Design of a -1 MV dc UHV power supply for ITER NBI

Watanabe, Kazuhiro; Yamamoto, Masanori; Takemoto, Jumpei; Yamashita, Yasuo*; Dairaku, Masayuki; Kashiwagi, Mieko; Taniguchi, Masaki; Tobari, Hiroyuki; Umeda, Naotaka; Sakamoto, Keishi; et al.

Nuclear Fusion, 49(5), p.055022_1 - 055022_5, 2009/05

https://doi.org/10.1088/0029-5515/49/5/055022

Japan Atomic Energy Agency as the Japan Domestic Agency (JADA) for ITER contributes procurement of dc -1 MV ultra-high voltage (UHV) components such as a dc -1 MV generator, a transmission line and a -1 MV insulating transformer for the ITER NBI power supply. Inverter frequency of 150 Hz in the -1 MV power supply and major circuit parameters have been proposed and adopted in the ITER NBI. The dc UHV insulation at the multi-layer insulation structure of the transformer for a long pulse up to 3600 s has been designed with electric field simulation. Based on the simulation overall dimensions of the dc UHV components have been finalized. The JADA contributes to provide an effective surge suppression system composed of core snubbers and resistors. Input energy into the accelerator from the power supply can be reduced to about 20 J which satisfies the design criteria of the total 50 J at -1 MV breakdown.

Fuel performance evaluation of rock-like oxide fuels

Shirasu, Noriko; Kuramoto, Kenichi; Nakano, Yoshihiro; Yamashita, Toshiyuki; Kimura, Yasuhiko; Nihei, Yasuo; Ogawa, Toru

Journal of Nuclear Materials, 376(1), p.88 - 97, 2008/05

https://doi.org/10.1016/j.jnucmat.2008.01.019

The concept of the rock-like oxide (ROX) fuel has been developed for the annihilation of excess plutonium in light water reactors. Irradiation tests and post-irradiation examinations were carried out on candidate ROX fuels. The ternary fuel of YSZ-spinel-corundum system, the single-phase fuels of YSZ, the particle dispersed fuels of YSZ in spinel or corundum matrix, and the blended fuels of YSZ and spinel or corundum matrix were fabricated and submitted to irradiation tests. The fuels containing spinel showed chemical instabilities with the vaporization of MgO component, which caused fuel restructuring. The swelling behavior was improved with the particle-dispersed fuels. However, the particle-dispersed fuels showed higher fractional gas release (FGR) than blended type fuels. The FGR of YSZ single-phase fuels were comparable to what would be expected for UO fuels. The YSZ single-phase fuel showed the best irradiation performance among the ROX fuels investigated.

Development of a dc 1MV power supply technology for NB injectors

Watanabe, Kazuhiro; Kashiwagi, Mieko; Kawashima, Shuichi*; Ono, Yoichi*; Yamashita, Yasuo*; Yamazaki, Choji*; Hanada, Masaya; Inoue, Takashi; Taniguchi, Masaki; Okumura, Yoshikazu; et al.

Nuclear Fusion, 46(6), p.S332 - S339, 2006/06

https://doi.org/10.1088/0029-5515/46/6/S15

no abstracts in English

JAERI-JNC joint research report; A Study on degradation of structural materials used under the irradiation environment in nuclear reactors

Ueno, Fumiyoshi; Nagae, Yuji*; Nemoto, Yoshiyuki; Miwa, Yukio; Takaya, Shigeru*; Hoshiya, Taiji*; Tsukada, Takashi; Aoto, Kazumi*; Ishii, Toshimitsu; Omi, Masao; et al.

JAERI-Research 2005-023, 132 Pages, 2005/09

JAERI-Research-2005-023.pdf:33.03MB

JAERI and JNC have started a JAERI-JNC joint research program in fiscal year 2003, which has been aimed for efficient progress and synergistic effect on the research activities in both Institutes. This study has been chosen one of the joint research themes because it has been our common objective in the field of structural materials of FBR and LWR components. The purpose of the study is to clarify damage mechanism of structural materials used under irradiation, and then to develop the methods for damage evaluation and detection in earlier stage of progressing process of damage. In fiscal year 2004 and 2005, micro-corrosion measurement, electrochemical corrosion test and leakage magnetic flux density measurement apparatuses were developed and equipped in two hot facilities and irradiated and unirradiated crept specimens, irradiated high purity model austenitic stainless alloys were also prepared and applied to this study. These apparatuses and specimens were used for damage evaluation, and these feasibilities for nuclear power plant materials were studied.

Electrochemical behaviors of PuN and (U, Pu)N in LiCl-KCl eutectic melts

Shirai, Osamu; Kato, Tetsuya*; Iwai, Takashi; Arai, Yasuo; Yamashita, Toshiyuki

Journal of Physics and Chemistry of Solids, 66(2-4), p.456 - 460, 2005/02

https://doi.org/10.1016/j.jpcs.2004.06.040

Electrochemical behaviors of PuN and (U, Pu)N in the LiCl-KCl eutectic melt containing UCl and PuCl at 773 K were investigated by cyclic voltammetry. The electrochemical dissolution of PuN and (U, Pu)N began nearly at -1.0 V vs. the Ag/AgCl reference electrode. The rest potentials of PuN and (U, Pu)N were observed at about 0.15 V more negative potential than that of UN since the equilibrium potential of UN is about 0.15 V more positive than that of PuN. In the cyclic voltammogram measured by using (U, Pu)N as the working electrode, a steep rise of the positive current was observed at more positive potential than -0.4 V in analogy with the cyclic voltammogram measured by using UN as the working electrode. In addition, there were two anodic current waves in the voltammogram with (U, Pu)N, though the wave form was not clear. This indicates that UN and PuN would be dissolved independently irrespective of formation of the solid solution, (U, Pu)N.

Re-evaluation of the phase relationship between plutonium and zirconium dioxides

Serizawa, Hiroyuki; Nakajima, Kunihisa; Arai, Yasuo; Yamashita, Toshiyuki; Kuramoto, Kenichi; Kinoshita, H.*; Yamanaka, Shinsuke*; Uno, Masayoshi*; Kurosaki, K.*

Progress in Nuclear Energy, 38(3-4), p.237 - 240, 2001/02

https://doi.org/10.1016/S0149-1970(00)00107-4

no abstracts in English

Test and research ice-blasting equipment, II

Nishimoto, Wataru*; Kimuro, Harumi*; Ishibashi, Seijiro*; Miyahara, Shuji*; Yamashita, Saburo*; Hayashi, Mitsuo*; Suzuki, Yoji*; Hirose, Yasuo*

PNC TJ118 85-06VOL2, 221 Pages, 1985/04

PNC-TJ118-85-06VOL2.pdf:20.84MB

None

Development of flexible fuel cycle initiative, 3; Uranium removal

Yamashita, Junichi*; Fukasawa, Tetsuo*; Kawamura, Fumio*; Hoshino, Kuniyoshi*; Sasahira, Akira*; Minato, Kazuo; Akabori, Mitsuo; Arai, Yasuo

no journal, , 

no abstracts in English

Development of dc -1 MV power supply and negative ion beam accelerator for ITER

Watanabe, Kazuhiro; Yamamoto, Masanori; Taniguchi, Masaki; Umeda, Naotaka; Kobayashi, Kaoru; Hanada, Masaya; Kashiwagi, Mieko; Tobari, Hiroyuki; Dairaku, Masayuki; Sakamoto, Keishi; et al.

no journal, , 

Japan Atomic Energy Agency as a Japanese Domestic Agency will procure the high voltage part of the power supply for the ITER neutral beam injector (NBI). Design studies have been performed on high voltage components and a surge suppression system of the -1 MV power supply. It was confirmed by circuit analysis that an input energy from the power supply to the accelerator can be reduced to 20 joule which is smaller than the design criteria of 50 joule at 1 MV breakdowns. Present status of the development on the negative ion accelerators and high voltage bushing will be also reported.

Structural specification of high voltage bushing for the ITER NBI

Tobari, Hiroyuki; Umeda, Naotaka; Watanabe, Kazuhiro; Inoue, Takashi; Sakamoto, Keishi; Yamashita, Yasuo*

no journal, , 

no abstracts in English