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-rays radiolysis (Contract research); FY2021 Nuclear Energy Science & Technology and Human Resource Development ProjectCollaborative Laboratories for Advanced Decommissioning Science; Tohoku University*
JAEA-Review 2022-069, 114 Pages, 2023/03
JAEA-Review-2022-069.pdf:5.91MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2021. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station (1F), Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2020, this report summarizes the research results of the "Development of a new corrosion mitigation technology using nanobubbles toward corrosion mitigation in PCV system under the influence of //-rays radiolysis" conducted in FY2021. In this work, in order to ensure the long-term reliability of steel structures that ensure important confinement functions in the debris removal process, such as existing PCVs and newly constructed negative pressure maintenance systems and piping, corrosion phenomena in wet environments where - and -ray emitting nuclides come into contact with steel are clarified for the first time.
//-rays radiolysis (Contract research); FY2020 Nuclear Energy Science & Technology and Human Resource Development ProjectCollaborative Laboratories for Advanced Decommissioning Science; Tohoku University*
JAEA-Review 2022-002, 85 Pages, 2022/06
JAEA-Review-2022-002.pdf:3.39MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2020. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2020, this report summarizes the research results of the "Development of a new corrosion mitigation technology using nanobubbles toward corrosion mitigation in PCV system under the influence of //-rays radiolysis" conducted in FY2020. In this work, in order to ensure the long-term reliability of steel structures that ensure important confinement functions in the debris removal process, such as existing PCVs and newly constructed negative pressure maintenance systems and piping, corrosion phenomena in wet environments where - and -ray emitting nuclides come into contact with steel are clarified for the first time.
Umeda, Ryota; Shimoyama, Kazuhito; Kurihara, Akikazu
Nihon Genshiryoku Gakkai Wabun Rombunshi, 19(4), p.234 - 244, 2020/12
Sodium-water reaction caused by failure of the steam generator tube of sodium-cooled fast reactor induce the wastage phenomenon, which has erosive and corrosive feature. In this report, the authors have performed the self-wastage experiments under high sodium temperature condition to evaluate the effect of wastage form/geometry by using two types of initial defect such as the micro fine pinhole and fatigue crack, and water leak rate on self-wastage rate. Based on the consideration of crack type influence, it was confirmed that self-wastage rate did not strongly depend on the initial defect geometry. As a mechanism of the self-plug phenomenon, it is speculated that sodium oxide intervenes and inhibits the progress of self-wastage. The dependence of initial sodium temperature on self-wastage rate was clearly observed, and new self-wastage correlation was derived considering the initial sodium temperature.
Ohashi, Hirofumi; Nishihara, Tetsuo; Takeda, Tetsuaki; Inagaki, Yoshiyuki
Proceedings of 13th International Conference on Nuclear Engineering (ICONE-13) (CD-ROM), 8 Pages, 2005/05
A hydrogen production system connected to the High-Temperature Engineering Test Reactor (HTTR) is being designed to be able to produce hydrogen using a nuclear heat of 10 MW supplied by the HTTR. The HTTR hydrogen production system is first connected to a nuclear reactor in the world, hence an mock-up model test is planned to carry out prior to the demonstration test of the HTTR hydrogen production system. In parallel to the mock-up model test, the following tests as an essential problem, a corrosion test of a reforming tube, a permeation test of hydrogen isotopes through a heat exchanger tube, an integrity test of a high-temperature isolation valve, and a performance test of a hydrogen permselective membrane are carried out to obtain detailed data for a safety review and development of analytical codes. This paper describes the present status of the component tests on the R&D of the HTTR hydrogen production system.
Hori, Junichi; Maekawa, Fujio; Wada, Masayuki*; Ochiai, Kentaro; Yamauchi, Michinori*; Morimoto, Yuichi*; Terada, Yasuaki; Klix, A.; Nishitani, Takeo
Fusion Engineering and Design, 63-64, p.271 - 276, 2002/12
Times Cited Count：2 Percentile：15.85(Nuclear Science & Technology)In order to the waste management method and the safety design of future D-T fusion reactor, it is important to consider the radioactivity productions via not only primary neutron reactions but also sequential charged particle reactions (SCPR). Especially, on the surface of a coolant channel many recoiled protons are generated by the neutron irradiation with coolant water, so it is apprehensive that the undesirable radioactive nuclide production yields via SCPR are enhanced. In this work, the laminated sample pieces of fusion material foils (V, Fe, W, Ti, Pb, Cu) were made and attached on a polyethylene board to simulate water flowing inside a coolant channel. They were irradiated with D-T neutrons. The effective radioactivity cross section and the depth distribution of the radioactivity production yields due to SCPR were obtained for each material. On the other hand, the estimated values were compared with the experimental ones.
Shiozawa, Shusaku; Ogawa, Masuro; Inagaki, Yoshiyuki; Onuki, Kaoru; Takeda, Tetsuaki; Nishihara, Tetsuo; Hayashi, Koji; Kubo, Shinji; Inaba, Yoshitomo; Ohashi, Hirofumi
Proceedings of 17th KAIF/KNS Annual Conference, p.557 - 567, 2002/04
The research and development program on nuclear production of hydrogen was started on January in 1997 as a study consigned by Ministry of Education, Culture, Sports, Science and Technology. A hydrogen production system connected to the HTTR is being designed to be able to produce hydrogen of about 4000 m3/h by steam reforming of natural gas, using a nuclear heat of 10 MW supplied by the HTTR. In order to confirm controllability, safety and performance of key components in the HTTR hydrogen production system, the facility for an out-of-pile test was constructed on the scale of approximately 1/30 of the HTTR hydrogen production system. Essential tests are also carried out to obtain detailed data for safety review and development of analytical codes. Other basic studies on the hydrogen production technology of thermochemical water splitting called an iodine sulfur (IS) process, has been carried out for more effective and various uses of nuclear heat. This paper describes the present status and a future plan on the R&D of the HTTR hydrogen production systems in JAERI.
Kozai, Naofumi; Adachi, Yoshifusa*; Kawamura, Sachi*; Inada, Koichi*; Kozaki, Tamotsu*; Sato, Seichi*; Ohashi, Hiroshi*; Onuki, Toshihiko; Bamba, Tsunetaka
Journal of Nuclear Science and Technology, 38(12), p.1141 - 1143, 2001/12
This study briefly reports characteristics of Fe-montmorillonite. Fe-montmorillonite was used as a simulant of buffer material in which corrosion products of carbon steel overpack, Fe
, were diffused. We have found that this clay retains Se(VI) for which natural montmorillonite, such as Na+-type and Ca-type, has little retentivity.
Yamashita, Masato*; Konishi, Hiroyuki; Takahashi, Masamitsu; Mizuki, Junichiro; Uchida, Hitoshi*
Materials Science Research International, Special Technical Publication, 1, p.398 - 401, 2001/05
A rust layer on a weathering low-alloy steel has strong protective ability for atmospheric corrosion of the steel. In order to control the rust layer on steels, it is so important to know the detailed structure of rust and relate it to the protective ability of the rust layer. Especially, the position of atoms of the alloying elements in the rust layer directly control the structure and properties of the rust layer. We tried to find the atomic arrangement of the rust layer of Fe-Cr alloy film covered with thin film of electrolyte using synchrotron radiation. Grazing incidence X-ray diffraction and M
ssbauer spectra showed that the rust layer was composed of -FeOOH and ultra-fine -FeOOH. By examining EXAFS spectra, Cr coming from Fe-Cr alloy film would be present in the -FeOOH. Some of Cr would be present between Fe-0-OH octahedron as interstitial atoms, as well as substituting Fe lattice site in the octahedron.
Kurata, Yuji; Tachibana, Katsumi; Suzuki, Tomio
Nihon Kinzoku Gakkai-Shi, 65(4), p.262 - 265, 2001/04
no abstracts in English
O+SO
atmosphereKurata, Yuji; Suzuki, Tomio; Shimizu, Saburo
JAERI-Research 2000-011, p.56 - 0, 2000/03
JAERI-Research-2000-011.pdf:14.24MB
no abstracts in English
Ioka, Ikuo; Onuki, Kaoru; Futakawa, Masatoshi; Kuriki, Yoshiro*; ; Nakajima, Hayato; Shimizu, Saburo
Zairyo, 46(9), p.1041 - 1045, 1997/09
no abstracts in English
;
JAERI-Tech 97-029, 47 Pages, 1997/07
no abstracts in English
Minato, Kazuo; Fukuda, Kosaku; Ishikawa, Akiyoshi; Mita, Naoaki
Journal of Nuclear Materials, 246(2-3), p.215 - 222, 1997/00
Times Cited Count：17 Percentile：76.35(Materials Science, Multidisciplinary)no abstracts in English
; ; ; ; ; ; ; Nagasaki, Shinya*
Nihon Genshiryoku Gakkai-Shi, 35(5), p.420 - 437, 1993/05
Times Cited Count：6 Percentile：55.13(Nuclear Science & Technology)no abstracts in English
Minato, Kazuo; Ogawa, Toru; Kashimura, Satoru; Fukuda, Kosaku; ; ;
Journal of Nuclear Materials, 172, p.184 - 196, 1990/00
Times Cited Count：74 Percentile：97.92(Materials Science, Multidisciplinary)no abstracts in English
Suwa, Takeshi; Yasunaka, Hideo
Boshoku Gijutsu, 32(12), p.721 - 729, 1983/00
no abstracts in English
; ;
Nihon Genshiryoku Gakkai-Shi, 16(9), p.478 - 485, 1974/09
no abstracts in English
Otani, Kyohei
no journal, ,
This is a comprehensive paper of the corrosion of carbon steel in air/solution alternating condition. From cross-sectional observation and analysis of the iron rust layer formed on the surface of carbon steel in the alternating condition, it was found that a multilayered iron rust layer composed of red rust layer, rust crust layer, inner crystal, and inner rust layer was formed on carbon steel. The multi-layered iron rust layer would accelerate the cathodic oxygen reduction reaction, and the reason why the corrosion rate of the carbon steel in the alternating condition was accelerated. The effect of artificial seawater (ASW) composition on the corrosion rate of carbon steel in air/solution alternating condition was investigated. It was found that the corrosion rate increased with increasing concentration from pure water to 200 times diluted ASW, and decreased with increasing concentration from 20 times diluted ASW to no diluted ASW. The Mg and Ca ions in ASW precipitated on the reaction interface and formed a metal cation layer, which inhibited the oxygen reduction reaction, and thus the corrosion of carbon steel was inhibited in the highly concentrated ASW. This is a commemorative lecture for the awarding of the Progress Award by the Japan Society of Corrosion Engineering.
