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Journal Articles

Chapter 5, Sodium-cooled Fast Reactor (SFRs)/ Chapter 12, Generation-IV Sodium-cooled Fast Reactor (SFR) concepts in Japan

Kubo, Shigenobu; Chikazawa, Yoshitaka; Ohshima, Hiroyuki; Kamide, Hideki

Handbook of Generation IV Nuclear Reactors, Second Edition, p.173 - 194, 2023/03

Handbook of Generation IV Nuclear Reactors, Second Edition is a fully revised and updated comprehensive resource on the latest research and advances in generation IV nuclear reactor concepts. Editor Igor Pioro and his team of expert contributors have updated every chapter to reflect advances in the field since the first edition published in 2016. JAEA contributes to Chapter 5; Sodium-cooled Fast Reactors (SFRs) and Chapter 12; Generation-IV Sodium-cooled Fast Reactor (SFR) concepts in Japan. Major characteristics and current technology developments including safety enhancement were described in Chapter 5. Chapter 12 shows design activities of SFR. Innovative technology developments, and update of the Japan sodium-cooled fast reactor design with lessons learned from the TEPCO Fukushima Daiichi NPP accident.

Journal Articles

Experimental evidence for the significance of optical phonons in thermal transport of tin monosulfide

Wu, P.*; Murai, Naoki; Li, T.*; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Kofu, Maiko; Nakajima, Kenji; Xia, K.*; Peng, K.*; Zhang, Y.*; et al.

New Journal of Physics (Internet), 25(1), p.013032_1 - 013032_11, 2023/01

 Times Cited Count:0 Percentile:0(Physics, Multidisciplinary)

Journal Articles

$$^{60}$$Fe and $$^{244}$$Pu deposited on Earth constrain the r-process yields of recent nearby supernovae

Wallner, A.*; Froehlich, M. B.*; Hotchkis, M. A. C.*; Kinoshita, N.*; Paul, M.*; Martschini, M.*; Pavetich, S.*; Tims, S. G.*; Kivel, N.*; Schumann, D.*; et al.

Science, 372(6543), p.742 - 745, 2021/05

 Times Cited Count:41 Percentile:96.64(Multidisciplinary Sciences)

Half of the chemical elements heavier than iron are produced by the rapid neutron capture process (r-process). The sites and yields of this process are disputed, with candidates including some types of supernovae (SNe) and mergers of neutron stars. We search for two isotopic signatures in a sample of Pacific Ocean crust-iron-60 ($$^{60}$$Fe) (half-life, 2.6 million years), which is predominantly produced in massive stars and ejected in supernova explosions, and $$^{244}$$Pu (half-life, 80.6 million years), which is produced solely in r-process events. We detect two distinct influxes of $$^{60}$$Fe to Earth in the last 10 million years and accompanying lower quantities of $$^{244}$$Pu. The $$^{244}$$Pu/$$^{60}$$Fe influx ratios are similar for both events. The $$^{244}$$Pu influx is lower than expected if SNe dominate r-process nucleosynthesis, which implies some contribution from other sources.

Journal Articles

Chapter 11, Generation IV concepts: Japan

Kamide, Hideki; Ohshima, Hiroyuki; Sakai, Takaaki; Morishita, Masaki

Handbook of Generation IV Nuclear Reactors, First Edition, p.283 - 307, 2016/00

Handbook of Generation IV Nuclear Reactors is comprehensive resource on the research and advances in generation IV nuclear reactor concepts and the first edition is issued in 2016. The authors wrote the chapter 11: Generation IV nuclear reactor concepts: Japan, where developments activities on sodium cooled fast reactor in Japan are shown. Especially, concept of Japan sodium-cooled fast reactor (JSFR) is explained on the points of innovative technologies and safety enhancements after the TEPCO Fukushima Daiichi Nuclear Power Plant accident.

Journal Articles

Interplay between oxidized monovacancy and nitrogen doping in graphene

Hou, Z.*; Shu, D.-J.*; Chai, G.-L.*; Ikeda, Takashi; Terakura, Kiyoyuki*

Journal of Physical Chemistry C, 118(34), p.19795 - 19805, 2014/08

 Times Cited Count:11 Percentile:35.66(Chemistry, Physical)

In most of the N-doped graphene which attracts strong attention in the context of precious-metal free catalysts and nanoelectronics, the oxygen content is generally higher than or at least comparable to the nitrogen content. We perform density functional theory calculations to study the interplay of oxidized monovacancies and the nitrogen doping, motivated by the fact that MV is more frequently observed and more chemically active than divacancy and Stone-Wales defect. We determine the phase diagrams of un-doped and nitrogen-doped oxidized MVs as a function of temperature and partial pressure of O$$_{2}$$ and H$$_{2}$$ gases. The modification of the electronic structure of MV by oxidation and N doping is studied. Our results show that the ether group is a common component in stable configurations of oxidized MVs. Most of the stable configurations of oxidized MVs do not induce any carriers.

Journal Articles

Distribution of supernova properties in the early universe

Tominaga, Nozomu*; Iwamoto, Nobuyuki; Nomoto, Kenichi*

AIP Conference Proceedings 1594, p.52 - 57, 2014/05

 Times Cited Count:1 Percentile:48.93(Astronomy & Astrophysics)

The first metal enrichment in the universe was made by a supernova (SN) explosion of a population (Pop) III star. Chemical abundance in the early universe is recorded in abundance patterns of extremely metal-poor (EMP) stars. Increasing number of the EMP stars is now being discovered and allows us to statistically constrain explosion properties of Pop III SNe. We present Pop III SN models that reproduce well individual abundance patterns of 48 most metal-poor stars with [Fe/H] $$_sim^{<}$$ -3.5, and derive relations between abundance ratios and explosion properties of Pop III SNe.

Journal Articles

Minor actinide neutron capture cross-section measurements with a 4$$pi$$ Ge spectrometer

Koizumi, Mitsuo; Osa, Akihiko; Toh, Yosuke; Kimura, Atsushi; Mizumoto, Motoharu; Oshima, Masumi; Igashira, Masayuki*; Osaki, Toshiro*; Harada, Hideo*; Furutaka, Kazuyoshi*; et al.

Nuclear Instruments and Methods in Physics Research A, 562(2), p.767 - 770, 2006/06

 Times Cited Count:6 Percentile:43.77(Instruments & Instrumentation)

In order to measure the neutron capture cross section of minor actinides, we have proposed the use of a 4$$pi$$ Ge spectrometer. A Time-of-Flight neutron beam line for the experiment has been constructed at the KURRI electron LINAC. The assembling of the 4$$pi$$ Ge spectrometer is in progress. We are also developing a new data acquisition system based on a digital processing technique.

Journal Articles

Conference summary; Progress in experiments on confinement, plasma-material interactions and innovative confinement concepts

Ninomiya, Hiromasa

Nuclear Fusion, 45(10), p.S13 - S31, 2005/10

 Times Cited Count:0 Percentile:0.01(Physics, Fluids & Plasmas)

This paper summarizes the results presented at the 20th IAEA Fusion Energy Conference 2004 in the sessions of confinement, plasma-wall interaction and innovative confinement concept. The highlights of the presentations are as follows. Long pulse operation with high beta and high bootstrap fraction much longer than the current diffusion time has been achieved. The discharge scenario optimization and its extrapolation towards ITER have progressed remarkably. Significant progress has been made in understanding of global confinement and transport physics.

JAEA Reports

Report on the 8th Workshop on the Innovative Water Reactor for Flexible Fuel Cycle; February 10, 2005, Koku-kaikan, Minato-ku, Tokyo

Kobayashi, Noboru; Okubo, Tsutomu; Uchikawa, Sadao

JAERI-Review 2005-029, 119 Pages, 2005/09

JAERI-Review-2005-029.pdf:11.01MB

The research on Innovative Water Reactor for Flexible fuel cycle (FLWR) has been performed in JAERI for the development of future innovative reactors. The workshop on the FLWRs has been held every year since 1998 aiming at information exchange between JAERI and other organizations. The 8th workshop was held on Feb. 10, 2005 under the joint auspices of JAERI and North Kanto and Kanto-Koetsu branches of Atomic Energy Society of Japan with 75 participants. The workshop began with 3 presentations on FLWRs entitled "Framework and Status of Research and Development on FLWRs", "Long-Term Fuel Cycle Scenarios for Advanced Utilization of Plutonium from LWRs", and "Experiments on Characteristics on Hydrodynamics in Tight-Lattice Core". Then 3 lectures followed: "Development of Evaluation Method for Accuracy in Predicting Neutronics Characteristics of Tight-Lattice Core" by Osaka University, "Development of Cost-Reduced Low-Moderation Spectrum Boiling Water Reactor" by Toshiba Corporation and "Design and Analysis on Super-Critical Water Cooled Power Reactors" by Tokyo University.

JAEA Reports

Basic concept of Common reactor physics Code Systems; Final report of working party on Common reactor physics Code Systems (CCS)

Research Committee on Reactor Physics

JAERI-Review 2004-003, 152 Pages, 2004/03

JAERI-Review-2004-003.pdf:5.8MB

A working party was organized for two years (2001-2002) on common reactor physics code systems under the Research Committee on Reactor Physics of JAERI. This final report is compilation of activity of the working party on common reactor physics code systems during two years. Objectives of the working party is to clarify basic concept of common reactor physics code systems to improve convenience of reactor physics code systems for reactor physics researchers in Japan on their various field of research and development activities. We have held four meetings during 2 years, investigated status of reactor physics code systems and innovative software technologies, and discussed basic concept of common reactor physics code systems.

JAEA Reports

Nuclear Energy System Department annual report; April 1, 2002 - March 31, 2003

Department of Nuclear Energy System

JAERI-Review 2003-023, 232 Pages, 2003/09

JAERI-Review-2003-023.pdf:16.58MB

The Department has carried out researches and developments (R&Ds) of innovative nuclear energy system and their related fundamental technologies to ensure the long-term energy supply in Japan. The report deals with the R&Ds of an innovative water reactor, called Reduced-Moderation Water Reactor (RMWR), which has the capability of multiple recycling and breeding of plutonium using light water reactor technologies. In addition, as basic studies and fundamental researches of nuclear energy system in general, described are intensive researches in the fields of reactor physics, thermal-hydraulics, nuclear data, nuclear fuels, and materials. These activities are essential not only for the R&Ds of innovative nuclear energy systems but also for the improvement of safety and reliability of current nuclear energy systems. The maintenance and operation of reactor engineering facilities belonging to the Department support experimental activities.

Journal Articles

Containment pressure suppression system with functions of water injection and noncondensable gas confinement

Yonomoto, Taisuke; Okubo, Tsutomu; Iwamura, Takamichi; Ishida, Toshihisa

Proceedings of 11th International Conference on Nuclear Engineering (ICONE-11) (CD-ROM), 8 Pages, 2003/04

An innovative concept of the pressure suppression system having functions of water injection and non-condensable gas confinement is developed for the next generation light water reactors (LWRs). The use of the system is advantageous for the mitigation of effects of the loss-of-coolant accidents (LOCAs) in (1) keeping the containment pressure as low as for the conventional LWRs, (2) injecting water to the containment for cooling the reactor pressure vessel (RPV) and/or flooding a break, and (3) confining the non-condensable gas in the drywell. The gas confinement function makes the system considerably suitable for reactor designs with passive cooling systems utilizing heat exchangers, such as the steam generator (SG) secondary side cooling system for an integral reactor, and the passive containment cooling system (PCCS), because it avoids adverse effects of non-condensable gas on the heat transfer performance during LOCAs. The usefulness of the developed concept is confirmed in the RELAP5/MOD3 code calculation.

Journal Articles

Research and development of Reduced-Moderation Water Reactor (RMWR)

Iwamura, Takamichi; Okubo, Tsutomu

Proceedings of 2nd Asian Specialist Meeting on Future Small-Sized LWR Development, p.7_1 - 7_5, 2003/00

An innovative water-cooled reactor concept named Reduced-Moderation Water Reactor (RMWR) is under development at JAERI, aiming at effective fuel utilization through plutonium (Pu) multiple recycling based on the well-experienced water-cooled reactor technology. The reactor is able to achieve a high conversion ratio more than 1.0 with MOX fuel, to establish the sustainable Pu recycling. Such a high conversion ratio can be attained by reducing the moderation of neutrons, i.e. reducing the water fraction in the core. Detailed research and development activities have been performed on the core design, in conjunction with the other related studies such as on the thermal hydraulics in the tight-lattice core, the reactor physics and the fuel irradiation behavior, including the experimental activities. Also, for the total feasibility demonstration of the RMWR technologies, a design investigation for Reduced-Moderation Demonstration Reactor (RMDR) of 180MWt is being performed.

JAEA Reports

Proceedings of the 3rd Symposium on Science of Hadrons under Extreme Conditions; January 29-31, 2001, JAERI, Tokai, Japan

Chiba, Satoshi

JAERI-Conf 2001-012, 116 Pages, 2001/09

JAERI-Conf-2001-012.pdf:6.33MB

The third symposium on Science of Hadrons under Extreme Conditions, organized by the Research Group for Hadron Science, Advanced Science Research Center, was held at Tokai Research Establishment of JAERI on January 29 to 31, 2001. The symposium was devoted for discussions and presentations of research results in wide variety of hadron physics such as nuclear matter, high-energy nuclear reactions, quantum chromodynamics, neutron stars,supernovae, nucleosynthesis as well as finite nuclei to understand various aspects of hadrons under extreme conditions. Twenty two papers on these topics, including a special talk on the present status of JAERI-KEK joint project on high-intentisy proton accelerator, presented at the symposium aroused lively discussions among approximately 40 participants.

Journal Articles

Magnetic safety factor profile before and after sawtooth crashes investigated with toroidicity and ellipticity induced Alfv$'e$n eigenmodes

Kramer, G. J.; Cheng, C. Z.*; Kusama, Yoshinori; Nazikian, R. M.*; Takeji, Satoru; Tobita, Kenji

Nuclear Fusion, 41(9), p.1135 - 1151, 2001/09

 Times Cited Count:37 Percentile:72.51(Physics, Fluids & Plasmas)

no abstracts in English

Journal Articles

Present status and future programme of HTTR and the innovative basic research on high temperature engineering

Hayashi, Kimio; Ishihara, Masahiro; Shibata, Taiju; Ishino, Shiori*; Terai, Takayuki*; Ito, Hisayoshi; Tagawa, Seiichi*; Katsumura, Yosuke*; Yamawaki, Michio*; Shikama, Tatsuo*; et al.

Proceedings of 1st Information Exchange Meeting on Basic Studies on High-Temperature Engineering, p.41 - 58,268, 1999/09

no abstracts in English

Journal Articles

Linear theory of Alfv$'e$n eigenmodes in tokamak plasmas

Fukuyama, Atsushi*; Ozeki, Takahisa

Purazuma, Kaku Yugo Gakkai-Shi, 75(5), p.537 - 547, 1999/05

no abstracts in English

Journal Articles

Destabilization of ellipticity-induced Alfven eigenmodes during ICRF heating and stabilization by negative-ion-based neutral beam injection in JT-60U

Kusama, Yoshinori; Fu, G. Y.*; Kramer, G. J.*; Saigusa, Mikio*; Oikawa, Toshihiro; Ozeki, Takahisa; Moriyama, Shinichi; Tchernychev, F. V.*; Nemoto, Masahiro; Kondoh, Takashi; et al.

Plasma Physics and Controlled Fusion, 41(9), p.1167 - 1177, 1999/00

 Times Cited Count:5 Percentile:20.1(Physics, Fluids & Plasmas)

no abstracts in English

Journal Articles

Toroidal alfven eigenmodes driven with ICRF accelerated protons in JT-60U negative shear discharges

Kusama, Yoshinori; Kimura, Haruyuki; Ozeki, Takahisa; Saigusa, Mikio*; Kramer, G. J.*; Oikawa, Toshihiro; Moriyama, Shinichi; Nemoto, Masahiro; Fujita, Takaaki; Tobita, Kenji; et al.

Nuclear Fusion, 38(8), p.1215 - 1223, 1998/08

 Times Cited Count:41 Percentile:76.58(Physics, Fluids & Plasmas)

no abstracts in English

JAEA Reports

Stability of toroidal Alfven eigenmode in JT-60 super upgrade

Ozeki, Takahisa; C.Z.Cheng*; Nagashima, Keisuke

JAERI-Research 95-065, 22 Pages, 1995/10

JAERI-Research-95-065.pdf:0.75MB

no abstracts in English

26 (Records 1-20 displayed on this page)