Yamada, Yoshikazu; Segawa, Tomomi; Kato, Masato
Proceedings of International Conference on Fast Reactors and Related Fuel Cycles; Next Generation Nuclear Systems for Sustainable Development (FR-17) (USB Flash Drive), 8 Pages, 2017/06
Japan Atomic Energy Agency (JAEA) have proposed the transmutation of minor actinides by fast reactors as a way to contribute significantly to the reduction of the volume and the potential radiotoxicity of radioactive wastes. In order to achieve this goal, it is important to introduce a fully automated and remote operation fuel fabrication plant with shielded hot cells and manipulators. JAEA's facilities including Plutonium Fuel Production Facility (PFPF) have fabricated MOX fuel. On the basis of the operational and technical experience obtained in above facilities, the conceptual design of engineering-scale plant applied the simplified MA-bearing fuel fabrication process with shielded hot cells and manipulator was done. It will be able to fabricate high MA-bearing fuel and to perform the maintenance and repairing of each equipment with manipulators. This plant will be constructed based on this concept and development plan.
Amemiya, Kuniaki*; Koshikawa, Hiroshi; Yamaki, Tetsuya; Maekawa, Yasunari; Shitomi, Hiroshi*; Numata, Takayuki*; Kinoshita, Kenichi*; Tanabe, Minoru*; Fukuda, Daiji*
Nuclear Instruments and Methods in Physics Research B, 356-357, p.154 - 159, 2015/08
Broadband low reflectance materials have various applications in the field of optical energy management; however, materials with ultra-low reflectance (below 0.1%) have been considered as mechanically delicate. We have developed a novel hard-surface optical absorber with microstructured, diamond-like carbon coated ion tracks on CR-39 plastic substrate. The spectral reflectance of the first prototype was below 2% for wavelengths ranging from 400 nm to 1400 nm; moreover, the optical absorber had mechanically hard surface and exhibited temporal durability. Choosing the appropriate design of the surface structure and coating layer is likely to reduce the reflectance to the order of 0.1%. This technique yields easy-to-handle broadband ultra-low reflectance absorbers.
Tamaki, Hitoshi; Hamaguchi, Yoshikane; Yoshida, Kazuo; Muramatsu, Ken
Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10
A PSA procedure for MOX fuel fabrication facilities is being developed at the JAERI. This procedure consists of four steps, which are hazard analysis, accident scenario analysis, frequency evaluation and consequence evaluation. The proposed procedure is characterized by the hazard analysis step. The Hazard analysis step consists of two sub-steps. In the first sub-step, a variety of functions of equipment composing the facility are analyzed to identify potential abnormal events exhaustively. In the second sub-step, these potential events are screened to select abnormal events by using a risk matrix based on the rough estimation of likelihood and maximum unmitigated release of radioactive material. One of the unique technical issues in this research is the estimation of likelihood of criticality event. A method is also proposed as a part of PSA procedure taking into consideration of failure of a computerized control system for MOX powder handling process. The applicability of the PSA procedure was demonstrated through the trial application of it to a model plant of MOX fuel fabrication facility.
Nakajima, Kunihisa; Iwai, Takashi; Kikuchi, Hironobu; Serizawa, Hiroyuki; Arai, Yasuo
JAERI-Research 2005-027, 42 Pages, 2005/09
Nitride fuel pins containing inert matrix such as ZrN and TiN were fabricated for the irradiation test at JMTR, aiming at understanding irradiation behavior of nitride fuel for transmutation of minor actinides. Minor actinides are surrogated by plutonium in the present fuel pin. This report describes the preparation and characterization of fuel pellets, and fabrication of fuel pins. The irradiation for 11 cycles from May 2002 to November 2004 at JMTR was completed without any failure of fuel pins.
Tashiro, Shinsuke; Abe, Hitoshi; Morita, Yasuji
JAERI-Conf 2005-007, p.348 - 350, 2005/08
Hot test at Rokkasho Reprocessing plant has been started since last year. In addition, construction of the MOX fuel fabrication facility at Rokkasho site is planning. So, the importance of safety evaluation of the nuclear fuel cycle facility is increasing. Under the fire accident, one of the serious postulated accidents in the nuclear fuel cycle facility, the equipments (glove-box, ventilation system, ventilation filters etc.) for the confinement of the radioactive materials within the facility could be damaged by a large amount of heat and smoke released from the combustion source. Therefore, the fundamental data and models calculating for the amount of heat and smoke released from the combustion source under such accident are important for the safety evaluation of the facility. In JAERI, the study focused on the evaluation of amount of heat and smoke released from the combustion source is planning. In this paper, the outline of experimental apparatus, measurement items and evaluation terms are described.
Tamaki, Hitoshi; Yoshida, Kazuo; Watanabe, Norio; Muramatsu, Ken
Proceedings of International Topical Meeting on Probabilistic Safety Analysis (PSA '05) (CD-ROM), 11 Pages, 2005/00
A probabilistic safety assessment (PSA) procedure for Mixed Oxide (MOX) fuel fabrication facilities is being developed applicable to nuclear facilities at Japan Atomic Energy Research Institute (JAERI). As part of the PSA procedure, the approach to hazard analysis was established, which consists of two analysis steps: Functional Failure Modes and Effects Analysis (Functional FMEA) and Risk Matrix Analysis. In the Functional FMEA, a variety of functions of equipment composing the facility are analyzed to identify potential abnormal events exhaustively. In the second step, these potential events are screened to select abnormal events as candidate events to be analyzed for frequency and consequence by using two-dimensional matrix based on the rough estimation of likelihood and maximum unmitigated release of radioactive material. The applicability of the hazard analysis approach established was demonstrated through the trial application of the PSA procedure being developed to model plant of MOX fuel fabrication facility.
Department of Materials Science
JAERI-Conf 2004-015, 143 Pages, 2004/12
This report is the Proceedings of the Symposium of Nitride Fuel Cycle Technology, which was held on July 28, 2004, at Tokai Research Establishment of Japan Atomic Energy Research Institute (JAERI). The purpose of this symposium is to exchange information and views on nitride fuel cycle technology among researchers from foreign and domestic organizations, and to discuss the recent and future research activities. The topics discussed in the symposium are Present State of the Technology Development in the World and Japan, Fabrication Technology, Property Measurement and Pyrochemical Process. The intensive discussion was made among 53 participants.
Sawa, Kazuhiro; Ueta, Shohei
Nuclear Engineering and Design, 233(1-3), p.163 - 172, 2004/10
In the high temperature gas-cooled reactors (HTGRs), refractory coated fuel particles are employed as fuel to permit high outlet coolant temperature. The High Temperature Engineering Test Reactor (HTTR) employs Tri-isotropic (Triso) coated fuel particles in the prismatic fuel assembly. Research and development on the HTTR fuel has been carried out spread over about 30 years, in fuel fabrication technologies, fuel performance, and so on. Furthermore, for upgrading of HTGR technologies, an extended burnup TRISO-coated fuel particle and an advanced type of coated fuel particle, ZrC-coated fuel particle in order to keep the integrity at higher operating temperatures has been developed. The present paper provides experiences and current status of research and development works for the HTGR fuel in the HTTR Project.
JAERI-Conf 2004-012, 237 Pages, 2004/07
This report is the Proceedings of "the Eleventh International Workshop on Ceramic Breeder Blanket Interactions" which was held as a workshop on ceramic breeders Under the IEA Implementing Agreement on the Nuclear Technology of Fusion Reactors, and the Japan-US Fusion Collaboration Framework. In the workshop, information exchange was performed for designs of solid breeder blankets and test blankets in EU, Russia and Japan, recent results of irradiation tests, HICU, EXOTIC-8 and the irradiation tests by IVV-2M, modeling study on tritium release behavior of LiTiO and other breeders, fabrication technology developments and characterization of the LiTiO and LiSiO pebbles, research on measurements and modeling of thermo-mechanical behaviors of LiTiO and LiSiO pebbles, and interfacing issues, such as, fabrication technology for blanket box structure, neutronics experiments of blanket mockups by fusion neutron source and tritium recovery system.
Minato, Kazuo; Akabori, Mitsuo; Takano, Masahide; Arai, Yasuo; Nakajima, Kunihisa; Ito, Akinori; Ogawa, Toru
Journal of Nuclear Materials, 320(1-2), p.18 - 24, 2003/09
In the Japan Atomic Energy Research Institute, the concept of the transmutation of minor actinides (MA: Np, Am and Cm) with accelerator-driven systems is being studied. The MA nitride fuel has been chosen as a candidate because of the possible mutual solubility among the actinide mononitrides and excellent thermal properties besides supporting hard neutron spectrum. MA nitrides of AmN, (Am,Y)N, (Am,Zr)N and (Cm0.4Pu0.6)N were prepared from the oxides by the carbothermic reduction method. The prepared MA nitrides were examined by X-ray diffraction and the contents of impurities of oxygen and carbon were measured. The fabrication conditions for MA nitrides were improved so as to reduce the impurity contents. For an irradiation test of U-free nitride fuels, pellets of (Pu,Zr)N and PuN+TiN were prepared and a He-bonded fuel pin was fabricated. The irradiation test started in May 2002 and will go on for two years in the Japan Materials Testing Reactor.
Sawa, Kazuhiro; Kawasaki, Kozo
Kensa Gijutsu, 8(6), p.17 - 22, 2003/06
This report describes outline of High Temperature Gas-cooled Reactors (HTGR), present status of HTTR Project, which is proceeded by JAERI. Fabrication technique and inspection methods of the HTGR fuel, which is are one of the special features of the HTGR, are also introduced.
Minato, Kazuo; Ogawa, Toru
Proceedings of GLOBAL2003 Atoms for Prosperity; Updating Eisenhower's Global Vision for Nuclear Energy (CD-ROM), p.1068 - 1074, 2003/00
The research and development of the ZrC-Triso coated particle fuel was reviewed, especially on the fabrication, chemical reactions, high-temperature stability, and retention of fission products. The fabrication process of stoichiometric ZrC coating layer has been established based on the in-situ generation of zirconium halide vapor. The irradiation experiments, the postirradiation heating tests, and the out-of-reactor experiments demonstrated that the ZrC coating layer is less susceptible than the SiC coating layer to chemical attack by the fission product palladium, and that the ZrC-Triso coated UO particles perform better than the normal Triso-coated particles at high temperatures, especially above 1873 K. It was revealed that the ZrC-Triso coated particles retain the fission products better than the SiC-Triso coated particles, though the ZrC coating layer is a less effective barrier to ruthenium than the SiC coating layer.
Hatano, Toshihisa; Enoeda, Mikio; Kuroda, Toshimasa*; Akiba, Masato
JAERI-Tech 2002-075, 59 Pages, 2002/10
no abstracts in English
Kosaku, Yasuo; Kuroda, Toshimasa*; Enoeda, Mikio; Hatano, Toshihisa; Sato, Satoshi; Akiba, Masato
JAERI-Tech 2002-063, 98 Pages, 2002/07
no abstracts in English
Fu, X.*; Takahashi, Masashi; Ueta, Shohei; Sawa, Kazuhiro
JAERI-Tech 2002-049, 35 Pages, 2002/05
no abstracts in English
Takahashi, Masashi; Ueta, Shohei; Yasuda, Atsushi*; Yoshimuta, Shigeharu*; Kato, Shigeru*; Sawa, Kazuhiro
JAERI-Tech 2001-091, 29 Pages, 2002/01
no abstracts in English
Minato, Kazuo; Arai, Yasuo; Akabori, Mitsuo; Nakajima, Kunihisa
Proceedings of American Nuclear Society Conference "Nuclear Applications in the New Millennium" (AccApp-ADTTA '01) (CD-ROM), 6 Pages, 2002/00
In the Japan Atomic Energy Research Institute (JAERI), the concept of the transmutation of minor actinides (MA: Np, Am and Cm) with accelerator-driven systems (ADS) is being studied, where MA nitride is adopted as a fuel material of sub-critical core. The nitride fuel has been chosen as a candidate because of the possible mutual solubility among the actinide mononitrides and excellent thermal properties besides supporting hard neutron spectrum. Highly enriched N-15 would have to be used for the nitride fuel in order to prevent the formation of hazardous C-14. By applying pyrochemical process in the treatment of spent fuel, N-15 could be readily recovered and recycled. The present paper describes an overview of the research on the nitride fuel performed in JAERI. Fabrication experiments of actinide nitrides, measurements of vaporization behavior and thermal properties, and irradiation tests of actinide nitrides are summarized.
Zusetsu Zoryu; Tsubu No Sekai Arekore, p.131 - 133, 2001/10
no abstracts in English
Sawa, Kazuhiro; Sumita, Junya; Ueta, Shohei; Suzuki, Shuichi*; Tobita, Tsutomu*; Saito, Takashi; Minato, Kazuo; Koya, Toshio; Sekino, Hajime
Journal of Nuclear Science and Technology, 38(6), p.403 - 410, 2001/06
no abstracts in English