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Hoshino, Takanori; Ogino, Hideki; Arai, Yoichi; Kase, Takeshi; Nakajima, Yasuo
no journal, ,
no abstracts in English
Takano, Masato; Horiguchi, Kenichi
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no abstracts in English
Aizawa, Kosuke; Oshima, Jun*; Kamide, Hideki; Kasahara, Naoto
no journal, ,
JSFR adopts a Selector-valve method for the failed fuel detection and location (FFDL) system. A Selector-valve FFDL system identifies the failed fuel subassembly by sampling outlet sodium of each fuel subassembly. One of the JSFR design features is an upper internal structure (UIS) with a radial slit, in which an arm of fuel handling machine can move and access the fuel assemblies under the UIS. This UIS can simplify a fuel handling system, and can downscale the reactor vessel diameter. Thus, JSFR cannot place the sampling ports right above the fuel subassemblies located under the slit. So, it is necessary that the sampling ports will be set around the UIS slit so as to catch the sodium flow from the fuel subassemblies located under the slit. To demonstrate sampling performance of under-slit subassemblies, water experiments and numerical analyses have been conducted.
Narita, Ayumi; Baba, Yuji; Sekiguchi, Tetsuhiro; Shimoyama, Iwao; Hirao, Norie; Yaita, Tsuyoshi
no journal, ,
no abstracts in English
Nakamichi, Shinya; Komeno, Akira
no journal, ,
no abstracts in English
Iwata, Masayuki*; Okadome, Yoshihiro*; Arai, Tsuyoshi*; Nagayama, Katsuhisa*; Suzuki, Tatsuya*; Horiguchi, Kenichi; Sugaya, Atsushi
no journal, ,
no abstracts in English
Okadome, Yoshihiro*; Iwata, Masayuki*; Arai, Tsuyoshi*; Nagayama, Katsuhisa*; Suzuki, Tatsuya*; Horiguchi, Kenichi; Sugaya, Atsushi
no journal, ,
no abstracts in English
by molecular dynamics simulationUchida, Teppei
no journal, ,
In this study, thermal expansion and thermal conductivity of UO containing Schottky defects were evaluated as a first step of evaluating thermal properties of MOX fuel containing MA by molecular dynamics simulation. Compared to thermal conductivity of perfect crystal UO, that of UO containing Schottky defects were lower. It is considered that defect structures scattered phonon vibrations and thermal conductivity decreased.
Ishimi, Akihiro; Katsuyama, Kozo; Maeda, Koji; Nagamine, Tsuyoshi; Asaka, Takeo
no journal, ,
no abstracts in English
emission of the hydrogen ironmaking plant using HTGR and thermochemical IS processKasahara, Seiji
no journal, ,
Thermochemical water-splitting IS (iodine-sulfur) process can produce hydrogen using heat of around 900 
C. Application of hydrogen from IS process using nuclear heat from High Temperature Gas-cooled Reactors to ironmaking plants theoretically enables CO-free ironmaking. An ironmaking plant composed of IS process and hydrogen direct reduction shaft furnace was proposed and heat balance and CO emission were examined by flowsheet calculation. Total heat input was greater compared with the blast furnace ironmaking plant. On the other hand, CO emission was reduced to only 7% of the blast furnace ironmaking plant.
Ikeuchi, Hirotomo; Katsurai, Kiyomichi; Kondo, Yoshikazu; Sano, Yuichi; Washiya, Tadahiro; Koizumi, Tsutomu
no journal, ,
no abstracts in English
Kitagaki, Toru; Washiya, Tadahiro; Myochin, Munetaka
no journal, ,
no abstracts in English
Yamaji, Akifumi
no journal, ,
An advanced LWR concept (FLWR) is being developed based on the well experienced LWR technologies for ensuring sustainable energy supply in the future. For developing the core concept, a light water fuel rod analysis code, FEMAXI-6 has been verified with MOX fuel rods irradiated at Halden. The results showed that uncertainties in fission gas release calculations were particularly high. The basic fission gas release mechanism of MOX fuels should be the same as that of UO fuels, but the parameters in the model need to be revised for MOX fuels. More experimental data are needed. However, frequent reactor shutdowns and restarts may cause pellet relocation changes and give difficulties in code verifications.
Tobari, Hiroyuki; Inoue, Takashi; Dairaku, Masayuki; Yamanaka, Haruhiko; Umeda, Naotaka; Taniguchi, Masaki; Kashiwagi, Mieko; Takemoto, Jumpei; Watanabe, Kazuhiro; Sakamoto, Keishi
no journal, ,
The high voltage bushing in the ITER NBI has a five-stage structure composed of large bore ceramic rings. The ceramic ring must be 1.56 m in diameter because many conductors are located keeping insulation inside the ceramic ring. However, in conventional technique, the diameter has been limited less than 1 m. The joining technique of the brazing between the large ceramic ring with metal has not been established. Then, new forming method of the large ceramic ring and the brazing technique were developed. As a result, the large ceramic of 1.56 m in diameter was successfully manufactured and the ceramic ring was brazed to Kovar rings with vacuum tightness. To enhance voltage holding capability of the manufactured insulator, stress ring to suppress the breakdown staring from the joining point of the ceramic and metal was also developed. In the high voltage test of the insulator, 240 kV was sustained stably over 1 hour, and the voltage holding capability required in ITER was verified.
Hata, Kuniki; Fu, H. Y.*; Katsumura, Yosuke*; Lin, M.; Muroya, Yusa*; Yamashita, Shinichi; Kudo, Hisaaki*; Nakagawa, Hidehiko*
no journal, ,
no abstracts in English