamine, Jun
Journal of Nuclear Science and Technology, 57(8), p.975 - 988, 2020/08
Times Cited Count：4 Percentile：44.4(Nuclear Science & Technology)Koizumi, Mitsuo; Goto, Jun*; Matsuki, Seishi*
Journal of Semiconductors, 39(8), p.082001_1 - 082001_5, 2018/08
Dynamic nuclear self-polarization (DYNASP) is a phenomenon observed in III-V semiconductors. When electrons of the valence band of a semiconductor are optically excited to the conduction band, a relaxation process of the conduction electrons induces a large nuclear polarization to suddenly occur below a critical temperature. Extending the original theoretical work of Dyakonov et al., we examined the effect of spin distribution of valence electrons excited by the circularly polarized light and the effect of external magnetic field on the phenomenon of the nuclear self-polarization. We found that the nuclear polarization is achieved even above the critical temperatures by the effect of electron polarization and of the external magnetic field. To investigate the phenomenon experimentally, we constructed an apparatus for low-temperature experiments.
Kinsho, Michikazu; Kamiya, Junichiro; Koizumi, Oji*; Nasu, Shogo*
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.668 - 670, 2018/08
Crystallinity, crystalline structure and internal force of thin films were measured by Laser Raman spectroscopy for the purpose of analyzing the fracture mechanism of the charge exchange foil due to beam hitting in this study. Thin films were used four types of HBC foil, pure carbon film (C foil) formed by arc discharge method, graphene, and carbon nanotube (CNT foil). As a result of changing the laser output and measuring the Raman peak shift of each foil, the HBC foil and the C foil had large Raman peak shift change, the D-band was negative and the G-band was opposite sign with positive. On the other hand, the graphene and the CNT foil showed small change in Raman peak shift, and both D-band and G-band were negative. From these results, it was found that a large stress occurs in the HBC foil and the C foil due to the heat load by the laser which was used for Raman spectrum measurements.
-ray pipe-monitoring capabilities for real-time process monitoring safeguards applications in reprocessing facilitiesRodriguez, D.; Tanigawa, Masafumi; Nishimura, Kazuaki; Mukai, Yasunobu; Nakamura, Hironobu; Kurita, Tsutomu; Takamine, Jun; Suzuki, Satoshi*; Sekine, Megumi; Rossi, F.; et al.
Journal of Nuclear Science and Technology, 55(7), p.792 - 804, 2018/07
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)Nuclear material in reprocessing facilities is safeguarded by random sample verification with additional continuous monitoring applied to solution masses and volume in important tanks to maintain continuity-of-knowledge of process operation. Measuring the unique rays of each solution as the material flows through pipes connecting all tanks and process apparatuses could potentially improve process monitoring by verifying the compositions in real time. We tested this ray pipe-monitoring method using plutonium-nitrate solution transferred between tanks at the PCDF-TRP. The rays were measured using a lanthanum-bromide detector with a list-mode data acquisition system to obtain both time and energy of -ray. The analysis and results of this measurement demonstrate an ability to determine isotopic composition, process timing, flow rate, and volume of solution flowing through pipes, introducing a viable capability for process monitoring safeguards verification.
Kamiya, Junichiro; Kinsho, Michikazu; Abe, Kazuhiko*; Higa, Kyusaku*; Koizumi, Oji*
Journal of Vacuum Science and Technology A, 36(3), p.03E106_1 - 03E106_10, 2018/05
Times Cited Count：0 Percentile：0.01(Materials Science, Coatings & Films)The 3 GeV Rapid Cycling Synchrotron (RCS) in J-PARC aims to generate one of the highest power protons in the world, whose design extraction beam power is 1 MW. Beam pipes of alumina ceramics are used to prevent the induced current, which is caused by the rapid change of the magnetic field. In the beam injection section, ceramics beam pipes for a quadrupole magnet and a horizontal shift bump magnet are connected without bellows due to the very limited space. To improve maintainability, the ceramics beam pipes for the quadrupole magnet were newly designed to insert the bellows. We will report the design concept of the new alumina ceramics beam pipes with low spring constant bellows and the several results of the verification tests.
Kamiya, Junichiro; Kinsho, Michikazu; Abe, Kazuhiko*; Higa, Kyusaku*; Koizumi, Oji*
Proceedings of 14th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1222 - 1225, 2017/12
The 3 GeV Rapid Cycling Synchrotron aims to generate one of the highest power protons in the world. Beam pipes of alumina ceramics are used to prevent the induced current, which is caused by the rapid change of the magnetic field. In the beam injection section, ceramics beam pipes for a quadrupole magnet and a horizontal shift bump magnet are connected without bellows due to the narrow space. To improve maintainability, the ceramics beam pipes for the quadrupole magnet were newly designed. The end shape of ceramics unit duct was revised and 30 mm length are ensured to insert the bellows. The titanium bellows with low spring constant was successfully developed. Verification test for brazing of newly designed unit ducts and titanium sleeve was performed in order to examine the effect of the unique cross-sectional shape, racket shape fitting into 500 mm due to accept the injection beam and circulating beam passing through the injection quadrupole magnet.
-ray spectroscopy combined with active neutron interrogation for nuclear security and safeguardsKoizumi, Mitsuo; Rossi, F.; Rodriguez, D.; Takamine, Jun; Seya, Michio; Bogucarska, T.*; Crochemore, J.-M.*; Varasano, G.*; Abbas, K.*; Pedersen, B.*; et al.
EPJ Web of Conferences, 146, p.09018_1 - 09018_4, 2017/09
Times Cited Count：3 Percentile：86.09(Nuclear Science & Technology)Kitatani, Fumito; Tsuchiya, Harufumi; Koizumi, Mitsuo; Takamine, Jun; Hori, Junichi*; Sano, Tadafumi*
EPJ Web of Conferences, 146, p.09032_1 - 09032_3, 2017/09
Times Cited Count：0 Percentile：0.08(Nuclear Science & Technology)Rodriguez, D.; Rossi, F.; Takamine, Jun; Koizumi, Mitsuo; Seya, Michio; Crochemore, J. M.*; Varasano, G.*; Bogucarska, T.*; Abbas, K.*; Pedersen, B.*
Proceedings of INMM 58th Annual Meeting (Internet), 6 Pages, 2017/07
The JAEA is collaborating with the EC-JRC to develop a NDA system combining four active techniques to improve safeguards verification. Delayed gamma-ray spectroscopy can determine nuclide ratios by correlating observed fission products' time-dependent, high-energy, rays to the sample's complex fission yield. To quantify fissile nuclides of significant interest, the fast neutrons from compact, transportable sources must be thermalized to where the fissile nuclides have large cross-sections while maintaining high fluxes to provide significant signals. Experiments are underway at some facilities to improve DGS, including the PUNITA system at JRC-Ispra. These neutron fluxes and measurement conditions are used to develop a Monte Carlo that will be used to analyze the DGS data by an inverse-MC method. The DGS program described here summarizes the 3-year development to optimize the moderator, perform experiments, and create the IMC in preparation for a demonstration of the technique.
Rossi, F.; Koizumi, Mitsuo; Rodriguez, D.; Takamine, Jun; Seya, Michio; Pedersen, B.*; Crochemore, J. M.*; Abbas, K.*; Bogucarska, T.*; Varasano, G.*
Proceedings of INMM 58th Annual Meeting (Internet), 7 Pages, 2017/07
In the field of nuclear safeguards, new and improved active-interrogation NDA technologies are needed for the independent verification of the fissile composition in HRNM. JAEA and the JRC are now collaborating to develop DGS to determine ratios of fissile nuclides present in the sample measuring the decay gamma rays from FP. Measurements of LRNM samples are underway using different facilities. To minimize the interference from the LLFP, it is important to use shielding and to consider those gamma rays above 3-MeV. Different compact neutron sources are available, but all of them need to be slowed down to the thermal energy region. We are optimizing moderator and reflector materials using MCNP. Optimization of the irradiation, transfer and measurement sequence is now underway. The experiments we are conducting using certified mono-elemental U/Pu samples allow us to associate observed DG to the proportional isotopic compositions. In this paper we will present the current status of the optimization process and the experimental campaign for the determination of the ratio of fissile materials of U and Pu in a sample.
Rossi, F.; Koizumi, Mitsuo; Rodriguez, D.; Takamine, Jun; Seya, Michio
Dai-37-Kai Kaku Busshitsu Kanri Gakkai Nihon Shibu Nenji Taikai Rombunshu (CD-ROM), 8 Pages, 2017/02
Koizumi, Mitsuo; Rossi, F.; Rodriguez, D.; Takamine, Jun; Seya, Michio; Bogucarska, T.*; Crochemore, J.-M.*; Varasano, G.*; Abbas, K.*; Pedersen, B.*; et al.
EUR-28795-EN (Internet), p.868 - 872, 2017/00
