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Kawano, Takahiro*; Mizuta, Naoki; Ueta, Shohei; Tachibana, Yukio; Yoshida, Katsumi*
JAEA-Technology 2023-014, 37 Pages, 2023/08
JAEA-Technology-2023-014.pdf:2.35MB
Fuel compact for High Temperature Gas-cooled Reactor (HTGR) is fabricated by calcinating a matrix consisting of graphite and binder with the coated fuel particle. The SiC-matrixed fuel compact uses a new matrix made of silicon carbide (SiC) replacing the conventional graphite. Applying the SiC-matrixed fuel compact for HTGRs is expected to improve their performance such as power densities. In this study, the sintering conditions for applying SiC as the matrix of fuel compacts for HTGR are selected, and the density and thermal conductivity of the prototype SiC are measured.
Takeda, Tetsuaki*; Inagaki, Yoshiyuki; Aihara, Jun; Aoki, Takeshi; Fujiwara, Yusuke; Fukaya, Yuji; Goto, Minoru; Ho, H. Q.; Iigaki, Kazuhiko; Imai, Yoshiyuki; et al.
High Temperature Gas-Cooled Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.5, 464 Pages, 2021/02
As a general overview of the research and development of a High Temperature Gas-cooled Reactor (HTGR) in JAEA, this book describes the achievements by the High Temperature Engineering Test Reactor (HTTR) on the designs, key component technologies such as fuel, reactor internals, high temperature components, etc., and operational experience such as rise-to-power tests, high temperature operation at 950
C, safety demonstration tests, etc. In addition, based on the knowledge of the HTTR, the development of designs and component technologies such as high performance fuel, helium gas turbine and hydrogen production by IS process for commercial HTGRs are described. These results are very useful for the future development of HTGRs. This book is published as one of a series of technical books on fossil fuel and nuclear energy systems by the Power Energy Systems Division of the Japan Society of Mechanical Engineers.
Aihara, Jun; Ueta, Shohei; Honda, Masaki*; Mizuta, Naoki; Goto, Minoru; Tachibana, Yukio; Okamoto, Koji*
Journal of Nuclear Science and Technology, 58(1), p.107 - 116, 2021/01
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)The concept of a Pu-burner high temperature gas-cooled reactor (HTGR) has been proposed for purpose of more safely reducing amount of recovered Pu. This concept employs coated fuel particles (CFPs) with ZrC coated PuO
-YSZ kernel and with tristructural (TRISO) coating for very high Pu burn-up and high nuclear proliferation resistance. In this report, we investigate the microstructure of the region that includes the surface of an as-fabricated CeO-YSZ kernel simulating PuO-YSZ kernel. We found both Zr-rich grains and Ce-rich grains to be densely distributed in that region including surface of CeO-YSZ kernel. On the other hand, it has been reported that there was a porous region near surface of the CeO-YSZ kernel of Batch I. This finding confirms that Ce-rich grains near surface of CeO-YSZ kernels coated with ZrC layers have been corroded during the deposition of the ZrC layer, whereas the Zr-rich grains were hardly affected.
Ueta, Shohei; Mizuta, Naoki; Fukaya, Yuji; Goto, Minoru; Tachibana, Yukio; Honda, Masaki*; Saiki, Yohei*; Takahashi, Masashi*; Ohira, Koichi*; Nakano, Masaaki*; et al.
Nuclear Engineering and Design, 357, p.110419_1 - 110419_10, 2020/02
Times Cited Count：1 Percentile：12.16(Nuclear Science & Technology)The concept of a plutonium (Pu) burner HTGR is proposed to incarnate highly-effective Pu utilization by its inherent safety features. The security and safety fuel (3S-TRISO fuel) employs the coated fuel particle with a fuel kernel made of plutonium dioxide (PuO) and yttria stabilized zirconia (YSZ) as an inert matrix. This paper presents feasibility study of Pu burner HTGR and R&D on the 3S-TRISO fuel.
Aihara, Jun; Ueta, Shohei; Honda, Masaki*; Mizuta, Naoki; Goto, Minoru; Tachibana, Yukio; Okamoto, Koji*
Journal of Nuclear Materials, 522, p.32 - 40, 2019/08
Times Cited Count：3 Percentile：31.89(Materials Science, Multidisciplinary)In order to realize Pu-burner high temperature gas-cooled reactor (HTGR), coated fuel particles (CFPs) with PuO-yittria stabilized zirconia (YSZ) fuel kernel coated with ZrC is employed for high nuclear proliferation resistance and very high burn-up. Japan Atomic Energy Agency (JAEA) have carried out ZrC coatings of particles which simulated PuO-YSZ kernels (CeO-YSZ particles or commercially available YSZ particles). Ce was used as simulating element of Pu. In this manuscript, microstructures of ZrC coated CeO-YSZ or YSZ particles were reported.
Ueta, Shohei; Aihara, Jun; Mizuta, Naoki; Goto, Minoru; Fukaya, Yuji; Tachibana, Yukio; Okamoto, Koji*
Proceedings of 9th International Topical Meeting on High Temperature Reactor Technology (HTR 2018) (USB Flash Drive), 7 Pages, 2018/10
The security and safety fuel (3S-TRISO fuel) employs the coated fuel particle with a fuel kernel made of plutonium dioxide (PuO) and yttria stabilized zirconia (YSZ) as an inert matrix. Especially, a zirconium carbide (ZrC) coating is one of key technologies of the 3S-TRISO, which performs as an oxygen getter to reduce the fuel failure due to internal pressure during the irradiation. R&Ds on ZrC coating directly on the dummy CeO-YSZ kernel have been carried in the Japanese fiscal year 2017. As results of ZrC coating tests by the bromide chemical vapor deposition process, stoichiometric ZrC coatings with 3 - 18 microns of thicknesses were obtained with 0.1 kg of particle loading weight.
Mizuta, Yukio*; Morishita, Norio; Kuwata, Keiji*
Proceedings of 2nd Asia-Pacific EPR/ESR Symposium, P. 173, 1999/11
no abstracts in English
Mizuta, Yukio*; Morishita, Norio; Kuwata, Keiji*
Proceedings of 2nd Asia-Pacific EPR/ESR Symposium, P. 14, 1999/11
no abstracts in English
Mizuta, Yukio*; Morishita, Norio; Kuwata, Keiji*
Chemistry Letters, (328), p.311 - 312, 1999/00
no abstracts in English
Mizuta, Yukio*; Morishita, Norio; Kuwata, Keiji*
Magnetic Resonance and Related Phenomena, Volume 1, p.931 - 932, 1998/00
no abstracts in English
Aihara, Jun; Ueta, Shohei; Honda, Masaki*; Ogawa, Hiroaki; Shibata, Taiju; Mizuta, Naoki; Inaba, Yoshitomo; Tachibana, Yukio
no journal, ,
Development of fabrication technology of fuel element of high temperature gas-cooled reactor with SiC/C mixed matrix was carried out to modify oxidation resistance. Dummy fuel elements with matrix, which Si/C ratio (about 0.551) was three times as large as those fabricated in precursor research, were fabricated. No Si peak was detected in XRD of matrix.
Ueta, Shohei; Aihara, Jun; Mizuta, Naoki; Tachibana, Yukio; Kunitomi, Kazuhiko; Okamoto, Koji*
no journal, ,
To extend burnup of security and safety fuel for Pu-burner HTGR, zirconium carbide (ZrC) acting as an oxygen getter is coated directly on the inert matrix fuel kernel. In the fiscal year 2017, ZrC layer with the thickness of about 18 
m has been coated successfully on CeO-YSZ (cerium dioxide - yttria stabilized zirconia) dummy fuel kernel with the diameter of 0.4 mm, and then the chemical vapor deposition condition has demonstrated reproducibility of stoichiometric ZrC coating and contributed to obtaining growing rate of ZrC. Also, the material properties at the boundary between ZrC and CeO-YSZ was characterized by Scanning Transmission Electron Microscope (STEM).
