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JAEA Reports

Development of methodology combining chemical analysis technology with informatics technology to understand perspectives property of debris and tie-up style human resource development (Contract research); FY2020 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Fukushima University*

JAEA-Review 2021-035, 89 Pages, 2021/12

JAEA-Review-2021-035.pdf:6.37MB

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 FY2019, this report summarizes the research results of the "Development of methodology combining chemical analysis technology with informatics technology to understand perspectives property of debris and tie-up style human resource development" conducted in FY2020. The present study aims to Goal of this study is to implement a research plan relate to a development of combinational technology of new chemical analysis with informatics, and the aim is to develop new system for whole image estimation system using small quantities of information. Conducting the collaboration study with JAEA researchers (tie-up style) make connect to the development of human resource from master's course student to post-doctoral researchers who are progress in the local-based and/or many academics

JAEA Reports

Development of methodology combining chemical analysis technology with informatics to understand perspectives property of debris and tie-up style human resource development (Contract research); FY2019 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Fukushima University*

JAEA-Review 2020-065, 30 Pages, 2021/01

JAEA-Review-2020-065.pdf:1.87MB

JAEA/CLADS had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project in FY2019. Among the adopted proposals in FY2019, this report summarizes the research results of the "Development of methodology combining chemical analysis technology with informatics to understand perspectives property of debris and tie-up style human resource development" conducted in FY2019.

Journal Articles

Chemical forms of uranium evaluated by thermodynamic calculation associated with distribution of core materials in the damaged reactor pressure vessel

Ikeuchi, Hirotomo; Yano, Kimihiko; Washiya, Tadahiro

Journal of Nuclear Science and Technology, 57(6), p.704 - 718, 2020/06

 Times Cited Count:4 Percentile:43.05(Nuclear Science & Technology)

To suggest efficient process of the fuel debris treatment after the retrieval from the Fukushima Daiichi Nuclear Power Plant (1F), thorough investigation is indispensable on potential source of U in the fuel debris. Estimation on the fuel debris accumulated in the reactor pressure vessel is specifically important due to its limited accessibility. The present study aims to estimate the chemical forms of U in the in-vessel fuel debris, especially in the minor phases such as metallic phases, by performing the thermodynamic calculation considering the material relocation and changing environment during the accident progression in the 1F Unit 2. Input conditions for the thermodynamic calculation such as composition, temperature, and oxygen amount were assumed mainly based on the results of severe accident analysis. The chemical form of U varied depending on the local amount of Fe and O. In regions of low steel content, the U-containing metallic phase was dominated by $$alpha$$-(Zr,U)(O), while regions of high steel content were dominated by Fe$$_{2}$$(Zr,U) (Laves phase). A few percent of U was transferred to the metallic phases under reducing conditions, raising challenging issues on the chemical removal of nuclear material from fuel debris.

JAEA Reports

Development of measurement technique of the equilibrium vapor pressure of simulated fission products

Takai, Toshihide; Nakajima, Kunihisa; Furukawa, Tomohiro

JAEA-Technology 2015-002, 20 Pages, 2015/03

JAEA-Technology-2015-002.pdf:3.46MB

To improve the evaluation technique of source term, the measurement technique of the equilibrium vapor pressure using a high temperature mass spectrometer is required to expand the thermodynamic database of the simulated FPs. Existing test apparatus was adapted for this purpose. A mass spectrometer capable of measuring a wide mass number range and glove box for handling simulated FPs were installed for analyzing heavy FPs and preventing deterioration of simulated FPs in an air atmosphere, respectively. Function verification using standard sample and precision investigation using simulated FP sample were carried out. The oxygen dissociation pressure and standard enthalpy of formation of RuO$$_{2}$$(s) were evaluated, and it was confirmed these evaluated values were agreed with the calculated value from existing thermodynamic data and evaluation value written in the literature. Consequently, it was proven that high precision thermodynamic data was able to obtain by using this apparatus.

Journal Articles

Challenge to ultra-trace analytical techniques of nuclear materials in environmental samples for safeguards at JAERI; Methodologies for physical and chemical form estimation

Usuda, Shigekazu; Yasuda, Kenichiro; Kokubu, Yoko; Esaka, Fumitaka; Lee, C. G.; Magara, Masaaki; Sakurai, Satoshi; Watanabe, Kazuo; Hirayama, Fumio; Fukuyama, Hiroyasu; et al.

International Journal of Environmental Analytical Chemistry, 86(9), p.663 - 675, 2006/08

 Times Cited Count:14 Percentile:41.71(Chemistry, Analytical)

The IAEA introduced the environmental sample analysis method, as a powerful tool to detect undeclared nuclear activities, into strengthened safeguards system. The principle of the method is that nuclear signatures can be evidenced if trace amount of nuclear materials in environmental samples taken from inside and outside of nuclear facilities are accurately analyzed. Currently, isotope ratios of uranium and plutonium in "swipe" samples are measured, which are collected in nuclear facilities. In future, the subject of environmental sample analysis will expand to soil, sediment, vegetation, water and airborne dust taken from outside of the nuclear facilities. If physical and chemical form of the nuclear materials is identified, we may estimate their origin, treatment process and migration behavior. This paper deals with the developed analytical techniques for the safeguards environmental samples, the current R&D on techniques related to estimation of the physical and chemical form, and possible analytical methodologies applicable to ultra-trace amounts of nuclear materials.

Journal Articles

CFC indicating renewal of the Japan Sea deep water in winter 2000-2001

Tsunogai, Shizuo*; Kawada, Kentaro*; Watanabe, Shuichi*; Aramaki, Takafumi

Journal of Oceanography, 59(5), p.685 - 693, 2003/10

 Times Cited Count:25 Percentile:46.52(Oceanography)

The water column distributions of CFC (chlorofluorocarbon) were determined twice in 2000 and 2001 in the northwestern Japan Sea. In 2000, the CFC-11 concentration decreased almost exponentially with depth from 6 pmol/kg at a few hundred m deep to 0.3 pmol/kg or less at the bottom of about 3400 m depth at 3 stations about 300 km off Vladivostok. In 2001, the CFC-11 concentration increased extremely up to 2 pmol/kg in the bottom water, while it did not increase at a station about 450 km away to the northeast. This is due to the renewal of the bottom water replaced by the surface water flowing down along the continental slope. The increase in the CFC-11 concentration was observed even in the whole water column above 3000 m depth. The increase in inventory is almost four times larger than that in the bottom water below 3000 m depth and equals about 1/6 of the total inventory found in 2000. The increase also means that 3 % of the deep water was replaced by the recent surface water or the turnover time of the deep water to be about 30 years, if the turnover occurs every year.

Journal Articles

Accumulation and potential dissolution of Chernobyl-derived radionuclides in river bottom sediments

Sanada, Yukihisa*; Matsunaga, Takeshi; Yanase, Nobuyuki; Nagao, Seiya; Amano, Hikaru; Takada, Hideshige*; Tkachenko, Y.*

Applied Radiation and Isotopes, 56(5), p.751 - 760, 2002/04

 Times Cited Count:13 Percentile:64.52(Chemistry, Inorganic & Nuclear)

Areas contaminated with radionuclides from the Chernobyl nuclear accident have been identified in Pripyat River near the Chernobyl Nuclear Power Plant. The bottom sediments contained $$^{137}$$Cs (10$$^{5}$$ - 10$$^{6}$$ Bq/m$$^{2}$$) within 0-30 cm depth, which is comparable to the ground soil of in the vicinity of the nuclear power plant (the Exclusion Zone). The sediments also accumulated $$^{90}$$Sr (10$$^{5}$$ Bq/m$$^{2}$$ ), $$^{239,240}$$Pu (10$$^{4}$$ Bq/m$$^{2}$$ ), $$^{241}$$Am (10$$^{4}$$ Bq/m$$^{2}$$ ) derived from the accident.The comparison of these inventories with those of the released radionuclides at the accident and the experimental analysis using the selective sequential extraction of the radionuclides in the sediments suggest that the potential mobility of $$^{137}$$Cs and $$^{239,240}$$Pu is low compared with $$^{90}$$Sr in the bottom sediment, while the potential dissolution of $$^{90}$$Sr from the river bottom sediment should be taken into account with respect to the long-term radiological influence on the aquatic environment.

Journal Articles

Research and development of HTTR hydrogen production systems

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.

Journal Articles

Airborne gaseous $$^{13}$$N species and noxious gases produced at the 12GeV proton synchrotron

Kanda, Yukio*; Oki, Yuichi*; Endo, Akira; Numajiri, Masaharu*; Kondo, Kenjiro*

Journal of Radioanalytical and Nuclear Chemistry, 247(1), p.25 - 31, 2001/01

 Times Cited Count:9 Percentile:57.14(Chemistry, Analytical)

no abstracts in English

Journal Articles

Evaluation of internal and external doses from $$^{11}$$C produced in the air in high energy proton accelerator tunnels

Endo, Akira; Oki, Yuichi*; Kanda, Yukio*; Oishi, Tetsuya; Kondo, Kenjiro*

Radiation Protection Dosimetry, 93(3), p.223 - 230, 2001/00

 Times Cited Count:6 Percentile:45.06(Environmental Sciences)

no abstracts in English

JAEA Reports

Study of prediction of fission product behaviours in severe accident; Scoping experiment and basic findings of Cs, Ba and Sr

*; J.Huang*; *; *; *; Yamaguchi, Kenji*; Sugimoto, Jun

JAERI-Tech 98-003, 32 Pages, 1998/02

JAERI-Tech-98-003.pdf:1.12MB

no abstracts in English

Journal Articles

Development of methane conversion improvement method by recycling of residual Methane for steam reforming as a part of R&D of HTGR-hydrogen production system

Inagaki, Yoshiyuki; Haga, Katsuhiro; ; Sekita, Kenji; *; Hino, Ryutaro

Nihon Genshiryoku Gakkai-Shi, 40(1), p.59 - 64, 1998/00

 Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Chemical interactions between B$$_{4}$$C and stainless steel at high temperatures

Nagase, Fumihisa; Uetsuka, Hiroshi;

Journal of Nuclear Materials, 245(1), p.52 - 59, 1997/00

 Times Cited Count:34 Percentile:90.82(Materials Science, Multidisciplinary)

no abstracts in English

Journal Articles

Preparation for the 2nd edition of nuclear criticality safety handbook

; Nomura, Yasushi

Nihon Genshiryoku Gakkai-Shi, 39(10), p.832 - 841, 1997/00

 Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Characteristics of the chemical forms of $$^{11}$$C, $$^{13}$$N, and $$^{15}$$O induced in air by the operation of a 100MeV electron linear accelerator

Endo, Akira; Kikuchi, Masamitsu; ; Ikezawa, Yoshio

Health Physics, 68(1), p.80 - 88, 1995/01

 Times Cited Count:6 Percentile:55.59(Environmental Sciences)

no abstracts in English

Journal Articles

Assessment of the chemical form of gaseous $$^{35}$$S species produced during the production of H$$_{332}$$PO$$_{4}$$

Endo, Akira; *; ; Kajimoto, Yoichi;

Health Physics, 65(1), p.92 - 95, 1993/07

 Times Cited Count:1 Percentile:27.94(Environmental Sciences)

no abstracts in English

Journal Articles

Analysis on evolving environments of engineered barriers of high-level radioactive waste repositories during the first 1,000 years

*; *; *; *; *; *; ; Nagasaki, Shinya*

Nihon Genshiryoku Gakkai-Shi, 35(5), p.420 - 437, 1993/05

 Times Cited Count:6 Percentile:56.75(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Assessment of chemical form of gaseous $$^{35}$$S species produced during production of H$$_{332}$$PO$$_{4}$$ and effective reduction of $$^{35}$$S release

Endo, Akira; ; ; ; Kajimoto, Yoichi; Ikezawa, Yoshio

Proc. of Asia Congress on Radiation Protection, p.730 - 733, 1993/00

no abstracts in English

Journal Articles

Development of a chemical form discrimination system for $$^{14}$$C species in gaseous waste

Endo, Akira; *; ; ;

Health Physics, 62(4), p.319 - 327, 1992/04

 Times Cited Count:3 Percentile:35.93(Environmental Sciences)

no abstracts in English

Journal Articles

Interlaboratory modeling for performance assessment of engineered barriers in high-level radioactive waste disposal

; *; *; *; *; *; Kimura, Hideo; Munakata, Masahiro

Nihon Genshiryoku Gakkai-Shi, 34(4), p.342 - 364, 1992/04

 Times Cited Count:2 Percentile:27.96(Nuclear Science & Technology)

no abstracts in English

33 (Records 1-20 displayed on this page)