Development plan for coupling technology between high temperature gas-cooled reactor HTTR and hydrogen production facility, 1; Overview of the HTTR heat application test plan to establish high safety coupling technology

Nomoto, Yasunobu; Mizuta, Naoki; Morita, Keisuke; Aoki, Takeshi; Okita, Shoichiro; Ishii, Katsunori; Kurahayashi, Kaoru; Yasuda, Takanori; Tanaka, Masato; Isaka, Kazuyoshi; et al.

Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 7 Pages, 2023/05

Sodium-cooled Fast Reactors

Ohshima, Hiroyuki; Morishita, Masaki*; Aizawa, Kosuke; Ando, Masanori; Ashida, Takashi; Chikazawa, Yoshitaka; Doda, Norihiro; Enuma, Yasuhiro; Ezure, Toshiki; Fukano, Yoshitaka; et al.

Sodium-cooled Fast Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.3, 631 Pages, 2022/07

https://shop.elsevier.com/books/sodium-cooled-fast-reactors/morishita/978-0-12-824076-2

This book is a collection of the past experience of design, construction, and operation of two reactors, the latest knowledge and technology for SFR designs, and the future prospects of SFR development in Japan. It is intended to provide the perspective and the relevant knowledge to enable readers to become more familiar with SFR technology.

PSTEP: Project for solar-terrestrial environment prediction

Kusano, Kanya*; Ichimoto, Kiyoshi*; Ishii, Mamoru*; Miyoshi, Yoshizumi*; Yoden, Shigeo*; Akiyoshi, Hideharu*; Asai, Ayumi*; Ebihara, Yusuke*; Fujiwara, Hitoshi*; Goto, Tadanori*; et al.

Earth, Planets and Space (Internet), 73(1), p.159_1 - 159_29, 2021/12

https://doi.org/10.1186/s40623-021-01486-1

The PSTEP is a nationwide research collaboration in Japan and was conducted from April 2015 to March 2020, supported by a Grant-in-Aid for Scientific Research on Innovative Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan. It has made a significant progress in space weather research and operational forecasts, publishing over 500 refereed journal papers and organizing four international symposiums, various workshops and seminars, and summer school for graduate students at Rikubetsu in 2017. This paper is a summary report of the PSTEP and describes the major research achievements it produced.

Real time and automatic analysis program for WASAVIES; Warning system for aviation exposure to solar energetic particles

Sato, Tatsuhiko; Kataoka, Ryuho*; Shiota, Daiko*; Kubo, Yuki*; Ishii, Mamoru*; Yasuda, Hiroshi*; Miyake, Shoko*; Park, I.*; Miyoshi, Yoshizumi*

Space Weather, 16(7), p.924 - 936, 2018/07

https://doi.org/10.1029/2018SW001873

A physics-based warning system of aviation exposure to solar energetic particles, WASAVIES, is improved to be capable of real-time and automatic analysis. In the improved system, the count rates of several neutron monitors (NM) at the ground level, as well as the proton fluxes measured by the GOES satellite are continuously downloaded at intervals of 5 min and used for determining the model parameters. The performance of WASAVIES is examined by analyzing the three major GLE events of the 21st century. A web-interface of WASAVIES is also developed and will be released in the near future through the public server of NICT.

Horonobe Underground Research Laboratory Project; Synthesis of phase I investigation 2001 - 2005, Volume "Geological disposal research"

Fujita, Tomoo; Taniguchi, Naoki; Matsui, Hiroya; Tanai, Kenji; Maekawa, Keisuke; Sawada, Atsushi; Makino, Hitoshi; Sasamoto, Hiroshi; Yoshikawa, Hideki; Shibata, Masahiro; et al.

JAEA-Research 2011-001, 193 Pages, 2011/03

JAEA-Research-2011-001.pdf:5.23MB

This report summarizes the progress of research and development on geological disposal during the surface-based investigation phase (2001-2005) in the Horonobe Underground Research Laboratory project, of which aims are to apply the design methods of geological disposal and mass transport analysis to actual geological conditions obtained from the surface-based investigations in the Horonobe Underground Research Laboratory project as an example of actual geological environment.

Horonobe Underground Research Laboratory project synthesis of phase I investigation 2001-2005 volume "Geological Disposal Research"

Fujita, Tomoo; Taniguchi, Naoki; Matsui, Hiroya; Tanai, Kenji; Nishimura, Mayuka; Kobayashi, Yasushi; Hiramoto, Masayuki; Maekawa, Keisuke; Sawada, Atsushi; Makino, Hitoshi; et al.

JAEA-Research 2007-045, 140 Pages, 2007/03

JAEA-Research-2007-045-1.pdf:38.33MB
JAEA-Research-2007-045-2.pdf:44.62MB

This report summarizes the progress of research and development on geological disposal during the surface-based investigation phase (2001-2005) in the Horonobe Underground Research Laboratory project (HOR), of which aims are to apply the design methods of geological disposal and mass transport analysis to actual geological environments and derive future subjects based on the results. The design methods of geological disposal were reviewed based on the recent knowledge and the advertences were identified. Then the parameters for virtual design of engineered barrier system, backfill deposition hole and tunnel were set up based on actual geological conditions obtained from the surface-based investigations in HOR as an example of actual geological environment. The conceptual structure from site investigation and evaluation to mass transport analysis was represented as a work flow at first. Then following this work flow a series of procedures for mass transport analysis were carried out based on actual geological conditions obtained from the surface-based investigations in HOR to illustrate the functioning of the work flow and the applicability of this methodology. Consequently, knowledge that will help follow-up or future execution and planning activities was obtained.

Resonant inelastic X-ray scattering study of the hole-doped manganites LaSrMnO (, )

Ishii, Kenji; Inami, Toshiya; Owada, Kenji; Kuzushita, Kaori; Mizuki, Junichiro; Murakami, Yoichi; Ishihara, Sumio*; Endo, Yasuo*; Maekawa, Sadamichi*; Hirota, Kazuma*; et al.

Physical Review B, 70(22), p.224437_1 - 224437_6, 2004/12

https://doi.org/10.1103/PhysRevB.70.224437

Electronic excitations in the hole doped manganese oxides (LaSrMnO, and ) have been elucidated by using the resonant inelastic X-ray scattering (RIXS) method. A doping effect in the strongly correlated electron systems has been observed for the first time. The scattering spectra show that a salient peak appears in low energies indicating the persistence of the Mott gap. At the same time, the energy gap is partly filled by doping holes and the spectral weight energy shifts toward lower energies. The excitation spectra show little change in the momentum space as is in undoped LaMnO. On the other hand, the scattering intensities in the low energy excitations of are anisotropic in temperature dependence, which indicates an anisotropy of magnetic interaction and underlying effect of the orbital.

Nuclear structure study of nuclei in the A=180 region using nucleon transfer reactions

Shizuma, Toshiyuki; Ishii, Tetsuro; Makii, Hiroyuki; Matsuda, Makoto; Hayakawa, Takehito; Ideguchi, Eiji*; Liu, M.*; Zheng, Y.*; Morikawa, Tsuneyasu*; Mitarai, Shiro*; et al.

no journal, , 

no abstracts in English

A Tree diagram for compiling a methodology to evaluate suitability of host rock for geological disposal

Hayano, Akira; Sawada, Atsushi; Goto, Junichi*; Ishii, Eiichi*; Moriya, Toshifumi*; Inagaki, Manabu*; Kubota, Shigeru*; Ebashi, Takeshi*

no journal, , 

Detailed Investigation Areas have to be selected with focusing on suitability of the host rock in the siting process for high-level radioactive waste disposal in Japan. The suitability of the host rock is evaluated in terms of the preferable disposal condition such as thermal, hydraulic, mechanical and geochemical condition, and the feasibility of the geological disposal project relevant to volumetric capacity of host rock and economics, based on the site model. However, due to a limited number of surveys at relatively early stage of the investigation, the lack of understanding of geological environment at the site causes an uncertainty of the site model. It is essential to clarify an association the important factors relevant to safety assessment (SA) and a repository design (Design) with the information obtained by the site investigation through the site model. In this study, the methodology not only for defining evaluation factors relevant to SA in term of hydrogeology, but also for visualizing the methods to evaluate the factors through the site model is organized into a tree diagram. A method to evaluate groundwater travel time which is one of evaluation factors in granitic rock is organized into a first version of the tree diagram.

Radiation protection of humans in space and aviation; Current states and future needs on the warning system for aviation exposure to SEP (WASAVIES)

Sato, Tatsuhiko; Ishii, Mamoru*; Kataoka, Ryuho*; Kubo, Yuki*; Minoshima, Takashi*; Miyoshi, Yoshizumi*; Nagamatsu, Aiko*; Shiota, Daiko*; Takashima, Takeshi*; Yasuda, Hiroshi*

no journal, , 

Forecast of radiation doses for astronauts as well as aircrews due to the exposure to solar energetic particles (SEP) is one of the greatest challenges in space weather research. In last 5 years, we have developed a WArning System for AVIation Exposure to Solar energetic particles: WASAVIES. In this system, the SEP fluxes incident to the atmosphere are calculated by physics-based models, and they are converted to radiation doses using a database developed on the basis of air-shower simulation. However, it takes approximately 2.5 hours to determine the parameters used in the physics-based models after the detection of GLEs, and thus, the current WASAVIES cannot predict doses during the peak of GLEs. Therefore, we are trying to reduce the time for evaluating the parameters, as well as to develop a nowcast system for the radiation dose due to SEP exposure, under the framework of Project for Solar-Terrestrial Environment Prediction (PSTEP) in Japan. A brief outline of WASAVIES together with our future strategy will be presented at the meeting.