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C absorber material on melt progression and chemical forms of iodine or cesium under severe accident conditionsHidaka, Akihide
Insights Concerning the Fukushima Daiichi Nuclear Accident, Vol.4; Endeavors by Scientists, p.341 - 356, 2021/10
Takada, Hiroshi
Plasma and Fusion Research (Internet), 13(Sp.1), p.2505013_1 - 2505013_8, 2018/03
The pulsed spallation neutron source of Japan Proton Accelerator Research Complex (J-PARC) has been supplying users with high intensity and sharp pulse cold neutrons using the moderators with following distinctive features; (1) 100% para-hydrogen for increasing pulse peak intensity with decreasing pulse tail, (2) cylindrical shape with 14 cm diam.
12 cm long for providing high intensity neutrons to wide neutron extraction angles of 50.8
, (3) neutron absorber made from Ag-In-Cd alloy to make pulse width narrower and pulse tails lower. Actually, it was measured at a low power operation that high neutron intensity of 4.510
n/cm
/s/sr could be emitted from the coupled moderator surface for 1-MW operation, and a superior resolution of 
d/d = 0.035% was achieved at a beamline (BL8) with a poisoned moderator, where d is the d-spacing of reflection. Towards the goal to achieve the target operation at 1-MW for 5000 h in a year, technical developments to mitigate cavitation damages on the target vessel with injecting gas micro-bubbles into mercury target and design improvement of target vessel structure to reducing welds and bolt connections as much as possible are under way.
Teshigawara, Makoto; Ikeda, Yujiro; Oi, Motoki; Harada, Masahide; Takada, Hiroshi; Kakishiro, Masanori*; Noguchi, Gaku*; Shimada, Tsubasa*; Seita, Kyoichi*; Murashima, Daisuke*; et al.
Nuclear Materials and Energy (Internet), 14, p.14 - 21, 2018/01
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)We developed an Au-In-Cd (AuIC) decoupler material to reduce induced radioactivity instead of Ag-In-Cd one, which has a cut off energy of 1eV. In order to implement it into an actual moderator-reflector assembly, a number of critical engineering issues need to be resolved with regard to large-sized bonding between AuIC and A5083 alloys by the hot isostatic pressing process. We investigated this process in terms of the surface conditions, sizes, and heat capacities of large AuIC alloys. We also show a successful implementation of an AuIC decoupler into a reflector assembly, resulting in a remarkable reduction of radioactivity by AuIC compared to AIC without sacrificing neutronic performance.
Hidaka, Akihide; Yokoyama, Hiroya
Proceedings of Symposium on Water Chemistry and Corrosion in Nuclear Power Plants in Asia 2017 (AWC 2017) (USB Flash Drive), p.29 - 42, 2017/09
no abstracts in English
C absorber material on melt progression and chemical forms of iodine or cesium under severe accident conditionsHidaka, Akihide
Nihon Genshiryoku Gakkai Wabun Rombunshi, 14(1), p.51 - 61, 2015/03
BC used mainly for BWR and EPR absorbers could cause phenomena which never happen in PWR with Ag-In-Cd absorbers during severe accident. BC would make a eutectic interaction with stainless steel and enhance melt relocation. Boron oxidation could increase H
generation and change of liberated carbon to CH could enhance CH
I generation. HBO generated during BC oxidation could be changed to CsBO by combining with Cs. This may increase Cs deposition in reactor coolant system. There could be differences in configuration, surface area, stainless steel-BC weight ratio between BC powder and pellet absorbers. Present issue is to clarify effect of these differences on full scale melt progression, BC oxidation and source term. Advancement of this research domain could contribute to further sophistication of prediction tool for melt progression and source terms, and treatment of organic iodide formation in safety evaluation.
Yamamoto, Toshihiro; Miyoshi, Yoshinori; Takeda, Toshikazu*
Journal of Nuclear Science and Technology, 43(1), p.77 - 87, 2006/01
Times Cited Count：11 Percentile：56.9(Nuclear Science & Technology)no abstracts in English
Nishihara, Tetsuo; Inagaki, Yoshiyuki
Nuclear Technology, 153(1), p.100 - 106, 2006/01
Times Cited Count：9 Percentile：53.29(Nuclear Science & Technology)Japan Atomic Energy Research Institute (JAERI) has performed the research and development of hydrogen production using the high temperature engineering test reactor (HTTR). One of the key issues for the HTTR hydrogen production system is the development of control technology for stable operation. A thermal load absorber concept using a steam generator installed downstream of a reformer is proposed to mitigate a variation of helium temperature. Thermal hydraulic analyses for the start up operation and the suspension of feed gas supply to the reformer are carried out. These results show that a large variation of the reformer outlet helium temperature takes place due to a change of the feed gas flow rate. However the steam generator can mitigate the variation of helium temperature. It is clarified that the HTTR can continue normal operation independently of the feed gas flow rate.
Nishihara, Tetsuo; Inagaki, Yoshiyuki
Proceedings of GLOBAL2003 Atoms for Prosperity; Updating Eisenhower's Global Vision for Nuclear Energy (CD-ROM), p.320 - 324, 2003/00
HTGR hydrogen production system has potential possibility to provide hydrogen without CO emission. Key technology for developing this system is to establish the control technology for preventing propagation of thermal turbulence from the hydrogen production system to the HTGR. Japan Atomic Energy Research Institute (JAERI) has planed a demonstration test of hydrogen production using an HTGR named high temperature engineering test reactor (HTTR) to develop the control technology. Thermal load absorber concept using the steam generator located downstream of the chemical reactor is proposed to mitigate the variation of outlet helium temperature of the chemical reactor. This concept leads to the stable controllability and enables to operate the HTGR and the hydrogen production plant independently. Plant simulation analyses are carried out to verify the performance of this concept.
Tsunoda, Hirokazu*; Sato, Osamu*; Okajima, Shigeaki; Yamane, Tsuyoshi; Iijima, Susumu; Kobe, Mitsuru*
Proceedings of International Congress on Advanced Nuclear Power Plants (ICAPP) (CD-ROM), 6 Pages, 2002/00
no abstracts in English
Fujimoto, Nozomu; Yamashita, Kiyonobu; Akino, Fujiyoshi
JAERI-Research 99-052, p.51 - 0, 1999/09
JAERI-Research-99-052.pdf:2.05MB
no abstracts in English
Nagaoka, Yoshiharu; Komukai, Bunsaku; ; Koike, Sumio; Saito, Minoru;
JAERI-M 92-098, 81 Pages, 1992/07
no abstracts in English
Fujii, Kimio; Nomura, Shinzo; *; Shindo, Masami
Journal of Nuclear Materials, 187, p.32 - 38, 1992/00
Times Cited Count：7 Percentile：57.42(Materials Science, Multidisciplinary)no abstracts in English
; ; Saito, Junichi; Komukai, Bunsaku; Ando, Hiroei; ; ; ; Saito, Minoru;
Proc. on 12th Int. Meeting,Reduced Enrichment for Research and Test Reactors, p.269 - 280, 1991/00
no abstracts in English
Okajima, Shigeaki; Osugi, Toshitaka; Sakurai, Takeshi; *
Journal of Nuclear Science and Technology, 27(10), p.950 - 959, 1990/10
no abstracts in English
Annals of Nuclear Energy, 14(8), p.451 - 454, 1987/08
Times Cited Count：3 Percentile：51.52(Nuclear Science & Technology)no abstracts in English
; ; ; ;
JAERI-M 85-088, 39 Pages, 1985/07
no abstracts in English
;
Annals of Nuclear Energy, 10(11), p.589 - 599, 1983/00
Times Cited Count：1 Percentile：22.48(Nuclear Science & Technology)no abstracts in English
; ; ; Ono, Akio; Murakami, Kiyonobu; *; *; *; *
JAERI-M 8020, 162 Pages, 1979/01
no abstracts in English
Amemiya, Kuniaki*; Koshikawa, Hiroshi; Yamaki, Tetsuya; Maekawa, Yasunari; Shitomi, Hiroshi*; Kinoshita, Kenichi*; Numata, Takayuki*; Tanabe, Minoru*; Fukuda, Daiji*
no journal, ,
The novel broadband near-perfect black absorber for an absolute radiometer has been developed. Microstructured surface having high-aspect-ratio conical pores was fabricated by swift heavy ion beam irradiation and following etching process; subsequently, the surface was coated with black layer. Incident light which enters into the surface microstructure experiences multiple reflections which enhance optical absorption; therefore, the net reflectance decreases much less than 1% with sufficient pit aspect ratio and absorption layer thickness, which can be designed by finite differential time domain (FDTD) method calculation. Furthermore, a prototype of the novel black absorber also exhibited good mechanical durability. This newly developed black material is also expected to have potential application in various fields of optical energy management such as stray light elimination.
