Fusion Engineering and Design, 98-99, p.1788 - 1791, 2015/10
Demonstration power reactors require advanced tritium breeders that have high stability at high temperatures. Therefore, an original material of LiTiO with excess Li (LiTiO) as an advanced tritium breeder that can make up to the lithium loss has been proposed. Furthermore, The author has been developing a technique of fabricating LiTiO pebbles using the emulsion method. Considering the tritium release characteristics and the packing factor of the blanket, the desired pebble diameter and grain size after sintering were 1 mm and 5 m, respectively. To prevent the grain growth of pebbles, calcined LiTiO pebbles were sintered in a vacuum atmosphere at 1073 K for 3 h and in a 1%H-He atmoshere at 1323K for 5 h. The average grain size on the surfaces and cross sections of the sintered LiTiO pebbles was 5 m. In addition, the diameter of sintered LiTiO pebbles was 1.07 mm.
Desalination, 359, p.59 - 63, 2015/03
Lithium (Li) procurement is becoming a matter of importance worldwide. Herein, I propose a method for recovering Li from seawater by using world-first dialysis, wherein Li only permeates from the negative electrode side to the positive electrode side through a Li ionic superconductor functioning as a Li separation membrane (LISM). Measurements of the Li ion concentration at the positive electrode side as a function of dialysis duration showed that the Li concentration increased to approximately 7% after 72 h with no applied electric voltage. Moreover, other ions in the seawater did not permeate the LISM. With both ends of the LISM bound with a negative and positive electrode, hydrated Li ion was transformed to Li ion only because Li ion can permeate through the LISM. This new recovery method shows good energy efficiency and is easily scalable and is thus suitable for the industrialized mass production of Li in South American countries, which have briny water containing Li.
Hoshino, Tsuyoshi; Ochiai, Kentaro; Edao, Yuki; Kawamura, Yoshinori
Fusion Science and Technology, 67(2), p.386 - 389, 2015/03
Demonstration power reactors (DEMOs) require advanced tritium breeders that have high stability at high temperatures. Therefore, the pebble fabrication of LiTiO with excess Li (LiTiO) as an advanced tritium breeder was carried out. In this study, a preliminary examination of the tritium release properties of advanced tritium breeders was performed. DT neutron irradiation experiments were performed at the fusion neutronics source (FNS) facility in JAEA. The LiTiO pebbles exhibited good tritium release properties similar to the LiTiO pebbles. In particular, the released amount of HT gas for easier tritium handling was higher than that of HTO water.
Enoeda, Mikio; Tanigawa, Hisashi; Hirose, Takanori; Nakajima, Motoki; Sato, Satoshi; Ochiai, Kentaro; Konno, Chikara; Kawamura, Yoshinori; Hayashi, Takumi; Yamanishi, Toshihiko; et al.
Fusion Engineering and Design, 89(7-8), p.1131 - 1136, 2014/10
The development of a Water Cooled Ceramic Breeder (WCCB) Test Blanket Module (TBM) is being performed as one of the most important steps toward DEMO blanket in Japan. Regarding the fabrication technology development using F82H, the fabrication of a real scale mockup of the back wall of TBM was completed. Also the assembling of the complete box structure of the TBM mockup and planning of the pressurization testing was studied. The development of advanced breeder and multiplier pebbles for higher chemical stability was performed for future DEMO blanket application. From the view point of TBM test result evaluation and DEMO blanket performance design, the development of the blanket tritium simulation technology, investigation of the TBM neutronics measurement technology and the evaluation of tritium production and recovery test using D-T neutron in the Fusion Neutronics Source (FNS) facility has been performed.
Fusion Engineering and Design, 89(7-8), p.1431 - 1435, 2014/10
Demonstration power reactors (DEMOs) require advanced tritium breeders with high thermal stability. For the mass production of advanced tritium breeder pebbles, pebble fabrication by the emulsion method is a promising technique. To develop the most efficient pebble fabrication method, a new direct pebble fabrication process utilizing the emulsion method was implemented. A prior pebble fabrication process consisted of the preparation of raw materials followed by granulation. The new process integrates the preparation and granulation of raw materials. The slurry for the emulsion granulation of LiTiO as a tritium breeder consists of mixtures of LiCO and TiO at specific ratios. The average diameter of the obtained sintered LiTiO pebbles were 1.0 mm. The trial fabrication results suggest that the new process has the potential to increase the fabrication efficiency of advanced tritium breeder pebbles.
Ochiai, Kentaro; Kawamura, Yoshinori; Hoshino, Tsuyoshi; Edao, Yuki; Takakura, Kosuke; Ota, Masayuki; Sato, Satoshi; Konno, Chikara
Fusion Engineering and Design, 89(7-8), p.1464 - 1468, 2014/10
We have performed the tritium recovery experiment on fusion reactor blanket with DT neutrons at the Fusion Neutronics Source facility in Japan Atomic Energy Agency. The candidate breeding material, LiTiO pebble, was put into the container which was set up it into an assembly simulating water cooled ceramic breeding (WCCB) blanket. Helium sweep gas including H (1%) and/or HO (1%) was flowed and extracted tritium was collected to water bubblers during DT neutron irradiation. The LiTiO pebble was also heated up to a constant temperature at 573, 873 and 1073 K, respectively. We arranged the tritium recovery system to measure tritiated water moisture and tritium gas, separately, and to investigate the amount of recovered tritium and the chemical form. From our experiments, it was showed that the amount of recovered tritium was corresponded to the calculation value and the ratio of chemical form depended to the temperature and kinds of sweep gas.
Fusion Engineering and Design, 88(11), p.2956 - 2959, 2013/11
The tritium as a fuel for fusion reactors is produced by the reaction of lithium-6 (Li) with neutron in tritium breeding material. However, Li is one of 31 rare metal elements. Furthermore, as a means of addressing global warming, the world is increasingly turning to the use of Li-ion batteries in electric vehicles and as storage batteries in the home; therefore, there is a growing need for Li. In view of Japanese high dependence on imports for material resources, the securing of enough Li resources is an important policy for domestic industry in Japan. We proposed new method for Li recovery from seawater. The method involves the use of an ionic liquid through which only the Li ions in seawater and not the other ions, including Na, Mg, Ca and K, permeate from the anode side to the cathode side during electrodialysis. Thus, the Li ions become concentrated on the cathode side and can be recovered. With both ends of an ionic liquid covered with a SELEMION to prevent outflow of the ionic liquid, Li concentration increased from 4.5% after 2 h to 11.0% after 24 h with an applied electric voltage of 2 V.
Journal of Nuclear Materials, 442(1-3), p.S425 - S428, 2013/11
Development of reprocessing and reuse of this spent breeder including unburned Li is important from viewpoint of effective utilization Li as a limited resource. This activity has been started between Japan and the EU in the Broader Approach activities. The effect of solvent on dissolution of LiTiO powder was evaluated. LiTiO powder with 99.9% purity was prepared as a starting powder. Solubility of Li was evaluated from the measurement result of the Li content in solution by ICP (inductively coupled plasma) atomic emission spectrometry. Peroxide hydrogen (HO) was selected as solvent. Most of LiTiO was soluble in room temperature, and then the solubility of Li were larger than 90%.
Fusion Engineering and Design, 88(9-10), p.2264 - 2267, 2013/10
Lithium titanate (LiTiO) has been recognized as a prominent candidate material for use in a tritium breeder. However, the mass of LiTiO is decreased over time by Li evaporation in a hydrogen atmosphere, Li burn-up under the high temperatures, and high neutron fluence irradiation found in a DEMO reactor. To compensate for this decrease in mass at high temperatures, LiTiO with additional Li (LiTiO) have been developed as an advanced tritium breeder. Pebble fabrication using the sol-gel method is one of the promising techniques for the mass production of the advanced tritium breeder pebbles. The authors have been developing a technique of fabricating LiTiO pebbles using the sol-gel method. To increase the density of sintered LiTiO pebbles, the sintering temperature was changed, and at 1473 K, the density of the pebbles was increased to approximately 75%T.D., without any increase in the grain size. This shows the pore size in sintered LiTiO pebbles is decreased by vacuum sintering.
Hoshino, Tsuyoshi; Oikawa, Fumiaki; Natori, Yuri*; Kato, Kenichi*; Sakka, Tomoko*; Nakamura, Mutsumi*; Tatenuma, Katsuyoshi*
Fusion Engineering and Design, 88(9-10), p.2268 - 2271, 2013/10
Lithium titanate with additional Li (LiTiO) and lithium orthosilicate (LiSiO) is one of the most promising candidates for use in a tritium breeder because of its good chemical and mechanical stabilities. Currently, mixtures of tritium breeder pebble and neutron multiplier (Be or BeTi) pebble are being considered for use in increasing the tritium breeding ratio in a breeding blanket. However, lithium and beryllium are gradually reacted under practical operating conditions, and therefore a high-functional tritium breeder such as lithium beryllium oxide (LiBeO) needs to be developed to compensate for this reactive characteristic under high temperature use. In this study, methods of synthesizing LiBeO have been extensively investigated by means of solid-phase reaction. The solid-phase reaction of LiOH(HO) and BeO is a suitable synthesis method for lithium beryllium oxide (LiBeO). It is expected that single-phase LiBeO will be stable under the mixture conditions of a tritium breeder and neutron multiplier in the blanket region at high temperatures.
Desalination, 317, p.11 - 16, 2013/05
Lithium (Li), one of the 31 rare metal elements among the 112 known elements, is fast becoming a valuable commodity. As a means of addressing global warming, the world is increasingly turning to the use of Li-ion batteries in electric vehicles and as storage batteries in the home; therefore, there is a growing need for Li. Li is primarily recovered from salt lakes in South America but is also present in seawater. Thus, I propose a new method for recovering Li from seawater by electrodialysis, wherein Li selectively permeates from the anode side to the cathode side through an ionic liquid. Hoshino developed a novel Li-isotope separation technique that uses an ionic liquid. This technique could also be used to recover Li from seawater. Measurements of the ion concentration at the cathode side as a function of dialysis duration showed that the Li concentration increased to 5.94% after 2 h with an applied electric voltage of 2 V. Moreover, the other ions in the seawater did not permeate an ionic liquid. With both ends of an ionic liquid covered with a MEA (Membrane Electrode Assembly) to prevent outflow of the ionic liquid, the Li concentration increased. This new recovery method shows good energy efficiency and is easily scalable and thus is suitable for use in seawater desalination plants.
Someya, Yoji; Tobita, Kenji; Uto, Hiroyasu; Hoshino, Kazuo; Asakura, Nobuyuki; Nakamura, Makoto; Tanigawa, Hisashi; Enoeda, Mikio; Tanigawa, Hiroyasu; Nakamichi, Masaru; et al.
Proceedings of 24th IAEA Fusion Energy Conference (FEC 2012) (CD-ROM), 8 Pages, 2013/03
This paper presents the conceptual design of a blanket with simplified structure whose interior consists of the mixture of breeder and multiplier pebble bed, cooling tubes and support for them only. Neutronics calculation indicated that the blanket satisfies a self-sufficient production of tritium. An important finding is that little decrease is seen in TBR even when the gap between neighboring blanket modules is as wide as 0.03 m. This means that blanket modules can be arranged with such a significant clearance gap without sacrifice of tritium production. On the other hand, the thickness of blanket housing is important from the viewpoint of safety. The blanket housing may rupture when the cooling pipe in the blanket is tearing, because thickness of structure materials is thin as 22 mm. This thickness is expected to maintain to 8 MPa in the steam pressure. Finally, the blanket housing, and aspect ratio of blanket shape is proposed in consideration of TBR, and engineering problem such as maintenance and manufacture are discussed.
Edao, Yuki; Kawamura, Yoshinori; Ochiai, Kentaro; Hoshino, Tsuyoshi; Takakura, Kosuke; Ota, Masayuki; Iwai, Yasunori; Yamanishi, Toshihiko; Konno, Chikara
JAEA-Research 2012-040, 15 Pages, 2013/02
Tritium generation and recovery studies on LiTiO as a solid breeding material under neutron irradiation carried out in the Fusion Neutron Source (FNS) facility. A capsule with LiTiO packed bed was put in a system which simulated an actual blanket system which built in beryllium blocks and lithium titanate ones. Estimated values of the amount of tritium generation by a numerical calculation agreed closely with experimental values. The capsule was heated up to 300C, and helium, helium with water vapor, hydrogen or hydrogen/water vapor were selected as purge gas. In the case of purge by helium added water vapor, the ratio of HTO to total tritium release was 98%. In helium with hydrogen/water vapor purge, the ratio of HTO to total tritium release was 80%, which was confirmed that HTO released by isotope exchange reaction between water vapor and tritium. In helium with hydrogen purge, the ratio of HT to total tritium release was 6070%, which was shown that HT released by isotope exchange reaction between hydrogen gas and tritium. HTO released by water generation reaction between hydrogen in purge gas and oxygen in LiTiO although water vapor was not added in purge gas. The ratio of HTO release seemed to be small under the deoxidized condition of the LiTiO surface. Tritium release behavior in the LiTiO depended on the composition of purge gas, and its chemical form was affected by the surface conditions of LiTiO.
Hoshino, Tsuyoshi; Nakamichi, Masaru
Fusion Engineering and Design, 87(5-6), p.486 - 492, 2012/08
DEMO reactors require advanced tritium breeder and neutron multiplier that have higher stability at high temperature. LiTiO with added Li (LiTiO) have been developed such as advanced tritium breeder. LiTiO have higher stability at high temperatures with reduction atmosphere. We have been promoting the development of fabrication technique of LiTiO pebbles by the emulsion method, one of the sol-gel methods. The average diameter and the sphericity of pebbles by the emulsion method were 0.95 mm and 1.02, respectively. On the other hand, beryllium intermetallic compounds (beryllides) are promising material for advanced neutron multipliers. In this study, trial fabrication examinations were carried out. The formation of BeTi intermetallic was identified using a mixture of Be and Ti particles for the plasma sintering method.
Enoeda, Mikio; Tanigawa, Hisashi; Hirose, Takanori; Suzuki, Satoshi; Ochiai, Kentaro; Konno, Chikara; Kawamura, Yoshinori; Yamanishi, Toshihiko; Hoshino, Tsuyoshi; Nakamichi, Masaru; et al.
Fusion Engineering and Design, 87(7-8), p.1363 - 1369, 2012/08
The development of a Water Cooled Ceramic Breeder (WCCB) Test Blanket Module (TBM) is being performed as one of the most important steps toward DEMO blanket in Japan. For the TBM testing and evaluation toward DEMO blanket, the module fabrication technology development by a candidate structural material, reduced activation martensitic/ferritic steel, F82H, is one of the most critical items from the viewpoint of realization of TBM testing in ITER. Fabrication of a real scale first wall, side walls, a breeder pebble bed box and assembling of the first wall and side walls have succeeded. Recently, the real scale partial mockup of the back wall was fabricated. The fabrication procedure of the back wall, whose thickness is up to 90 mm, was confirmed toward the fabrication of the real scale back wall by F82H. This paper overviews the recent achievements of the development of the WCCB TBM in Japan.
Kawamura, Yoshinori; Ochiai, Kentaro; Hoshino, Tsuyoshi; Kondo, Keitaro*; Iwai, Yasunori; Kobayashi, Kazuhiro; Nakamichi, Masaru; Konno, Chikara; Yamanishi, Toshihiko; Hayashi, Takumi; et al.
Fusion Engineering and Design, 87(7-8), p.1253 - 1257, 2012/08
Tritium generation and recovery study on lithium ceramic packed bed was started by use of FNS in JAEA. Lithium titanate was selected as tritium breeding material. In this work, the effect of sweep gas species on tritium release behavior was investigated. In case of sweep by helium with 1% of hydrogen, tritium in water form was released sensitively corresponding to the irradiation. This is due to existence of the water vapor in the sweep gas. On the other hand, in case of sweep by dry helium, tritium in gaseous form was released first, and release of tritium in water form was delayed and was gradually increased.
Nishitani, Takeo; Yamanishi, Toshihiko; Tanigawa, Hiroyasu; Nozawa, Takashi; Nakamichi, Masaru; Hoshino, Tsuyoshi; Koyama, Akira*; Kimura, Akihiko*; Hinoki, Tatsuya*; Shikama, Tatsuo*
Fusion Engineering and Design, 86(12), p.2924 - 2927, 2011/12
Several technical R&D activities related to the blanket materials are newly launched as a part of the Broader Approach (BA) activities, which was initiated by the EU and Japan. According to the common interests of these parties for DEMO, R&Ds on reduced activation ferritic/martensitic (RAFM) steels as structural material, SiCf/SiC composites as a flow channel insert material and/or alternative structural material, advanced tritium breeders and neutron multipliers, and tritium technology are carried out through the BA DEMO R&D program, in order to establish the technical bases on the blanket materials and the tritium technology required for DEMO design. This paper describes overall schedule of those R&D activities and recent progress in Japan carried out by JAEA as the domestic implementing agency on BA, collaborating with Japanese universities and other research institutes.
Hoshino, Tsuyoshi; Terai, Takayuki*
Fusion Engineering and Design, 86(9-11), p.2168 - 2171, 2011/10
The tritium needed as a fuel for fusion reactors is produced by the neutron capture reaction of lithium-6 (Li) in tritium breeding materials. However, natural Li contains only about 7.6 at.% Li. In Japan, new lithium isotope separation technique using ionic-liquid impregnated organic membranes have been developed. The improvement in the durability of the ionic-liquid impregnated organic membrane is one of the main issues for stable, long-term operation of electrodialysis cells while maintaining good performance. Therefore, we developed highly-durable ionic-liquid impregnated organic membrane. Both ends of the ionic-liquid impregnated organic membrane were covered by a nafion 324 overcoat to prevent the outflow of the ionic liquid. The transmission of Lithium aqueous solution after 10 hours under the highly-durable ionic-liquid impregnated organic membrane is almost 13%. So this highly-durable ionic-liquid impregnated organic membrane for long operating of electrodialysis cells has been developed through successful prevention of ion liquid dissolution.
Hoshino, Tsuyoshi; Oikawa, Fumiaki
Fusion Engineering and Design, 86(9-11), p.2172 - 2175, 2011/10
Lithium titanate (LiTiO) is one of the most promising candidates among tritium breeding materials because of its good tritium release characteristics. However, the mass of LiTiO decreased with time in a hydrogen atmosphere by Li evaporation and with Li burn up. In order to prevent the mass decrease at high temperatures, LiTiO with added Li have been developed as one of advanced tritium breeders. We have been promoting the development of fabrication technique of LiTiO pebbles by the sol-gel method. The fabrication techniques of advanced tritium breeder pebbles have not been established for large quantities. Therefore, trial fabrication tests of advanced breeder pebbles were carried out using previous sol-gel method. The diameter of the pebbles is 1.18 mm, and the sphericity is 1.04. It is expected that an advanced tritium breeder with added Li will be stable under operating conditions, namely in a neutron environment at a high temperatures. Thus, these results show that the pebble fabrication using the sol-gel method is a promising production technique for mass production of the advanced tritium breeder pebbles.
Hoshino, Tsuyoshi; Terai, Takayuki*
Journal of Nuclear Materials, 417(1-3), p.696 - 699, 2011/10
The tritium as a fuel for fusion reactors is produced by the reaction of lithium-6 (Li) with a neutron in tritium breeding material. However, natural Li contains only about 7.6% Li, and the enrichment of Li up to 30 - 90% is required for tritium breeding material in the fusion reactor. The mercury amalgam method is superior as one of the lithium isotope enrichment methods, and might be currently utilized in practice. In Japan, on the other hand, the development of lithium isotope enrichment methods using the ion exchange membrane and molten salt has been conducted to avoid the environmental pollution. However, the isotope separation coefficient and efficiency is too low in the case of these methods. Therefore, these methods were difficult to apply to mass production for the large need of fusion blanket. Preliminary experiments were conducted. Organic membranes impregnated with TMPA-TFSI and PP13-TFSI as ionic liquids were prepared, and the relationship between the Li separation coefficient and the applied dialysis electric current was measured. The results showed that Li isotope separation coefficient by this method (about 1.21.4) was larger than that by the mercury amalgam method (about 1.06).