R&D on Accelerator Driven Nuclear Transmutation System (ADS) at J-PARC, 1; Accelerator Driven Nuclear Transmutation System (ADS)

Maekawa, Fujio

Purazuma, Kaku Yugo Gakkai-Shi, 98(5), p.201 - 205, 2022/05

The nuclear transmutation technology is a powerful solution to the "nuclear waste" problem that accompanies nuclear power generation. The Accelerator Driven System (ADS), which combines a high-intensity accelerator and a subcritical core, is a promising tool for nuclear transmutation. In this paper, we will explain the significance and principle of nuclear transmutation by ADS, design examples of ADS, partitioning and transmutation technology and its effects, required performance of high-intensity accelerators, overseas trends, etc.

Critical mass evaluation of minor actinides in aqueous solution; Data for criticality safety assessment of separation process

Morita, Yasuji; Fukushima, Masahiro; Kashima, Takao*; Tsubata, Yasuhiro

JAEA-Data/Code 2020-013, 38 Pages, 2020/09

JAEA-Data-Code-2020-013.pdf:1.94MB

Critical Masses of Cm, Am and the mixture were calculated in metal-water mixtures with water reflector as a basic data for criticality safety assessment of minor actinide separation process. In the mixture of Cm-244 and Cm-245, higher ratio of Cm-245 gives smaller critical mass, but the amount of Cm-245 in the critical mass can be obtained by concentration of Cm-245 in the Cm mixture without depending on the Cm-245 ratio. Critical mass of Cm isotope mixture with 30% Cm-245 was smaller than that of Pu isotope mixture in the practical reprocessing (71% Pu-239 + 17% Pu-240 + 12% Pu-241). When Cm is separated from other element including Am and the solution is concentrated, measure for the critical accident has to be taken. Critical mass of Am-242m is smaller than that of Cm-245, but the ratio of Am-242m in the Am contained in practical spent fuel is small enough, about several percent, and therefore the critical accident by Am does not have to be considered. That by the mixture of Am and Cm does not either.

Highly practical and simple ligand for separation of Am(III) and Eu(III) from highly acidic media

Suzuki, Hideya; Tsubata, Yasuhiro; Kurosawa, Tatsuya; Shibata, Mitsunobu; Kawasaki, Tomohiro; Urabe, Shunichi*; Matsumura, Tatsuro

Analytical Sciences, 32(4), p.477 - 479, 2016/04

https://doi.org/10.2116/analsci.32.477

An impeccable, high-performance new reagent called alkyl diamide amine (ADAAM) was examined from the viewpoint of mutual separation of Am(III) and Eu(III). ADAAM has three donor atoms, one soft N-donor atom and two hard O-donor atoms, in the central frame. The combination of soft and hard atoms affords a tridentate donor set of atoms that ensures remarkable extractability and selectivity of Am(III) and Eu(III) in highly acidic media.

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.

Parametric survey on possible impact of partitioning and transmutation of high-level radioactive waste

Oigawa, Hiroyuki; Yokoo, Takeshi*; Nishihara, Kenji; Morita, Yasuji; Ikeda, Takao*; Takaki, Naoyuki*

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

The benefit of implementing Partitioning and Transmutation (P&T) of high-level wastes was parametrically surveyed. The possible reduction of the geological repository area was estimated. By recycling minor actinides (MA), the repository area required for unit spent fuel was reduced significantly in the case of MOX-LWR. This effect was caused by removal of Am which is a long-term heat source. By partitioning the fission products, in addition to MA recycling, further 70-80% reduction from the MA-recovery case can be expected for both UO and MOX. This significant reduction was independent of the cooling time before the partitioning process.

Research and development on partitioning in JAERI; Review of the research activities until the development of 4-group partitioning process

Morita, Yasuji; Kubota, Masumitsu*

JAERI-Review 2005-041, 35 Pages, 2005/09

JAERI-Review-2005-041.pdf:2.24MB

Research and development on Partitioning in JAERI are reviewed in the present report from the beginning to the development of the 4-Group Partitioning Process and its test with real high-level liquid waste (HLLW). In the 3-Group Partitioning Process established in around 1980, elements in HLLW are separated into 3 groups of transuranium element group, Sr-Cs group and the other element group. The 4-Group Partitioning Process subsequently developed contains the separation of Tc-platinum group metals additionally. The process was tested to demonstrate its performance with real concentrated HLLW. Until then, various separation methods for various elements were studied and selection and optimization of the separation methods were carried out to establish the process. Review of the experience, findings and results is very important and valuable for future study on partitioning. The present report is prepared from this point of view.

Elemental separation simulation in the ARTIST process; Separation simulation of counter-current extractor by commercial software

Yamaguchi, Isoo*; Suzuki, Shinichi; Sasaki, Yuji; Yamagishi, Isao; Matsumura, Tatsuro; Kimura, Takaumi

JAERI-Tech 2005-037, 56 Pages, 2005/07

JAERI-Tech-2005-037.pdf:2.31MB

For the development of the reprocessing of spent nuclear fuels, the solvent extraction using the mixer-settler equipment is greatly available. This method has the advantages of the treatment of the large mass of materials and continuous operations. In case of the application of the mixer-settler devise, the precise calculation using the distribution ratio of metals in order to determine the metal concentration at each stage is indispensable. This calculation is performed in the development of ARTIST process. The metal concentration in each stage of ARTIST process is calculated by the simulation using excel software equipped with counter-current equations. This method is not taken into consideration of the change of acid concentration, therefore, we developed the new method to calculate the metal concentration even after acidity change. This method can calculate not only the metal concentration at each extraction step but also at each stage of mixer-settler. Using this calculation, we evaluated the optimum condition of solvent extraction in ARTIST process.

The Accelerator driven system strategy in Japan

Kurata, Yuji; Takizuka, Takakazu; Osugi, Toshitaka; Takano, Hideki

Journal of Nuclear Materials, 301(1), p.1 - 7, 2002/02

https://doi.org/10.1016/S0022-3115(01)00731-0

no abstracts in English

ARTIST process; A Novel chemical process for treatment of spent nuclear fuel

Tachimori, Shoichi

JAERI-Research 2001-048, 23 Pages, 2001/10

JAERI-Research-2001-048.pdf:1.88MB

A new chemical process, ARTIST process, is proposed for the treatment of spent nuclear fuel. The main concept of the ARTIST process is to recover and stock all actinides (Ans) in two groups, uranium (U) and a mixture of transuranics (TRU), to preserve their resource value and to dispose solely fission products (FPs). The process composed of two main steps, an U exclusive isolation and a total recovery of TRU; which copes with the nuclear non-proliferation measures, and additionally Pu separation process and soft N-donor process if requested, and optionally processes for separation of long-lived FPs. These An products: U-product and TRU-product, are to be solidified by calcination and allowed to the interim stockpile for future utilization. These separations are achieved by use of amidic extractants in accord with the CHON principle. The technical feasibility of the ARTIST process was explained by the performance of both the branched-alkyl monoamides the diglycolic amide (TODGA) in thorough extraction of all TRU by tridentate fashon.

A Review on studies of the transport and the form of radionuclides in the fluvial environment

Matsunaga, Takeshi

JAERI-Review 2001-018, 121 Pages, 2001/06

JAERI-Review-2001-018.pdf:5.95MB

The present report reviews a series of studies conducted in JAERI which have dealt with the behavior of atmospherically-derived radionuclides in a fluvial environment. The studies cited here firstly include investigations of the evaluation of the transport rate of the atmospherically-derived 137Cs, 210Pb and 7Be from the ground via a river to the downstream areas where the affected water is consumed. The studies validated i) the importance of suspended particulate materials in the fluvial discharge of those radionuclides, and ii) a methodology to estimate the discharge of those radionuclides. Secondly, studies in rivers and lakes in the vicinity of the Chernobyl Nuclear Power Plant revealed the role of natural dissolved organics in affecting the dissolution and transport of 239,240Pu, 241Am through complexation to form soluble species with the aid of a chemical equilibrium model The same sort of a model was also applied successfully for the behavior of iron and manganese (hydr)oxides in river recharged aquifers which could bear riverborne radionuclides.