Preliminary tests on adsorption / desorption of alumina adsorbents

Suzuki, Yoshitaka; Ishida, Takuya*; Suzuki, Yumi*; Matsukura, Minoru*; Kurosaki, Fumio*; Nishikata, Kaori; Mimura, Hitoshi*; Tsuchiya, Kunihiko

JAEA-Technology 2016-027, 24 Pages, 2016/12

JAEA-Technology-2016-027.pdf:4.15MB

The research and development (R&D) on the production of Mo/Tc by (n,) method has been carried out in the Neutron Irradiation and Testing Reactor Center. The Mo production by (n,) reaction is a simple and easy method, and it also is advantageous from viewpoints of nuclear proliferation resistance and waste management. However, it is difficult to produce the Tc solution with high radioactive concentration because the specific radioactivity of Mo by this method is extremely low. Up to now, various Mo absorbents such as Polyzirconium Compound (PZC) and Polytitanium Compound (PTC) have been developed with high Mo adsorption efficiency. It is necessary for utilization to the generator of these absorbents to evaluate the effect of elements containing these absorbents and to assure the quality of Tc solution. In this report, the status of R&D of the Mo adsorbents was investigated. The alumina as Mo adsorbent, which uses in medical Mo/Tc generator, was focused and Mo adsorption/desorption properties of three kinds of alumina was evaluated by different properties such as crystal structure and specific surface.

Fabrication and installation of equilibrium field coils for the JT-60SA

Tsuchiya, Katsuhiko; Kizu, Kaname; Murakami, Haruyuki; Kashiwa, Yoshitoshi; Yoshizawa, Norio; Yoshida, Kiyoshi; Hasegawa, Mitsuru*; Kuno, Kazuo*; Nomoto, Kazuhiro*; Horii, Hiroyuki*

Fusion Engineering and Design, 88(6-8), p.551 - 554, 2013/10

https://doi.org/10.1016/j.fusengdes.2013.02.096

The programme of constructing JT-60SA device is progressing under the framework of the Broader Approach project. Superconducting poloidal field (PF) coil system, which was decided to be procured by Japan, consists of a central solenoid (CS) with four solenoid modules and six equilibrium field (EF) coils. Each of EF coil has individual diameters, 4.5 to 12 m. Fabrication of EF4 coil, which is set at the lowermost of torus, was started from the beginning of 2009 as a first EF coil. EF4 coil has ten double pancake (DP) coils, and sizes of circularity were measured for all DP coil after curing process. Maximum error of circularity was 3.1 mm, which was nearly a half of the design tolerance, 6 mm. After stacking these DP coils, winding pack of EF4 was completed in the spring of 2012. After optimizing the positions of DP coils to cancel the error of circulation which each DP coil has, error of radial current centre of DP coils will be achieved in the range between + 0.2 to - 0.4 mm. Structural analysis of terminal structure was also performed. Terminal part has a pair of conductors bended toward the lower side of winding pack. A side of them (positive terminal) was covered by stainless steel armor to prevent the movement by electromagnetic force because a length of conductor was longer due to starting from the top of winding pack. Another side (negative terminal) was not covered by armor in the first design because this length was relatively short. However, it was clear on the structural analysis that mechanical strength of insulation around this terminal was not sufficient. Therefore, we also reinforced this side with stainless steel. From this April, fabrication of EF coils with large bore (larger than 8 m of diameter) will be started at the facility built in JAEA Naka site. In this paper, we will discuss about technological problem during the fabrication of large bore EF coils, such as temperature control at the winding process.

Construction of the jacketing facility and first production results of superconductor for JT-60SA

Kizu, Kaname; Tsuchiya, Katsuhiko; Kashiwa, Yoshitoshi; Murakami, Haruyuki; Yoshida, Kiyoshi

IEEE Transactions on Applied Superconductivity, 20(3), p.538 - 541, 2010/06

https://doi.org/10.1109/TASC.2010.2041760

The CS and EF coils in JT-60SA are procured by Japan. The conductor for CS is NbSn cable-in-conduit (CIC). On the other hand, EF coil conductors are NbTi CIC conductor. Delivered superconducting cables and jackets are fabricated into CIC conductors at the jacketing facility constructed in the Naka site of JAEA. The length of jacketing facility is about 660 m. The production of superconducting cables and jackets were started from April 2008. Since the superconducting cables and jackets following the specifications were produced well, the mass production was started. In this paper, the design of jacketing line and the first production results of CIC conductor will be described.

Status and perspective of the NbAl development

Takeuchi, Takao*; Kikuchi, Akihiro*; Banno, Nobuya*; Kitaguchi, Hitoshi*; Iijima, Yasuo*; Tagawa, Kohei*; Nakagawa, Kazuhiko*; Tsuchiya, Kiyosumi*; Mitsuda, Shiori*; Koizumi, Norikiyo; et al.

Cryogenics, 48(7-8), p.371 - 380, 2008/07

https://doi.org/10.1016/j.cryogenics.2008.04.007

NbAl has advantages of better tolerance to strain/stress and a higher critical magnetic field (30 T at 4.2 K) for stoichiometric composition over NbSn. The rapid-heating, quenching and transformation annealing (RHQT) process enables to form a stoichiometric NbAl with fine grain structures via metastable bcc supersaturated-solid-solution. As a result a large critical current density of NbAl is achieved over the whole range of magnetic fields without trading off the excellent strain tolerance. A long-length of RHQ processing has been established, and a rectangular but Cu stabilized NbAl strand is about be commercially available for NMR uses. Ag or Cu internal stabilization and Cu ion-plating/electroplating techniques have been also developed to enable the stabilized round wire for accelerator and fusion magnets. Successfully energized test coils that were manufactured with a wind-and-react technique have demonstrated that a long piece of Cu stabilized RHQT NbAl wire is really available for practical applications.

Internally Cu-stabilized RHQT NbAl superconductors with Ta matrix

Takeuchi, Takao*; Tagawa, Kohei*; Noda, Tetsuji*; Banno, Nobuya*; Iijima, Yasuo*; Kikuchi, Akihiro*; Kitaguchi, Hitoshi*; Kosuge, Michio*; Tsuchiya, Kiyosumi*; Koizumi, Norikiyo; et al.

IEEE Transactions on Applied Superconductivity, 16(2), p.1257 - 1260, 2006/06

https://doi.org/10.1109/TASC.2006.870804

Next generation nuclear fusion magnets would require a high-current conductor in fields more than 16 T. A CIC conductor of the rapid RHQT processed NbAl may be a promising candidate. Good deformability of intermediately-formed bcc supersaturated-solid solution indeed allowed fabricating such a CIC conductor, which would be subsequently transformation annealed. Ag has been internally included as a basic constituent of a round strand so far, because Ag is almost non-reactive with Nb matrix during the RHQ. However, both of Ag and Nb are not suitable nuclei from the viewpoint of radioactivity when irradiated with neutrons. Recently, we have succeeded in replacing the Nb matrix with Ta that has the advantage of shorter half-life of radioactivity. In the present study, an attempt has been made to replace the Ag internal stabilizer with Cu, in the aim of further reducing radioactivity, based on anticipation that Ta would be less reactive with Cu than Nb did.

Construction of the jacketing facility and first production results of superconductor for JT-60SA

Kizu, Kaname; Tsuchiya, Katsuhiko; Kashiwa, Yoshitoshi; Murakami, Haruyuki; Yoshida, Kiyoshi

no journal, , 

In JT-60SA, magnets system consists of 18 toroidal field coils, 4 stacks of central solenoid (CS) and 6 plasma equilibrium field (EF) coils. The maximum magnetic field and current of CS and EF coils is 9 T, 20 kA and 6.2 T, 20 kA, respectively. The conductor for CS is NbSn cable-in-conduit conductor. On the other hand, EF coil conductors are NbTi conductor. Delivered superconducting cables and jackets are fabricated into conductors at the jacketing facility constructed in the Naka site of JAEA. The length of jacketing facility is about 660 m. The production of superconducting cables and jackets were started from April 2008. Since the superconducting strands and copper dummy cables following the specifications were produced well, the mass production of strands was started. The first superconducting cable will be delivered to Naka site in April 2009. In this paper, the design of jacketing line and the first production results of conductor will be described.

Status of design and manufacturing for the superconducting coil system in the JT-60SA tokamak

Tsuchiya, Katsuhiko; Kizu, Kaname; Murakami, Haruyuki; Kamiya, Koji; Kashiwa, Yoshitoshi; Honda, Atsushi; Yoshida, Kiyoshi

no journal, , 

no abstracts in English

Design and manufacturing of CS conductors for JT-60SA

Kizu, Kaname; Murakami, Haruyuki; Tsuchiya, Katsuhiko; Kashiwa, Yoshitoshi; Ichige, Toshikatsu; Yoshida, Kiyoshi

no journal, , 

The novel cooling method of central solenoid (CS) was studied to extend the inner space and to shorten the total height of CS for JT-60SA. The cooling pipes and insulation breaks become 0 and 50% of initial design, respectively. The height becomes 2.3 m shorter. The thermo hydraulic analysis showed the sufficient temperature margin 1K. The superconductor manufacturing factory was constructed at Naka site of JAEA in 2008. The manufacturing of CS conductors was started in 2011. One 238 m and six 466 m conductors were produced.

Manufacturing and assembly status of superconducting magnet components for the JT-60SA

Yoshida, Kiyoshi; Kizu, Kaname; Tsuchiya, Katsuhiko; Murakami, Haruyuki; Honda, Atsushi; Kashiwa, Yoshitoshi; Koide, Yoshihiko; Usui, Katsutomi; Natsume, Kyohei

no journal, , 

http://csj.or.jp/conference/2014a/2B.pdf

The upgrade of the JT-60U magnet system to the superconducting coils (JT-60SA) is progressing as a satellite facility for ITER by both parties of Japanese government and European commission (EU) in the Broader Approach agreement. Three equilibrium field coils were installed in the cryostat base before assembly of plasma vacuum vessel. This report shows the Manufacturing and assembly status of superconducting magnet components for the JT-60SA.

Upgrade of the molybdenum adsorption properties of alumina for Mo/Tc generator

Suzuki, Yoshitaka; Ishida, Takuya; Suzuki, Yumi*; Matsukura, Minoru*; Kurosaki, Fumio*; Nishikata, Kaori; Mimura, Hitoshi*; Tsuchiya, Kunihiko

no journal, , 

no abstracts in English