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Nakamura, Kinya*; Ogata, Takanari*; Kikuchi, Hironobu; Iwai, Takashi; Nakajima, Kunihisa; Kato, Tetsuya*; Arai, Yasuo; Uozumi, Koichi*; Hijikata, Takatoshi*; Koyama, Tadafumi*; et al.
Nihon Genshiryoku Gakkai Wabun Rombunshi, 10(4), p.245 - 256, 2011/12
Sodium-bonded metallic fuel elements were fabricated for the first time in Japan for the irradiation test in the experimental fast test reactor JOYO. U-20Pu-10Zr fuel slugs of 200 mm in length and approximately 5 mm in diameter were fabricated in a small-scale injection casting furnace. Each fuel slug was loaded into the ferritic martenstic stainless steel (PNC-FMS) cladding tube with the sodium thermal bond, thermal insulator and reflector in a helium gas atmosphere glove box. After top-end plug welding to the cladding tube and heat treatment of the welding area, each fuel element was subjected to the sodium bonding process. After the inspection such as element length, gas plenum length and helium-leak tightness, six metallic fuel elements are transported to the JOYO site for the coming irradiation test.
Nakamura, Kinya*; Ogata, Takanari*; Kikuchi, Hironobu; Iwai, Takashi; Nakajima, Kunihisa; Kato, Tetsuya*; Arai, Yasuo; Koyama, Tadafumi*; Itagaki, Wataru; Soga, Tomonori; et al.
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 8 Pages, 2011/12
CRIEPI and JAEA have fabricated sodium-bonded metallic fuel elements for the first time in Japan as a collaborative research, for use in the irradiation test at the experimental fast test reactor Joyo. The irradiation test aims to assess the irradiation behavior of the fuel and the internal wastage of the stainless-steel cladding by rare-earth fission products at a maximum cladding temperature above 873 K. U-20 wt% Pu-10 wt% Zr alloy fuel slugs of 200 mm length were fabricated in an injection-casting furnace using U metal, U-Pu alloy and Zr metal. Two types of fuel slug were fabricated, i.e., 5.05 mm and 4.95 mm in diameter, and loaded into a ferritic-martensitic stainless-steel cladding tubes, respectively. After top-end-plug welding to the cladding tube, each fuel element was subjected to sodium bonding to fill the annular gap between the fuel slug and the cladding with melted sodium. The fabrication results indicated that the characteristics of the fuel elements were within the required specifications.
Maeda, Shigetaka; Yamamoto, Masaya; Soga, Tomonori; Sekine, Takashi; Aoyama, Takafumi
Journal of Nuclear Science and Technology, 48(4), p.693 - 700, 2011/04
Core modification was investigated to further increase the core burn-up of the experimental fast reactor Joyo. This modification also enables the core to accommodate more irradiation test subassemblies that have lower fissile material content compared to the driver fuel. The design calculations showed that the replacement of the radial reflector elements made of stainless steel with those made of zirconium of nickel-base ally is effective in improving neutron efficiency. The irradiation tests capacity can be increased by reducing the number of control rods based on the re-evaluation of the design margin in the control rod worth calculation. These modifications will be useful to save driver fuels and to enhance the Joyo's irradiation capability.
Donomae, Takako; Katsuyama, Kozo; Tachi, Yoshiaki; Maeda, Koji; Yamamoto, Masaya; Soga, Tomonori
Journal of Nuclear Science and Technology, 48(4), p.580 - 584, 2011/04
One of the challenges in developing a long-life control rod is to restrain absorber-cladding mechanical interaction (ACMI). Its lifetime was limited by ACMI, which is induced by the swelling and relocation of B
C pellets. To restrain ACMI, a shroud tube was inserted into the gap between the BC pellets and the cladding tube. And sodium was selected as bonding material instead of helium to restrain increases in the pellet temperature. As a result of these improvements, the estimated lifetime of the control rod at Joyo was doubled. In this paper, the results of post irradiation examination are reported.
Maeda, Yukimoto; Ito, Chikara; Soga, Tomonori
Transactions of the American Nuclear Society, 102(1), p.742 - 743, 2010/06
The experimental fast reactor Joyo is the first sodium cooled fast reactor in Japan. Irradiation tests in Joyo were commenced from 1983 after the completion of core conversion work from the MK-I breeder core to the MK-II irradiation test bed core. Many valuable irradiation tests were carried out to develop fuels and materials for the prototype fast reactor Monju and a demonstration fast reactor. After the 35 duty cycles operation by the MK-II core, Joyo was upgraded to the high performance MK-III core to increase irradiation capability in 2003. Unique irradiation tests for the FaCT project such as MA bearing MOX fuel and ODS ferritic steel were carried out in the MK-III core. In light of the shutdown of several fast reactors around the world, the ability to make such major contributions to reactor development takes on even greater significance. Irradiation tests in Joyo contribute to the FaCT project, and also to promote the international cooperation such as Generation-IV.
Matsui, Yoshinori; Takahashi, Hiroyuki; Yamamoto, Masaya; Nakata, Masahito; Yoshitake, Tsunemitsu; Abe, Kazuyuki; Yoshikawa, Katsunori; Iwamatsu, Shigemi; Ishikawa, Kazuyoshi; Kikuchi, Taiji; et al.
JAEA-Technology 2009-072, 144 Pages, 2010/03
JAEA-Technology-2009-072.pdf:45.01MB
"R&D Project on Irradiation Damage Management Technology for Structural Materials of Long-life Nuclear Plant" was carried out from FY2006 in a fund of a trust enterprise of the Ministry of Education, Culture, Sports, Science and Technology. The coupled irradiations or single irradiation by JOYO fast reactor and JRR-3 thermal reactor were performed for about two years. The irradiation specimens are very important materials to establish of "Evaluation of Irradiation Damage Indicator" in this research. For the acquisition of the examination specimens irradiated by the JOYO and JRR-3, we summarized about the overall plan, the work process and the results for the study to utilize these reactors and some facilities of hot laboratory (WASTEF, JMTR-HL, MMF and FMF) of the Oarai Research-and-Development Center and the Nuclear Science Research Institute in the Japan Atomic Energy Agency.
Soga, Tomonori; Sekine, Takashi; Tanaka, Kosuke; Kitamura, Ryoichi; Aoyama, Takafumi
Journal of Power and Energy Systems (Internet), 2(2), p.692 - 702, 2008/00
The mixed oxide containing minor actinides (MA-MOX) fuel irradiation program is being conducted using Joyo. Two irradiation experiments were conducted in the MK-III 3rd operational cycle. Six prepared fuel pins included MOX fuel containing americium, MOX fuel containing americium and neptunium, and reference MOX fuel. The first test was conducted with high linear heat rates of 430 W/cm maintained during only 10 minutes in order to confirm whether or not fuel melting occurred. After 10 minutes irradiation in May 2006, the test subassembly was transferred to the hot cell facility and two test pins were replaced with dummy pins. The test subassembly loaded with the remaining four fuel pins was re-irradiated in Joyo for 24 hours in August 2006 to obtain re-distribution data on MA-MOX fuel. Linear heat rates for each pin were calculated using MCNP. Post irradiation examination of these pins to confirm the irradiation behavior of MA-MOX fuel is underway.
Soga, Tomonori; Sekine, Takashi; Takamatsu, Misao; Kitamura, Ryoichi; Aoyama, Takafumi
UTNL-R-0453, p.13_1 - 13_8, 2006/03
no abstracts in English
Takamatsu, Misao; Itagaki, Wataru; Soga, Tomonori; Sekine, Takashi; Aoyama, Takafumi
no journal, ,
no abstracts in English
Soga, Tomonori; Kitamura, Ryoichi; Abe, Kazuyuki; Koyama, Shinichi; Kato, Masato
no journal, ,
no abstracts in English
Wootan, D. W.; Sekine, Takashi; Soga, Tomonori; Aoyama, Takafumi
no journal, ,
Methods for performing detailed linear heat rate calculations for MA-MOX fuel irradiation tests in the Joyo MK-III core using MCNP were developed that include heterogeneous geometry modeling and account for the generation, transport, and eventual deposition of the prompt and delayed neutron, 
ray, and charged particle energy contributions.
Okawachi, Yasushi; Sugino, Kazuteru; Sekine, Takashi; Soga, Tomonori; Kitamura, Ryoichi; Aoyama, Takafumi
no journal, ,
A mixed oxide containing minor actinides fuel irradiation program is being conducted using the experimental fast reactor Joyo to develop a low decontamination TRU fuel cycle technology. In the program, irradiation test subassemblies were fabricated, which contains test fuel pins including MOX fuel containing 5% americium in maximum and MOX fuel containing 2% americium and 2% neptunium. Short-term and steady-state irradiation experiments were planned in Joyo. The short-term test of 10 minutes irradiation was conducted in May 2006 to research early thermal behavior of MA-MOX fuel. Thus, the operation fulfilling the necessary test conditions has been achieved.
Sekine, Takashi; Soga, Tomonori; David, W.*; Koyama, Shinichi; Aoyama, Takafumi
no journal, ,
MA-MOX irradiation program is being conducted to research early thermal behavior of MA-MOX fuel. Two irradiation tests were conducted as part of the short-term phase. Six prepared fuel pins included MOX fuel containing 3 % or 5 % americium, and MOX fuel containing 2 % americium and 2 % neptunium. The first test was conducted with high linear heat rates of approximately 444 W/cm maintained during only 10 minutes. The linear heat rates for each MA-MOX test fuel pin were calculated using Monte Carlo calculation code MCNP. The calculated fission rates which adjusted by a bias factor from a dosimetry were compared with the measured data based on the Nd-148 method. The maximum linear heat rate, which was evaluated with the Nd-148 method, was approximately 438 W/cm. The test results are expected to reduce uncertainties on the design margin in the thermal design for MA-MOX fuel.
Itagaki, Wataru; Soga, Tomonori; Yamamoto, Masaya; Sekine, Takashi
no journal, ,
no abstracts in English
Soga, Tomonori; Yamamoto, Masaya; Sekine, Takashi; Aoyama, Takafumi
no journal, ,
The standard control rod in the fast reactor bundles the control elements which contain boron carbide pellets as neutron absorber in the stainless steel cladding tube. The lifetime of the control rod in the experimental fast reactor Joyo, is limited to approximately 40
10
/cm
by the Absorber Cladding Mechanical Interaction (ACMI) which originates from relocation and swelling of the boron carbide pellets. The sodium bonded control rod, which has a shroud tube, has been developed to attempt a lifetime extension by solving this problem as a part of the development of control rod in the fast reactor. The first sodium bonded control rod has been used since the 1st operation cycle of MK-III core. The maximum burn-up is achieved to 10010/cm which is approximately 2.5 times of the conventional control rods in Joyo.
Okawachi, Yasushi; Maeda, Shigetaka; Ito, Chikara; Soga, Tomonori; Aoyama, Takafumi
no journal, ,
no abstracts in English
Sasaki, Shinji; Maeda, Koji; Soga, Tomonori; Osato, Yukihiro*; Onuma, Yasuhiro*; Nukaga, Sadayoshi*
no journal, ,
no abstracts in English
Itagaki, Wataru; Soga, Tomonori; Baba, Shinichi; Morozumi, Katsufumi; Aoyama, Takafumi; Miyake, Osamu
no journal, ,
no abstracts in English
Abe, Kazuyuki; Katsuyama, Kozo; Soga, Tomonori; Maeda, Koji; Nagamine, Tsuyoshi; Nakamura, Yasuo
no journal, ,
The sodium bonded type control rod was developed by Joyo as part of the long-lived control rod development, and use was begun from the MK-III reactor core of Joyo. It reports on the externals observation result of the shroud tube adopted to control ACMI of BC pellet.
Soga, Tomonori; Morozumi, Katsufumi; Aoyama, Takafumi; Miyake, Osamu
no journal, ,
no abstracts in English
