Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 67

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Enhanced electrochemical oxidation of spent organic solvent under ultrasonic agitation

Sugikawa, Susumu; Umeda, Miki; Kobayashi, Fuyumi; Nagata, Masanobu*; Dojiri, Shigeru; Amano, Masae*

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 4 Pages, 2005/10

The mineralization of radioactive contaminated organic wastes by mediated electrochemical oxidation process has some attractive features as alternative to incineration process: The process operates safely at low temperatures and ambient pressures. JAERI has been investigated the process since 1996 and confirmed complete mineralization of this organic solvent. In order to greatly improve current efficiency for the oxidation reaction, further experiments were performed under condition of strong mixing of organic solvent and anolyte with an aide of ultrasonic wave. The current efficiencies for the oxidation reaction by ultrasonic agitation between organic solvent and anolyte were twice to that by mechanical agitation. On the basis of these results, two processes, one for destruction of a small amount of TBP/dodecane and the other for destruction of intermediate compounds following alkaline hydrolysis of a large amount of TBP/dodecane, were proposed.

Journal Articles

Helium chemistry in high-temperature gas-cooled reactors; Chemistry control for avoiding Hastelloy XR corrosion in the HTTR-IS system

Sakaba, Nariaki; Hirayama, Yoshiaki*

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10

The high-temperature gas-cooled reactor (HTGR) is capable of producing a massive quantity of hydrogen with no carbon dioxide emission during its production by a thermo chemical IS (Iodine-Sulphur) process. The HTTR (High Temperature Engineering Test Reactor), which is the first high-temperature gas-cooled reactor in Japan, will be connected to some heat utilization system in the near future. The thermo chemical IS process is one of the progressive candidates. The metallic material of the heat transfer tube of the intermediate heat exchanger (IHX) and liner in the concentric hot gas duct in the HTTR-IS system, which allows usage in high-temperature conditions, is the nickel-based high-temperature alloy Hastelloy XR. Since the coolant helium contains small amounts of impurities, it is necessary to control the chemical composition in order to minimize corrosion of the Hastelloy XR. Major corrosion phenomena of the Hastelloy XR are carburization, decarburization, oxidation, and carbon deposition depending upon the particular gas composition and its temperature. The carburization and decarburization phenomena can be restricted by controlling the carbon activity and oxygen partial pressure. This paper describes the effect of each coolant impurity for the carburization and decarburization. Also a chemical composition limit was evaluated to avoid the Hastelloy XR corrosion.

Journal Articles

Development of a simple reprocessing process using selective precipitant for uranyl ions; Precipitation behaviors of plutonium and other transuranium elements

Morita, Yasuji; Kawata, Yoshihisa*; Mineo, Hideaki; Koshino, Nobuyoshi*; Asanuma, Noriko*; Ikeda, Yasuhisa*; Yamasaki, Kazuhiko*; Chikazawa, Takahiro*; Tamaki, Yoshihisa*; Kikuchi, Toshiaki*

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10

N-cyclohexyl-2-pyrrolidone (NCP) can selectively precipitate U(VI) ions in aqueous nitric acid solutions. Utilizing this property, we have been developing a simple reprocessing process of spent nuclear fuel based only on precipitation method. In the first precipitation step, only U is separated by precipitation in a yield of about 70%, and in the second precipitation step both U and Pu are recovered and separated from fission products (FP) and other transuranium elements (TRU). In JAERI, precipitation behaviors of Pu and other TRU were examined experimentally, and the results showed the feasibility of the process establishement.

Journal Articles

Development of a simple reprocessing process using selective precipitant for uranyl ions; Engineering studies for precipitating and separating systems

Yamasaki, Kazuhiko*; Chikazawa, Takahiro*; Tamaki, Yoshihisa*; Kikuchi, Toshiaki*; Morita, Yasuji; Kawata, Yoshihisa*; Mineo, Hideaki; Koshino, Nobuyoshi*; Asanuma, Noriko*; Harada, Masayuki*; et al.

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 4 Pages, 2005/10

N-cyclohexyl-2-pyrrolidone (NCP), can selectively precipitate U(VI) ions in aqueous nitric acid solutions. Utilizing this property, we have been developing a simple reprocessing process of spent nuclear fuel based only on precipitation method. In the first precipitation step, only U is separated by precipitation in a yield of about 70%, and in the second precipitation step both U and Pu are recovered and separated from fission products (FP) and other transuranium elements (TRU). In the present study, a precipitator and a precipitate separator were designed and built up, and were tested with aspets of operationability and system performance.

Journal Articles

Separation of Np from U and Pu using a salt-free reductant for Np(VI) by continuous counter-current back-extraction

Ban, Yasutoshi; Asakura, Toshihide; Morita, Yasuji

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 5 Pages, 2005/10

An idea for controlling Np behavior in the Purex process is that Np(VI) extracted by TBP is selectively reduced to Np(V) by salt-free reagents and separated from U and Pu. Allylhydrazine is expected as a selective Np(VI) reductant from a view point of reduction rates for Np(VI) and Pu(IV). To confirm the applicability of allylhydrazine, a continuous counter-current back-extraction test of Np(VI) has been carried out using a miniature mixer-settler that consists of two steps: U-Pu recovery (3 stages) and Np separation (4 stages). Experimental results show that at least 90% of Np in feed are back-extracted and separated from U and Pu, therefore, it is confirmed that allylhydrazine is expected to be a selective salt-free reductant of Np(VI).

Journal Articles

R&D on safeguards environmental sample analysis at JAERI

Sakurai, Satoshi; Magara, Masaaki; Usuda, Shigekazu; Watanabe, Kazuo; Esaka, Fumitaka; Hirayama, Fumio; Lee, C. G.; Yasuda, Kenichiro; Kono, Nobuaki; Inagawa, Jun; et al.

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10

no abstracts in English

Journal Articles

Experimental study on long-term safety assessment considering uncertainties for geological disposal of radioactive wastes; JAERI status at 2005

Yamaguchi, Tetsuji; Sakamoto, Yoshifumi; Iida, Yoshihisa; Negishi, Kumi; Taki, Hiroshi; Akai, Masanobu; Jinno, Fumika; Kimura, Yuichiro; Ueda, Masato; Tanaka, Tadao; et al.

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10

no abstracts in English

Journal Articles

Sorption and migration of neptunium in porous sedimentary materials

Tanaka, Tadao; Mukai, Masayuki; Nakayama, Shinichi

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10

no abstracts in English

Journal Articles

Present status and future perspective of research and development on partitioning and transmutation technology at JAERI

Oigawa, Hiroyuki; Minato, Kazuo; Kimura, Takaumi; Morita, Yasuji; Arai, Yasuo; Nakayama, Shinichi; Nishihara, Kenji

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10

JAERI is engaging in the R&D on the Double-strata Fuel Cycle concept in accordance with the results of the check and review on the Partitioning and Transmutation (PT) technology made by the Atomic Energy Commission of Japan in 2000. As for the partitioning process, after the establishment of the "4-group Partitioning Process Concept", an innovative concept called ARTIST is also being studied. As for the fuel technology, minor actinide nitrides such as NpN and AmN were synthesized and their material properties have been measured. To reprocess the irradiated fuel, the pyrochemical process has been studied. The R&D of the accelerator-driven transmutation system are in progress for an accelerator, lead-bismuth, and a subcritical reactor. In addition, JAERI has started the high-intensity proton accelerator project (J-PARC), which includes the Transmutation Experimental Facility (TEF) as the Phase-II. The impact of PT technology on the backend of the nuclear energy utilization is also being discussed.

Journal Articles

Study of the $$^{17}$$N reactor power monitor

Komeda, Masao

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 5 Pages, 2005/10

no abstracts in English

Journal Articles

Research activities for development of CTBT-related technologies in JAERI

Shinohara, Nobuo; Asano, Yoshie; Hirota, Naoki*; Hokida, Takanori; Inoue, Yoji; Kumata, Masahiro; Nakahara, Yoshinori*; Oda, Tetsuzo*; Uchikoshi, Takako*; Yamamoto, Yoichi

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 3 Pages, 2005/10

Research activities of JAERI related to the CTBT verification regime are presented in the International Conference. The subjects of this presentation are (1) an overview of the CTBT verification regime, (2) construction and operation of the radionuclide monitoring stations of Okinawa (RN37) and Takasaki (RN38) and the certified radionuclide laboratory (RL11), and (3) preparation of the National Data Center at Tokai (JAERI NDC) for radionuclide data. The RN38 station has been certified by the CTBTO/PrepCom and sending the measured data every day. The infrastructures and operational manuals for RN37 and RL11 are now preparing for their operations. The JAERI NDC has experimentally analyzed and evaluated the radionuclide data from all over the world through International Data Center (IDC). As an example of the JAERI NDC works, atmospheric dispersion backtracking system has been developing by using WSPEEDI (Worldwide Version of System for Prediction of Environmental Emergency Dose Information) code to estimate a source location of radionuclide release by nuclear explosion/accident.

Journal Articles

Geologic disposal of radioactive waste produced by application of partitioning-transmutation technology to nuclear fuel cycle

Nakayama, Shinichi; Morita, Yasuji; Nishihara, Kenji; Oigawa, Hiroyuki

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10

The effects of partitioning-transmutation (PT) technology to waste management was assessed based on the chemical and physical properties and estimated amounts of radioactively contaminated wastes that may be generated in the JAERI's PT cycle. The volume of high-level waste after partitioning was about a third that of non-partitioned vitrified waste form. The required repository area was about sixth, which implies increase in capacity of geologic repositories.

Journal Articles

Research and development program on accelerator driven subcritical system in JAERI

Tsujimoto, Kazufumi; Oigawa, Hiroyuki; Ouchi, Nobuo; Kikuchi, Kenji; Kurata, Yuji; Mizumoto, Motoharu; Sasa, Toshinobu; Nishihara, Kenji; Saito, Shigeru; Umeno, Makoto*; et al.

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10

The Japan Atomic Energy Research Institute (JAERI) has been proceeding with the research and development (R&D) on accelerator-driven subcritical system (ADS). The ADS proposed by JAERI is a lead-bismuth (Pb-Bi) eutectic cooled fast subcritical core with 800 MWth. To realize such an ADS, some technical issues should be studied, developed and demonstrated. JAERI has started a comprehensive R&D program since the fiscal year of 2002 to acquire knowledge and elemental technology that are necessary for the validation of engineering feasibility of the ADS. The first stage of the program had been continued for three years. The program is conducted by JAERI, and many institutes, universities and private companies were involved. Items of R&D are concentrated on three technical areas peculiar to the ADS: (1) superconducting linear accelerator (SC-LINAC), (2) Pb-Bi eutectic as spallation target and core coolant, and (3) subcritical core design and technology. In the present work, the outline and the results in the first stage of the program are reported.

Journal Articles

Development of the ERIX process for reprocessing spent FBR-MOX fuel; A Study on minor actinides separation process

Hoshi, Harutaka*; Wei, Y.*; Kumagai, Mikio*; Asakura, Toshihide; Morita, Yasuji

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10

For the development of nuclear fuel cycle, it is one of the most important tasks to improve reprocessing more economically and efficiently. Especially, to establish the Fast Breeder Reactor (FBR) cycle system for the future, it is strongly desirable to develop a new reprocessing which uses more compact equipments and produces less radioactive wastes compared to the present PUREX process. For this purpose, we have proposed a novel aqueous reprocessing system named ERIX Process to treat spent FBR-MOX fuels. This process consists of (1) Pd removal by selective adsorption using a specific anion exchanger; (2) electrolytic reduction for the valence adjustment of the major actinides including U, Pu, Np and some fission products (FP) such as Tc and Ru; (3) anion exchange separation for the recovery of U, Pu and Np using a new type of anion exchanger, AR-01; and (4) selective separation of long-lived minor actinides (MA = Am and Cm) by extraction chromatography. In this work, MA separation process was studied.

Journal Articles

Subchannel analysis of 37-rod tight-lattice bundle experiments for reduced-moderation water reactor

Nakatsuka, Toru; Tamai, Hidesada; Akimoto, Hajime

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10

The subchannel analysis code NASCA was applied to critical power prediction of 37-rod tight-lattice bundle experiments which JAERI has been carrying out to confirm the thermal-hydraulic feasibility of the RMWR. The NASCA can yield good predictions of critical power for the gap width of 1.3 mm while the prediction accuracy of critical power deteriorated in case of the gap width of 1.0 mm. Predicted BT positions agree with the experimental results. Models in the code will be improved to consider the effect of the gap width based on further studies in the future.

Journal Articles

Critical power prediction for tight lattice rod bundles

Liu, W.; Onuki, Akira; Tamai, Hidesada; Akimoto, Hajime

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 5 Pages, 2005/10

In this research, the newest version of critical power correlation for tight-lattice rod bundles is proposed by using 7-rod and 37-rod bundle data derived in Japan Atomic Energy Research Institute (JAERI). For comparatively high mass velocity region, the correlation is written in local critical heat flux - critical quality type. For low mass velocity region, it is written in critical quality - annular flow length type. The correlation is verified by JAERI data and Bettis Atomic Power Laboratory data. It is confirmed the correlation is able to give good prediction for the effects of mass velocity, inlet temperature, pressure and heated equivalent diameter on critical power. The correlation is further implemented into TRAC code to analyze flow decrease and power increase transients. It is confirmed transient BT can be predicted within the accuracy of the implemented critical power correlation.

Journal Articles

Experiments on the behavior of americium in pyrochemical process

Hayashi, Hirokazu; Akabori, Mitsuo; Minato, Kazuo

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 3 Pages, 2005/10

For a basis of the future nuclear cycle, it is very important to understand and control the behavior of TRU (Np, Pu, Am, Cm) in the nuclear fuel cycle. Experimental study of pyrochemical process of fuels containing TRU requires the facility having not only shielding for $$gamma$$-ray and neutron but also ability to keep a high purity inert gas atmosphere; because minor actinide chlorides can easily react with oxygen or water vapor in an atmosphere. The module for TRU high temperature chemistry (TRU-HITEC) had been installed to study the basic properties of TRU in the pyrochemical processes. In the present work, the behavior of $$^{241}$$Am in pyrochemical process was investigated by electrochemical methods.

Journal Articles

System of the advanced volume reduction facilities for LLW at JAERI

Higuchi, Hidekazu; Momma, Toshiyuki; Nakashio, Nobuyuki; Kozawa, Kazushige; Tohei, Toshio; Sudo, Tomoyuki; Mitsuda, Motoyuki; Kurosawa, Shigenobu; Hemmi, Ko; Ishikawa, Joji; et al.

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10

The JAERI constructed the Advanced Volume Reduction Facilities(AVRF). The AVRF consists of the Waste Size Reduction and Storage Facilities(WSRSF) and the Waste Volume Reduction Facilities(WVRF). By operating the AVRF, it will be able to produce waste packages for final disposal and to reduce the amount of the low level solid wastes. Cutting installations for large wastes such as tanks in the WSRSF have been operating since June 1999. The wastes treated so far amount to 600 m$$^{3}$$ and the volume reduction ratio is around 1/3. The waste volume reduction is carried out by a high-compaction process or melting processes in the WVRF. The metal wastes from research reactors are treated by the high-compaction process. The other wastes are treated by the melting processes that enable to estimate radioactivity levels easily by homogenization and get chemical and physical stability. The WVRF have been operating with non-radioactive wastes since February 2003 for the training and the homogeneity investigation in the melting processes. The operation with radioactive wastes will start in FY2005.

Journal Articles

Novel compounds, Diglycolamides (DGA), for extraction of various metal ions from nitric acid to n-dodecane

Sasaki, Yuji; Zhu, Z.-X.; Sugo, Yumi; Kimura, Takaumi

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 5 Pages, 2005/10

The extraction of metals by N,N,N',N'-tetraoctyl-diglycolamide (TODGA) from nitric acid to n-dodecane was investigated. From the measurement of distribution ratios, it was obvious that Ca (ionic radius: 100pm), trivalent and tetravalent ions with ionic radii of 87-113 and 83-94 pm are highly extractable by TODGA. In order to evaluate the extraction capacity in extraction solvent using DGA compounds, we measured the limits of metal concentration (LOC) for Ca(II), Nd(III) and Zr(IV). For the purpose to enhance the LOC value, we examined the modifier of solvent, N,N-dihexyl-octanamide(DHOA) and DGA with longer alkyl chain. It is evident that LOC is increased with DHOA concentration and the length of alkyl chain attached to N atom of DGA.

Journal Articles

Investigation on Innovative Water Reactor for Flexible Fuel Cycle (FLWR), 2; Recycle characteristics

Okubo, Tsutomu; Uchikawa, Sadao; Kugo, Teruhiko; Akie, Hiroshi; Takeda, Renzo*

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10

In order to ensure sustainable energy supply in the future based on the commercialized LWR technologies, a concept of Innovative Water Reactor for Flexible Fuel Cycle (FLWR) has been investigated in JAERI. Results on the FLWR recycling characteristics under possible various reprocessing schemes are presented in the present paper. The results show the recycling is possible a few times at most as long as the fissile Pu content stays over 60%, even in the high conversion type core with the conversion ratio around 0.9, under the simplified PUREX reprocessing, with relatively high average decontamination factor. For breeding core, the results have indicated that even under the reprocessing with relatively low DFs and with whole MA, the recycling is also feasible, suggesting all MAs from the core can be possibly recycled itself, although the core performances are a little degraded depending on MA and FP contents.

67 (Records 1-20 displayed on this page)