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Morihira, Masayuki
JAEA-Research 2012-021, 25 Pages, 2012/08
JAEA-Research-2012-021.pdf:9.24MB
Cladding inner corrosion is one of the life control factors of FBR MOX fuels. Because excess oxygen during fission brings the corrosion, oxygen getter option was proposed and a feasibility study has been conducted. In the previous study, an option was proposed to locate getter titanium in the lower end of the upper axial blanket region of a fuel element. Also the titanium roll pellet method was proposed to reduce the smear density of the getter titanium to absorb the swelling during the oxidation. In this study, producibility of titanium roll pellets and their oxidation behavior were evaluated.
Morihira, Masayuki; Mizusako, Fumiki*; Tsuboi, Yasushi*
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 6 Pages, 2011/12
Cladding inner corrosion is one of the life controlling factors of FBR MOX fuels and it depends on the oxygen potential in a fuel element. Oxygen potential increases with extension of burn-up due to the cumulated excess oxygen during fission. The oxygen getter method is idea way to locate metal fragments in a fuel element as an excess oxygen absorber. Since almost nothing has been reported concerning the application of an oxygen getter in pellet type fuels, conceptual development of the oxygen getter for pellet type MOX fuel and a feasibility study were done. For getter material, titanium was mainly evaluated in this study except for compatibility tests carried out for titanium and zirconium. Concerning the location of getter material in a fuel element, the pellet-cladding gap and axial blanket region are potential options to avoid melting of titanium or obtaining a eutectic solution with MOX fuel. At the same time, an adequate temperature for oxidation as well as compatibilities with cladding material and fuel must be realized. Three options were proposed for titanium and their potentials were evaluated from this viewpoint. As a result, locating the titanium pellets in the upper axial blanket region of the fuel element was identified as the most promising option and it could provide the required low smear density titanium pellet.
Morihira, Masayuki
JAEA-Research 2011-018, 32 Pages, 2011/07
JAEA-Research-2011-018.pdf:2.73MB
In the FaCT project, high bundle peak burn-up to 250 GWd/t is targeted. Cladding inner corrosion is one of the life control factors of FBR MOX fuels. Because it increases with extension of burn-up, significant corrosion is expected in the high burn-up. Considering the excess oxygen during fission is the cause of corrosion, reduction of initial O/M ratio of MOX fuel pellets is one of the solutions. But it is not always easy to obtain low O/M ratio pellets especially in mass production. Oxygen getter option is an idea to coexistence of oxidizable metal fragments in a fuel element as an excess oxygen absorber. A feasibility study for oxygen getter options which was focused on pellet type MOX fuel was conducted. This report describes latest evaluation result for the loading options of oxygen getter materials and the oxidation behavior of the candidates such as Ti and Zr as well as their compatibilities with FMS cladding material and UO
.
Morihira, Masayuki; Segawa, Tomoomi
JAEA-Research 2007-085, 29 Pages, 2008/02
JAEA-Research-2007-085.pdf:2.88MB
The "FaCT project" is a program toward the commercialization of FBR cycle carried out in JAEA. High burn-up of 250 GWd/HMt at bundle peak is targeted in the project. To restrain the fuel cladding chemical interaction (FCCI) in a high burn-up, adoption of low O/M ratio pellets is chosen. Considering the difficulty of accurate oxygen potential control in a commercial scale electric furnace as well as the difficulty of keeping O/M ratio of sintered pellets under the high decay heat from the low decontaminated TRU MOX, it may be difficult to realize commercial mass production of low O/M ratio pellets. If so, excess oxygen released during irradiation should be absorbed by an oxygen getter not but in the matrix of low O/M ratio MOX pellets. Then MOX pellets with higher initial O/M ratio can be acceptable. In this research, a selection of oxygen getter candidates was carried out with the examination of their loading method in a cladding.
Tomita, Yutaka; Morihira, Masayuki; Tamaki, Yoshihisa*; Nishimura, Kazuhisa*; Shoji, Shuichi*; Kihara, Yoshiyuki; Kase, Takeshi; Koizumi, Tsutomu
JAEA-Research 2006-088, 95 Pages, 2007/01
JAEA-Research-2006-088.pdf:23.02MB
JAEA has developed sphere-pac fuels in the feasibility study on commercialized FBR cycle systems as one of the candidates for low decontamination TRU fuels. Optimization of the fabrication condition for coarse spheres, development of an improved external gelation process, and examination of peculiar problems for the low decontamination fuel were carried out in Phase II. The results are shown as follows. (1) Fabrication condition of coarse spheres was optimized. (2) Feasibility of the improved external gelation process was confirmed. (3) Rare earth elements did not bring any problem for the characteristic of spheres and fabrication condition. (4) Radiation resistant data of the feed solution was acquired. Results of tests show the feasibility of the external gelation process for the low decontamination TRU fuel microsphere fabrication.
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.
Tomita, Yutaka; Morihira, Masayuki; Kihara, Yoshiyuki; Tamaki, Yoshihisa*
Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 4 Pages, 2005/10
High economic competitiveness and low environmental impact are required for advanced FBR cycle systems. Sphere-pac fuel has been considered as promising fuel systems, due to its inherent advantage in remote operation, dustfree fuel fabrication process and cost reduction. Japan Nuclear Cycle Development Institute (JNC) has been investigated the external gelation process for sphere-pac fuel. In this report, the result of the sphere fabrication test by the external gelation process is reported.
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.
Morihira, Masayuki; Ozawa, Takayuki; ; Suzuki, Masahiro; Shigetome, Yoshiaki; Kihara, Yoshiyuki; Kono, Shusaku
JNC TN8400 2004-014, 193 Pages, 2004/07
JNC-TN8400-2004-014.pdf:24.52MB
The collaboration project concerning sphere-pac fuel among JNC, Swiss PSI (Paul Scherrer Institut) and Dutch NRG (Nuclear Research and Consultancy Group) is in progress.Final target of the project is comparative irradiation tests of Sphere-pac fuel in the HFR (High Flux Reactor) in Petten in the Netherlands with pellet type fuel and vipack fuel. Total 16 fuel segments (8 pins) of these three types of fuel are planned to be irradiated. Two sphere-pac fuel segments contain 5%Np in addition to 20%Pu-MOX. Other segments contain no Np. Fabrication of irradiation test pins was completed till May 2003 in PSI. After transportation of the fuel pins to Petten, two times of irradiation were performed in January to March in 2004 and now post irradiation tests are in progress. Later two irradiations will be done till the autumn in 2004.This report summarized the basic plan, fuel design, and fabrication of irradiation test pins concerning this collaboration project.
Sphere-Pac Fuels Irradiated with Pellet Type Fuels in G
sgen-PWR and HBWR -IFA-550.11 Irradiation Test-Morihira, Masayuki
JNC TY8400 2004-006, 64 Pages, 2004/06
JNC-TY8400-2004-006.pdf:68.01MB
Comparative irradiation tests between sphere-pac fuel (SPF) and pellet type fuel (PF) were performed in the frame work among PSI (Paul Scherrer Institut) in Switzerland, Siemens Ltd in Germany and Swiss KKG (Kernkraftwerk Gsgen).Those fuel pins were irradiated in Gsgen-PWR for four cycles up to 40 GWd/tU. One SPF and one PF segment were taken out from the one cycle irradiation pin and the three cycle pin respectively. Those four segments were cut and re-instrumented on-line pressure tranducers subsequently applied to the ramp test in the Halden-BWR. This report describes the PIE result of rod S04 (SPF) and N06 (PF) which were applied to the ramp test after the three cycle base irradiation. It bases on the PIE reports by IFE/Kjeller and analysis reports by PSI.
Kamimura, Katsuichiro; Yano, Soichiro; Kono, Shusaku; Kato, Masato; Morimoto, Kyoichi; Morihira, Masayuki; Kikuchi, Keiichi
PNC TN8410 97-067, 452 Pages, 1997/02
None
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.
Morihira, Masayuki
no journal, ,
no abstracts in English
Segawa, Tomoomi; Kato, Masato; Morimoto, Kyoichi; Kashimura, Motoaki; Morihira, Masayuki; Uno, Hiroki*; Tamura, Tetsuya*; Sunaoshi, Takeo*
no journal, ,
no abstracts in English
Morihira, Masayuki; Segawa, Tomoomi; Matsuyama, Shinichiro*; Yuda, Ryoichi*; Namekawa, Takashi
no journal, ,
Removal of excess oxygen in a MOX fuel element during the irradiation is required to attain a high burn up of FBR fuel because the increase of the oxygen potential in a fuel element during the irradiation accelerates FCCI. The oxygen getter method is an alternative to the low O/M ratio pellet option. Preliminary surveillance suggested Zr and Ti were most expecting candidates. In this study, the compatibility of these candidate materials with MOX, UO and FMS as well as their oxygen uptake abilities were evaluated.
Kato, Masato; Morihira, Masayuki
no journal, ,
no abstracts in English
Morihira, Masayuki; Segawa, Tomoomi; Namekawa, Takashi; Matsuyama, Shinichiro*; Yuda, Ryoichi*; Mizusako, Fumiki*
no journal, ,
Investigation of oxygen getter option is in progress for FBR MOX fuel to restrain the cladding inner surface corrosion at the high burn-up of 150 GWd/t. Evaluation of the requirement for the oxygen getter materials showed that Zr and Ti were promising candidate materials. Method of loading getter materials into a fuel element was also investigated. Their oxygen uptake ability and restructuring behavior during the oxidation were evaluated by the heating at 1573 K for 10 h under the controlled oxygen potential. As a result, it was shown that both Zr and Ti were available as an oxygen absorber but Ti was superior from the geometrical stability.
and FMSSegawa, Tomoomi; Morihira, Masayuki; Namekawa, Takashi; Matsuyama, Shinichiro*; Yuda, Ryoichi*; Mizusako, Fumiki*
no journal, ,
Heating tests were carried out for the disc pares of Zr-FMS, Ti-FMS, Zr-UO and Ti-UO to evaluate the compatibility of the candidate materials of oxygen getter with UO and FMS, and the interfaces of each disc were investigated. No reaction was observed between Zr and UO also FMS in the test conditions. For Ti and FMS, Ti-Fe-O phase with the maximum thickness of 14 
m was formed in the Ti disc at 700
C for 100 h but no penetration of Ti into FMS disc was observed. For Ti and UO, Ti-U or Ti-U-O phase were formed near the surface of the Ti disc but these were limited in Ti disc side. No penetration of Ti into UO disc was observed. As a result, it is considered that no harmful influence is expected for Zr and Ti on the integrity of UO and FMS cladding.
Morihira, Masayuki; Mizusako, Fumiki*; Tsuboi, Yasushi*
no journal, ,
A feasibility study for oxygen getter options is conducted in JAEA to reduce cladding inner corrosion of FBR MOX fuels to attain high burn-up. Investigation of oxygen getter loading options for pellet type MOX fuels as well as evaluation results of oxidation behavior of the candidate materials are reported.
Morihira, Masayuki; Mizusako, Fumiki*; Nagata, Akito*; Takayasu, Teruki*
no journal, ,
Cladding inner corrosion is one of the life controlling factors of FBR MOX fuels and it depends on the oxygen potential in a fuel element. The oxygen getter method is idea way to locate metal fragments in a fuel element as an excess oxygen absorber. Since almost nothing has been reported concerning the application of an oxygen getter in pellet type fuels, conceptual development of the oxygen getter for pellet type MOX fuel and a feasibility study has been conducted. In the previous study, titanium was chosen as the most promising candidate material. Concerning the method to install the getter material in a fuel element, an option to locate titanium pellets in the upper axial blanket region was proposed. In this case, it is necessary to reduce the smear density. To realize it, the titanium roll pellet option was proposed. In this study, producibility of titanium roll pellets and their oxidation behavior were evaluated. Additional oxidation data for titanium was also obtained.