Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Igarashi, Hiroshi
JAEA-Review 2020-006, 261 Pages, 2020/09
JAEA-Review-2020-006.pdf:4.42MB
A literature review was conducted on the increase in surface area of vitrified products of HLW due to the fracturing caused by cooling during glass pouring process and by mechanical impact, from the perspective of a parameter of the radionuclide release model in the performance assessment of geological disposal system studied overseas. The review was focused on the value of surface area increase factor set as a parameter in the model, the experimental work to evaluate an increase in surface area, and how the parameters on surface area were determined based on the experimental results. The surface area obtained from the experiments executed in Japan was also discussed in comparison with the overseas studies. On the basis of the investigation, the effects of various conditions on the surface area were studied, such as a diameter of vitrified product, cooling condition during and after the glass pouring, impact on vitrified products during their handling, environment after the closure of disposal facility, and others. The causes of fracturing are associated with the phenomena or events in the waste management process such as production, transport, storage, and disposal. The surface area increase factors set in the nuclide release model of the glass and their bases were reviewed. In addition, the measured values and the experimental methods for surface increase factors published so far were compared. Accordingly, the methods for measuring surface area as the bases were identified for these factors set in the models. The causes of fracturing and features of these factors were studied with respect to the relation with the waste management process. The results from the review and assessment can contribute to the expanding the knowledge for the conservative and realistic application of these factors to performance assessment, and to the developing and upgrading of safety case as a consequence.
Igarashi, Masayasu*; Matsumoto, Tomohiro*; Yagihashi, Fujio*; Yamashita, Hiroshi*; Ohara, Takashi; Hanashima, Takayasu*; Nakao, Akiko*; Moyoshi, Taketo*; Sato, Kazuhiko*; Shimada, Shigeru*
Nature Communications (Internet), 8, p.140_1 - 140_8, 2017/07
Times Cited Count：25 Percentile：64.07(Multidisciplinary Sciences)Toyama, Takeshi*; Arakawa, Dai*; Hiramatsu, Shigenori*; Igarashi, Susumu*; Lee, S.*; Matsumoto, Hiroshi*; Odagiri, Junichi*; Tejima, Masaki*; Tobiyama, Makoto*; Hashimoto, Yoshinori*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.981 - 983, 2010/05
Experiences of operating BPM's during beam commissioning at the J-PARC MR are reported. The subjects are: (1) bug report, statistics and especially the effect of a beam duct step, (2) position resolution estimation (
30 micrometers with 1 sec averaging), (3) beam based alignment.
Sato, Susumu; Miura, Akihiko; Igarashi, Zenei*; Ikegami, Masanori*; Ueno, Akira; Sako, Hiroyuki; Morishita, Takatoshi; Yoshikawa, Hiroshi; Hasegawa, Kazuo; Kobayashi, Tetsuya
Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.298 - 300, 2010/03
no abstracts in English
Miura, Akihiko; Sato, Susumu; Sako, Hiroyuki; Yoshikawa, Hiroshi; Hasegawa, Kazuo; Igarashi, Zenei*; Ikegami, Masanori*
Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.733 - 735, 2010/03
no abstracts in English
Sato, Susumu; Miura, Akihiko; Tomisawa, Tetsuo; Sako, Hiroyuki; Morishita, Takatoshi; Ueno, Akira; Hasegawa, Kazuo; Yoshikawa, Hiroshi; Igarashi, Zenei*; Ikegami, Masanori*
Proceedings of 2009 Particle Accelerator Conference (PAC '09) (DVD-ROM), p.3591 - 3593, 2009/05
Yoshimoto, Masahiro; Ueno, Tomoaki; Togashi, Tomohito; Takeda, Osamu; Kanazawa, Kenichiro; Watanabe, Masao; Yamazaki, Yoshio; Kamiya, Junichiro; Takayanagi, Tomohiro; Kuramochi, Masaya; et al.
IEEE Transactions on Applied Superconductivity, 18(2), p.297 - 300, 2008/06
Times Cited Count：4 Percentile：30.89(Engineering, Electrical & Electronic)Yamada, Fumitaka; Sonobe, Hitoshi; Igarashi, Hiroshi
JAEA-Review 2007-061, 67 Pages, 2008/02
JAEA-Review-2007-061.pdf:8.39MB
In JAEA, various systems associated with the collaboration with industries and universities are enacted. These systems have been operated considering the needs of JAEA's program, industry and academia, resultantly contributed, for example, to basic research and the project development. Activities under these systems contain personal exchanges, the publication of the accomplishments and utilization of those, in R&D concerning geological disposal technology of HLW. These activities have progressed in PNC and JNC, through JAEA. The accomplishments from these systems have contributed to the advancement of the national program on the geological disposal of HLW. In this report, the progress of the R&D under these systems was investigated from the beginning of their operation. The contribution to the R&D on geological disposal technology of HLW was also studied. On the basis of these studies, the future utilization of the systems of the collaboration was also discussed.
Ikegami, Masanori*; Lee, S.*; Akikawa, Hisashi*; Igarashi, Zenei*; Kondo, Yasuhiro; Okawa, Tomohiro; Ueno, Akira; Sako, Hiroyuki; Ao, Hiroyuki; Sato, Susumu; et al.
KEK Proceedings 2006-15 (CD-ROM), p.347 - 349, 2007/03
We plan to start the beam commissioning of J-PARC linac with reduced energy of 181 MeV in the end of this year. Detailed commissioning strategies for the linac and the succeeding beam transport line, to which we refer as L3BT or Linac-to-3-GeV-synchrotron Beam Transport, will be presented in this talk. The emphasis will be put on the commissioning procedures for two debuncher cavities and a transverse collimator system located in L3BT, because they are key elements in determining the final beam quality at the injection point to the succeeding 3-GeV synchrotron. The unique design and features of the collimator system are also presented.
Ishikawa, Hirohisa; Igarashi, Hiroshi; Umeki, Hiroyuki; Shimizu, Kazuhiko; Miyahara, Kaname; Ishimaru, Tsuneari; Mitsui, Seiichiro
Proceedings of 6th Pacific Rim Conference on Ceramic and Glass Technology (PacRim6) (CD-ROM), 17 Pages, 2006/09
Final disposal of high-level radioactive waste is essential issue to utilize nuclear energy. JNC has promoted the research and development on disposal technology to contribute to the implementation and safety regulation in the implementation phase after the legislation of the Act on final disposal. The field of the R&D covers geological environment, engineering of geological disposal and performance assessment. As to the two underground laboratories (URLs), surface-based investigations have been carried out and the constructions of both have already started. On the basis of these investigations, geologic environmental models have been developed. The study on natural phenomena such as volcanism and faulting has been conducted. In the above ground research facilities, the development of advanced models, databases for the long-term evolution of the near-field and engineering technologies has been carried out. In terms of safety assessment methodologies, development of relevant databases and advanced safety assessment models and techniques has been carried out. The H17 report will be published in autumn 2005 for the studies conducted in the surface-based investigation phase at the URLs.
Watanabe, Masao; Irie, Yoshiro; Kamiya, Junichiro; Shimada, Taihei; Takayanagi, Tomohiro; Fujimori, Hiroshi*; Igarashi, Susumu*; Kawakubo, Toshimichi*; Nakayama, Hisayoshi*
IEEE Transactions on Applied Superconductivity, 16(2), p.1350 - 1353, 2006/06
Times Cited Count：2 Percentile：18.89(Engineering, Electrical & Electronic)Thick septa are used in the injection and extraction section of the 3 GeV rapid cycling synchrotron of the J-PARC. We have been designing seven thick septum magnets, two for injection, two for beam dump and three for extraction, respectively. These septa require low-loss operations. For the mechanical stability they are operated by direct current. The yoke is made of the soft-iron block. We have been designing them by using the three-dimensional magnet static field calculation code, TOSCA. In this presentation, we discuss about magnetic field flatness in the gap and effects of the leakage fields in the synchrotron.
Sato, Susumu; Tomisawa, Tetsuo; Hiroki, Fumio; Lee, S.*; Igarashi, Zenei*; Ikegami, Masanori*; Ueno, Akira; Kondo, Yasuhiro; Hasegawa, Kazuo; Toyama, Takeshi*; et al.
Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.467 - 469, 2004/08
As a joint project of KEK and JAERI, a MW class of high intensity proton accelerator (J-PARC), consisting of Linac, 3 GeV-RCS, 50 GeV-MR, is under construction. For this accelerator, it is required to minimize the beam loss (typically, lower than0.1
1 W/m at the linac). To achieve the requirement, beam trajectory needs to be controlled with accuracy of some 100 
m. The first stage of the acceleration (up to 181 MeV during the first stage of construction) is done by linac. The beam position monitor (BPM) in the linac utilizes 4 stripline pickups (50 ohm) on the beam transportation chamber. In this paper, systematic calibration of the BPM is described.
Sato, Susumu; Igarashi, Zenei*; Lee, S.*; Tomisawa, Tetsuo; Hiroki, Fumio; Kishiro, Junichi; Ikegami, Masanori*; Kondo, Yasuhiro; Hasegawa, Kazuo; Ueno, Akira; et al.
Proceedings of 22nd International Linear Accelerator Conference (LINAC 2004), p.429 - 431, 2004/00
As a joint project of KEK and JAERI, a MW class of high intensity proton accelerator (J-PARC), consisting of Linac, 3 GeV-RCS, 50 GeV-MR, is under construction at Tokai, Japan. For this accelerator, it is required to minimize the beam loss (typically, lower than 0.11 W/m at the linac). To achieve the requirement, beam trajectory needs to be controlled with accuracy of some 100 micro-meter. The first stage of the acceleration (up to 181 MeV during the first stage of construction) is done by linac. The beam position monitor (BPM) in the linac utilizes 4 strip-line pickups (50 ohm) on the beam transportation chamber. In this paper, systematic calibration of the BPM is described.
Bi at intermediate energiesHaba, Hiromitsu; Kasaoka, Makoto*; Igarashi, Manabu*; Washiyama, Koshin*; Matsumura, Hiroshi*; Oura, Yasuji*; Shibata, Seiichi*; Sakamoto, Ko*; Furukawa, Michiaki*; Fujiwara, Ichiro*
Radiochimica Acta, 90(7), p.371 - 382, 2002/08
Times Cited Count：2 Percentile：17.03(Chemistry, Inorganic & Nuclear)The reaction yields of 63 radionuclides with the mass number A = 56-135 produced in the photofission of Bi by bremsstrahlung of end-point energies (E
) from 450 to 1100 MeV have been measured using a catcher foil technique. The charge distribution was well reproduced by a Gaussian function with the most probable charge (Z
) expressed by Z = RA + S, and with the A-independent FWHME
. The charge distribution parameters R, S and FWHM were independent of E above 600 MeV. The weighted mean values at E 
600 MeV were R = 0.421 
0.001, S = 0.6 0.1 and FWHM = 2.1 0.1 charge unit (c.u.). Based on the charge distribution parameters, the symmetric mass yield distributions with the most probable mass A of 96 1 mass unit (m.u.) and the width FWHM
of 33 1 m.u. were also obtained. The characteristics of the charge and mass yield distributions are discussed by referring to those for 
Au based on the results of calculations using PICA3/GEM.
Igarashi, Hiroshi; Aoki, Kazuhiro; Miyahara, Kaname; Shiotsuki, Masao; Tachi, Yukio
Nihon Kikai Gakkai Dai-8-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu, p.467 - 472, 2002/06
no abstracts in English
King, C.-Y.; Azuma, S.; Igarashi, G.; Saito, Hiroshi; Wakita, H.
Journal of Geophysical Research; Solid Earth, 104(B6), p.13073 - 13082, 1999/00
Times Cited Count：102 Percentile：86.35(Geochemistry & Geophysics)None
Masaki, Toshio; ; Kobayashi, Hiroaki; Kawamura, Kazuhiro; Igarashi, Hiroshi
NO.105 P.47-55, (105), p.47 - 55, 1998/03
None
Kikuta, Seishi*; Yoda, Yoshitaka*; Koyama, Ichiro*; Shimizu, Tatsuo*; Igarashi, Hiroshi*; Izumi, Koichi*; Kunimune, Yorinobu*; Seto, Makoto*; Mitsui, Takaya; Harami, Taikan; et al.
X-Ray and Inner Shell-Processes (AIP Conference Proceedings 389), p.351 - 365, 1997/01
no abstracts in English
; Kawamura, Kazuhiro; Igarashi, Hiroshi; Ouchi, Jin
Proceedings of 5th International Conference on Radioactive Waste Management and Environmental Remediation (ICEM '95), p.389 - 393, 1995/00
None
