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Nakahara, Masaumi; Watanabe, So; Aihara, Haruka; Takahatake, Yoko; Arai, Yoichi; Ogi, Hiromichi*; Nakamura, Masahiro; Shibata, Atsuhiro; Nomura, Kazunori
Proceedings of International Conference on Nuclear Fuel Cycle; Sustainable Energy Beyond the Pandemic (GLOBAL 2022) (Internet), 4 Pages, 2022/07
Various radioactive wastes have been generated from Chemical Processing Facility for basic research on advanced reactor fuel reprocessing, radioactive waste disposal, and nuclear fuel cycle technology. Many types of reagents have been used for the experiments, and some troublesome materials were produced in the course of experiments. The radioactive liquid wastes were treated for stable and safe storage using decomposition, solvent extraction, precipitation, and solidification methods. In this study, current status of harmless treatment for the radioactive liquid wastes would be reported.
Senzaki, Tatsuya; Arai, Yoichi; Yano, Kimihiko; Sato, Daisuke; Tada, Kohei; Ogi, Hiromichi*; Kawanobe, Takayuki*; Ono, Shimpei; Nakamura, Masahiro; Kitawaki, Shinichi; et al.
JAEA-Testing 2022-001, 28 Pages, 2022/05
JAEA-Testing-2022-001.pdf:2.33MB
In preparation for the decommissioning of Laboratory B of the Nuclear Fuel Cycle Engineering Laboratory, the nuclear fuel material that had been stored in the glove box for a long time was moved to the Chemical Processing Facility (CPF). This nuclear fuel material was stored with sealed by a polyvinyl chloride (PVC) bag in the storage. Since it was confirmed that the PVC bag swelled during storage, it seems that any gas was generated by radiolysis of the some components contained in the nuclear fuel material. In order to avoid breakage of the PVC bag and keep it safety for long time, we began the study on the stabilization treatment of the nuclear fuel material. First, in order to clarify the properties of nuclear fuel material, radioactivity analysis, component analysis, and thermal analysis were carried out. From the results of thermal analysis, the existence of organic matter was clarified. Then, ion exchange resin with similar thermal characteristics was selected and the thermal decomposition conditions were investigated. From the results of these analyzes and examinations, the conditions for thermal decomposition of the nuclear fuel material contained with organic matter was established. Performing a heat treatment of a small amount of nuclear fuel material in order to confirm the safety, after which the treatment amount was scaled up. It was confirmed by the weight change after the heat treatment that the nuclear fuel material contained with organic matter was completely decomposed.
-P column by neutron resonance absorption imagingMiyazaki, Yasunori; Watanabe, So; Nakamura, Masahiro; Shibata, Atsuhiro; Nomura, Kazunori; Kai, Tetsuya; Parker, J. D.*
JPS Conference Proceedings (Internet), 33, p.011073_1 - 011073_7, 2021/03
Neutron resonance absorption imaging was adapted to observe the Eu band adsorbed in the CMPO/SiO-P column for minor actinide recovery by extraction chromatography. Several wet columns were prepared by either light water or heavy water and compared with the dry column to evaluate the neutron transmission. The neutron transmission spectra showed that 45% was transmitted through the dry column while 20% and 40% were transmitted through the wet columns of light water and heavy water, respectively. The results indicated that heavy water is more applicable than light water to observe the Eu adsorption band in the CMPO/SiO-P column.
Arai, Yoichi; Watanabe, So; Ono, Shimpei; Nakamura, Masahiro; Shibata, Atsuhiro; Nakamura, Fumiya*; Arai, Tsuyoshi*; Seko, Noriaki*; Hoshina, Hiroyuki*; Hagura, Naoto*; et al.
International Journal of PIXE, 29(1&2), p.17 - 31, 2019/00
The spent PUREX solvent containing U and Pu is generated from the reprocessing process of spent nuclear fuel. The nuclear material removal is important for the safe storage or disposal of the spent solvent. Our previous study revealed that the adsorbent with the iminodiacetic acid (IDA) functional group is one of the most promising materials for designing the nuclear material recovery process. Accordingly, an IDA-type adsorbent was synthesized by using graft polymerization technology or a chemical reaction to improve the adsorption rate and capacity. The synthesized IDA-type adsorbent was characterized by micro particle-induced X-ray emission (PIXE) and extended X-ray absorption fine structure (EXAFS) analyses. The micro-PIXE analysis revealed that Zr was adsorbed on the whole synthesized adsorbents and quantified the microamount of adsorbed Zr. Moreover, EXAFS suggested that Zr in the aqueous solution and solvent can be trapped by the IDA group with different mechanisms.
Arai, Yoichi; Watanabe, So; Takahatake, Yoko; Nakamura, Masahiro; Nakajima, Yasuo
Proceedings of 2014 Nuclear Plant Chemistry Conference (NPC 2014) (USB Flash Drive), 8 Pages, 2014/10
no abstracts in English
Yano, Kimihiko; Nakahara, Masaumi; Nakamura, Masahiro; Shibata, Atsuhiro; Nomura, Kazunori; Nakamura, Kazuhito*; Tayama, Toshimitsu; Washiya, Tadahiro; Chikazawa, Takahiro*; Kikuchi, Toshiaki*; et al.
Proceedings of International Conference on Advanced Nuclear Fuel Cycle; Sustainable Options & Industrial Perspectives (Global 2009) (CD-ROM), p.143 - 150, 2009/09
Nakamura, Masahiro; Ozawa, Takayuki; Morihira, Masayuki; Kihara, Yoshiyuki
JAEA-Research 2006-028, 146 Pages, 2006/03
JAEA-Research-2006-028.pdf:37.95MB
The collaboration project concerning sphere-pac fuel among JNC (Japan Nuclear Cycle Development Institute, now Japan Atomic Energy Agency), Swiss PSI (Paul Scherrer Institut) and Dutch NRG (Nuclear Research and Consultancy Group) was performed from 1996 till 2005. The target of this project is comparative irradiation tests of sphere-pac fuel in the HFR (High Flux Reactor) in Petten in the Netherlands with pellet fuel and vipac fuel. Total 16 fuel segments (8 pins) containing 5%Np-MOX sphere-pac segments were irradiated. No fuel failure was occurred. Restructuring of sphere-pac fuel was quickly progressed in early stage of irradiation, and formation of the central hole was almost completed within 48 hours steady state irradiation. According to the results of the power-to-melt test, the power to melt linear heat rates were estimated as 60kW/m for the sphere-pac fuel and as 73kW/m for the pellet fuel under HFR irradiation conditions. Irradiation behaviors of the vipac fuel and Np-MOX sphere-pac fuel were basically similar to that of the MOX sphere-pac fuel. However, the central hole of the Np-MOX sphere-pac fuel was larger than that of MOX sphere-pac fuel in the restructuring test. It suggests that the thermal conductivity of Np-MOX fuel is smaller than that of MOX fuel.
Morihira, Masayuki; Hellwig, C.*; Bakker, J.*; Nakamura, Masahiro; Ozawa, Takayuki; Bart, G.*; Kihara, Yoshiyuki
Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10
Comparative irradiation tests of sphere-pac fuel (SPF) with pellet type fuel (PF) and vipac fuel (VPF) were performed in the HFR in the Netherlands in a framework of the collaboration project amog JNC, PSI and NRG. Three restructuring tests and a powet-to-melt test were performed in 2004 and 2005 to obtain rerestructuring data of SPF in the beginning of life as well PTM data. This paper focuses the result of irradiation tests and post irradiation examinations.
Morihira, Masayuki; Nakamura, Masahiro; Ozawa, Takayuki; Kihara, Yoshiyuki; Hellwig, C.*; Ingold, F.*; Bakker, K.*
JNC TY8400 2005-006, 320 Pages, 2005/08
JNC-TY8400-2005-006.pdf:18.0MB
The collaboration project concerning sphere-pac fuel (SPF) among JNC, PSI and NRG was performed from 1996 till 2005. Total sixteen fuel segments (eight pins) of three types of fuel were fabricated in PSI. Two SPF segments contained 5%Np in addition to 20%Pu-MOX. Other segments contained no Np. The fuel microsphere for SPF was fabricated by the internal gelation process. The trial to apply the internal gelation process to Np-MOX fabrication was successfully attained. The test pins were transported to Petten in the Netherlands in September 2003 and assembling of the sample holders was done. Three steady state irradiation tests and one power-to-melt test were performed in HFR. Two test pins (four segments) were irradiated every tests simultaneously. The former tests were performed mainly to obtain the restructuring data of SPF in the early beginning of irradiation. The later was done to evaluate PTM linear heat rate of SPF with the reference data for pellet fuel. The irradiation tests were performed in January to March 2004 and December 2004 to March 2005. Post irradiation examination was completed in August 2005. In this project the irradiation tests in HFR was doubtless main task but so many other works were also performed i.e. transfer of the technology concerning modeling and design of sphere-pac fuel from PSI to JNC, additional destructive PIE of IFA-550.11 fuel (a power ramp test of sphere-pac fuel segment irradiated in the Gösgen PWR), fabrication tests in PSI, etc. This report summarized the planning of the irradiation tests, fuel design, result of fabrication, irradiation, post irradiation examination and data analysis. SPF design codes, DIRAD-S, SIMPLE-S which was developed by implanting SPF models of PSI into the pellet design codes in JNC, were verified with the irradiation test data in this project to show good accuracy.
Nakamura, Masahiro
JNC TN8400 2004-007, 76 Pages, 2004/04
JNC-TN8400-2004-007.pdf:3.72MB
The low-decontaminated fuel, which contains significant amount of fission products from the beginning of the irradiation, is investigated as a fuel for the advanced fuel cycle. Comparison between the measured and the estimated thermal conductivity shows Klemens-Adeles formula is appropriate to the estimation of the thermal conductivity of the low-decontaminated fuel. The estimated thermal conductivity of the low contaminated fuel is smaller than that of UO2 fuel by 16% at 500degrees, and by 7% at 1500degrees in case of the fuel originated from dry reprocessing. And they are 10% and 4% in case of the low-decontaminated fuel originated from wet reprocessing.
Nakamura, Masahiro; Mizuno, Mineo*; Kosaka, Yuji*; Ogawa, Shinta*
JNC TJ8440 2002-003, 55 Pages, 2002/02
JNC-TJ8440-2002-003.pdf:13.04MB
no abstracts in English
; ; Pouchon, M. A.
Proceedings of Actinides 2001, 0 Pages, 2001/11
In the feasibility study of a FBRcycle system,alternative nuclear fuel designs are considered. The "sphere-pac" fuel design is one option, which consists of a spherical particle bed vibro-packed into the fuel pin cladding. The advantages of this concept would be a less-powder in fuel production and a lower mechanical interaction between fuel and cladding. JNC has developed a new fuel irradiation behavi
Pouchon, M. A.;
Proceedings of Actinides 2001, 0 Pages, 2001/11
As an alternative concept,a particle arrangement(sphere-pac or vibro-pac type)is considered as fuel-form for burning actinides. The fuel material is potentially MOX or an Inert Matrix like yttria stabilized zirconia. A weak point of particle fuel is its thermal conductivity at startup.Before sintering initiates the macroscopic structure of the sphere-pac decreases the energy transport. For a partial
Pouchon, M. A.; ;
Beikoku Seramikku Gakkai Dai-103-Kai Nenji Taikai, 0 Pages, 2000/00
None
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Journal of Physics; Condensed Matter, 10, p.11565 - 11570, 1998/00
Times Cited Count：3 Percentile：22.1(Physics, Condensed Matter)None
Nakamua, Masahiro*; Shibata, Keiichi
JAERI-Research 95-068, 51 Pages, 1995/10
JAERI-Research-95-068.pdf:1.38MB
no abstracts in English
Nakamura, Masahiro; Morihira, Masayuki; Kihara, Yoshiyuki; Sekine, Nobuyuki*; Hellwig, C.*; Bakker, K.*
no journal, ,
In the framework of collaboration among JNC (now JAEA), PSI and NRG called "he FUJI project" calculation results of a sphere-pac fuel design code, DIRAD-S were compared to the PIE results. DIRAD-S contains a thermal conductivity model of a particle bed, named SPACON, and mechanistic models for the necking calculation between particles. The calculation results had good agreement with the PIE results.
