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Maeda, Shigetaka; Naito, Hiroyuki; Soga, Tomonori; Aoyama, Takafumi
Nuclear Data Sheets, 118, p.494 - 497, 2014/04
Times Cited Count：4 Percentile：31.29(Physics, Nuclear)The evaluation of the spatial distribution of 
heating in fast reactors requires consideration of all the intensity components. However, the delayed ray yield data of all actinides are not prepared in evaluated nuclear data files such as ENDF or JEDNL. In this study, new neutron/ cross section constants based on JENDL-3.2 and -4 were developed. The delayed yields were added to JENDL-3.2 and JENDL-4. Based on these modified JENDL-3.2 and -4, MATXSLIB-type library for conventional discrete ordinate multi-group transport code were generated. Neutron and ray coupling calculations for the experimental fast reactor Joyo core, based on transport theory as a fixed source problem, revealed that the flux increased by approximately 40% when the delayed intensity in both JENDL-3.2 and -4 were considered. The calculated heat rates were verified by comparison with the measured data obtained by on-line irradiation rigs. It was confirmed that the calculated heat rates agreed with the measurements within 3-12%.
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
Tobita, Koichi; Soga, Tomonori; Mitsugi, Takeshi
Saikuru Kiko Giho, (21,別冊), p.27 - 39, 2003/12
Concerning with JOYO MK-3 program for improvement of its irradiation ability, design and fabrication of the shielding subassembly have been performed. And as a result of the achievement high neutron flux in MK-3 core, lifetime extension of control rod and reflector was required to decrease the reactor operation cost and the quantity of radioactive wastage. Therefore, the sodium bonded control rod and the ferritic stainless steel reflector have been developed for long-life design. This report describes about JOYO core component developments in the view point of those designs.
Soga, Tomonori; Tobita, Koichi; Mitsugi, Takeshi; Miyakawa, Shunichi
Saikuru Kiko Giho, (8), p.13 - 22, 2000/09
None
Soga, Tomonori; Miyakawa, Shunichi; Mitsugi, Takeshi
JNC TN9400 99-052, 355 Pages, 1999/06
Currently, the lifetime of control rods in JOYO is limited by Absorber-Cladding Mechanical Interaction (ACMI) due to swelling of BC(boron carbide) pellets accelerated by relocation of pellet fragments. A sodium bonded type control rod was developed which improves the thermal conductivity by means of charging sodium into the gap between BC and cladding and by utilizing a shroud which wraps the pellet fragments in a thin tube. This new design will be able to enlarge the gap between BC and cladding, without heating BC or fragment relocation, thus extending the life of the control rod. The sodium bonded type will be fabricated as the ninth reload control rods in JOYO. (1)The specification of a sodium bonded type control rod was determined with the wide gap between BC and cladding. In the design simulation, main component temperature were below the maximum limit. And the local heating by helium bubble generated from BC in the sodium gap, was not a serious problem in the analysis which was considered. (2)A structural design for the sodium entrance into the pin was determined. A formula was developed which the limit for sodium charging given physical dimension of the structure and sodium property. Result from sodium out-pile experiments validated the theoretical formula. (3)The analysis of ACMI indicated a lifetime extension of the sodium bonded type by 4.6% in comparison with lifetime of the helium bonded type of 1.6%. This is due to the boron10 burn-up rate being three times higher in the sodium bonded type than in the helium bonded type. To achieve a target burn-up 10% in the future, it will be necessary to modify design based on irradiation data which will be obtained by practical use of the sodium bonded control rods in JOYO. (4)The effects due to Absorber-Cladding Chemical Interaction (ACCI) were reduced by controlling the cladding temperature and chromium coating to the cladding's inner surface. It was confirmed that ...
Miyakawa, Shunichi; ; Soga, Tomonori
PNC TN9410 97-068, 113 Pages, 1997/07
Since the first control rod design for the Joyo Mk-II core (about twenty years ago), there have been several challenging improvements; for example, a helium venting mechanism and a flow induced vibration prevention mechanism. Forty-four control rods with these various modifications have been fabricated. To date, thirty-four have been irradiated and the sixteen have been examined, This experience and effort has produced fruitful results: (1)Efficiency and reliability of the diving-bell type Helium venting mechanism (2)Efficiency of the flow induced vibration prevention mechanism (3)Efficiency of the improvement for scram damping mechanism (4)Clarification of absorvber-pellet-cladding-mechanical-interaction (ACMI)phenomena and preventive methods The fourth result listed above has been a subject of investigation for fifteen years in several countries, that is a main phenomena to dominate control rod life time. The results of this investigation of ACMI in absorber elements are summarized below: (a)In five of Joyo Mk-II control rods, cladding cracks were found in fifteen of the elements. These cracks were caused by a acceleration ACMI, due to BC fragments relocation. They occurred over a wide burnup range from 5E+26 Cap./m
to 45E+26Cap./m in a nearly typical provability distribution. The cladding cracked because of its low ductility (approximately 1/4 lower than the uniform elongation of usual tensile testing for irradiated 316SS cladding) due to neutron irradiation and the ultra slow ACMI induced strain rate. (b)In this case the crack growth rate is extremely slow and the ACMI induced cracking in absorber elements do not influence either the reactor or plant operations. It is on this basis that a strict limitation to avoid the cladding crack is not necessary. According1y, it is suggested that a realistic design standard should consider the ACMI phenomena and the burnup limit be based on the nominal base calculation for average plastic strain use ...
Donomae, Takako; Katsuyama, Kozo; Tachi, Yoshiaki; Maeda, Koji; Yamamoto, Masaya; Soga, Tomonori
no journal, ,
Sodium bonded control rods for fast reactors have been developed in Japan. Their irradiation test was done in the experimental fast reactor Joyo. The control rods were irradiated at 100
10
cap/cm for the maximum burn up of the boron carbide (B C) pellets. To control against absorber-cladding mechanical interaction (ACMI), a shroud tube was inserted between the B C pellet stack and cladding. The inside of the control rod pins was filled with sodium. After irradiation, there was no remarkable change in the integrity of the cladding tubes. On the other hand, some cracks were found on the shroud tube at the high burn-up region of B C pellets. It was concluded from these results that if cracks of shroud tubes occurred, there was almost no diameter increase of the cladding tube. So the B C pellet relocation was safely restrained by the shroud tube and the cladding tube at an irradiation of 10010 cap/cm.
Soga, Tomonori; Itagaki, Wataru; Noguchi, Koichi
no journal, ,
For the various irradiation tests, the compartment type rigs that set the coolant temperature individually, and the capsule type rig that can irradiate the advanced fuel pins, were developed in Joyo. Moreover, the online irradiation rigs which can measure or control the temperature with high accuracy had been developed and utilized in Joyo. These rigs contribute the basic research in the irradiation effect on material, and the research for the LWR or the fusion reactor. In addition, the high temperature irradiation test device, and the device which has function of the neutron energy spectrum tailoring will be prepared to expand the range of the irradiation condition. In PIE facilities that are adjacent to Joyo, parts of irradiation rigs or samples can be exchanged after irradiation. Then re-assembled rig can be re-loaded to Joyo. This technique enables to obtain the data on the way to the target burn-up or fluence, and to conduct the longer irradiation test than the lifetime of rigs.
Nakamura, Kinya*; Kikuchi, Hironobu; Ogata, Takanari*; Iwai, Takashi; Arai, Yasuo; Uozumi, Koichi*; Hijikata, Takatoshi*; Koyama, Tadafumi*; Itagaki, Wataru; Soga, Tomonori
no journal, ,
Irradiation test of metallic fuel at fast test reactor JOYO is planned. By using techniques of casting, fabrication, analysis and inspection, metallic fuel elements were made for the first time in Japan. In this paper, fabrication technique of metallic fuel elements is reported. After filling up thermal bond (Na), a reflector element, a thermal shelter element and a fuel slug, the upper plug was welded. Sodium bonding treatment was carried out by vibrating the fuel element under heating. By inspection, it was confirmed that the specifications were satisfied.
Nakamura, Kinya*; Ogata, Takanari*; Nakajima, Kunihisa; Kato, Tetsuya*; Iwai, Takashi; Arai, Yasuo; Koyama, Tadafumi*; Itagaki, Wataru; Soga, Tomonori
no journal, ,
Irradiation test of metallic fuel at fast test reactor JOYO is planned. By using techniques of casting, fabrication, analysis and inspection, metallic fuel elements were made for the first time in Japan. In this paper, results of fabrication of U-Pu-Zr alloy fuel slug by emit casting method. Using U metal, U-Pu alloy metal and Zr metal as raw materials, fuel slugs were fabricated by emit casting apparatus in argon gas atmosphere glove box. By inspection, it was confirmed that the specifications were satisfied.
Soga, Tomonori; Itagaki, Wataru; Someya, Hiroyuki; Yamamoto, Masaya; Tobita, Koichi
no journal, ,
Takamatsu, Misao; Itagaki, Wataru; Soga, Tomonori; Sekine, Takashi; 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
