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Kokubun, Yuji; Hosomi, Kenji; Nagaoka, Mika; Seya, Natsumi; Inoue, Kazumi; Koike, Yuko; Uchiyama, Rei; Sasaki, Kazuki; Maehara, Yushi; Matsuo, Kazuki; et al.
JAEA-Review 2024-054, 168 Pages, 2025/03
JAEA-Review-2024-054.pdf:2.73MB
The Nuclear Fuel Cycle Engineering Laboratories conducts environmental radiation monitoring around the reprocessing plant in accordance with the "Safety Regulations for Reprocessing Plant of JAEA, Part IV: Environmental Monitoring". This report summarizes the results of environmental radiation monitoring conducted during the period from April 2023 to March 2024 and the results of dose calculations for the surrounding public due to the release of radioactive materials from the plant into the atmosphere and ocean. In the results of the above environmental radiation monitoring, several items were affected by radioactive materials emitted from the accident at the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Company, Incorporated (changed to Tokyo Electric Power Holdings, Inc. on April 1, 2016), which occurred in March 2011. In addition, environmental monitoring plan, analysis and measurement methods, monitoring data and their chronological change, meteorological data after statistical processing, status of radioactive waste release and evaluation results of the data over the normal range are included as appendices.
Sn strand during coolingSuwa, Tomone*; Hemmi, Tsutomu*; Saito, Toru*; Takahashi, Yoshikazu*; Koizumi, Norikiyo*; Luzin, V.*; Suzuki, Hiroshi; Harjo, S.
IEEE Transactions on Applied Superconductivity, 28(3), p.6001104_1 - 6001104_4, 2018/04
Times Cited Count：1 Percentile：6.85(Engineering, Electrical & Electronic)
/D ion source for IFMIF (International Fusion Materials Irradiation Facility)Shinto, Katsuhiro; Sen
e, F.*; Ayala, J.-M.*; Bolzon, B.*; Chauvin, N.*; Gobin, R.*; Ichimiya, Ryo; Ihara, Akira; Ikeda, Yukiharu; Kasugai, Atsushi; et al.
Review of Scientific Instruments, 87(2), p.02A727_1 - 02A727_3, 2016/02
Times Cited Count：9 Percentile：39.80(Instruments & Instrumentation)Okumura, Yoshikazu; Gobin, R.*; Knaster, J.*; Heidinger, R.*; Ayala, J.-M.*; Bolzon, B.*; Cara, P.*; Chauvin, N.*; Chel, S.*; Gex, D.*; et al.
Review of Scientific Instruments, 87(2), p.02A739_1 - 02A739_3, 2016/02
Times Cited Count：8 Percentile：36.30(Instruments & Instrumentation)IFMIF is an accelerator based neutron facility having two set of linear accelerators each producing 125mA/CW deuterium ion beams (250mA in total) at 40MeV. The LIPAc (Linear IFMIF Prototype Accelerator) being developed in the IFMIF-EVEDA project consists of an injector, a RFQ accelerator, and a part of superconducting Linac, whose target is to demonstrate 125mA/CW deuterium ion beam acceleration up to 9MeV. The injector has been developed in CEA Saclay and already demonstrated 140mA/100keV deuterium beam. The injector was disassembled and delivered to the International Fusion Energy Research Center (IFERC) in Rokkasho, Japan, and the commissioning has started after its reassembly 2014; the first beam production has been achieved in November 2014. Up to now, 100keV/120mA/CW hydrogen ion beam has been produced with a low beam emittance of 0.2 
.mm.mrad (rms, normalized).
Okumura, Yoshikazu; Ayala, J.-M.*; Bolzon, B.*; Cara, P.*; Chauvin, N.*; Chel, S.*; Gex, D.*; Gobin, R.*; Harrault, F.*; Heidinger, R.*; et al.
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.203 - 205, 2015/09
Under the framework of Broader Approach (BA) agreement between Japan and Euratom, IFMIF/EVEDA project was launched in 2007 to validate the key technologies to realize IFMIF. The most crucial technology to realize IFMIF is two set of linear accelerator each producing 125mA/CW deuterium ion beams up to 40MeV. The prototype accelerator, whose target is 125mA/CW deuterium ion beam acceleration up to 9MeV, is being developed in International Fusion Research Energy Center (IFERC) in Rokkasho, Japan. The injector developed in CEA Saclay was delivered in Rokkasho in 2014, and is under commissioning. Up to now, 100keV/120mA/CW hydrogen ion beams and 100keV/90mA/CW duty deuterium ion beams are successfully produced with a low beam emittance of 0.21 .mm.mrad (rms, normalized). Delivery of RFQ components will start in 2015, followed by the installation of RF power supplies in 2015.
Shinto, Katsuhiro; Ichikawa, Masahiro; Takahashi, Hiroki; Kondo, Keitaro; Kasugai, Atsushi; Gobin, R.*; Sene, F.*; Chauvin, N.*; Ayala, J.-M.*; Marqueta, A.*; et al.
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.493 - 495, 2015/09
Development of the prototype accelerator (LIPAc) for the engineering validation of the International Fusion Materials Irradiation Facility (IFMIF) which is an accelerator driven neutron source has been progressed at Rokkasho. The LIPAc is a deuteron linear accelerator consisting of an injector, a radio-frequency quadrupole (RFQ) linac and a superconducting linac. The objective of LIPAc is to produce a CW beam with the energy and current of 9 MeV and 125 mA, respectively. The injector was developed at CEA/Saclay and succeeded to produce CW proton and deuteron beams of 100 keV/140 mA by autumn 2012. After the test at CEA/Saclay, the injector was shipped to the International Fusion Energy Research Centre (IFERC) in Rokkasho, Aomori and started to reassemble from the end of 2013. It was successfully produced proton beams in November 2014 at Rokkasho. While the ion source conditioning was done, the beam test was progressed. In this paper, the present status of the LIPAc injector at Rokkasho with some experimental results will be presented.
Ozeki, Hidemasa; Saito, Toru; Kawano, Katsumi; Takahashi, Yoshikazu; Nunoya, Yoshihiko; Yamazaki, Toru; Isono, Takaaki
Physics Procedia, 67, p.1010 - 1015, 2015/07
Times Cited Count：4 Percentile：78.11(Physics, Applied)Takahashi, Yoshikazu; Suwa, Tomone; Nabara, Yoshihiro; Ozeki, Hidemasa; Hemmi, Tsutomu; Nunoya, Yoshihiko; Isono, Takaaki; Matsui, Kunihiro; Kawano, Katsumi; Oshikiri, Masayuki; et al.
IEEE Transactions on Applied Superconductivity, 25(3), p.4200904_1 - 4200904_4, 2015/06
Times Cited Count：4 Percentile：24.12(Engineering, Electrical & Electronic)The Japan Atomic Energy Agency (JAEA) is responsible for procuring all amounts of Central Solenoid (CS) Conductors for ITER, including CS jacket sections. The conductor is cable-in-conduit conductor (CICC) with a central spiral. A total of 576 NbSn strands and 288 copper strands are cabled around the central spiral. The maximum operating current is 40 kA at magnetic field of 13 T. CS jacket section is circular in square type tube made of JK2LB, which is high manganese stainless steel with boron added. Unit length of jacket sections is 7 m and 6,300 sections will be manufactured and inspected. Outer/inner dimension and weight are 51.3/35.3 mm and around 90 kg, respectively. Eddy Current Test (ECT) and Phased Array Ultrasonic Test (PAUT) were developed for non-destructive examination. The defects on inner and outer surfaces can be detected by ECT. The defects inside jacket section can be detected by PAUT. These technology and the inspected results are reported in this paper.
Sn cable assembled with conduit for ITER central solenoidNabara, Yoshihiro; Suwa, Tomone; Takahashi, Yoshikazu; Hemmi, Tsutomu; Kajitani, Hideki; Ozeki, Hidemasa; Sakurai, Takeru; Iguchi, Masahide; Nunoya, Yoshihiko; Isono, Takaaki; et al.
IEEE Transactions on Applied Superconductivity, 25(3), p.4200305_1 - 4200305_5, 2015/06
Times Cited Count：0 Percentile：0.00(Engineering, Electrical & Electronic)Shinto, Katsuhiro; Ichikawa, Masahiro; Takahashi, Yasuyuki*; Kubo, Takashi*; Tsutsumi, Kazuyoshi; Kikuchi, Takayuki; Kasugai, Atsushi; Sugimoto, Masayoshi; Gobin, R.*; Girardot, P.*; et al.
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1009 - 1012, 2014/10
The prototype accelerator is being developed as an engineering validation for the International Fusion Materials Irradiation Facility (IFMIF) equipped with an accelerator-driven-type neutron source for developing fusion reactor materials. This prototype accelerator is a deuteron linear accelerator consisting of an injector, an RFQ, a superconducting linac and their auxiliaries. It aims to produce a CW D beam with the energy and current of 9 MeV/125 mA. The injector test was completed at CEA/Saclay in 2012 for producing a CW H beam and a CW D beam with the energy and current of 100 keV/140 mA. After the beam test at CEA/Saclay, the injector was transported to the International Fusion Energy Research Centre (IFERC) located in Rokkasho, Aomori, Japan. In the end of 2013, installation of the injector was started at IFERC for the injector beam test beginning from summer 2014 in order to obtain better beam qualities to be satisfied with the injection and acceleration of the following accelerators. In this paper, some results of the injector beam test performed at CEA/Saclay and the status quo of the installation of the injector at IFERC are presented.
Ozeki, Hidemasa; Hamada, Kazuya; Takahashi, Yoshikazu; Nunoya, Yoshihiko; Kawano, Katsumi; Oshikiri, Masayuki; Saito, Toru; Teshima, Osamu*; Matsunami, Masahiro*
IEEE Transactions on Applied Superconductivity, 24(3), p.4800604_1 - 4800604_4, 2014/06
Times Cited Count：16 Percentile：60.39(Engineering, Electrical & Electronic)
Sn conductors for toroidal field coils in ITERNabara, Yoshihiro; Hemmi, Tsutomu; Kajitani, Hideki; Ozeki, Hidemasa; Suwa, Tomone; Iguchi, Masahide; Nunoya, Yoshihiko; Isono, Takaaki; Matsui, Kunihiro; Koizumi, Norikiyo; et al.
IEEE Transactions on Applied Superconductivity, 24(3), p.6000605_1 - 6000605_5, 2014/06
Times Cited Count：7 Percentile：38.10(Engineering, Electrical & Electronic)no abstracts in English
Sn conductor for ITER central solenoidTakahashi, Yoshikazu; Nabara, Yoshihiro; Ozeki, Hidemasa; Hemmi, Tsutomu; Nunoya, Yoshihiko; Isono, Takaaki; Matsui, Kunihiro; Kawano, Katsumi; Oshikiri, Masayuki; Uno, Yasuhiro; et al.
IEEE Transactions on Applied Superconductivity, 24(3), p.4802404_1 - 4802404_4, 2014/06
Times Cited Count：28 Percentile：74.09(Engineering, Electrical & Electronic)Japan Atomic Energy Agency (JAEA) is procuring all amounts of NbSn conductors for Central Solenoid (CS) in the ITER project. Before start of mass-productions, the conductor should be tested to confirm superconducting performance in the SULTAN facility, Switzerland. The original design of cabling twist pitches is 45-85-145-250-450 mm, called normal twist pitch (NTP). The test results of the conductors with NTP was that current shearing temperature (Tcs) is decreasing due to electro-magnetic (EM) load cycles. On the other hand, the results of the conductors with short twist pitches (STP) of 25-45-80-150-450 mm show that the Tcs is stabilized during EM load cyclic tests. Because the conductors with STP have smaller void fraction, higher compaction ratio during cabling is required and possibility of damage on strands increases. The technology for the cables with STP was developed in Japanese cabling suppliers. The several key technologies will be described in this paper.
Hemmi, Tsutomu; Harjo, S.; Kajitani, Hideki; Nabara, Yoshihiro; Takahashi, Yoshikazu; Nunoya, Yoshihiko; Koizumi, Norikiyo; Abe, Jun; Gong, W.; Aizawa, Kazuya; et al.
KEK Progress Report 2013-4, p.45 - 47, 2013/11
The gradual degradation was observed in the results for ITER CS conductor samples. To investigate its origin, the internal strain in the sample after the testing was successfully measured using a neutron diffraction technique non-destructively. Up to now, the transverse electromagnetic loading has been considered as an origin of the degradation due to the local bending at the high loading side (HLS). However, as a result of the neutron diffraction measurement, the large bending at the LLS of the HFZ was found. The large bending was considered as an origin of the strand buckling due to the large void generated by the transverse electromagnetic loading and the thermally induced residual compressive strain. For the improvement of the conductor performance on the strand buckling, the shorter twisting pitch (STP) can be considered. The result of the SULTAN testing of the conductor sample with STP found very effective, and the performance degradation was negligible.
Nakajima, Hideo; Shimamoto, Susumu*; Iguchi, Masahide; Hamada, Kazuya; Okuno, Kiyoshi; Takahashi, Yoshikazu
Teion Kogaku, 48(10), p.508 - 516, 2013/10
JAEA is procuring both structural materials and structural design of Toroidal Field (TF) coil and Central Solenoid (CS) for ITER. Although 316LN is used in the most parts of the superconducting magnets system, the cryogenic stainless steels, JJ1 and JK2LB, which were newly developed by JAEA and Japanese steel companies, are used in the highest stress area of TF coil case and whole CS conductor jackets, respectively. These two materials became commercially available based on demonstration of productivity and weldability of materials, and evaluations of 4 K mechanical properties of trial products including welded parts. In order to simplify quality control in mass production, JAEA has used materials specified in the material section of "Codes for Fusion Facilities - Rules on Superconducting Magnet Structure (2008)" issued by the Japan Society of Mechanical Engineers (JSME). The design of structural materials, production technology and quality control are described in this paper.
Sn conductors for ITER central solenoidsNabara, Yoshihiro; Hemmi, Tsutomu; Kajitani, Hideki; Ozeki, Hidemasa; Iguchi, Masahide; Nunoya, Yoshihiko; Isono, Takaaki; Takahashi, Yoshikazu; Matsui, Kunihiro; Koizumi, Norikiyo; et al.
IEEE Transactions on Applied Superconductivity, 23(3), p.4801604_1 - 4801604_4, 2013/06
Times Cited Count：10 Percentile：46.63(Engineering, Electrical & Electronic)no abstracts in English
Sn conductors for ITER toroidal field coils in JapanTakahashi, Yoshikazu; Nabara, Yoshihiro; Hemmi, Tsutomu; Nunoya, Yoshihiko; Isono, Takaaki; Hamada, Kazuya; Matsui, Kunihiro; Kawano, Katsumi; Koizumi, Norikiyo; Oshikiri, Masayuki; et al.
IEEE Transactions on Applied Superconductivity, 23(3), p.4801504_1 - 4801504_4, 2013/06
Times Cited Count：11 Percentile：49.17(Engineering, Electrical & Electronic)Japan Atomic Energy Agency (JAEA) is the first to start the mass production of the TF conductors in March 2010 among the 6 parties who are procuring TF conductors in the ITER project. The height and width of the TF coils are 14 m and 9 m, respectively. The conductor is cable-in-conduit conductor (CICC) with a central spiral. A circular multistage superconducting cable is inserted into a circular stainless steel jacket with a thickness of 2 mm. A total of 900 NbSn strands and 522 copper strands are cabled around the central spiral and the cable is inserted into a round-in-round stainless steel jacket. It was observed that the cabling pitch of the destructive sample is longer than the original pitch at cabling. The JAEA carried out the tensile tests of the cable and the measurement of the cable rotation during the insertion to investigate the cause of the elongation. The cause of elongation was clarified and the results will be described in this paper.
Shimamoto, Susumu*; Nakajima, Hideo; Takahashi, Yoshikazu
Teion Kogaku, 48(2), p.60 - 67, 2013/03
JAEA started development of cryogenic structural material for Tokomak fusion reactor 30 years ago. Because, there was no specialized steel and mechanical data at 4K, JAEA settled target of mechanical characteristics which should satisfy requirements for coil structure at 4K and equipped evaluation facilities at 4K such as tensile test, fatigue test and so on. On the other hand JAEA initiated collaboration with steel industries in order to realize new cryogenic structural material and carried out mechanical evaluation at 4K on numerous samples which were supplied from industries. JAEA contributed standardization of these testing methods at 4K specified in the Japanese industrial standards (JIS). JAEA also supported to establish a construction code for structure of superconducting coil for fusion facility at the Japan Society of Mechanical Engineer (JSME), which is used in manufacture of the ITER toroidal field coil. This paper describes history over 30 years on the material development.
Sn conductors for ITER toroidal field coilsNabara, Yoshihiro; Nunoya, Yoshihiko; Isono, Takaaki; Hamada, Kazuya; Takahashi, Yoshikazu; Matsui, Kunihiro; Hemmi, Tsutomu; Kawano, Katsumi; Koizumi, Norikiyo; Ebisawa, Noboru; et al.
IEEE Transactions on Applied Superconductivity, 22(3), p.4804804_1 - 4804804_4, 2012/06
Times Cited Count：18 Percentile：64.22(Engineering, Electrical & Electronic)no abstracts in English
Nunoya, Yoshihiko; Nabara, Yoshihiro; Matsui, Kunihiro; Hemmi, Tsutomu; Takahashi, Yoshikazu; Isono, Takaaki; Hamada, Kazuya; Koizumi, Norikiyo; Nakajima, Hideo
IEEE Transactions on Applied Superconductivity, 22(3), p.4803804_1 - 4803804_4, 2012/06
Times Cited Count：0 Percentile：0.00(Engineering, Electrical & Electronic)no abstracts in English
