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.

Study on In-Vessel Thermohydraulics Phenomena of Sodium-Cooled Fast Reactors (4) Numerical Analysis of 1/10 Scaled Water Experiment with the AQUA Code

Muramatsu, Toshiharu; Yoshizawa, Norio*; Yamaguchi, Akira

JNC TN9400 2003-099, 129 Pages, 2004/01

JNC-TN9400-2003-099.pdf:83.58MB

A large-scale sodium-cooled fast breeder reactor in the feasibility studies on commercialized fast reactors has a feature of consideration of thorough simplified and compacted systems and components design to realize drastic economical improvements. Therefore, special attentions should be paid to thermohydraulic designs for gas entrainment behavior from free surface, flow-induced vibration of in-vessel components, thermal stratification in the plenum,thermal shock for various structures due to high-speed coolant flows, nonsymmetrical coolant flows, etc. in the reactor vessel. A numerical analysis was carried out with a multi-dimensional code AQUA to confirm an applicability to the evaluations for the in-vessel thermohydraulic phenomena using a 1/10 scaled water experiment simulating the large-scale fast breeder reactor in the feasibility studies. From the analysis, the following results were obtained.

IAEA/RCA personal dosimetry intercomparison in Asian and Pacific region during the years of 1990-2004

Tsujimura, Norio; Momose, Takumaro; Yoshizawa, Michio; Yamamoto, Hideaki; Cruz-Suarez, R.*; Murakami, Hiroyuki

no journal, , 

As one of the IAEA/RCA projects, three phases of personal dosimetry intercomparison programs had been conducted during the years of 1990 to 2004. The purpose of the program was to assess the ability of the personal dosimetry services in the RCA Member States and also to provide technical help in improving a performance of their dosimetry systems and in implementing the operational quantities recommended by ICRU. The purpose of this paper is to trace the history of and to present a summarized review of the results of the intercomparison programs. The trend of the phase-by-phase results showed that the quality of individual monitoring in most of the Member States has become dramatically improved to an acceptable level. There was a successful achievement and advancement over the 15 years effort.