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Journal Articles

Levelized cost of electricity evaluation of SFR system considering safety measures

Mukaida, Kyoko; Kato, Atsushi; Kamiya, Masayoshi; Ishii, Katsunori

Proceedings of 2019 International Congress on Advances in Nuclear Power Plants (ICAPP 2019) (Internet), 10 Pages, 2019/05

The levelized cost of electricity is one of key indicator to evaluate economic competitiveness of energy systems. This report estimated the levelized cost of SFR system considering additional safety measures identified after the 1F incident and social cost, using major calculation tools: G4-ECONS and the calculation tool developed by the Governmental WG in Japan (CEWG-tool). The calculation results of G4-ECONS showed that the additional safety measures raise 160% of levelized cost in the case of the safety enhanced SFR system with 1500 MWe of twin looped cooling system. As a result of calculation with 3% discount rate and social cost, the levelized cost of the safety enhanced SFR system with 1200 MWe of Single looped cooling system was estimated 84 mills/kWh by CEWG-tool. This result is almost equal to the estimated levelized cost of similar standard LWR system, and it was indicated the economic competitiveness of the future SFR system.

Journal Articles

Study on optimizing microwave heating denitration method and powder characteristics of uranium trioxide

Segawa, Tomoomi; Kawaguchi, Koichi; Kato, Yoshiyuki; Ishii, Katsunori; Suzuki, Masahiro; Fujita, Shunya*; Kobayashi, Shohei*; Abe, Yutaka*; Kaneko, Akiko*; Yuasa, Tomohisa*

Proceedings of 2019 International Congress on Advances in Nuclear Power Plants (ICAPP 2019) (Internet), 9 Pages, 2019/05

A solution of plutonium nitrate and uranyl nitrate is converted into a mixed oxide by microwave heating denitration method. In the present study, for improving the efficiency of microwave heating and achieving high-temperature uniformity to produce homogeneous UO$$_{3}$$ powder, the microwave heating test of potassium chloride and uranyl nitrate solution, and numerical simulation analysis were conducted. The potassium chloride agar was adjusted to the dielectric loss, which is close to that of the uranyl nitrate solution and the optimum support table height was estimated to be 50 mm for denitration of the uranyl nitrate solution by microwave heating. The adiabator improved the efficiency of microwave heating denitration. Moreover, the powder yield was improved by using the adiabator owing to ease of scraping of the denitration product from the bottom of the denitration vessel.

Journal Articles

Development of granulation system for simplified MOX pellet fabrication process

Ishii, Katsunori; Segawa, Tomoomi; Kawaguchi, Koichi; Suzuki, Masahiro

Proceedings of 2019 International Congress on Advances in Nuclear Power Plants (ICAPP 2019) (Internet), 5 Pages, 2019/05

Japan Atomic Energy Agency (JAEA) is developing a simplified pelletizing process for MOX fuel fabrication. In this process, the flowability of MOX powder produced by de-nitration conversion based on microwave heating, calcination, and reduction is improved using the wet granulation method. In a previous paper, to produce MOX granules of appropriate sizes for pelletizing them effectively, we proposed a granulation system composed of a wet granulator and a sizing machine. In the present work, we modernized the wet granulator, completed the granulation system by adding auxiliary equipment, and conducted performance tests of the granulation system with WO$$_{3}$$ powder. The results of a performance test indicated that it is possible to convert raw powder into granules characterized by appropriate size and excellent flowability. The time required to process 5 kg of WO$$_{3}$$ powder was about 70 min, which almost satisfies the target time.

Journal Articles

The Prospect of economics of fast reactor cycle

Mukaida, Kyoko; Kato, Atsushi; Kamiya, Masayoshi; Ishii, Katsunori

Nippon Genshiryoku Gakkai-Shi, 61(1), p.40 - 47, 2019/01

Japan Atomic Energy Agency has proceeded on the research and development (R&D) of fast neutron rector fuel cycle with a system which has economic competitiveness in contrast with light water reactor systems as one of development objectives, from the start of its development. This report shows the evaluation results of generation cost of fast reactor fuel cycle in light of additional safety measure cost and social cost, based on the design of fast reactor and related fuel cycle facilities which considered in FaCT phase I.

Journal Articles

Mechanism of flashing phenomena by microwave heating and influence of high dielectric constant solution

Fujita, Shunya*; Abe, Yutaka*; Kaneko, Akiko*; Yuasa, Tomohisa*; Segawa, Tomoomi; Kato, Yoshiyuki; Kawaguchi, Koichi; Ishii, Katsunori

Proceedings of 11th Korea-Japan Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-11) (Internet), 7 Pages, 2018/11

Mixed uranium oxide and plutonium oxide powder is produced from uranyl nitrate and plutonium nitrate mixed solution by the microwave heating denitration method in the spent fuel reprocessing process. Since the microwave heating method is accompanied by a boiling phenomenon, it is necessary to fully grasp the operating conditions in order to avoid flashing and spilling in the mass production of denitrification technology for the future. In this research, it was clarified that the heat transfer coefficient became lower as the dielectric constant increased. The dominant factor of the blowing up phenomena is supposed to be generation of the innumerable bubble rather than bubble's growth.

Journal Articles

Mechanism of flashing phenomena induced by microwave heating

Fujita, Shunya*; Abe, Yutaka*; Kaneko, Akiko*; Yuasa, Tomohisa*; Segawa, Tomoomi; Yamada, Yoshikazu; Kato, Yoshiyuki; Ishii, Katsunori

Proceedings of 26th International Conference on Nuclear Engineering (ICONE-26) (Internet), 8 Pages, 2018/07

Mixed uranium oxide and plutonium oxide powder is produced from uranyl nitrate and plutonium nitrate mixed solution by the microwave heating denitration method in the spent fuel reprocessing process. Since the microwave heating method is accompanied by a boiling phenomenon, it is necessary to fully grasp the operating conditions in order to avoid flashing and spilling in the mass production of denitrification technology for the future. In this research, it was confirmed that a potassium chloride aqueous solution as a simulant of uranyl nitrate aqueous solution with high dielectric loss cause loss of microwave at the solution surface as the dielectric loss increased with the increase of KCl concentration by experimental and electromagnetic field analysis, and revealed that the change in the heating condition affects the generation of flushing.

Journal Articles

Nickel oxide powder synthesis from aqueous solution of nickel nitrate hexahydrate by a microwave denitration method

Segawa, Tomoomi; Kawaguchi, Koichi; Ishii, Katsunori; Suzuki, Masahiro; Arimitsu, Naoki*; Yoshida, Hideto*; Fukui, Kunihiro*

Advanced Powder Technology, 26(3), p.983 - 990, 2015/05

 Times Cited Count:3 Percentile:76.15(Engineering, Chemical)

Denitration of the aqueous solution of nickel nitrate hexahydrate (Ni(NO$$_{3}$$)$$_{2}$$$$cdot$$6H$$_{2}$$O) by a microwave heating method was investigated. Since Ni(NO$$_{3}$$)$$_{2}$$$$cdot$$6H$$_{2}$$O aqueous solution cannot be heated to over 300 $$^{circ}$$C by microwave irradiation owing to the low microwave absorptivity of its intermediate, NiO could not previously be obtained by microwave heating. We propose a novel NiO synthesis method that uses microwave heating without the risk of chemical contamination. A NiO powder reagent was added to the solution as a microwave acceptor. The denitration efficiency to NiO could be improved by an adiabator around the reactor to increase the temperature homogeneity in the reactor. Numerical simulations also reveal that the use of the adiabator results in remarkable changes in the electromagnetic field distribution in the reactor, temperature inhomogeneity decreases.

Journal Articles

Prevention of powder adhesion on substrate using nanoparticle coating

Suzuki, Michitaka*; Yoshikawa, Mao*; Iimura, Kenji*; Satone, Hiroshi*; Ishii, Katsunori

Funtai Kogaku Kaishi, 50(6), p.405 - 409, 2013/06

The glass substrate is coated by the silica nanoparticle suspension using dipping or spin coat method and dried in an electric oven. The glass substrate surface is covered with nanoparticle thin layer and the transparent and tiny rugged surface can be produced on a substrate. It was experimentally confirmed to prevent dust adhesion by covering the surface of the glass substrate with nanoparticle. The adhesion force between particle and substrate is measured by the centrifugal method and the relation between the adhesion force and the surface roughness is discussed from experimental and theoretical point of view. The measured and calculated results by Van der Waals force show that adhesion force decreased with the increment of the surface roughness. From the results, nanoparticle coating is very effective to prevent the dust adhesion on the substrate and the various application of nanoparticle coating can be expected.

Journal Articles

Flowability measurement of coarse particles using vibrating tube method

Ishii, Katsunori; Suzuki, Masahiro; Yamamoto, Takuma; Kihara, Yoshiyuki; Kato, Yoshiyuki; Kurita, Tsutomu; Yoshimoto, Katsunobu; Yasuda, Masatoshi*; Matsusaka, Shuji*

Journal of Chemical Engineering of Japan, 42(5), p.319 - 324, 2009/05

 Times Cited Count:7 Percentile:63.65(Engineering, Chemical)

The flowability of coarse particles has been experimentally investigated using the vibrating tube method, to evaluate the applicability of this method to MOX (mixed oxide of PuO$$_{2}$$ and UO$$_{2}$$) particles which are nuclear fuel used for electric power production. Five sizes of non-radioactive model particles, smaller than 850 micrometers, made of ZrO$$_{2}$$ were prepared, and the experiments were carried out using vibrating tubes with an outlet diameter from 2 to 4 mm. The outlet diameter significantly affected the flowability measurements. When using the tube with a 4-mm-outlet diameter, the flowability of all the model particles was successfully measured. The inclination angle of the tube, also, affected the flowability measurements. From the advantages of high sensitivity, short measurement time, simple structure, and easy operation, the vibrating tube method is expected to be applied to the remote flowability measurement of the MOX particles.

Journal Articles

Application of microwave heating to MOX fuel production and its contribution to Japanese energy strategy

Suzuki, Masahiro; Ishii, Katsunori; Yamamoto, Takuma; Kihara, Yoshiyuki; Kato, Yoshiyuki; Kurita, Tsutomu; Yoshimoto, Katsunobu; Fujii, Kanichi

Proceedings of Global Congress on Microwave Energy Applications (GCMEA 2008/MAJIC 1st), p.501 - 504, 2008/08

The natural resources, oil and uranium, would dry up around the midway of this century. FBR cycle most probably rescues this difficult situation. Mass production of MOX fuel for FBR, therefore, is the supreme subject to Japanese energy strategy. For this subject, we are attacking with Microwave heating technology. Up to present, we have succeeded to produce excellent PuO$$_{2}$$/UO$$_{2}$$ bulk, 2 kgMOX/batch, advancing toward the mass production target, 5 kgU/h for one batch.

Journal Articles

Feasibility study on particle flowability evaluation in simplified MOX pellet fabrication process using vibrating tube method

Ishii, Katsunori; Suzuki, Masahiro; Yamamoto, Takuma; Kihara, Yoshiyuki; Yasuda, Masatoshi*; Matsusaka, Shuji*

Funtai Kogaku Kaishi, 45(5), p.290 - 296, 2008/05

Particle flowability test using a vibrating tube with a tapered end was carried out to evaluate the applicability of this method to the analysis of MOX particles for nuclear fuel pellet fabrication. In this experiment, zirconia particles were used as model particles, which are less than several hundred micrometers in diameter. The sample particles were prepared by mixing the particles with different sizes, whose shape and surface state were changed by a mechanical treatment. The experimental results showed that the removal of smaller particles is more effective than the mechanical surface treatment to improve the flowability. Furthermore, it was found that the vibrating tube method can identify the difference of the particle flowability more easily and clearly than the method based on Carr's flowability index.

Journal Articles

Extended steady-state and high-beta regimes of net-current free heliotron plasmas in the Large Helical Device

Motojima, Osamu*; Yamada, Hiroshi*; Komori, Akio*; Oyabu, Nobuyoshi*; Muto, Takashi*; Kaneko, Osamu*; Kawahata, Kazuo*; Mito, Toshiyuki*; Ida, Katsumi*; Imagawa, Shinsaku*; et al.

Nuclear Fusion, 47(10), p.S668 - S676, 2007/10

 Times Cited Count:31 Percentile:20.71(Physics, Fluids & Plasmas)

The performance of net-current free heliotron plasmas has been developed by findings of innovative operational scenarios in conjunction with an upgrade of the heating power and the pumping/fuelling capability in the Large Helical Device (LHD). Consequently, the operational regime has been extended, in particular, with regard to high density, long pulse length and high beta. Diversified studies in LHD have elucidated the advantages of net-current free heliotron plasmas. In particular, an internal diffusion barrier (IDB) by a combination of efficient pumping of the local island divertor function and core fuelling by pellet injection has realized a super dense core as high as $$5$$$times$10^{20} m^{-3}$$, which stimulates an attractive super dense core reactor. Achievements of a volume averaged beta of 4.5% and a discharge duration of 54 min with a total input energy of 1.6 GJ (490 kW on average) are also highlighted. The progress of LHD experiments in these two years is overviewed by highlighting IDB, high-beta and long pulse.

Journal Articles

Vibro-packing experiment of non-spherical uranium dioxide particles with spherical metallic uranium particles

Matsuyama, Shinichiro*; Ishii, Katsunori; Hirai, Mutsumi*; Tsuboi, Yasushi*; Kihara, Yoshiyuki

Journal of Nuclear Science and Technology, 44(3), p.317 - 322, 2007/03

 Percentile:100(Nuclear Science & Technology)

Japan Atomic Energy Agency has been developing vibro-packed fuel as one candidate for commercial fast breeder reactor fuels. In this study, vibro-packing experiments were carried out to investigate particle behavior during vibro-packing and particle distribution after vibro-packing in a cladding tube. Non-spherical uranium dioxide particles and spherical metallic uranium particles were used to simulate mixed oxide particles and oxygen getter particles. These experiments revealed that it is important to feed each size of fuel particles uniformly into a cladding tube without size segregation in order to obtain a vibro-packed fuel pin with oxygen getter particles uniformly dispersed. "Simultaneous feeding" with volumetric powder feeders is useful to obtain a vibro-packed fuel pin with oxygen getter particles uniformly dispersed.

Journal Articles

Extended steady-state and high-beta regimes of net-current free heliotron plasmas in the large helical device

Motojima, Osamu*; Yamada, Hiroshi*; Komori, Akio*; Oyabu, Nobuyoshi*; Kaneko, Osamu*; Kawahata, Kazuo*; Mito, Toshiyuki*; Muto, Takashi*; Ida, Katsumi*; Imagawa, Shinsaku*; et al.

Proceedings of 21st IAEA Fusion Energy Conference (FEC 2006) (CD-ROM), 12 Pages, 2007/03

The performance of net-current free Heliotron plasmas has been developed by findings of innovative operational scenarios in conjunction with an upgrade of the heating power and the pumping/fueling capability in the Large Helical Device (LHD). Consequently, the operational regime has been extended, in particular, with regard to high density, long pulse length and high beta. Diversified studies in LHD have elucidated the advantages of net-current free heliotron plasmas. In particular, an Internal Diffusion Barrier (IDB) by combination of efficient pumping of the local island divertor function and core fueling by pellet injection has realized a super dense core as high as 5$$times$$10$$^{20}$$m$$^{-3}$$, which stimulates an attractive super dense core reactor. Achievements of a volume averaged beta of 4.5 % and a discharge duration of 54-min. with a total input energy of 1.6 GJ (490 kW in average) are also highlighted. The progress of LHD experiments in these two years is overviewed with highlighting IDB, high $$beta$$ and long pulse.

Journal Articles

Neutron diffraction study of distorted-triangular-lattice ising-like antiferromagnet TlCoCl$$_{3}$$

Nishiwaki, Yoichi*; Kato, Tetsuya*; Ohara, Yasuaki*; Osawa, Akira*; Todoroki, Norikazu*; Igawa, Naoki; Ishii, Yoshinobu; Iio, Katsunori*

Journal of the Physical Society of Japan, 75(3), p.034707_1 - 034707_8, 2006/03

 Times Cited Count:10 Percentile:41.78(Physics, Multidisciplinary)

no abstracts in English

Journal Articles

Vibro-packing experiment of granular UO$$_{2}$$ with uranium particles

Matsuyama, Shinichiro; Ishii, Katsunori; Hirai, Mutsumi*; Tsuboi, Yasushi*; Kihara, Yoshiyuki

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10

In the vipac fuel, it is considered that spherical metallic particles mainly consisting of uranium are added as an oxygen getter into vipac MOX fuel for FBR to prevent cladding inner corrosion by fuel-cladding chemical interaction (FCCI). In this study, vibro-packing experiments of granular UO$$_{2}$$ particles and spherical metallic uranium particles and post-packing examinations such as destructive experiment were carried out. This study revealed that that it is important to feed particles uniformly into a cladding tube to obtain a vipac fuel with getter particles uniformly dispersed. Constant-volume feeder seems to be useful to obtain a vipac fuel with getter particles uniformly dispersed.

Journal Articles

Observation of Small Particles Infiltration Process in Sphere-Pac Fuel Pin Fabrication

Ishii, Katsunori; Suzuki, Masahiro; Kihara, Yoshiyuki; Fujii, Kanichi*

Funtai Kogaku Kaishi, 42(7), p.472 - 477, 2005/00

To optimize sphere-pac fuel pin fabrication process, internal structure of fuel pin under small particles infiltration process was observed by micro focus X-ray CT system. Some small particles block the space among large particles. Small particles arrive at the bottom of fuel column, and fill the space among large particles, and form completed packing layer. Sphere-pac process progresses with growth of the layer from bottom to top of the column. A unique layer is formed around the top of fuel column shot time after starting vibration. Small particles completely intrude between large particles and pin wall in the layer. The structure never changes after completion of small particles infiltration process. The formation of the unique layer can be qualitatively explained by simulation.

Journal Articles

One consideration on infiltration property of oxide particles

Ishii, Katsunori; Kihara, Yoshiyuki; Fujii, Kanichi*

Japanese Journal of Applied Physics, 44(4A), p.1955 - 1956, 2005/00

 Times Cited Count:1 Percentile:94.39(Physics, Applied)

A vibrational sphere-pack technology employing large and small particles is discussed in the manner of simulation to the fabrication of atomic fuel pin, by four kinds of model particles.The infiltration property is almost free from the sort of materials and the weifht density.From this result,the feasibility to mix the heavy metallic uranium as the getter for absorbing oxygen, thereby prevents the oxidization of fuel pin is suggested.

Journal Articles

Direct writing of conductive aluminum line on aluminum nitride ceramics by transversely excited atmospheric CO$$_{2}$$ laser

Ishii, Katsunori; Takahashi, Akira*; *; Obara, Minoru*

Applied Physics Letters, 71(19), p.2758 - 2760, 1997/00

no abstracts in English

Oral presentation

Feasibility study on powder flowability evaluation on simplified pelletizing MOX fuel fabrication process using vibrating capillary method; Influence of particle shape and diameter on flowability

Ishii, Katsunori; Suzuki, Masahiro; Yamamoto, Takuma; Kihara, Yoshiyuki; Matsusaka, Shuji*; Yasuda, Masatoshi*; Suna, Takayuki*; Kurita, Tsutomu; Kato, Yoshiyuki

no journal, , 

JAEA is developing simplified pelletizing MOX fuel fabrication process for fast breeder reactor. The final product of de-nitration, conversion and granulation process, are MOX fuel particles, of which diameter is hundres micrometer. These particles should have high flowability for easy handling in next process. The powder flowability is now evaluated by Carr's flowability index. In this oral presentation, the feasibility of powder flowability evaluation using vibrationg capillary method is investigated, employing ZrO$$_{2}$$ particles of shich parameters are diameter and particle shape (shapes are varied by gronding particle edge). Screening small particles under about 100 micrometer contribute best the improvement of powder flowability, screening small particle under 50 micrometer in the second, and rounding particle shape in the third.

46 (Records 1-20 displayed on this page)