Kofuji, Hirohide; Watanabe, So; Takeuchi, Masayuki; Suzuki, Hideya; Matsumura, Tatsuro; Shiwaku, Hideaki; Yaita, Tsuyoshi
Progress in Nuclear Science and Technology (Internet), 5, p.61 - 65, 2018/11
Haga, Yoshinori; Yamamura, Tomoo*
Nippon Genshiryoku Gakkai-Shi, 60(3), P. 181, 2018/03
no abstracts in English
Partitioning and Transmutation Technology Division, Nuclear Science and Engineering Center
JAEA-Technology 2017-033, 383 Pages, 2018/02
JAEA is pursuing research and development (R&D) on volume reduction and mitigation of degree of harmfulness of high-level radioactive waste. Construction of Transmutation Experimental Facility (TEF) is under planning as one of the second phase facilities in the Japan Proton Accelerator Complex (J-PARC) program to promote R&D on the transmutation technology with using accelerator driven systems (ADS). The TEF consists of two facilities: ADS Target Test Facility (TEF-T) and Transmutation Physics Experimental Facility (TEF-P). Development of spallation target technology and study on target materials are to be conducted in TEF-T with impinging a high intensity proton beam on a liquid lead-bismuth eutectic target. Whereas in TEF-P, by introducing a proton beam to minor actinide loaded cores, reactor physical properties of the cores are to be studied, and operation experiences of ADS are to be acquired. This report summarizes results of safety design for establishment permit of one of two TEF facilities, TEF-P.
Rai, D.*; Kitamura, Akira
Journal of Chemical Thermodynamics, 114, p.135 - 143, 2017/11
Isosaccharinic acid is a cellulose degradation product that can form in low-level nuclear waste repositories and is known to form strong complexes with many elements, including actinides, disposed of in these repositories. We (1) reviewed the available data for deprotonation and lactonisation constants of isosaccharinic acid, and the isosaccharinate binding constants for Ca, Fe(III), Th, U(IV), U(VI), Np(IV), Pu(IV), and Am(III), (2) summarized complexation constant values for predicting actinide behavior in geologic repositories in the presence of isosaccharinate, and (3) outlined additional studies to acquire reliable thermodynamic data where the available data are inadequate.
Suzuki, Hideya; Tsubata, Yasuhiro; Kurosawa, Tatsuya*; Sagawa, Hiroshi*; Matsumura, Tatsuro
Journal of Nuclear Science and Technology, 54(11), p.1163 - 1167, 2017/11
A highly practical diamide-type extractant, which is an alkyl diamide amine with 2-ethylhexyl alkyl chains (ADAAM(EH)), was investigated for mutual separation of Am(III) and Cm(III). ADAAM(EH) is a multidentate ligand with one soft N-donor atom and two hard O-donor atoms in its central frame. This tridentate arrangement of donor atoms provides selective binding to Am(III) compared to that with Cm(III) in highly acidic media, resulting in separation factors of up to 5.5. A continuous liquid-liquid extraction and stripping test was conducted using a multistage countercurrent mixer-settler extractor with ADAAM(EH) in n-dodecane. In this test, separation of Am(III) and Cm(III) was achieved with very high yield.
Sugawara, Takanori; Tsujimoto, Kazufumi
JAEA-Research 2017-011, 35 Pages, 2017/10
The construction of Transmutation Physics Experimental Facility (TEF-P) is planned in the J-PARC project. TEF-P is a critical assembly and it will treat minor actinide (MA) fuel in the experiment. The temperature when the air cooling for the TEF-P core would stop was estimated but there were no data to evaluate the soundness of the MA fuel pin. To set a tentative limit temperature for the TEF-P core, cladding tube burst experiment was performed. As the result, the cladding tube burst occurred at 660C as the severest case. Through these results and the estimation of creep rupture time, the tentative limit temperature for the TEF-P core was set to 600C.
Harada, Hideo; Iwamoto, Osamu; Iwamoto, Nobuyuki; Kimura, Atsushi; Terada, Kazushi; Nakao, Taro; Nakamura, Shoji; Mizuyama, Kazuhito; Igashira, Masayuki*; Katabuchi, Tatsuya*; et al.
EPJ Web of Conferences (Internet), 146, p.11001_1 - 11001_6, 2017/09
Miwa, Shuhei; Osaka, Masahiko
Journal of Nuclear Materials, 487, p.1 - 4, 2017/04
Oxidation and reduction behaviors of prototypic MgO-based inert matrix fuels (IMFs) containing PuO were experimentally investigated by means of thermogravimetry. The oxidation and reduction kinetics of the MgO-PuO specimen were determined. The oxidation and reduction rates of the MgO-PuO were found to be low compared with those of PuO. It is note that the changes in O/Pu ratios of MgO-PuO from stoichiometry were smaller than those of PuO at high oxygen partial pressure. From these results, it can be said that MgO matrix lower the oxygen supply and release of PuO, which is preferable as the minor actinides incineration devices, since the high oxygen potentials of minor actinide oxides can cause certain problems in terms of thermochemical aspects such as enlarged cladding inner-surface corrosion.
Sasaki, Shinji; Tanno, Takashi; Maeda, Koji
Proceedings of 54th Annual Meeting of Hot Laboratories and Remote Handling (HOTLAB 2017) (Internet), 6 Pages, 2017/00
During irradiation in a fast reactor, the microstructure change of the mixed oxide fuels and the changes of element distributions occur because of a radial temperature gradient. Therefore, it is important to study the irradiation behavior of MA-MOX for advancement of fast reactor fuels. In order to make detailed observations of microstructure and elemental analyses of MA-MOX, irradiated MA-MOX specimens were carried out PIE by using a FE-SEM equipped with WDX. Because fuel samples have high radio activities and emit alpha-particles, the instrument was modified. the instrument was installed in a lead shield box and the control unit was separately located outside the box. The microstructure changes were observed in irradiated MA-MOX specimen. The characteristic X-rays peaks were detected successfully. By measuring the intensities of characteristic X-rays, it was tried quantitative analysis of U, Pu, Am along radial direction of irradiated specimen.
Tazawa, Yujiro; Nishihara, Kenji; Sugawara, Takanori; Tsujimoto, Kazufumi; Sasa, Toshinobu; Eguchi, Yuta; Kikuchi, Masashi*; Inoue, Akira*
JAEA-Technology 2016-029, 52 Pages, 2016/12
Transmutation Physics Experimental Facility (TEF-P) planned in the J-PARC project uses minor actinide (MA) fuels in the experiments. These MA fuels are highly-radioactive, so the fuel handling equipment in TEF-P is necessary to be designed as remote-handling system. This report summarizes fabrication and test results of the testing equipment for fuel loading that is one of components of the testing equipment for remote-handling of MA fuels. The testing equipment which had a remote-handling system for fuel loading was fabricated. And the test in combination with the mock-up core was performed. Through the test, it was confirmed to load/take the dummy fuel pin to/from the mock-up core without failure. It was shown that the concept design of the fuel loading equipment of TEF-P was reasonable.
Watanabe, So; Nomura, Kazunori; Kitawaki, Shinichi; Shibata, Atsuhiro; Kofuji, Hirohide; Sano, Yuichi; Takeuchi, Masayuki
Procedia Chemistry, 21, p.101 - 108, 2016/12
Gochi, Jun*; Sumiyama, Akihiko*; Yamaguchi, Akira*; Motoyama, Gaku*; Kimura, Noriaki*; Yamamoto, Etsuji; Haga, Yoshinori; Onuki, Yoshichika
Physical Review B, 93(17), p.174514_1 - 174514_5, 2016/05
Takahashi, Yoshiyuki*; Hori, Junichi*; Sano, Tadafumi*; Yagi, Takahiro*; Yashima, Hiroshi*; Pyeon, C. H.*; Nakamura, Shoji; Harada, Hideo
Proceedings of International Conference on the Physics of Reactors; Unifying Theory and Experiments in the 21st Century (PHYSOR 2016) (USB Flash Drive), p.645 - 652, 2016/05
For the reduction of radioactive toxicities, feasibility study of nuclear transmutation of minor actinides (MAs) and long-lived fission products (LLFPs) by utilizing innovative nuclear reactor system (i.e. fast breeder reactors and accelerator-driven systems) has been actively conducted. To design these nuclear reactor systems, the accurate nuclear data are required. Therefore, to obtain more accurate nuclear data, the project entitled as "Research and development for Accuracy Improvement of neutron nuclear data on Minor ACtinides(AIMAC)" has been started as one of the "Innovative Nuclear Research and Development Program". In a part of this project, the nuclear data of MAs are verified in the variable neutron spectra field at Kyoto University Research Reactor Institute-LINear ACcelerator (KURRI-LINAC) and Kyoto University Critical Assembly (KUCA). And the differential TOF data is cross-checked with an integral data for the validation of Np, Am, and Am. In this summary, the results of reaction rate of neutron capture cross section of Np are reported as an example in the study.
Nishihara, Kenji; Tazawa, Yujiro; Inoue, Akira; Sugawara, Takanori; Tsujimoto, Kazufumi; Sasa, Toshinobu; Obayashi, Hironari; Yamaguchi, Kazushi; Kikuchi, Masashi*
JAEA-Technology 2015-051, 47 Pages, 2016/03
This report summarizes fabrication and test results of a testing equipment for fuel cooling that is a component of the testing equipment for remote-handling of highly-radioactive MA fuels in the transmutation physics experimental facility (TEF-P) planned in the J-PARC. Evaluation formula of pressure drop and temperature increase used in the design of TEF-P was validated by the test, and, feasibility of cooling concept was confirmed.
JAEA-Review 2015-042, 213 Pages, 2016/03
The first topical meeting on Asian Network for Accelerator-driven System (ADS) and Nuclear Transmutation Technology (NTT) was held on 26-27 October 2015 at the J-PARC Center, Japan Atomic Energy Agency, Japan. The meeting was an optional one in-between the regular meeting, which will be held in every second year. Instead of the regular meeting, which covers all research fields for ADS and NTT, such as accelerator, spallation target, subcritical reactor, fuel, and material, this topical meeting is focused on the specific topic to make technical discussions more deeply. In this meeting, the technology for lead-bismuth eutectic alloy was selected as one of the hot issues in the world and had deep discussions with specialists in Asian countries. Through the discussion, the importance of cooperation in Again region is recognized to solve the issues for application of LBE. This report summarizes all presentation materials discussed in the meeting.
Fukaya, Yuji; Goto, Minoru; Nishihara, Tetsuo
JAEA-Research 2015-023, 44 Pages, 2016/02
A study on innovative High Temperature Gas-cooled Reactor (HTGR) to reduce generation of potential radiotoxicity had been performed. Unlike the Fast Breeder Reactor (FBR) and Accelerated Driven System (ADS), which can confine radioactive nuclides into its fuel cycle as multi-recycling and transmute, in this study we attempt to reduce the generation of the radiotoxicity itself by preventing the generation of Pu and MA, which is generated with the energy generation. In this context, we proposed the innovative HTGR that employs the Highly Enriched Uranium (HEU) fuel by removing U : source of the Pu and MA. However, there are the problems of fuel integrity, nuclear proliferation, nuclear self-regulation characteristics, and economy of electricity generation which are caused by employing HEU. For these problems, we investigated and proposed the solutions. Especially for the nuclear self-regulation characteristics, which were improved by adding Er, the optimized nuclear design was quantitatively determined and elucidated by the Bondarenko approach. As a result, it was confirmed that the proposed reactor can solves these problem for employing HEU fuel and the high specification and economy as same as those of standard HTGR fueled uranium.
Hayashi, Hirokazu; Nishi, Tsuyoshi*; Sato, Takumi; Kurata, Masaki
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.1811 - 1817, 2015/09
Transmutation of long-lived radioactive nuclides including minor actinides (MA: Np, Am, Cm) has been studied in Japan Atomic Energy Agency (JAEA). Accelerator-driven system (ADS) is regarded as one of the powerful tools for transmutation of MA under the double strata fuel cycle concept. Uranium-free nitride fuel was chosen as the first candidate fuel for MA transmutation using ADS. To improve the transmutation ratio of MA, reprocessing of spent fuel and reusing MA recovered from the spent fuels is necessary. Our target is to transmute 99% of MA arisen from commercial power reactor fuel cycle, with which the period until the radiotoxicity drops below that of natural uranium can be shorten from about 5000 years to about 300 years. A pyrochemical process has been proposed as the first candidate for reprocessing of the spent nitride fuel. This paper overviews the current status of the nitride fuel cycle technology. Our recent study on fuel fabrication, fuel property measurements, reprocessing of spent fuel, development of the property database of MA nitride fuel, and fuel behavior simulation code are introduced. Our research and development (R&D) plan based on the roadmap of the development is also introduced.
Sugino, Kazuteru; Takeda, Toshikazu*
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.573 - 581, 2015/09
AAPPS Bulletin, 24(5), p.13 - 17, 2014/10
To reduce the burden of radiological nuclides contained in spent nuclear fuel, Partitioning-Transmutation (P-T) technology is noted as an option for nuclear waste management in the new national strategic energy policy. As for the system for waste transmutation, an accelerator-driven system is desirable as a dedicated transmutor. To perform basic studies for an accelerator-driven system, the Japan Atomic Energy Agency has promoted the design of the Transmutation Experimental Facility within the framework of the J-PARC project. A lead-bismuth spallation target, which is bombarded with 400 MeV - 250 kW protons, and a low-power subcritical reactor will be installed in the facility. Construction will start within a few years after the national review of P-T technology.
Matsumoto, Yuji*; Haga, Yoshinori; Tateiwa, Naoyuki; Aoki, Haruyoshi*; Kimura, Noriaki*; Matsuda, Tatsuma*; Yamamoto, Etsuji; Fisk, Z.; Yamagami, Hiroshi*
JPS Conference Proceedings (Internet), 3, p.011096_1 - 011096_5, 2014/06