Sakata, Shinya; Yamaguchi, Taiji; Sugimura, Toru; Kominato, Toshiharu; Kawamata, Yoichi; Totsuka, Toshiyuki; Sato, Minoru; Sueoka, Michiharu; Naito, Osamu
Fusion Science and Technology, 60(2), p.496 - 500, 2011/08
For a steady state operation of JT-60SA, a plasma feedback control using various diagnostic sensor signals plays an essential role. To realize this, Real Time Diagnostic Signals acquisition System, RTDS, which utilizes PC-based real-time OS "INtime", has been under consideration toward JT-60SA project. Moreover, long-time experiments more than 100 seconds will be planned in JT-60SA project. Therefore, real time monitoring will be required as an essential function that displays acquired diagnostic signals on real time during long-time experiment. This function will be also realized by utilizing RTDS.
Kawamata, Yoichi; Sugimura, Toru; Yamaguchi, Taiji; Sueoka, Michiharu; Sakata, Shinya; Totsuka, Toshiyuki; Sato, Minoru; Kominato, Toshiharu; Naito, Osamu
Fusion Science and Technology, 60(2), p.491 - 495, 2011/08
Tanaka, Teruya*; Sato, Satoshi; Kondo, Keitaro; Ochiai, Kentaro; Murata, Isao*; Takakura, Kosuke; Sato, Fuminobu*; Kada, Wataru*; Iida, Toshiyuki*; Konno, Chikara; et al.
Fusion Science and Technology, 60(2), p.681 - 686, 2011/08
Irradiation experiments of 14 MeV neutrons have been performed on a Li block assembly of 46 51 51 cm with a 5 cm thick V-alloy layer inside to examine the accuracy of neutronics calculations for the Li/V-alloy blanket design. Foils of Nb, Ni, In and Au for reaction rate measurements of Nb(n,2n)Nb, Ni(n,p)Co, In(n,n')In, Au(n,)Au reactions and Li enriched (Li: 95.5%) and Li enriched (Li: 99.9%) LiCO pellets for tritium production rate measurements were installed in the assembly. Results of the measurements were compared with those of calculations with MCNP5, JENDL-3.3 and JENDL/D-99. The comparisons for the reaction rates in the Nb, Ni and In foils indicate that measurements and calculations of the fast neutron transport are consistent almost within 10%. In the comparison for the reaction rates in the Au foils, the underestimation of 15% was found at a surface of the V-alloy layer. There is a possibility that this is due to the elastic scattering cross section of V around 4 keV as previously reported. The comparisons for tritium production rates in the Li enriched and Li enriched LiCO pellets indicate that calculated rates were larger than results of the measurements by 2-8% and 1-4%, respectively.
Hayashi, Takao; Sakurai, Shinji; Shibanuma, Kiyoshi; Sakasai, Akira
Fusion Science and Technology, 60(2), p.549 - 553, 2011/08
Design study of RH system, especially the expansion of the RH rail and replacement of the lower divertor cassettes, was described in this paper. The dimensions and weight of the divertor cassette, which is 10 degrees wide in toroidal direction, are 1.62 0.57 1.25 m and 800 kg, respectively. The RH system can use four horizontal ports whose inside dimensions are 0.66 1.83 m. The space for RH system is very limited. The RH rail is installed before transporting divertor cassettes. The RH rail can cover 180 degrees in toroidal direction. A divertor cassette can be replaced by heavy weight manipulator (HWM) consists of an end effector, a telescopic arm and a vehicle. The HWM brings the divertor cassette to the front of another horizontal port, which is used for supporting the rail and/or carrying in and out equipments. Then another RH device, which is installed from outside the vacuum vessel, receives and brings out the divertor cassette.
Iwai, Yasunori; Yamanishi, Toshihiko
Fusion Science and Technology, 60(1), p.144 - 149, 2011/07
Silica gel is a desiccant agent of favorable quality for air detritiation dryer incorporated into tritium handling facility. The effect of the residual tritiated water left on the silica gel following regeneration were demonstrated. The residual tritiated water left on the silica gel following regeneration significantly reduced the detritiation factor of air detritiation dryer. To maintain the detritiation factor more than 1000, space velocity lower than 100h should be selected for the design and operation of air detritiation dryer packed with silica gel. HTO/ HO separation factor of multi-cycle was 1.17 on the average. This value is considerably larger than that of multi-cycle evaluated using zeolite as desiccant agent. Silica gel is superior to commercial molecular sieves in dehydration ratio at room temperature. Dehydration from silica gel was dependent on the accumulated amount of purge gas, independent on flow rate. Consequently, silica gel is a promising desiccant agent for air detritiation dryer.
Hayashi, Takumi; Nakamura, Hirofumi; Isobe, Kanetsugu; Kobayashi, Kazuhiro; Oyaizu, Makoto; Oya, Yasuhisa*; Okuno, Kenji*; Yamanishi, Toshihiko
Fusion Science and Technology, 60(1), p.369 - 372, 2011/07
Kobayashi, Makoto*; Wang, W.*; Kurata, Rie; Matsuyama, Masao*; Hayashi, Takumi; Yamanishi, Toshihiko; Asakura, Yamato*; Oya, Yasuhisa*; Okuno, Kenji*
Fusion Science and Technology, 60(1), p.403 - 406, 2011/07
The trapping and release mechanisms of hydrogen isotopes for the stainless steel (SS) oxidized at various temperatures were investigated. The oxide layer was mainly consisted of iron oxides (FeO) and its decomposition temperature was almost consistent with the release temperature of deuterium, where major chemical form was a molecular deuterium (D). The deuterium retention was increased as the oxidation temperature increased. It was considered that the thickness of oxide layer would make a large influence on the retention of hydrogen isotopes. On the other hand, the amount of released deuterium as heavy water (DO) was independent with oxidation temperature. It was considered that the formation of hydrogen isotope as water form was depended on the amount of FeO on the top most surface layer of SS.
Munakata, Kenzo*; Kawamura, Yoshinori
Fusion Science and Technology, 60(1), p.426 - 430, 2011/07
Cryogenic adsorption is effective for the recovery of hydrogen isotopes of small concentrations from the bulk helium gas. Thus, the cryogenic adsorption method is considered to be applied to the recovery of tritium from the blanket sweep gas which recovers tritium from ceramic breeder materials. The authors performed a screening test to find more suitable adsorbents for the recovery of hydrogen isotopes from the bulk helium gas at 77K. The screening test indicates that a natural mordenite adsorbent has a quite high adsorption capacity for hydrogen under the helium atmosphere. The adsorption rate of hydrogen isotopes was quantified by analyzing breakthrough curves obtained in the experiments. Evaluated effective pore diffusivities of hydrogen isotopes in the mordenite adsorbents are comparable to that in MS5A adsorbents. Thus, it can be said that mordenite adsorbents are also suitable for adsorption of hydrogen isotopes from the viewpoint of adsorption rates.
Takatsu, Hideyuki; Hayashi, Takumi; Horiike, Hiroshi*; Sagara, Akio*
no journal, ,
no abstracts in English