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Yabe, Takanori; Murakami, Makio; Shiota, Yuki; Isobe, Yuta; Shiohama, Yasutaka; Hamano, Tomoharu; Takagi, Tsuyohiko; Nagaoki, Yoshihiro
JAEA-Technology 2022-002, 66 Pages, 2022/07
In the first stage of "Monju" decommissioning project, "Fuel Unloading Operations" have been carrying out. The operations consists of two processes. The first process is "Fuel Treatment and Storage" is that the fuel assemblies unloaded from the Ex-Vessel fuel Storage Tank are canned after sodium cleaning, and then transferred to the storage pool. The second process is "Fuel Unloading" that the fuel assemblies in the reactor core are replaced with dummy fuel assemblies and stored in the Ex-Vessel fuel Storage Tank. "Fuel Treatment and Storage" and "Fuel Unloading" are performed alternately until 370 fuel assemblies in the core and 160 fuel assemblies in the Ex-Vessel fuel Storage Tank are all transferred to the storage pool. In fiscal 2018, as "Fuel Treatment and Storage", 86 fuel assemblies were transferred to the storage pool. As "Fuel Unloading", 76 dummy fuel assemblies were stored in the Ex-Vessel fuel Storage Tank. In fiscal 2019, as "Fuel Unloading", 60 fuel assemblies and 40 blanket fuel assemblies were unloaded from the core. These assemblies were stored in the Ex-Vessel fuel Storage Tank, and dummy fuel assemblies were loaded into the core instead. During these operations, a total of 38 cases of alarming or equipment malfunctions classified into 24 types occurred. However, no significant events that menaces to safety have occurred. The operations were continued safely by removing the direct factors for the malfunctions in the equipment operation and performance.
Shiota, Yuki; Yabe, Takanori; Murakami, Makio; Isobe, Yuta; Sato, Masami; Hamano, Tomoharu; Takagi, Tsuyohiko; Nagaoki, Yoshihiro
JAEA-Technology 2022-001, 117 Pages, 2022/07
In the first stage of Monju decommissioning project, fuel unload work began to be carried out. There are two tasks in this work. One is fuel treatment and storage work that gets rid of sodium on the fuel assemblies unloaded from Ex-Vessel fuel Storage Tank (EVST) and carries it in the storage pool, and the other is fuel unloading that the fuel assemblies in the reactor core is replaced with dummy fuels and stored in EVST. Fuel treatment and storage work and fuel unloading work are performed alternately, and 370 bodies in the core and 160 pieces in EVST are all carried to the storage pool. 86 fuel assemblies was carried to the storage pool in fuel treatment and storage work in 2018 and 76 dummy fuels were stored in EVST for fuel unloading work. During the work, 86 types and 232 alarms / malfunctions occurred, but there was no impact on safety. There was one equipment's failure at gripper's claw open / close clutch of ex-vessel fuel transfer machine B, but it was repaired and restarted. Also it was eliminated the cause of problem or concession that the equipment failure due to the sticking of the sodium compound and continuous use of the equipment. Some problems related to system control occurred, but the work was done after checking the safety. With estimation of various troubles, reduction of frequency of trouble occurrence and minimization of impacts on schedule performed.
Kubota, Takahide*; Takano, Daichi*; Kota, Yohei*; Mohanty, S.*; Ito, Keita*; Matsuki, Mitsuhiro*; Hayashida, Masahiro*; Sun, M.*; Takeda, Yukiharu; Saito, Yuji; et al.
Physical Review Materials (Internet), 6(4), p.044405_1 - 044405_12, 2022/04
Times Cited Count:5 Percentile:43.81(Materials Science, Multidisciplinary)Kawabata, Masako*; Motoishi, Shoji*; Ota, Akio*; Motomura, Arata*; Saeki, Hideya*; Tsukada, Kazuaki; Hashimoto, Shintaro; Iwamoto, Nobuyuki; Nagai, Yasuki*; Hashimoto, Kazuyuki*
Journal of Radioanalytical and Nuclear Chemistry, 330(3), p.913 - 922, 2021/12
Times Cited Count:7 Percentile:69.06(Chemistry, Analytical)Both Cu and Cu are promising radionuclides in nuclear medicine. Production yields of these radionuclides were quantified by irradiating 55.4 g of natural zinc with accelerator neutrons. Clinically suitable Cu and Cu yields were estimated by experimental based numerical simulations using 100 g of enriched Zn and Zn, respectively, and elevated neutron fluxes from 40 MeV, 2 mA deuterons. A combined thermal- and resin-separation method was developed to isolate Cu and Cu from zinc, resulting in 73% separation efficiency and 97% zinc recovery. Such methods can provide large scale production of Cu and Cu for clinical applications.
Kubota, Takahide*; Shimada, Yusuke*; Tsuchiya, Tomoki*; Yoshikawa, Tomoki*; Ito, Keita*; Takeda, Yukiharu; Saito, Yuji; Konno, Toyohiko*; Kimura, Akio*; Takanashi, Koki*
Nanomaterials (Internet), 11(7), p.1723_1 - 1723_11, 2021/07
Times Cited Count:2 Percentile:13.44(Chemistry, Multidisciplinary)Sakoda, Akihiro; Kataoka, Noriaki*; Ishikawa, Junya*; Ota, Akio*; Suzuki, Tatsuhiko*; Nishiyama, Yuichi*; Hirouchi, Jun; Hokama, Tomonori
Hoken Butsuri, 51(3), p.181 - 186, 2016/09
The 49th annual meeting of the Japan Health Physics Society was held in Hirosaki, Aomori between June 30th and July 1st, 2016. This article gives the report on all of twelve special sessions in this meeting.
Tanase, Masakazu*; Fujisaki, Saburo*; Ota, Akio*; Shiina, Takayuki*; Yamabayashi, Hisamichi*; Takeuchi, Nobuhiro*; Tsuchiya, Kunihiko; Kimura, Akihiro; Suzuki, Yoshitaka; Ishida, Takuya; et al.
Radioisotopes, 65(5), p.237 - 245, 2016/05
no abstracts in English
Ishida, Takuya; Shiina, Takayuki*; Ota, Akio*; Kimura, Akihiro; Nishikata, Kaori; Shibata, Akira; Tanase, Masakazu*; Kobayashi, Masaaki*; Sano, Tadafumi*; Fujihara, Yasuyuki*; et al.
JAEA-Technology 2015-030, 42 Pages, 2015/11
The research and development (R&D) on the production of Mo/Tc by neutron activation method ((n, ) method) using JMTR has been carried out in the Neutron Irradiation and Testing Reactor Center. The specific radioactivity of Mo by (n, ) method is extremely low compared with that by fission method ((n,f) method), and as a result, the radioactive concentration of the obtained Tc solution is also lowered. To solve the problem, we propose the solvent extraction with methyl ethyl ketone (MEK) for recovery of Tc from Mo produced by (n, ) method. We have developed the Mo/Tc separation/extraction/concentration devices and have carried out the performance tests for recovery of Tc from Mo produced by (n, ) method. In this paper, in order to establish an experimental system for Mo/Tc production, the R&D results of the system are summarized on the improvement of the devices for high-recovery rate of Tc, on the dissolution of the pellets, which is the high-density molybdenum trioxide (MoO) pellets irradiated in Kyoto University Research Reactor (KUR), on the production of Tc, and on the inspection of the recovered Tc solutions.
Hashimoto, Kazuyuki; Nagai, Yasuki; Kawabata, Masako; Sato, Nozomi*; Hatsukawa, Yuichi; Saeki, Hideya; Motoishi, Shoji*; Ota, Masayuki; Konno, Chikara; Ochiai, Kentaro; et al.
Journal of the Physical Society of Japan, 84(4), p.043202_1 - 043202_4, 2015/04
Times Cited Count:8 Percentile:51.89(Physics, Multidisciplinary)Kawabata, Masako; Nagai, Yasuki; Hashimoto, Kazuyuki; Saeki, Hideya; Motoishi, Shoji*; Sato, Nozomi*; Ota, Akio*; Shiina, Takayuki*; Kawauchi, Yukimasa*
Journal of the Physical Society of Japan, 84(2), p.023201_1 - 023201_4, 2015/02
Times Cited Count:6 Percentile:44.19(Physics, Multidisciplinary)Tc for medical use can be separated by thermochromatography from a molten MoO sample. Effect of moist oxygen gas on the Tc release from molten MoO samples was investigated using a Mo/Tc generator. Mo was produced with Mo(n,2n)Mo. A new phenomenon has been observed: release rate, separation- and recovery-efficiencies of Tc were higher in the moist oxygen gas than those in the dry oxygen gas. The present result is a significant progress towards the stable production of a high quality Tc from a molten MoO sample with high separation efficiency. The result would also give us a new insight into the interaction between the moist oxygen gas and the molten MoO.
Nishikata, Kaori; Kimura, Akihiro; Ishida, Takuya; Shiina, Takayuki*; Ota, Akio*; Tanase, Masakazu*; Tsuchiya, Kunihiko
JAEA-Technology 2014-034, 34 Pages, 2014/10
As a part of utilization expansion after the Japan Material Testing Reactor (JMTR) re-start, research and development (R&D) on the production of medical radioisotope Mo/Tc by (n, ) method using JMTR has been carried out in the Neutron Irradiation and Testing Reactor Center of the Japan Atomic Energy Agency. Mo is usually produced by fission method. On the other hand, Mo/Tc production by the (n, ) method has advantages for radioactive waste, cost reduction and non-proliferation. However, the specific radioactivity per unit volume by the (n, ) method is low compared with the fission method, and that is the weak point of the (n, ) method. This report summarizes the investigation of raw materials, the fabrication tests of high-density MoO pellets by the plasma sintering method for increasing of Mo contents and the characterization of sintered high-density MoO pellets.
Shimazaki, Kazunori*; Kobayashi, Yuki*; Takahashi, Masato*; Imaizumi, Mitsuru*; Murashima, Mio*; Takahashi, Yu*; Toyota, Hiroyuki*; Kukita, Akio*; Oshima, Takeshi; Sato, Shinichiro; et al.
Proceedings of 40th IEEE Photovoltaic Specialists Conference (PVSC-40) (CD-ROM), p.2149 - 2154, 2014/06
The electrical performance of a glass-type space solar sheet (G-SSS) was demonstrated in space. G-SSS comprises InGaP/GaAs dual-junction and InGaP/GaAs/InGaAs triplejunction solar cells. It is lightweight solar generation sheet, less than 0.5 mm thick. It is mounted on the "HISAKI" (SPRINT-A) small scientific satellite, which was launched on September 14, 2013. The initial flight data were successfully acquired and this flight demonstration was a world-first experiment for G-SSS using III-V multi-junction thin-film solar cells. The cells demonstrated superior performance and the electrical outputs matched the flight prediction.
Kimura, Akihiro; Awaludin, R.*; Shiina, Takayuki*; Tanase, Masakazu*; Kawauchi, Yukimasa*; Gunawan, A. H.*; Lubis, H.*; Sriyono*; Ota, Akio*; Genka, Tsuguo; et al.
Proceedings of 3rd Asian Symposium on Material Testing Reactors (ASMTR 2013), p.109 - 115, 2013/11
Tc is generated by decay of Mo. Production of Mo is carried out by (n,f) method with high enriched uranium targets, and the production are currently producing to meet about 95% of global supply. Recently, it is difficult to carry out a stable supply for some problems such as aging of reactors etc. Furthermore, the production has difficulties in nuclear proliferation resistance etc. Thus, (n,) method has lately attracted considerable attention. The (n,) method has several advantages, but the extremely low specific activity makes its uses less convenient than (n,f) method. We proposed a method based on the solvent extraction, followed by adsorption of Tc with alumina column. In this paper, a practical production of Tc was tried by the method with 1Ci of Mo produced in MPR-30. The recovery yields were approximately 70%. Impurity of Mo was less than 4.010% and the radiochemical purity was over 99.2%.
Hiroki, Akihiro; Sato, Yuichi*; Nagasawa, Naotsugu; Ota, Akio*; Seito, Hajime; Yamabayashi, Hisamichi*; Yamamoto, Takayoshi*; Taguchi, Mitsumasa; Tamada, Masao; Kojima, Takuji
Physics in Medicine & Biology, 58(20), p.7131 - 7141, 2013/10
Times Cited Count:20 Percentile:59.19(Engineering, Biomedical)Kimura, Akihiro; Awaludin, R.*; Shiina, Takayuki*; Tanase, Masakazu*; Kawauchi, Yukimasa*; Gunawan, A. H.*; Lubis, H.*; Sriyono*; Ota, Akio*; Genka, Tsuguo; et al.
Proceedings of 6th International Symposium on Material Testing Reactors (ISMTR-6) (Internet), 7 Pages, 2013/10
JP, 2011-173260 Patent publication (In Japanese)This research is development of Tc production. Tc is generated by decay of Mo. The supply of Mo in Japan depends entirely on the import from foreign countries. Thus, it is needed to supply Mo stably by the domestic manufacturing. A practical production of Tc was tried by the method with 1 Ci of Mo produced in MPR-30. The results showed that the recovery yields were approximately 70%. The concentration of the product obtained was estimated to be corresponding to about 30 GBq (800 mCi)/ml when 150g of MoO was irradiated for 5 days in MPR-30. Impurity of Mo was less than 4.410%, which was lower than that of Japanese tentative regulation criteria. The radiochemical purity was higher than 99.8% that cleared the tentative regulation (95%) of Japan.
Tsuchiya, Kunihiko; Nishikata, Kaori; Tanase, Masakazu*; Shiina, Takayuki*; Ota, Akio*; Kobayashi, Masaaki*; Yamamoto, Asaki*; Morikawa, Yasumasa*; Takeuchi, Nobuhiro*; Kaminaga, Masanori; et al.
Proceedings of 6th International Symposium on Material Testing Reactors (ISMTR-6) (Internet), 9 Pages, 2013/10
no abstracts in English
Nagai, Yasuki; Hashimoto, Kazuyuki; Hatsukawa, Yuichi; Saeki, Hideya; Motoishi, Shoji; Sonoda, Nozomi; Kawabata, Masako; Harada, Hideo; Kin, Tadahiro*; Tsukada, Kazuaki; et al.
Journal of the Physical Society of Japan, 82(6), p.064201_1 - 064201_7, 2013/06
Times Cited Count:45 Percentile:85.48(Physics, Multidisciplinary)Nishikata, Kaori; Kimura, Akihiro; Shiina, Takayuki*; Ota, Akio*; Tanase, Masakazu*; Tsuchiya, Kunihiko
Proceedings of 2012 Powder Metallurgy World Congress & Exhibition (PM 2012) (CD-ROM), 8 Pages, 2013/02
The renewed Japan Materials Testing Reactor (JMTR) will be started from 2012, and it is expected to contribute to many nuclear fields. Especially, in case of Japan, the supplying of Mo depends on imports from foreign countries. Japan Atomic Energy Agency (JAEA) has a plan to produce Mo, which is the parent nuclide of radiopharmaceutical Tc, and JAEA has performed the R&D for Mo production by (n,) method in JMTR. Generally, molybdenum oxide (MoO) is the most popular chemical form as irradiation target for the Mo production. However, the Mo production capacity is low because of low (n,) cross section and isotope composition of Mo in Mo. Thus, it is necessary to fabricate the MoO pellets with high density for the increase of the Mo production amount. In this study, MoO pellets fabricated by a plasma activated sintering were developed and characterization of MoO pellets was carried out.
Nakamura, Toshiyuki*; Matsuda, Yasuhiro*; Her, J.-L.*; Kindo, Koichi*; Michimura, Shinji*; Inami, Toshiya; Mizumaki, Masaichiro*; Kawamura, Naomi*; Suzuki, Motohiro*; Chen, B.*; et al.
Journal of the Physical Society of Japan, 81(11), p.114702_1 - 114702_11, 2012/11
Times Cited Count:11 Percentile:56.91(Physics, Multidisciplinary)The X-ray absorption and magnetic circular dichroism (MCD) spectra at the Yb L edge were measured in the mixed-valent heavy fermion compound YbAgCu at high magnetic fields and low temperatures. The magnetic-field-temperature (H-T) phase boundary determined by the valence state is in very good agreement with that determined by the magnetization. It is clearly found that the metamagnetism of this compound is due to the field induced valence transition. A distinctive positive peak of the XMCD spectra appears in the vicinity of the white line of the absorption due to Yb state, while no feature is observed in the XMCD spectra corresponding to the Yb state. A small negative XMCD peak was observed at a lower energy and was attributed to the quadrupole trasition from theoretical calcuration, which explains its peculicar magnetic field dependence.
Tanase, Masakazu*; Shiina, Takayuki*; Kimura, Akihiro; Nishikata, Kaori; Fujisaki, Saburo*; Ota, Akio*; Kobayashi, Masaaki*; Yamamoto, Asaki*; Kawauchi, Yukimasa*; Tsuchiya, Kunihiko; et al.
Proceedings of 5th International Symposium on Material Testing Reactors (ISMTR-5) (Internet), 9 Pages, 2012/10
Tc is used as a radiopharmaceutical and manufactured from the parent nuclide of Mo. Extraction method of Tc from (n, ) Mo have been developed, as a part of the industrial use expansion after JMTR will re-start. In this research, the method proposed would be applicable to a practical production of Tc obtained from (n, ) Mo in large quantities. The method proposed would be applicable to a practical production of Tc obtained from (n, ) Mo in large quantities.