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Yoshida, Kazuo; Hiyama, Mina*; Tamaki, Hitoshi
JAEA-Research 2025-003, 24 Pages, 2025/06
JAEA-Research-2025-003.pdf:2.06MB
An accident of evaporation to dryness by boiling of high-level radioactive liquid waste (HLLW) is postulated as one of the severe accidents caused by the loss of cooling function at a fuel reprocessing plant. In this case, volatile radioactive materials, such as ruthenium (RuO
) are released from the tanks with water and nitric-acid mixed vapor into the atmosphere. Accurate quantitative estimation of released Ru is one of the important issues for risk assessment of those facilities. RuO is expected to be absorbed chemically into water dissolving nitrous acid. Condensation of mixed vapor plays an important role for Ru transporting behavior in the facility building. The thermal-hydraulic behavior in the facility building is simulated with MELCOR code. The latent heat, which is a governing factor for vapor condensing behavior, has almost same value for nitric acid and water at the temperature range under 120 centigrade. Considering this thermal characteristic, it is assumed that the amount of nitric acid is substituted with mole-equivalent water in MELCOR simulation. Compensating modeling induced deviation by this assumption have been assembled with control function features of MELCOR. The comparison results have been described conducted between original simulation and modified simulation with compensating model in this report. It has been revealed that the total amount of pool water in the facility was as same as both simulations.
Sector of Fast Reactor and Advanced Reactor Research and Development
JAEA-Evaluation 2020-001, 128 Pages, 2020/08
JAEA-Evaluation-2020-001.pdf:7.44MB
Japan Atomic Energy Agency consulted with the "Evaluation Committee of Research Activities for High Temperature Gas-cooled Reactor (hereinafter referred to as "HTGR") and Related Hydrogen Production Technology" (hereinafter referred to as "Evaluation Committee"), which consists of specialists in the fields of the evaluation subjects of high temperature gas-cooled reactor and related heat application technology, for interim assessment in the 3rd Mid-and Long-Term Plan about the relevance of the management and research activities of the HTGR and related application technology during the period from April 2017 to March 2020. As a result, three members of the Evaluation Committee concluded a score of "S", and seven members of the Evaluation Committee concluded a score of "A". The interim assessment to research and development activities from April 2017 to March 2020 was concluded a score of "A". In addition, the Evaluation Committee recommended that the judgement to move to the construction phase of the HTTR-heat utilization test plant be made after 2 years, after the HTTR will be restarted and the thermal load fluctuation tests using HTTR will be carried out. This report lists the members of the Evaluation Committee and outlines the assessment item and the review process for procedure of the assessment. The assessment report which was issued by the Evaluation Committee is attached.
Kunitomi, Kazuhiko; Nishihara, Tetsuo; Yan, X.; Tachibana, Yukio; Shibata, Taiju
Nihon Genshiryoku Gakkai-Shi ATOMO
, 60(4), p.236 - 240, 2018/04
High temperature gas-cooled reactor (HTGR) is a graphite-moderated and helium-gas-cooled thermal-neutron reactor that has excellent safety features and can produce high temperature heat of 950
C. It is expected to use for various heat applications as well as for electricity generation to reduce carbon dioxide emission. Japan Atomic Energy Agency (JAEA) has been promoted research and development to demonstrate the HTGR safety features using High temperature engineering test reactor (HTTR) and it's heat application. JAEA are also conducting the action to international deployment of Japanese HTGR technologies in cooperation with industries-government-academia. This paper reports status of the research and development of HTGR and domestic and international collaborations.
C operation of the HTTRSakaba, Nariaki; Ohashi, Hirofumi; Takeda, Tetsuaki
Journal of Nuclear Materials, 353(1-2), p.42 - 51, 2006/07
Times Cited Count：12 Percentile：61.29(Materials Science, Multidisciplinary)The permeation of hydrogen isotopes through the Hastelloy XR high-temperature alloy adopted for the heat transfer pipes of the intermediate heat exchanger in the HTTR, is one of the concerns in the hydrogen production system, which will be connected to the HTTR in the near future. The hydrogen permeation between the primary and secondary coolant through the Hastelloy XR was evaluated using the actual hydrogen concentration observed during the initial 950C operation of the HTTR. The hydrogen permeability of the Hastelloy XR was estimated conservatively high as follows. The activation energy E
and pre-exponential factor F of the permeability of hydrogen were E = 65.8 kJ/mol and F = 7.8
10
m
(STP)/(m
sPa
), respectively, in the temperature range from 707K to 900K.
Shiozawa, Shusaku; Komori, Yoshihiro; Ogawa, Masuro
Nihon Genshiryoku Gakkai-Shi, 47(5), p.342 - 349, 2005/05
For the purpose to extend high temperature nuclear heat application, JAERI constructed the HTTR, High Temperature Engineering Test Reactor, and has carried out research and development of high temperature gas cooled reactor system aiming at high efficiency power generation and hydrogen production. This paper explains the history, main results, present status of research and development of HTTR project, international cooperation of research and development of HTGR and future plan aiming at development of Japanese original future HTGR-Hydrogen production system. This paper includes results from the study, which is entrusted from Ministry of Education, Culture, Sports, Science and Technology of Japan.
Mironov, M. I.*; Khudoleev, A. V.*; Kusama, Yoshinori
Plasma Physics Reports, 30(2), p.164 - 168, 2004/02
Times Cited Count：0 Percentile：0.00(Physics, Fluids & Plasmas)High-energy charge-exchange diagnostics can determine the distribution function of fast atoms produced via the neutralization of hydrogen ions by hydrogen-like impurity ions. Deriving the distribution function requires to know the composition and spatial distribution of the target ions in a plasma. A charge-exchange target forms as a result of the interaction between impurity nuclei and beam atoms. Depending on the arrangement of heating beams with respect to the diagnostics, it is necessary to calculate their trajectories. A model which takes into account elementary processes resulting in the ionization equilibrium of the ions of impurities in a specific tokamak configuration is proposed. The model is applied to the JT-60U plasma. Mechanisms for the formation of charge-exchange atomic flows are considered. The relative contributions of different heating injectors to the charge-exchange flow are estimated. Based on the calculated results, a method is proposed for local measurements of the ion distribution function with a stationary analyzer.
Kato, Chiaki
JAERI-Research 2003-013, 143 Pages, 2003/08
JAERI-Research-2003-013.pdf:22.12MB
This study is investigation about stress corrosion cracking (SCC) of zirconium in nuclear fuel reprocessing. Chapter 1 is described background. Chapter 2 is explained experimental apparates. Chapter 3 is described the increased oxidization potential on the heat-transfer surface and suggested the initiation of SCC on a boiling heat-transfer surface. Chapter 4 is described that the SCC susceptibility increased with increasing nitric acid concentration and solution temperature on notched specimen by SSRT. In addition, the SCC susceptibility effected by the crystal anisotropy by the hot rolling direction and increased on a parallel face to the rolling direction. Chapter 5 is described that the SCC susceptibility increased in HAZ/base metal boundary in order to the preferential orientation of cleavage plane (0002). Chapter 6 is described that the increased oxidization potential on the heat-transfer surface is attributed to the reduction of nitrous acid concentration by the thermal decomposition on the surface and the removal of the decomposition product from solution by boiling bubbles.
Oba, Toshihiro; Suetsugu, Hidehiko*; Yano, Masaya*; Kato, Chiaki; Yanagihara, Takao
JAERI-Tech 2002-082, 47 Pages, 2003/01
JAERI-Tech-2002-082.pdf:1.87MB
The demonstration test for evaluating reliability of the acid recovery evaporator at Rokkasho Reprocessing Plant has been carried out at JAERI. For the nondestructive measurement of the thickness of heat transfer tubes of the acid recovery evaporator in corrosion test, we have developed thickness measurement apparatus for heat transfer tubes by ultrasonic immersion method with high resolution. The ultrasonic prove in a heat transfer tube can be moved vertically and radially. The results obtained by this apparatus coincident well with those obtained by a destructive method using an optical microscope.
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 of Nuclear Materials, 254, p.14 - 21, 1998/00
Times Cited Count：16 Percentile：75.46(Materials Science, Multidisciplinary)no abstracts in English
Nakanishi, Tomoko*; Matsubayashi, Masahito
Bioimages, 5(2), p.45 - 48, 1997/08
no abstracts in English
Takenaka, Nobuyuki*; Asano, Hitoshi*; Fujii, Terushige*; Ushiro, Toshihiko*; Iwatani, Junji*; Murata, Yutaka*; Mochiki, Koichi*; Taguchi, Akira*; Matsubayashi, Masahito; Tsuruno, Akira
Nuclear Instruments and Methods in Physics Research A, 377(1), p.174 - 176, 1996/07
Times Cited Count：1 Percentile：23.35(Instruments & Instrumentation)no abstracts in English
; ; Ogawa, Toru
JAERI-Tech 96-026, 21 Pages, 1996/06
no abstracts in English
; ; ; ; Matsubayashi, Masahito; Tsuruno, Akira
Fifth World Conf. on Neutron Radiography, 0, p.610 - 616, 1996/00
no abstracts in English
; ; ; ; Tsuruno, Akira; Matsubayashi, Masahito
Nuclear Instruments and Methods in Physics Research A, 377, p.144 - 147, 1996/00
Times Cited Count：7 Percentile：54.62(Instruments & Instrumentation)no abstracts in English
; ; Ogawa, Toru
JAERI-Tech 94-010, 33 Pages, 1994/07
no abstracts in English
microspheres; Takahashi, Yoshihisa
Journal of Nuclear Materials, 207, p.255 - 265, 1993/00
Times Cited Count：6 Percentile：55.27(Materials Science, Multidisciplinary)no abstracts in English
Saito, Shinzo
Energy, 16(1-2), p.129 - 136, 1991/00
Times Cited Count：0 Percentile：0.00(Thermodynamics)no abstracts in English
Saito, Shinzo
Proc. of IEA Int. Conf. on Technology Responses to Global Environmental Challenges,Vol. l, p.393 - 396, 1991/00
no abstracts in English
Saito, Shinzo
Sekiyu Gakkai-Shi, 34(6), p.486 - 499, 1991/00
no abstracts in English
