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Aihara, Haruka; Kitawaki, Shinichi; Nomura, Kazunori; Taguchi, Katsuya
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.1076 - 1083, 2015/09
Sasaki, Yuji; Tsubata, Yasuhiro; Shirasu, Noriko; Morita, Keisuke; Suzuki, Tomoya
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.1653 - 1656, 2015/09
The concept for the new partitioning method of high-level radioactive waste (HLW) by single-cycle extraction process has been investigated. This process is based on extraction of actinides (An) and fission products (FP), and mutual separation by reverse extraction. Solo extractant and several stripping reagents will be utilized in this process. The extractant employed in this process is required to extract soft (platinum metals), hard acid metals(An), and oxonium anions (Mo, Tc) simultaneously. NTAamide is one of the candidate extractants. After extraction of An and FP by NTAamide(C8), the mutual separation among these metals by reverse extraction will be followed using the suitable water-miscible reagents. The extraction of An and FP, and the masking effect by some water-miscible reagents has been studied.
Sugawara, Takanori; Nishihara, Kenji; Takei, Hayanori; Iwamoto, Hiroki; Oizumi, Akito; Sasa, Toshinobu; Tsujimoto, Kazufumi
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.648 - 656, 2015/09
The JAEA has investigated an accelerator-driven system (ADS) to transmute minor actinides which will be partitioned from the high level waste. There are various inherent issues for the research and development on the ADS. This study introduces the current two activities to get a feasible and reliable ADS concept. For the feasibility, the beam window design is one of the most important issues. To mitigate the design condition of the beam window, namely to reduce the proton beam current, the subcritical core concepts with subcriticality adjustment mechanism were investigated. As the result, the proton beam current reduced from 20mA to 10mA by the installation of the control rods. For the reliability, the two accelerators concept was proposed and the beam trip frequency was estimated by the J-PARC LINAC data and Monte-Carlo method. Through these investigations, it was confirmed that the two accelerators concept was useful to realize reliable accelerator operation for the ADS.
-dialkylamides as extractants for U and Pu by continuous counter-current extractorsBan, Yasutoshi; Hotoku, Shinobu; Tsubata, Yasuhiro; Tsutsui, Nao; Matsumura, Tatsuro
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.1147 - 1152, 2015/09
Extraction properties of -di(2-ethylhexyl)-2,2-dimethylpropanamide (DEHDMPA), -di(2-ethylhexyl)butanamide (DEHBA), and some of their degradation products for the metal elements Zr, Mo, Ru, Rh, and Pd were studied using a single-stage batch method, and the results showed that the degradation products barely extracted these metal elements. Furthermore, separation performance of DEHDMPA and DEHBA for U and Pu in a continuous counter-current process was evaluated using a calculation code, and it was confirmed that the calculated values of U concentration in the U fraction and U and Pu concentrations in the U-Pu fraction were similar to those measured experimentally. These results supported the applicability of DEHDMPA and DEHBA as extractants for separation processes and the validity of the calculation code for estimating the separation performance of the process.
,-dialkylamides-nitric acid systemsTsutsui, Nao; Ban, Yasutoshi; Hakamatsuka, Yasuyuki; Urabe, Shunichi; Matsumura, Tatsuro
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.1153 - 1157, 2015/09
,-Dialkylamides are promising alternative extractants to tri-
-butyl phosphate in the reprocessing of spent nuclear fuels, but the two-phase separation between their organic and aqueous phases has not been evaluated quantitatively. ,-Di(2-ethylhexyl)-2,2-dimethylpropanamide (DEHDMPA) in -dodecane were agitated with uranyl nitrate-containing nitric acid, and their turbidities and their uranium distribution ratios were measured with respect to the time for the quantitative evaluation. Increasing DEHDMPA, uranium, and nitric acid concentrations enhanced turbidities. Although turbidities decreased with respect to the time, uranium distribution ratios slightly changed, indicating the observed turbidities did not affect these uranium distribution ratios significantly. Therefore, DEHDMPA may act as suitable extractant for uranium in nitric acid from two-phase separation viewpoint, and turbidity may be an indicator for extractant performance evaluation.
-trimethylglycine to Ru(III), Rh(III) and Pd(II) for developing separation techniques from high-level liquid wasteSuzuki, Tomoya; Shimazaki, Shoma*; Morita, Keisuke; Sasaki, Yuji; Ozawa, Masaki*; Matsumura, Tatsuro
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.1539 - 1543, 2015/09
To understand the adsorption behaviors of ion-exchange resin bearing -trimethylglycine groups (AMP03), adsorption experiments using HNO
solutions containing Ru(III), Rh(III), and Pd(II) have been performed. AMP03 strongly adsorbed Pd(II), and Ru(III) and Rh(III) were moderately adsorbed. To control the adsorption abilities of AMP03 for the Ru(III), Rh(III) and Pd(II), adsorption experiments using sample solutions with added thiourea (TU), triethylamine (TEA), and betaine anhydrous were performed. The adsorption abilities for Ru(III) and Rh(III) greatly increased with the addition of TEA, whereas the ability to adsorb Pd(II) was not significantly affected. The addition of TU or betaine anhydrous remarkably decreased the adsorption ability for Pd(II), and contrastingly slight changes in the abilities to adsorb Ru and Rh were also observed. These results show that AMP03 has a significant potential for separation of platinoid elements from HNO solution.
Tsujimoto, Kazufumi; Sasa, Toshinobu; Maekawa, Fujio; Matsumura, Tatsuro; Hayashi, Hirokazu; Kurata, Masaki; Morita, Yasuji; Oigawa, Hiroyuki
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.657 - 663, 2015/09
To continue the utilization of the nuclear fission energy, the management of the high-level radioactive waste is one of the most important issues to be solved. Partitioning and Transmutation technology of HLW is expected to be effective to mitigate the burden of the HLW disposal by reducing the radiological toxicity and heat generation. The Japan Atomic Energy Agency (JAEA) has been conducting the research and development on accelerator-driven subcritical system (ADS) as a dedicated system for the transmutation of long-lived radioactive nuclides. This paper overviews the recent progress and future R&D plan of the study on the ADS and related fuel cycle technology in JAEA.
Takeda, Toshikazu*; Usami, Shin; Fujimura, Koji*; Takakuwa, Masayuki*
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.560 - 566, 2015/09
The Ministry of Education, Culture, Sports, Science and Technology in Japan has launched a national project entitled "technology development for the environmental burden reduction" in 2013. The present study is one of the studies adopted as the national project. The objective of the study is the efficient and safe transmutation and volume reduction of minor actinides with long-lived radioactivity and high decay heat contained in high level radioactive wastes by using sodium cooled fast reactors. We are developing MA transmutation core concepts which harmonize efficient MA transmutation with core safety. To accurately design the core concepts we have improved calculation methods for estimating the transmutation rate of individual MA nuclides, and estimating and reducing uncertainty of MA transmutation. The overview of the present project is first described. The method improvement is presented with numerical results for a minor-actinide transmutation fast reactor.
Nishihara, Kenji; Iwamura, Takamichi*; Akie, Hiroshi; Nakano, Yoshihiro; Van Rooijen, W.*; Shimazu, Yoichiro*
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.388 - 395, 2015/09
The present study focuses on transmutation of Pu and minor actinide in Japanese case without utilizing Pu as resource. Pu can be transmuted by two groups of technology: conventional ones without reprocessing of spent fuel from transmuter and advanced ones with reprocessing. Necessary number of transmuters, inventory reduction of actinide and impact on repository are revealed by nuclear material balance analysis. As a whole advanced technology performs better in transmutation efficiency, although required number of transmuters is larger.
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
Irisawa, Eriko; Seki, Masaharu*; Ueno, Fumiyoshi; Kato, Chiaki; Motooka, Takafumi; Abe, Hitoshi
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.1108 - 1112, 2015/09
Tachibana, Mitsuo; Murata, Masato; Tasaki, Tadayuki; Usui, Hideo; Kubota, Shintaro
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.1987 - 1996, 2015/09
230 various types of nuclear facilities were constructed in JAEA's R&D Institutes or Center until the establishment of the JAEA in 2005. The JAEA has efficiently and systematically decommissioned nuclear facilities that would no longer be required after the establishment of the JAEA. Decommissioning of nuclear facilities in each JAEA's R&D Institutes or Center was continued based on the second midterm plan of the JAEA from FY2010 to FY2014. Decommissioning of 2 nuclear facilities was completed during the second midterm. This report describes current status of decommissioning activities in the JAEA during the second midterm and outline of the decommissioning plan in the third midterm.
Takahatake, Yoko; Shibata, Atsuhiro; Nomura, Kazunori
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.2099 - 2104, 2015/09
Fujimura, Koji*; Oki, Shigeo; Takeda, Toshikazu*
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.592 - 598, 2015/09
Uchiyama, Gunzo; Tashiro, Shinsuke; Amano, Yuki; Abe, Hitoshi; Yamane, Yuichi; Yoshida, Kazuo; Ishikawa, Jun
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.1056 - 1063, 2015/09
The experimental study for source term data of radioactive materials has been conducted at a boiling accident of high active liquid waste (HALW) in reprocessing plants. In the study, three kinds of tests have been conducted including a cold small scale test, a cold engineering scale test and a hot small scale test. The following results were obtained: Ruthenium and Technetium were released into the gas phase in the form of both mist and gas under the boiling accident conditions of a simulated HALW. Non-volatile fission products (FPs) such as Nd and Cs were released into the gas phase in the form of mist. The release ratios of non-volatile FPs from a vessel of the simulated HALW were about 10
. The release ratios of actinide nuclides such as Am were almost the same as those of non-volatile FPs.
Oki, Shigeo
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.464 - 473, 2015/09
Yamagishi, Isao; Odakura, Makoto; Ichige, Yoshiaki; Kuroha, Mitsuhiko; Takano, Masahide; Akabori, Mitsuo; Yoshioka, Masahiro*
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.1113 - 1119, 2015/09
The characteristics of insoluble residues in fine suspension at the Rokkasho Reprocessing Plant were analyzed. The insoluble residues were washed with oxalic acid solution to dissolve zirconium molybdate residues. XRD profiles of unwashed residues showed the presence of a noble metal alloy, zirconium molybdate, and zirconia, but zirconium molybdate was not found after washing. More than 50% of the Sb-125 and Pu in thee residues was washed out as well. The noble metal alloy composed of Mo, Tc, Ru, Rh, and Pd occupied more than 90% of the total weight of 12 elements (Ca, Cr, Fe, Ni, Zr, Mo, Tc, Ru, Rh, Pd, Te, and U) found in the residues. In consideration of the chemical forms of 12 elements, the alloy-to-residue weight ratio was evaluated to be 64% and 78% with and without 18% of an unknown component, respectively.
Goto, Minoru; Demachi, Kazuyuki*; Ueta, Shohei; Nakano, Masaaki*; Honda, Masaki*; Tachibana, Yukio; Inaba, Yoshitomo; Aihara, Jun; Fukaya, Yuji; Tsuji, Nobumasa*; et al.
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.507 - 513, 2015/09
A concept of a plutonium burner HTGR named as Clean Burn, which has a high nuclear proliferation resistance, had been proposed by Japan Atomic Energy Agency. In addition to the high nuclear proliferation resistance, in order to enhance the safety, we propose to introduce PuO
-YSZ TRISO fuel with ZrC coating to the Clean Burn. In this study, we conduct fabrication tests aiming to establish the basic technologies for fabrication of PuO-YSZ TRISO fuel with ZrC coating. Additionally, we conduct a quantitative evaluation of the security for the safety, a design of the fuel and the reactor core, and a safety evaluation for the Clean Burn to confirm the feasibility. This study is conducted by The University of Tokyo, Japan Atomic Energy Agency, Fuji Electric Co., Ltd., and Nuclear Fuel Industries, Ltd. It was started in FY2014 and will be completed in FY2017, and the first year of the implementation was on schedule.
Sagayama, Yutaka
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no abstracts in English