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Journal Articles

Recent progress of a code system DEURACS toward deuteron nuclear data evaluation

Nakayama, Shinsuke; Iwamoto, Osamu; Watanabe, Yukinobu*

EPJ Web of Conferences, 239, p.03014_1 - 03014_4, 2020/09

Intensive neutron sources using deuteron accelerators have been proposed for various applications such as irradiation test for fusion reactor materials and production of radioisotopes for medical use. In addition, transmutation system using deuteron-induced spallation reactions has been recently proposed for LLFPs. Accurate and comprehensive deuteron nuclear data are indispensable in the design study of such facilities. Under the above situations, we have been developing a code system dedicated for deuteron-induced reactions, which is called DEURACS. In the present work, calculations using DEURACS are compared with available experimental data up to 200 MeV such as DDXs for emission of neutron or light charged particles. We also analyze isotopic production cross sections of residual nuclei. Validation of the present modelling in DEURACS is discussed through comparison with the experimental data.

JAEA Reports

Production of the minor actinide sources using the electrodeposition method

Nakamura, Satoshi; Kimura, Takahiro; Ban, Yasutoshi; Tsubata, Yasuhiro; Matsumura, Tatsuro

JAEA-Technology 2020-009, 22 Pages, 2020/08

JAEA-Technology-2020-009.pdf:2.92MB

Partitioning and transmutation technology division is planning to measure fission rate ratios that contribute to validate nuclear data of minor actinides (MA). For this purpose, MA sources for fission chambers were prepared using electrodeposition method. The radioactivity of each MA source was quantified, and its uncertainty was evaluated. Seven types of MA sources with different radioactivity were prepared using four nuclides of $$^{237}$$Np, $$^{241}$$Am, $$^{243}$$Am, and $$^{244}$$Cm. A $$^{244}$$Cm source solution of which radioactivity was quantified by isotope dilution method was used to prepare working standard sources of $$^{244}$$Cm. The radioactivities were quantified as 1461 Bq, 2179 Bq, and 2938 Bq for $$^{237}$$Np sources, 1.428 MBq for $$^{241}$$Am source, 370.5 kBq and 89.57 kBq for $$^{243}$$Am sources, and 2.327 MBq for $$^{244}$$Cm source with, the uncertainty of 0.35% (1$$sigma$$). This report summarizes the method for preparation and quantification of MA sources, and uncertainty evaluation.

Journal Articles

Long beam pulse extraction by the laser charge exchange method using the 3-MeV linac in J-PARC

Takei, Hayanori; Hirano, Koichiro; Meigo, Shinichiro; Tsutsumi, Kazuyoshi*

Proceedings of 8th International Beam Instrumentation Conference (IBIC 2019) (Internet), p.595 - 599, 2020/06

Japan Proton Accelerator Research Complex (J-PARC) has a plan to build the Transmutation Physics Experimental Facility (TEF-P), in which a 400-MeV proton beam will be delivered from negative hydrogen (H$$^{-}$$) accelerated by the linac. Since the TEF-P requires a stable proton beam with a power of less than 10 W, a steady and meticulous beam extraction method is required to extract a small amount of the proton beam from the high power beam using 250 kW. To fulfill this requirement, we have developed beam extraction based on the Laser Charge Exchange (LCE) method. For the demonstration present beam extraction technique, an experiment was conducted using H$$^{-}$$ beam accelerated by the 3-MeV linac at RFQ test-stand in J-PARC. As a result of the experiment with continuous wave (CW) of the Laser, a charge-exchanged long-pulsed H$$^{+}$$ beam with a power of about 0.70 W equivalent was successfully obtained under the TEF-P beam condition.

Journal Articles

Enhancement of element production by incomplete fusion reaction with weakly bound deuteron

Wang, H.*; Otsu, Hideaki*; Chiga, Nobuyuki*; Kawase, Shoichiro*; Takeuchi, Satoshi*; Sumikama, Toshiyuki*; Koyama, Shumpei*; Sakurai, Hiroyoshi*; Watanabe, Yukinobu*; Nakayama, Shinsuke; et al.

Communications Physics (Internet), 2(1), p.78_1 - 78_6, 2019/07

 Times Cited Count:4 Percentile:23.32(Physics, Multidisciplinary)

Searching for effective pathways for the production of proton- and neutron-rich isotopes through an optimal combination of reaction mechanism and energy is one of the main driving forces behind experimental and theoretical nuclear reaction studies as well as for practical applications in nuclear transmutation of radioactive waste. We report on a study on incomplete fusion induced by deuteron, which contains one proton and one neutron with a weak binding energy and is easily broken up. This reaction study was achieved by measuring directly the cross sections for both proton and deuteron for $$^{107}$$Pd at 50 MeV/u via inverse kinematics technique. The results provide direct experimental evidence for the onset of a cross-section enhancement at high energy, indicating the potential of incomplete fusion induced by loosely-bound nuclei for creating proton-rich isotopes and nuclear transmutation of radioactive waste.

Journal Articles

Disposal and recycling; Safer disposal and reassuring recycling

Nishihara, Kenji

ImPACT Fujita Puroguramu Kokai Seika Hokokukai "Kaku Henkan Niyoru Koreberu Hoshasei Haikibutsu No Ohaba Na Teigen, Shigenka" Seika Hokokusho, Shiryoshu, p.28 - 31, 2019/03

In this project, long-lived fission products (LLFP) contained in conventional high-level radioactive wastes are separated and their life is reduced, and elements that can be used as resources are separated. By shortening the life of LLFP, it has been shown that it may be possible to dispose in intermediate depth of several tens of meters, meeting safety requirements, instead of geological disposal. In addition, for reassuring recycling of usable elements, possible exposure pathways were evaluated to estimate the safe concentration level of radioactivity.

Journal Articles

Investigation of system for volume-reduction and recycling of HLW

Nishihara, Kenji

ImPACT Fujita Puroguramu Kokai Seika Hokokukai "Kaku Henkan Niyoru Koreberu Hoshasei Haikibutsu No Ohaba Na Teigen, Shigenka" Seika Hokokusho, Shiryoshu, p.130 - 133, 2019/03

High level radioactive waste contains elements with various characteristics. It is possible to reduce the load on the disposal site by separating them according to those characteristics and appropriately dealing with them. In this project, we are working to shorten the life span of long-lived fission products (LLFP). When this technology is realized, high-level radioactive wastes will become new radioactive wastes with low radioactivity. As a result of investigation of disposal concept of new radioactive waste, it turned out that intermediate-depth disposal currently considered for low level radioactive waste may be suitable. Intermediate-depth disposal is a method of small-scale disposal in shallow locations as compared to geological disposal for conventional high-level radioactive waste. We conducted a safety assessment when this disposal is applied to new radioactive wastes, and found that it is possible to safely dispose of for the four LLFPs addressed by this project.

Journal Articles

Nitride fuel cycle, 2; R&D for minor actinides transmutation

Takano, Masahide

Wagakuni Shorai Sedai No Enerugi O Ninau Kakunenryo Saikuru; Datsu Tanso Shakai No Enerugi Anzen Hosho; NSA/Commentaries, No.24, p.163 - 167, 2019/03

This article summarizes R&D status of the nitride fuel cycle for minor actinides (MA) transmutation. Status of nitride fuel fabrication, material properties and fuel performance code, pyrochemical reprocessing, and nitrogen-15 enrichment are described.

Journal Articles

Measurements of gamma-ray emission probabilities in the decay of americium-244g

Nakamura, Shoji; Terada, Kazushi*; Kimura, Atsushi; Nakao, Taro*; Iwamoto, Osamu; Harada, Hideo; Uehara, Akihiro*; Takamiya, Koichi*; Fujii, Toshiyuki*

Journal of Nuclear Science and Technology, 56(1), p.123 - 129, 2019/01

 Times Cited Count:1 Percentile:56.06(Nuclear Science & Technology)

Accurate data of $$gamma$$-ray emission probabilities are frequently needed when one quantitatively determines the amount of isotope by $$gamma$$-ray measurements or obtains neutron capture cross-sections using them. Americium-243, one of the most important minor actinides, produces $$^{244}$$Am after neutron capture. The 744-keV $$gamma$$-ray decaying from the ground state of $$^{244}$$Am has a relatively large $$gamma$$-ray emission probability c.a. 66%, however, its uncertainty is as large as 29%. The uncertainty of the $$gamma$$-ray emission probability leads to a major factor of the systematic uncertainty on determining an amount of isotope, and therefore the $$gamma$$-ray emission probability was measured by using an activation method and an examined level structure of $$^{244}$$Cm. In this study, the emission probability of 744-keV $$gamma$$ ray was derived as 66.5$$pm$$1.1%, and its uncertainty was improved from 29% to 2%.

Journal Articles

Evaluation of mean time between accidental interruptions for accelerator klystron systems based on the reliability engineering method

Takei, Hayanori; Furukawa, Kazuro*; Yano, Yoshiharu*; Ogawa, Yujiro*

Journal of Nuclear Science and Technology, 55(9), p.996 - 1008, 2018/09

 Times Cited Count:0 Percentile:100(Nuclear Science & Technology)

Experiences with existing high-power proton accelerators indicate that frequent beam trips are inevitable. One of the reasons for such frequent beam trips is the accidental interruption to protect accelerators against fatal failures. Generally, the failure frequency for the general machinery can be evaluated based on a reliability database for its components. On the other hand, the beam-trip frequency for the accidental interruption was not evaluated based on the reliability database because it has not yet been established. A principal reason for the lack of this reliability database is the inconsistency of data collection and analysis methods among laboratories. For example, there are at least three methods to estimate Mean Time Between accidental Interruptions (MTBI) for klystron systems. In the present study, the MTBI of the klystron systems of an electron/positron injector linac at the High Energy Accelerator Research Organization (KEK) was evaluated based on the reliability engineering method, in order to build the reliability database using the unified data collection and analysis method. As the result, the mean values of the MTBI by the traditional three methods were evaluated as 30.9, 32.0, and 50.4 hours. On the other hand, that by the reliability engineering method was evaluated as 57.3 hours, i.e., more than 1.14 times of the traditional results. Although these results are obviously different from traditional results, it appears that the present estimation based on the reliability engineering method is suitable for the MTBI of accelerator components as typified by the klystron system.

Journal Articles

Study on heterogeneous minor actinide loading fast reactor core concepts with improved safety

Ohgama, Kazuya; Oki, Shigeo; Kitada, Takanori*; Takeda, Toshikazu*

Proceedings of 21st Pacific Basin Nuclear Conference (PBNC 2018) (USB Flash Drive), p.942 - 947, 2018/09

Journal Articles

Target test facility for ADS and cross-section experiment in J-PARC

Meigo, Shinichiro; Iwamoto, Hiroki; Matsuda, Hiroki; Takei, Hayanori

Journal of Physics; Conference Series, 1021(1), p.012072_1 - 012072_4, 2018/06

 Times Cited Count:0 Percentile:100

no abstracts in English

Journal Articles

Conceptual design study of beam window for accelerator-driven system with subcriticality adjustment rod

Sugawara, Takanori; Eguchi, Yuta; Obayashi, Hironari; Iwamoto, Hiroki; Tsujimoto, Kazufumi

Nuclear Engineering and Design, 331, p.11 - 23, 2018/05

 Times Cited Count:2 Percentile:53.66(Nuclear Science & Technology)

This study aims to perform the coupled analysis for the feasible beam window concept. To mitigate the design condition, namely to reduce the necessary proton beam current, subcriticality adjustment rod (SAR) was installed to the ADS core. The burnup analysis was performed for the ADS core with SAR and the results indicated that the maximum proton beam current during the burnup cycle was reduced from 20 to 13.5 mA. Based on the burnup analysis result, the coupled analysis; particle transport, thermal hydraulics and structural analyses, was performed. As the final result, the most robust beam window design; the hemisphere shape, the outer radius = 235 mm, the thickness at the top of the beam window = 3.5 mm and the factor of safety for the buckling = 9.0, was presented. The buckling pressure was 2.2 times larger than the previous one and more feasible beam window concept was presented through this study.

Journal Articles

Design of LBE spallation target for ADS Target Test Facility (TEF-T) in J-PARC

Saito, Shigeru; Obayashi, Hironari; Wan, T.; Okubo, Nariaki; Sugawara, Takanori; Endo, Shinya; Sasa, Toshinobu

Proceedings of 13th International Topical Meeting on Nuclear Applications of Accelerators (AccApp '17) (Internet), p.448 - 457, 2018/05

JAEA proposes transmutation of minor actinides by accelerator-driven systems (ADS). To obtain the data for ADS design, JAEA plans to construct the ADS Target Test Facility (TEF-T) within the framework of the J-PARC project. In TEF-T, a 250 kW proton-beam-driven LBE (Lead-Bismuth Eutectic) spallation target will be installed to prepare an irradiation database for candidate ADS structural materials. Design activities of the LBE target and target trolley have been progressed. Conceptual design of hot-cells for LBE target loop maintenance and PIE (Post Irradiation Examination) of irradiated samples have been finished. Two LBE loops were manufactured. One is a loop for TEF-T target mock-up and the other is that for collection of material corrosion characteristics in flowing LBE. Oxygen potential control systems for LBE flow have been also developed. Remote handling tests for the target exchange are underway. In this paper, current activities and studies to realize TEF-T will be presented.

Journal Articles

Cross section measurement in J-PARC for neutronics of the ADS

Meigo, Shinichiro; Matsuda, Hiroki; Iwamoto, Hiroki

Proceedings of 13th International Topical Meeting on Nuclear Applications of Accelerators (AccApp '17) (Internet), p.396 - 402, 2018/05

no abstracts in English

Journal Articles

Beam extraction by the laser charge exchange method using the 3-MeV LINAC in J-PARC

Takei, Hayanori; Hirano, Koichiro; Tsutsumi, Kazuyoshi; Meigo, Shinichiro

Plasma and Fusion Research (Internet), 13(Sp.1), p.2406012_1 - 2406012_6, 2018/03

The Japan Proton Accelerator Research Complex (J-PARC) has a plan to build the Transmutation Physics Experimental Facility (TEF-P), in which a 400-MeV negative proton (H$$^{-}$$) beam will be delivered from the J-PARC linac. Since the TEF-P requires a stable proton beam with a power of less than 10 W, a stable and meticulous beam extraction method is required to extract a small amount of the proton beam from the high power beam using 250 kW. To fulfil this requirement, the Laser Charge Exchange (LCE) method has been developed. To demonstrate the charge exchange of the H$$^{-}$$, a preliminary LCE experiment was conducted using a linac with energy of 3 MeV in J-PARC. As a result of the experiment, a charge-exchanged H$$^{+}$$ beam with a power of about 8 W equivalent and an accuracy of about 2% was obtained under the J-PARC linac beam condition.

Journal Articles

Beam extraction by the laser charge exchange method using the 3-MeV linac in J-PARC

Takei, Hayanori; Hirano, Koichiro; Meigo, Shinichiro; Tsutsumi, Kazuyoshi*

Proceedings of 6th International Beam Instrumentation Conference (IBIC 2017) (Internet), p.435 - 439, 2018/03

The Japan Proton Accelerator Research Complex (J-PARC) has a plan to build the Transmutation Physics Experimental Facility (TEF-P), in which a 400-MeV negative proton (H$$^{-}$$) beam will be delivered from the J-PARC linac. Since the TEF-P requires a stable proton beam with a power of less than 10 W, a stable and meticulous beam extraction method is required to extract a small amount of the proton beam from the high power beam using 250 kW. To fulfil this requirement, the Laser Charge Exchange (LCE) method has been developed. To demonstrate the charge exchange of the H$$^{-}$$, a preliminary LCE experiment was conducted using a linac with energy of 3 MeV in J-PARC. As a result of the experiment, a charge-exchanged H$$^{+}$$ beam with a power of about 8 W equivalent and an accuracy of about 2% was obtained under the J-PARC linac beam condition.

Journal Articles

Method to reduce long-lived fission products by nuclear transmutations with fast spectrum reactors

Chiba, Satoshi*; Wakabayashi, Toshio*; Tachi, Yoshiaki; Takaki, Naoyuki*; Terashima, Atsunori*; Okumura, Shin*; Yoshida, Tadashi*

Scientific Reports (Internet), 7(1), p.13961_1 - 13961_10, 2017/10

 Times Cited Count:9 Percentile:12.6(Multidisciplinary Sciences)

Transmutation of long-lived fission products (LLFPs: $$^{79}$$Se, $$^{93}$$Zr, $$^{99}$$Tc, $$^{107}$$Pd, $$^{129}$$I, and $$^{135}$$Cs) into short-lived or non-radioactive nuclides by fast neutron spectrum reactors without isotope separation has been proposed as a solution to the problem of radioactive wastes disposal. Despite investigation of many methods, such transmutation remains technologically difficult. To establish an effective and efficient transmutation system, we propose a novel neutron moderator material, yttrium deuteride (YD$$_{2}$$), to soften the neutron spectrum leaking from the reactor core. Neutron energy spectra and effective half-lives of LLFPs, transmutation rates, and support ratios were evaluated with the continuous-energy Monte Carlo code MVP-II/MVP-BURN and the JENDL-4.0 cross section library. With the YD$$_{2}$$ moderator in the radial blanket and shield regions, effective half-lives drastically decreased from 10$$^{6}$$ to 10$$^{2}$$ years and the support ratios reached 1.0 for all six LLFPs. This successful development and implementation of a transmutation system for LLFPs without isotope separation contribute to developing a self-consuming cycle of LLFPs using fast spectrum reactors to reduce radioactive waste.

Journal Articles

Measurement of aluminum activation cross section and gas production cross section for 0.4 and 3-GeV protons

Meigo, Shinichiro; Nishikawa, Masaaki; Iwamoto, Hiroki; Matsuda, Hiroki

EPJ Web of Conferences, 146, p.11039_1 - 11039_4, 2017/09

 Times Cited Count:0 Percentile:100

no abstracts in English

Journal Articles

Research and development in Japan Atomic Energy Agency

Tsujimoto, Kazufumi

Enerugi Rebyu, 37(9), p.11 - 14, 2017/08

no abstracts in English

Journal Articles

Present status of the laser charge exchange test using the 3-MeV linac in J-PARC

Takei, Hayanori; Chishiro, Etsuji; Hirano, Koichiro; Kondo, Yasuhiro; Meigo, Shinichiro; Miura, Akihiko; Morishita, Takatoshi; Oguri, Hidetomo; Tsutsumi, Kazuyoshi

Proceedings of 5th International Beam Instrumentation Conference (IBIC 2016) (Internet), p.736 - 739, 2017/03

The Accelerator-driven System (ADS) is one of the candidates for transmuting long-lived nuclides, such as minor actinide (MA), produced by nuclear reactors. For efficient transmutation of the MA, a precise pre-diction of neutronics of ADS is required. In order to obtain the neutronics data for the ADS, the Japan Pro-ton Accelerator Research Complex (J-PARC) has a plan to build the Transmutation Physics Experimental Facility (TEF-P), in which a 400-MeV negative proton (H$$^{-}$$) beam will be delivered from the J-PARC linac. Since the TEF-P requires a stable proton beam with a power of less than 10W, a stable and meticulous beam extraction method is required to extract a small amount of the proton beam from the high power beam using 250kW. To fulfil this requirement, the Laser Charge Exchange (LCE) method has been developed. The LCE strips the electron of the H$$^{-}$$ beam and neutral protons will separate at the bending magnet in the proton beam transport. To demonstrate the charge exchange of the H$$^{-}$$, a preliminary LCE experiment was conducted using a linac with energy of 3MeV in J-PARC. As a result of the experiment, a charge-exchanged H$$^{+}$$ beam with a power of about 5W equivalent was obtained under the J-PARC linac beam condition, and this value almost satisfied the power requirement of the proton beam for the TEF-P.

158 (Records 1-20 displayed on this page)