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Sugita, Moe; Takayanagi, Tomohiro; Ueno, Tomoaki*; Ono, Ayato; Horino, Koki*; Kinsho, Michikazu; Oguri, Hidetomo; Yamamoto, Kazami
Proceedings of 20th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.519 - 522, 2023/11
In J-PARC RCS, paint bump magnets are used to displace the beam orbit during paint injection, which produces a high intensity beam. A pattern of command current and command voltage can be used to create an output current waveform that varies the beam orbit over time. The accuracy of beam orbit control is determined by the shape difference between the command current and output current waveforms. In the current paint pattern adjustment, a deviation of 
1% or less is achieved by manual adjustment after using software that adjusts the pattern according to the response function of the power supply control. However, we would like to reduce the adjustment time. In addition, since the accuracy of paint injection is determined by the adjustment system of the paint magnet power supply, we would like to achieve output current deviation 10 times more precise than before to reduce beam loss. An analytical model of the load-side impedance is necessary to create a high-precision paint pattern, but it is very difficult to construct an analytical model because the load-side impedance changes in a time-varying nonlinear paint pattern. We used machine learning to adjust the output pattern of the paint pattern and achieved a deviation of less than 0.5% through repeated learning. This presentation will report on the current status of the system and its prospects.
Yamamoto, Kazuya; Makino, Takayoshi; Iso, Hidetoshi; Segawa, Tomoomi; Kawaguchi, Koichi; Ishii, Katsunori
JAEA-Technology 2021-002, 31 Pages, 2021/05
JAEA-Technology-2021-002.pdf:4.37MB
In the MOX fuel fabrication process, a dry recycle technology has been developed to effectively utilize dry recovered powder obtained by crushing out of specification MOX pellets. The particle size of the dry recovery powder is divided into three classes; coarse size (about 250 
m or less), medium size (about 100 m or less), and fine size (about 10 m or less) by the current crushers, and the effect of controlling the density of sintered pellets is obtained to a certain extent by adding the dry recovered powder to the raw powder. In this report, with the aim of more finely adjusting the particle size of the dry recovery powder, a buhrstone mill and a collision plate-type jet mill were selected as grinders that can adjust the dry recovered powder within a particle size range of 250 m or less, and the particle size adjustment test was conducted to pulverize the tungsten-carbide-cobalt (WC-Co) pellets as a simulated material for the MOX pellets. The buhrstone mill can control the particle size within a certain range by adjusting the grindstone clearance, but particles with a particle size of 250 m or more may be discharged. On the contrary, it is expected that the particle size of the collision plate-type jet mill can be controlled in the range of 250 m or less by adjusting the classification zone clearance. Therefore, the collision plate-type jet mill is more suitable for adjusting the particle size of the dry recovered powder than the buhrstone mill.
Segawa, Tomoomi; Yamamoto, Kazuya; Makino, Takayoshi; Iso, Hidetoshi; Kawaguchi, Koichi; Ishii, Katsunori; Sato, Hisato; Fukasawa, Tomonori*; Fukui, Kunihiro*
Proceedings of International Nuclear Fuel Cycle Conference / Light Water Reactor Fuel Performance Conference (Global/Top Fuel 2019) (USB Flash Drive), p.738 - 745, 2019/09
In the MOX fuel fabrication process, the dry grinding technology of mixed oxide pellets have been developed for the effective use of nuclear fuel materials. To develop a technology to control the particle size of dry recovered powder, the performance of the buhrstone mill and the collision plate type jet mill were studied using a simulated powder of particle size distribution about 500 m. We found that the particle size can be controlled at the range of about 250 m or less by both by adjusting the clearance between the grinding wheels of the buhrstone mill, and the clearance and elevation angle of the clarification zone of the collision plate type jet mill. And furthermore, the collision plate type jet mill is considered to be suitable for particle size control because the operating parameters of the classifier can be finely adjusted.
Yokoyama, Kenji; Sugino, Kazuteru; Ishikawa, Makoto; Maruyama, Shuhei; Nagaya, Yasunobu; Numata, Kazuyuki*; Jin, Tomoyuki*
JAEA-Research 2018-011, 556 Pages, 2019/03
JAEA-Research-2018-011.pdf:19.53MB
JAEA-Research-2018-011-appendix1(DVD-ROM).zip:433.07MBJAEA-Research-2018-011-appendix2(DVD-ROM).zip:580.12MBJAEA-Research-2018-011-appendix3(DVD-ROM).zip:9.17MB
We have developed a new unified cross-section set ADJ2017, which is an improved version of the unified cross-section set ADJ2010 for fast reactors. The unified cross-section set is used for reflecting information of C/E values (analysis / experiment values) obtained by integral experiment analyses; the values are stored in the standard database for FBR core design via the cross-section adjustment methodology, which integrates with the information such as uncertainty (covariance) of nuclear data, uncertainty of integral experiment / analysis, sensitivity of integral experiment with respect to nuclear data. The ADJ2017 is based on Japan's latest nuclear data library JENDL-4.0 as in the previous version of ADJ2010, and it incorporates more information on integral experimental data sets related to minor actinides (MAs) and degraded plutonium (Pu). In the creation of ADJ2010, a total of 643 integral experimental data sets were analyzed and evaluated, and 488 of the integral experimental data sets were finally selected to be used for the cross-section adjustment. In contrast, we have evaluated a total of 719 data sets, and eventually adopted 620 integral experimental data sets to create ADJ2017. ADJ2017 shows almost the same performance as ADJ2010 for the main neutronic characteristics of conventional sodium-cooled MOX-fuel fast reactors. In addition, for the neutronic characteristics related to MA and degraded Pu, ADJ2017 improves the C/E values of the integral experimental data sets, and reduces the uncertainty induced by the nuclear data. ADJ2017 is expected to be widely used in the analysis and design research of fast reactors. Moreover, it is expected that the integral experimental data sets used for ADJ2017 can be utilized as a standard database of FBR core design.
Yokoyama, Kenji; Kitada, Takanori*
Journal of Nuclear Science and Technology, 56(1), p.87 - 104, 2019/01
Times Cited Count：4 Percentile：41.24(Nuclear Science & Technology)no abstracts in English
Kitatsuji, Yoshihiro
Radioisotopes, 67(10), p.483 - 493, 2018/10
Electrochemical reactions and redox properties of actinides such as uranium and neptunium are outlined. The flow electrolysis enables rapid and high-efficient treatment. It was demonstrated to measure slow processes of actinide redox. Experimental results of electrolysis of actinide ions and the preparation method of oxidation state of the ions based on the fundamental data are described. Mediator reaction and catalysis observed in the process of electrolysis of actinide ions are also explained.
Yokoyama, Kenji
Robutsuri No Kenkyu (Internet), (70), 12 Pages, 2018/04
no abstracts in English
Yokoyama, Kenji; Yamamoto, Akio*
Journal of Nuclear Science and Technology, 53(10), p.1622 - 1638, 2016/10
Times Cited Count：10 Percentile：68.36(Nuclear Science & Technology)On the basis of the minimum variance approach, the unified formulation for three types of the cross-section adjustment methods has been derived in a straightforward way without assuming the normal distribution. These methods are intended to minimize the variances of the predicted target core parameters, the adjusted cross-section set, and the calculated integral experimental values. The first and the second methods are found to be slightly different from the extended and the conventional cross-section adjustment methods based on the Bayesian approach with the normal distribution assumption, respectively. However, they become equivalent in some cases and results. The third method is a new method, which is necessary from the viewpoint of the symmetry of the formulation. The derivation procedure proposed in the present paper is potentially applicable to developing more sophisticated cross-section adjustment methods because of the less assumptions on the probability density function.
Iwamoto, Hiroki; Nishihara, Kenji; Katano, Ryota*; Fukushima, Masahiro; Tsujimoto, Kazufumi
JAEA-Research 2014-033, 82 Pages, 2015/03
JAEA-Research-2014-033.pdf:6.53MB
The effect of experiments using Transmutation Physics Experimental Facility (TEF-P) is analysed from the viewpoint of the reduction of uncertainties in reactor physics parameters (criticality and coolant void reactivity) of an accelerator-driven system (ADS). The analysis is conducted by the nuclear-data adjustment method using JENDL-4.0 on the assumption that ve types of reactor physics experiments (a total of 44 experiments) are performed in TEF-P: (1) criticality experiment, (2) lead void reactivity experiment, (3) reaction rate ratio experiment, (4) sample reactivity experiment, and (5) fuel replacement reactivity experiment. As the result, 1.0% of uncertainty in criticality is found to be reduced to approximately 0.4%, and effective experiments for the reduction of uncertainty in criticality and coolant void reactivity are shown to be fuel replacement reactivity experiments and lead void reactivity experiments, respectively. Although these effects depend largely on the composition and amount of minor-actinide (MA) fuels, it is found that a combination of different types of experiments and database of existing experiments is effective in reducing the uncertainties.
Aoyagi, Hisao*; Kitatsuji, Yoshihiro; Yoshida, Zenko; Kihara, Sorin*
Analytica Chimica Acta, 538(1-2), p.283 - 289, 2005/05
Times Cited Count：15 Percentile：41.62(Chemistry, Analytical)Redox behavior of Np(III), (IV), (V) and (VI) ions in aqueous perchloric, nitric and sulphuric acid solutions was elucidated by using column electrodes connected in series in a flow system. Using a glassy carbon fiber working electrode as the column electrode was found to be very useful for the investigation of current-potential relations of not only reversible redox processes such as Np(VI)/(V) or Np(IV)/(III) but also irreversible processes such as Np(V)/(IV) or Np(V)/(III), the latter not observed by conventional voltammetry which uses a glassy carbon or platinum electrode. Quantitative electrolysis could be executed even if the redox process was completely irreversible by the use of the column electrodes. By taking advantage of column electrode electrolysis, a novel method was developed for the rapid preparation of a neptunium species of a desired oxidation state, including unstable species. The multi-step column electrode system was demonstrated to be useful for the coulometric determination and speciation of Np(IV), (V) and (VI) in aqueous HNO
solution as an example.
Oshima, Takayuki; Iwasaki, Keita*; Shimizu, Kazuaki
Heisei-14-Nendo Tokyo Daigaku Sogo Gijutsu Kenkyukai Gijutsu Hokokushu, 3 Pages, 2003/03
no abstracts in English
Ishikawa, Nobuyuki; Abe, Kenichi*
Denki Gakkai Rombunshi, C, 123(2), p.317 - 323, 2003/02
This paper presents a method of designing a feedforward element of 2DOF controller based on the approximation in time domain. Since we deal with the discrete-time 2DOF controller parameterized with rational stable function, the relation of the controller parameter and output sequence is expressed in the form of simple linear equation, through which the feedforward element of 2DOF controller can be designed. In addition, we also propose a controller parameter tuning method to enhance the reference response characteristics of control system by applying the iterative solution commonly utilized in numerical calculation. The results of the numerical simulation show the effectiveness of the proposed methods.
Takamura, Shuichi*; Wakatani, Masahiro*; Ninomiya, Hiromasa; Kamada, Yutaka; Yatsu, Kiyoshi*; Hatae, Takaki; Sugihara, Masayoshi; Iio, Shunji*; Ozeki, Takahisa; Kawano, Yasunori
Purazuma, Kaku Yugo Gakkai-Shi, 79(1), P. 70, 2003/01
no abstracts in English
Ninomiya, Hiromasa; Takamura, Shuichi*; Wakatani, Masahiro*; Fujita, Takaaki; Fukuda, Takeshi; Toi, Kazuo*; Ogawa, Yuichi*; Takizuka, Tomonori; Miura, Yukitoshi; Hatae, Takaki; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 78(7), p.692 - 694, 2002/07
The second ITPA (International Tokamak Physics Activity) meeting was held at General Atomics (San Diego) and Princeton Plasma Physics Laboratory (Princeton) in U.S.A. In the meeting, topical physics group meetings of "Coordinating Committee", "Transport and Internal Barrier Physics", "Confinement Database and Modeling", "Edge and Pedestal Physics", "Scrape-off-layer and Divertor Physics", and "Diagnostics" were carried out. In getting many participants from Japan, Europe, Russia, ITER international team and U.S.A., the active discussions were carried out. On the other hand, the topical group members concerned that the contribution from Japan will be decreased if the experimental period of JT-60U is reduced. Here, the outline of discussions in each topical group is reported.
Yagyu, Junichi; Arai, Takashi; Kaminaga, Atsushi; Kizu, Kaname; Arai, Masaru*; Miya, Naoyuki
Proceedings of 19th IEEE/NPSS Symposium on Fusion Engineering (SOFE), p.388 - 391, 2002/00
no abstracts in English
Yokota, Wataru; Fukuda, Mitsuhiro; Okumura, Susumu; Arakawa, Kazuo; Ishibori, Ikuo; Nara, Takayuki; Agematsu, Takashi; Tamura, Hiroyuki; Kurashima, Satoshi; Nakamura, Yoshiteru; et al.
JAERI-Review 2000-024, TIARA Annual Report 1999, p.273 - 275, 2000/10
no abstracts in English
Shiba, Kiyoyuki; Klueh, R. L.*; Miwa, Yukio; Igawa, Naoki; Robertson, J. P.*
Fusion Materials Semiannual Progress Report (DOE/ER-0313/28), p.131 - 135, 2000/06
no abstracts in English
; Numata, Kazuyuki*; ; *; Oigawa, Hiroyuki*
JNC TY9400 2000-006, 162 Pages, 2000/04
JNC-TY9400-2000-006.pdf:4.57MB
no abstracts in English
Federation of Electric Power Companies of Japan*
JNC TY1400 2000-001, 464 Pages, 2000/03
JNC-TY1400-2000-001.pdf:16.87MB
None
; ; Saikawa, Takuya*; Sukegawa, Kazuya*
JNC TN9410 2000-008, 66 Pages, 2000/03
JNC-TN9410-2000-008.pdf:1.39MB
The experimental fast reactor "JOYO" served as the MK-II irradiation bed core for testing fuel and material for FBR development for 15 years from 1982 to 1997. During the MK-II operation, impurities concentrations in the sodium and the argon gas were determined by 67 samples of primary sodium, 81 samples of secondary sodium, 75 samples of primary argon gas, 89 samples of secondary argon gas (the overflow tank) and 89 samples of secondary argon gas (the dump tank). The sodium and the argon gas purity control data were accumulated from in thirty-one duty operations, thirteen special test operations and eight annual inspections. These purity control results and related plant data were compiled into database, which were recorded on CD-ROM for user convenience. Purity control data include concentration of oxygen, carbon, hydrogen, nitrogen, chlorine, iron, nickel and chromium in sodium, concentration of oxygen, hydrogen, nitrogen, carbon monoxide, carbon dioxide, methane and helium in argon gas with the reactor condition.
