Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Watanabe, Masashi; Yokoyama, Keisuke; Imai, Yoshiyuki; Ueta, Shohei; Yan, X.
Ceramics International, 48(6), p.8706 - 8708, 2022/03
Times Cited Count：7 Percentile：75.06(Materials Science, Ceramics)Previous studies have used various methods for sintering of SiC, carbon, and SiC/carbon functionally graded materials (FGM). However, no experimental studies on SiC/graphite FGM manufacturing using the spark plasma sintering (SPS) method have been reported. In this study, a SiC/graphite FGM specimen has been fabricated using SPS. The interface between the adjacent layers of the sintered specimen exhibits no apparent defects such as gaps or delaminations. The SiC and graphite phases in the specimen show no substantial change before and after sintering.
Abe, Takeyasu; Iida, Yoshihisa
Journal of Advanced Concrete Technology, 20(3), p.236 - 253, 2022/03
Times Cited Count：2 Percentile：13.23(Construction & Building Technology)This paper is a state-of-the-art report on the performance assessment of cementitious and related materials as components of engineered barrier systems for radioactive waste management. In this paper, (1) the concept of safety functions is reviewed as the engineering background of discussion, (2) an overview of the postclosure performance assessment for Belgian low- and intermediate-level short-lived radioactive waste disposal is provided, and (3) a modeling methodology for engineered barrier systems is analyzed using the concept of "mandala for durability mechanics". According to these works, authors present technical suggestions for technical stakeholders of Japanese low-level radioactive waste disposal.
Sasagawa, Tsuyoshi; Mukai, Masayuki; Sawaguchi, Takuma
JAEA-Data/Code 2021-012, 122 Pages, 2022/01
JAEA-Data-Code-2021-012.pdf:3.87MB
Reducing public dose is required when radioactive wastes such as high-level and from reactor core internals etc. are disposed of by means of multi barrier system consist of engineered and natural barriers. In these barriers, engineered barrier is expected to bring out confinement function of waste's radionuclides in the barrier. Materials used as the engineered barriers are altered and performances of the barrier materials are degraded in course of time. To estimate properly the degraded performances, analytical evaluation of long-term change of the engineered barrier state is important. Change state of the engineered barrier is given by mass-transport and geochemical-reaction inside the barrier materials and these phenomena are interrelated, it is necessary to calculate the state by means of coupled analysis procedure. We have developed a coupled mass-transport and geochemical-reaction calculation code (MC- BUFFER) to evaluate alteration of engineered barrier specially targeted for water permeability of bentonite buffer material as one of most important performances to engineered barrier. This report describes functions expected for the engineered barrier, influence parameters for the functions, implementation models in MC-BUFFER, structure and functions of MC-BUFFER, input file format and output examples, execution method of MC-BUFFER, and sample run with MC-BUFFER.
Kataoka, Takahiro*; Kanzaki, Norie; Sakoda, Akihiro; Shuto, Hina*; Yano, Junki*; Naoe, Shota*; Tanaka, Hiroshi; Hanamoto, Katsumi*; Terato, Hiroaki*; Mitsunobu, Fumihiro*; et al.
Journal of Radiation Research (Internet), 62(2), p.206 - 216, 2021/03
Times Cited Count：6 Percentile：61.83(Biology)Radon inhalation activates antioxidative functions in mouse organs, thereby contributing to inhibition of oxidative stress-induced damage. Therefore, in this study, we evaluated the redox state of various organs in mice following radon inhalation. Mice inhaled radon at concentrations of 2 or 20 kBq/m
for 1, 3, or 10 days. The relationship between antioxidative function and oxidative stress was evaluated by principal component analysis (PCA) and correlation coefficient compared with control mice subjected to sham inhalation. These findings suggested that radon inhalation altered the redox state in organs, but that the characteristics varied depending on the redox state in organs.
Kanzaki, Norie; Kataoka, Takahiro*; Kobashi, Yusuke*; Yunoki, Yuto*; Ishida, Tsuyoshi*; Sakoda, Akihiro; Ishimori, Yuu; Yamaoka, Kiyonori*
Radioisotopes, 67(2), p.43 - 57, 2018/02
We previously reported that low-dose radiation induces the anti-oxidative function in many organ systems of mice. This results in the suppression of several kinds of oxidative stress-induced damage. This study was conducted with the objective of revealing the health effects of low-dose radiation obtained from our previous reports and searching for a new treatment based on low-dose radiation, such as radon therapy. We extracted the characteristics of the effects of low dose radiation suppressing diseases and enhancing the anti-oxidative function using fuzzy answer by self-organizing map (SOM) based on mutual knowledge. The relationship between the suppressive effect and increased antioxidative function was shown in our result, and the concentration dependence of the effect against pain was shown on the output map. Although the effect against other organs depending on concentration was unpredictable, our results indicate that low-dose radiation may also be suitable for treatment of liver disease and brain disease.
Li, Y.; Hayashi, Shotaro*; Itabashi, Yu*; Nagai, Masaki*; Kanto, Yasuhiro*; Suzuki, Masahide*; Masaki, Koichi*
JAEA-Review 2017-005, 80 Pages, 2017/03
JAEA-Review-2017-005.pdf:16.85MB
For the improvement of the structural integrity assessment methodology on reactor pressure vessels (RPVs), the probabilistic fracture mechanics (PFM) analysis code PASCAL has been developed and improved in JAEA based on latest knowledge. The PASCAL code evaluates the failure probabilities and frequencies of Japanese RPVs under transient events such as pressurized thermal shock considering neutron irradiation embrittlement. In order to confirm the reliability of the PASCAL as a domestic standard code and to promote the application of PFM on the domestic structural integrity assessments of RPVs, it is important to verify the probabilistic variables, functions and models incorporated in the PASCAL and summarize the verification processes and results as a document. On the basis of these backgrounds, we established a working group, composed of experts on this field besides the developers, on the verification of the PASCAL3 which is a PFM analysis module of PASCAL, and the source program of PASCAL3 was released to the members of working group. Through one year activities, the applicability of PASCAL in structural integrity assessments of domestic RPVs was confirmed with great confidence. This report summarizes the activities of the working group on the verification of PASCAL in FY2015.
Matsui, Hiroya; Mikake, Shinichiro; Ikeda, Koki; Sasaki, Sadao
Dai-14-Kai Iwa No Rikigaku Kokunai Shimpojiumu Koen Rombunshu (Internet), 6 Pages, 2017/01
Japan Atomic Energy Agency (JAEA) has been conducting the groundwater recovery experiment to develop the methodology to estimate the recovery of geological environment after drift closure at GL-500m in Mizunami Underground Research Laboratory, Gifu prefecture, Japan. For the experiment, the impervious concrete plug was constructed to keep a recovered water pressure. The authors assessed the functions of the pluge based on monitoring and interpretation of the several kinds of measurements inside and outside of the plug during groundwater recovery process in a drift. As the results, the design concept and the expected function of the impervious plug assessed almost satisfied and it is supposed no problem will occur on the groundwater recovery experiment for several months.
Nishio, Satoshi; Omori, Junji*; Kuroda, Toshimasa*; Tobita, Kenji; Enoeda, Mikio; Tsuru, Daigo; Hirose, Takanori; Sato, Satoshi; Kawamura, Yoshinori; Nakamura, Hirofumi; et al.
Fusion Engineering and Design, 81(8-14), p.1271 - 1276, 2006/02
Times Cited Count：20 Percentile：78.83(Nuclear Science & Technology)The design guideline for the blanket is decided to meet the mission of the DEMO plant which is expected to use technologies to be proven by 2020 and present an economical prospect of fusion energy in the operational time of the reactor. To moderate the technological extrapolation, the structural material of reduced activation ferritic steel (F82H), ceramic tritium breeder of Li
TiO
and neutron multiplier of Be are introduced. To improve the economical aspect, the coolant material of the supercritical water with inlet/outlet temperatures of 280/510
C, coolant pressure of 25 MPa is chosen. Resultantly the thermal efficiency of 41% is achieved. To obtain higher plasma performance, MHD instabilities suppressing shell structure is adopted with structural compatibility to the blanket structure. To meet higher plant availability requirement (more than 75%), the hot cell maintenance approach is selected for the replaceable power core components.
Arakawa, Kazuo
Hoshasen Kagaku, (80), p.57 - 59, 2005/09
no abstracts in English
Honda, Atsushi; Kawai, Mikito; Okano, Fuminori; Oshima, Katsumi*; Numazawa, Susumu*; Oga, Tokumichi; Ikeda, Yoshitaka
Heisei-16-Nendo Osaka Daigaku Sogo Gijutsu Kenkyukai Hokokushu (CD-ROM), 4 Pages, 2005/03
no abstracts in English
Igawa, Naoki; Taguchi, Tomitsugu; Yamada, Reiji; Ishii, Yoshinobu; Jitsukawa, Shiro
Ceramic Engineering and Science Proceedings, Vol.26, No.2, p.27 - 34, 2005/00
no abstracts in English
Tamada, Masao; Seko, Noriaki; Yoshii, Fumio
Radiation Physics and Chemistry, 71(1-2), p.223 - 227, 2004/09
Times Cited Count：71 Percentile：96.47(Chemistry, Physical)Graft polymerization and crosslinking in radiation processing were attractive techniques to modify conventional polymers. In the case of graftpolymerization, metal adsorbent was prepared by introducing the chelate function to trunk polymer like polyethylene. The obtained metal adsorbent was applied to the recovery of uranium in seawater. Three years' marine experiment revealed that 1kg of uranium could be collected by using graft-adsorbent. Natural polymers such as derivatives of starch and cellulose led irradiation crosslinking at paste-like condition and formed hydrogels. These hydrogels had degradability even after crosslinking. The mat of degradable hydrogel was effective to prevent bedsores as a healthcare product. After use, the hydrogel can be converted to fertilizer by decompositions.
-ray, JAERI's nuclear research promotion program, H12-007 (Contract research)Tokita, Sumio*; Yoshida, Masaru
JAERI-Tech 2004-009, 37 Pages, 2004/03
JAERI-Tech-2004-009.pdf:3.12MB
no abstracts in English
Hosoyama, Hiroki*; Sueoka, Michiharu; Suzuki, Takahiro
KEK Proceedings 2003-16 (CD-ROM), 4 Pages, 2004/02
no abstracts in English
Sudo, Yukio
Hoshasen To Sangyo, (100), p.10 - 11, 2003/12
no abstracts in English
Ueshima, Yutaka; Kondo, Takao*; Isogai, Kentaro*
Joho Shori Gakkai MPS Shimpojiumu Rombunshu, 2003(14), p.151 - 158, 2003/10
no abstracts in English
Department of JMTR, Oarai
JAERI-Review 2003-026, 163 Pages, 2003/09
JAERI-Review-2003-026.pdf:16.05MB
no abstracts in English
Amano, Hikaru; Takahashi, Tomoyuki*; Uchida, Shigeo*; Matsuoka, Shungo*; Ikeda, Hiroshi*; Hayashi, Hiroko*; Kurosawa, Naohiro*
JAERI-Conf 2003-010, p.112 - 121, 2003/09
The functionality of MOGRA is being verified by applying it in the analyses of the migration rates of radioactive substances from the atmosphere to soils and plants and flow rates into the rivers. This has been achieved by also taking their mode classifications into consideration. In this report, a hypothetical combination of land usage was supposed to check the function of MOGRA. The land usage was consisted from cultivated lands, forests, uncultivated lands, urban area, river, and lake. Each land usage has its own inside model which is basic module. Also supposed was homogeneous contamination of the surface land from atmospheric deposition of Cs-137 (1.0 Bq/m
). The system can analyze the dynamic changes of Cs-137 concentrations in each compartment, fluxes from one compartment to another compartment.
Matsuhashi, Shimpei
Isotope News, (592), p.2 - 7, 2003/08
no abstracts in English
Tu, Z.; Kobayashi, Yasuhiko; Kiguchi, Kenji*; Watanabe, Hiroshi
Nuclear Instruments and Methods in Physics Research B, 206, p.591 - 595, 2003/05
no abstracts in English
