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Journal Articles

Design study and comparative evaluation of JSFR failed fuel detection system

Aizawa, Kosuke; Chikazawa, Yoshitaka; Ishikawa, Nobuyuki; Kubo, Shigenobu; Okazaki, Hitoshi*; Mito, Makoto*; Tozawa, Katsuhiro*; Hayashi, Masateru*

Proceedings of 2012 International Congress on Advances in Nuclear Power Plants (ICAPP '12) (CD-ROM), p.465 - 474, 2012/06

A conceptual design study of an advanced sodium-cooled fast reactor JSFR has progressed in the "Fast Reactor Cycle Technology Development (FaCT)" project in Japan. JSFR has two failed fuel detection systems in the core. One is a failed fuel detection (FFD) system which continuously monitors a fission product from failed fuel subassembly. The other is a failed fuel detection and location (FFDL) system which locates when it receives signals from FFD. In this study, requirements to the FFD-DN and the FFD-DN design to meet the requirements were investigated for the commercial and demonstration JSFR. For the FFDL systems, experiences in the previous fast reactors and the research and development of FFDL system for JSFR were investigated. Operation experiences of the Selector-valve FFDL system were accumulated in PFR and Phenix. Tagging-gas system experiences were accumulated in EBR-II and FFTF.

Journal Articles

Comparison of sodium-cooled reactor fuel-handling systems with and without an ex-vessel storage tank

Chikazawa, Yoshitaka; Uzawa, Masayuki*; Usui, Shinichi*; Tozawa, Katsuhiro*; Kotake, Shoji

Nuclear Technology, 177(3), p.293 - 302, 2012/03

 Times Cited Count:3 Percentile:28.72(Nuclear Science & Technology)

JSFR is a concept of a commercial sodium-cooled fast reactor which has been being studied in Fast Reactor Cycle Technology Development (FaCT) project since 2006. For the JSFR fuel handling, various fuel handling systems (FHSs) were investigated and an advanced FHS with an ex-vessel storage tank (EVST) has been selected. The other FHS concepts investigated are evolutional FHSs without an EVST. The result has indicated that the construction cost of the evolutional systems do not reduce the construction cost dramatically, which is mainly due to additional safety measures required higher decay heat handling in gas atmosphere and due to the necessity of separated fresh and failed fuel storage. From an economical point of view, a longer plant outage of the evolutional systems offsets its advantage of the lower construction cost. On the basis of the results of this comparative study, JSFR has selected the FHS with an EVST.

Journal Articles

Conceptual design study for the demonstration reactor of JSFR, 6; Fuel handling system design

Chikazawa, Yoshitaka; Kato, Atsushi; Obata, Hiroyuki*; Nishiyama, Noboru; Uzawa, Masayuki*; Tozawa, Katsuhiro*; Chishiro, Ryo*

Proceedings of 19th International Conference on Nuclear Engineering (ICONE-19) (CD-ROM), 7 Pages, 2011/10

A preliminary design of the JSFR fuel handling system has been proposed. FaCT phase I results of key technology evaluations on preliminary safety assessment, a pantograph fuel handling machine, a sodium pot with two core component positions, dry spent fuel cleaning and minor actinide-bearing fresh fuel shipping cask are provided.

Journal Articles

Comparative study on advanced fuel handling systems for JSFR

Chikazawa, Yoshitaka; Uzawa, Masayuki*; Usui, Shinichi*; Tozawa, Katsuhiro*; Kotake, Shoji

Proceedings of 2010 International Congress on Advances in Nuclear Power Plants (ICAPP '10) (CD-ROM), p.10142_1 - 10142_9, 2010/06

Journal Articles

Development of a slim manipulator type fuel handling machine for a commercialized fast reactor

Chikazawa, Yoshitaka; Usui, Shinichi; Konomura, Mamoru; Sadahiro, Daisuke*; Tozawa, Katsuhiro*; Hori, Toru*; Toda, Mikio*; Kotake, Shoji*

Proceedings of 14th International Conference on Nuclear Engineering (ICONE-14) (CD-ROM), 7 Pages, 2006/07

A seismic analysis has been performed showing that the seismic interaction between the UIS and the FHM can be avoided adopting gapless bearings at the FHM arm joint. An angular contact ball bearing is suitable for the new FHM since it can eliminate gaps by preload pressure. A major problem of the FHM bearings is lubrication since the contact pressure between steel rings and ball increases because of ball bearing. Additionally, FHM operating temperature is about 200 deg-C and normal grease is not applicable under argon gas with sodium vapor. A endurance test with 1/10 scale bearings in the air has been performed to show applicability of angular contact ball bearings to the FHM arm joint. The results with 20,000 cycle showed that bearings with combination of MoS$$_{2}$$ coating steel rings and ceramics balls can be tolerable as the FHM operating condition. A real scale bearing test in argon gas with sodium vapor has also been demonstrated to reveal bearing size and sodium vapor effects.

JAEA Reports

Study of the Hexagonal Block Fuel Subassembly with Vertical Coolant Flow Fabrication Facility for He Gas Cooled Reactor

Tozawa, Katsuhiro*; Yamada, Hiroyuki*; Ozaki, Hiroshi*; Suzuki, Yoshihiro*

JNC TJ9420 2005-006, 133 Pages, 2005/02

JNC-TJ9420-2005-006.pdf:11.17MB

Hexagonal block fuel subassembly dispersing coated particle nitride fuel fabrication facility for Helium gas cooled reactor on the Feasibility Study for FBR fuel cycle systems has been investigated to reflect plant design considering detail effect of nitride fuel and remote handling and to evaluate waste production and plant cost. Results of the study are follows.(1) Research for hexagonal block fuel fabrication plant concept Material balance was settled considering with coated particle with TiN layer and SiC layer. System configuration was settled based on capacity and number of each equipments. Production method of the hexagonal block is hexagonal block flame capped SiC plate after vibration compaction in vertical position at core particle section and vibration compaction in horizontal position at blanket particle section. Production facility of the hexagonal block is embodied.Fuel subassembly is made by the hexagonal block screwed shut with entrance nozzle and handling head. Inspection items of hexagonal block are picked up and density inspection method is settled in X-ray CT scanning.Reagent recovery system is settled based on the system of sphere packing method.(2) Data evaluation for system assessment Radioactive gaseous waste, liquid waste, and solid waste in the main process, analysis process and maintenance process are evaluated. From the result, it made clear that radioactive gaseous waste and liquid waste are decreased by recovering IPA, nitric acid, ammonia water in reagent recovery process.Cost of equipment of the plant and operation cost have been estimated. Main process equipment cost occupies 21% of construction cost. Cost of radioactive waste treatment process, analysis process, maintenance facilities, instrumentation facilities and utility, occupy 35% of it. Cost of building, electrical equipment and ventilating system occupy 34% of it. New fuel storage facility occupies 10% of it.

JAEA Reports

Study of the Coated Particle Nitride Fuel Fabrication Facility for He Gas Cooled Reactor

Tozawa, Katsuhiro*; Yamada, Hiroyuki*; Ozaki, Hiroshi*; Nakano, Masaaki*

JNC TJ9420 2005-007, 104 Pages, 2004/02

JNC-TJ9420-2005-007.pdf:6.68MB

Coated particle nitride fuel fabrication facility for He gas cooled reactor on the Feasibility Study for FBR and Related Fuel Cycle has been investigated to reflect plant design considering detail effect of nitride fuel and remote handling and to evaluate waste production and plant cost.

Journal Articles

Development of the for the materials transfer capability evaluation system in a Pyrochemical Reprocessing Plant

Okamura, Nobuo; Tozawa, Katsuhiro; Sato, Koji

Proceedings of 11th International Conference on Nuclear Engineering (ICONE-11) (CD-ROM), 0 Pages, 2003/00

None

JAEA Reports

Development of the system for the estimation of materials flow in pyrochemical reprocessing plant; Characteristic evaluation of the oxide electrowinning plant

; Tozawa, Katsuhiro;

JNC TN9400 2002-041, 57 Pages, 2002/07

JNC-TN9400-2002-041.pdf:4.76MB

The operation of the plant with the non-aqueous reprocessing technology depends on the materials handling equipment closely. Because the value of decontamination factor of the products in the plant is low, treatment of nuclear materials requires remote operation technology. So the system for the evaluation of materials flow in the plant was built to evaluate the production ability of the plant and to check out the plant operation from the viewpoint of materials flow. The system is only based on information of the treatment abilities of materials handling machines and process installations and the arrangement of process installations in the reprocessing cell that influences a way to operate materials handling machines intensely. Therefore the system can be used to estimate the characteristics of non-aqueous plants that are not in detail design stage. The amount of production and the characteristics of the oxide electrowinning plant (operation term 200days/year, plant capacity 50tHM/year in design) designed in Feasibility Study Phase-1 were estimated using the system. The results show that the practical amount of production of the plant design is about 88% of the designed value. To increase the amount of production, it is more useful to speed up materials handling machine time than to install new installations or to give priority to conduct bottleneck processes. It is because materials handling influences the production ability of the plant deeply.

JAEA Reports

Development of system analysis code for pyrochemical process using molten salt electrorefining part2; Cathode processor calculation code with distillation process and parameter surveys using developed analytical model for cooling system of pyrochemical process cell

; Tozawa, Katsuhiro;

JNC TN9400 2001-094, 114 Pages, 2001/07

JNC-TN9400-2001-094.pdf:10.56MB

This report describes accomplishment of development of a cathode processor calculation code to simulate the mass and heat transfer phenomena with the distillation process and parameter survey using developed analytical model for cooling behavior of the pyrochemical process cell on personal computers. The pyrochemical process using molten salt electrorefining would introduce new technologies for new fuels of particle oxide, particle nitride and metallic fuels. Evaporation calculations using cathode processor calculation code with distillation process, which was developed in 2000, were evaluated. By selecting proper input data (time step, mesh size etc.), the results showed that the present code agreed well for the evaporation rate of cadmium., and the capability of the distillation process design and simulation with the code has been confirmed. Parameter surveys using developed analytical model were performed for the purpose of reflection of cooling system design of the pyrochemical process cell. 4 cases of cooling flow patterns were surveyed at the normal and low flow rate conditions. From the result of parameter surveys, It was shown that the cooling pattern with direct cooling for heating facilities in the lower cen and balk cooling for upper cell is desirable.

JAEA Reports

Desgin study of pyrochemical process operation by using virtual engineering models

; Tozawa, Katsuhiro; ; ; *

JNC TN9400 2000-053, 99 Pages, 2000/04

JNC-TN9400-2000-053.pdf:7.47MB

This report describes accomplishment of simulations of Pyrochemical Process Operation by using virtual engineering models. The pyrochemical process using molten salt electrorefining would introduce new technologies for new fuels of particle oxide, particle nitride and metallic fuels. This system is a batch treatment system of reprocessing and re-fabrication, which transports products of solid form from a process to next process. As a result, this system needs automated transport system for process operations by robotics. ln this study, a simulation code system has been prepared, which provides virtual engineering environment to evaluate the pyrochemical process operation of a batch treatment system using handling robots. And the simulation study has been conducted to evaluate the required system functions, which are the function of handling robots, the interactions between robot and process equipment, and the time schedule of process, in the automated transport system by robotics. As a result of simulation of the process operation, which we have designed, the automated transport system by robotics of the pyrochemical process is realistic. And the issues for the system development have been pointed out.

JAEA Reports

Development of system analysis code for pyrochemical process using molten salt electrorifining

Tozawa, Katsuhiro; ;

JNC TN9400 2000-052, 110 Pages, 2000/04

JNC-TN9400-2000-052.pdf:4.39MB

This report describes accomplishment of development of a cathode processor calculation code to simulate the mass and heat transfer phenomena with the distillation process and development of an analytical model for cooling behavior of the pyrochemical process cell on personal computers. The pyrochemical process using molten salt electrorefining would introduce new technologies for new fuels of particle oxide, particle nitride and metallic fuels. The cathode processor calculation code with distillation process was developed. A code validation calculation has been conducted on the basis of the benchmark problem for natural convection in a square cavity. Results by using the present code agreed well for the velocity-temperature fields, the maximum velocity and its location with the benchmark solution published in a paper. The functions have been added to advance the reality in simulation and to increase the efficiency in utilization. The test run has been conducted using the code with the above modification for an axisymmetric enclosed vessel simulating a cathode processor, and the capability of the distillation process simulation with the code has been confirmed. An analytical model for cooling behavior of the pyrochemical process cell was developed. The analytical model was selected by comparing benchmark analysis with detailed analysis on engineering workstation. Flow and temperature distributions were confirmed by the result of steady state analysis. In the result of transient cooling analysis, an initial transient peak of temperature occurred at balanced heat condition in the steady-state analysis. Final gas temperature distribution was dependent on gas circulation flow in transient condition. Then there were different final gas temperature distributions on the basis of the result of steady-state analysis. This phenomenon has a potential for it's own metastable condition. Therefore it was necessary to design gas cooling flow pattern without ...

Journal Articles

Design study an advanced nuclear fuel recycling system; Conceptual design of recycling system using dry reprocessing technology

; ; Moro, Satoshi; Yonezawa, Shigeaki; ; Tozawa, Katsuhiro

Proceedings of International Conference on Future Nuclear Systems (GLOBAL'99), 0 Pages, 1999/00

None

Journal Articles

None

; Ogawa, Shinta*; ; ; ; Tozawa, Katsuhiro; ;

PP.27$$sim$$39, (105), p.27 - 40, 1998/03

None

JAEA Reports

Conceptual design study of the actinide recycle reactor; Study of core structural with ductless fuel assemblies

Ogawa, Shinta; Hayafune, Hiroki; Tozawa, Katsuhiro; Ichimiya, Masakazu; Hayashi, Hideyuki; Mukaibo, Ryuichi

PNC TN9430 96-007, 354 Pages, 1996/07

PNC-TN9430-96-007.pdf:13.67MB

It is required enhanced core safety characteristics, recycle cost reduction, mitigation of risk to the environment and nuclear non proliferation for the fast reactor at the commercial use age of actinide recycle. The ductless fuel assembly, which has no wrapper tube, is promising for these requirements. In this study, the thermal hydraulic and mechanical characteristics of the ductless fuel core are evaluated for 600MWe MOX core with high burnup and long operating cycle length, and conceptual structure of the ductless fuel assembly core was established. The results of the study are summarized as follows; (1)Structural of Ductless Fuel Assembly. Conceptual design of components of the ductless fuel assembly, e.g. grid spacer, tie rod, upper shielding, lower nozzle and mechanical hold down spring, were performed and conceptual structure was established. Detail study of fuel pin bundle stiffness are required in the following design study. (2)Thermo-hydraulic Characteristics of Ductless Core and Ductless Fuel Assembly. The bypass flow rate strongly depends on the gap between core region and core barrel. For this bypass flow, it is found that thermal hydraulic feasibility is expected when the gaps between core region and core barrel are decreased($$<$$1mm). Since the core flow distribution is uniform, a coolant temperature distribution depend on the power distribution into core region. For fuel assembly, if the gaps between fuel assemblies are enlarged, the maximum sodium temperature increases (20$$^{circ}$$C/mm), therefore a proper gap design are needed. (3)Mechanical Characteristics of Ductless Core. The seismic safety of ductless core, in which a mechanical hold down are used, is assured. To decrease the impact force at spacer grid, however, some considerations on the grid design is necessary to avoid buckling. (4)Thermohydraulic Safety Characteristics. The maximum sodium temperatures are roughly evaluation under the condition of natural circulation and coolant ...

JAEA Reports

Progress report of the design study on actinide recycle reactor concept; Study on the plant system

Akatsu, Minoru; Tozawa, Katsuhiro; Watanabe, Ichiro; Ichimiya, Masakazu; Hayashi, Hideyuki; Mukaibo, Ryuichi

PNC TN9430 96-005, 237 Pages, 1996/07

PNC-TN9430-96-005.pdf:9.6MB

In 1995, a design study on the mixed-oxide fuel core of the large breeder reactor was done to realize actinide (including minor actinide) 600MWe recycle reactor plant aiming at minimization of the radioactive waste products at the view point of not only to lighten the burden of the environment but also to utilize efficiently the resources, Study was carried out and R&D items were clarified as to the following items, as plant system design. (1)influences to the plant system from decay heat increase. (2)reactor structure concept due to adoption ductless fuel assembly concept. The study results are as follows. The coolant flow pass concept to core assemblies and the core support concept were studied by taking account of ductless core system and the large floating force on core assemblies due to ductless core system, the features of the concepts were clarified and the mechanical hold down (MHD) mechanism concept was adopted against the floating force. The characteristics of the connection between the upper internal structure and the core assemblies were studied for the large eccentricity of the two structures due to installation error, thermal expansion difference, inclination of core assemblies, etc. The connection that were led by MHD was guessed to be done with no large problem by special connection procedure. The reactor auxiliary cooling system capacity of 16MW a loop is sufficient to remove core decay heat to maintain the integrity of the coolant boundary structure. The heat removal characteristics under natural convection circulation coolant flow is confirmed to be superior than ducted core plant because of the lower pressure drop property of the ductless core plant. The cask car type fuel handling system was selected as referenceex-vessel fuel handling system. Because the cask car type system was able to simplify the fuel handling system by the in-line configuration of fuel handling facilities. The decay heat of ductless spent fuel assembly in sodium pot ...

JAEA Reports

JFY 1995 Progress report of the development on the actinide recycle test reactor(ARTR)

Kasai, Shigeo; Tozawa, Katsuhiro; Akatsu, Minoru; Ogawa, Shinta; Watanabe, Ichiro; Hayafune, Hiroki; Naganuma, Masayuki; Ichimiya, Masakazu; Hayashi, Hideyuki; Mukaibou, Ryuichi

PNC TN9430 96-004, 152 Pages, 1996/07

PNC-TN9430-96-004.pdf:6.15MB

Authors are studying the Actinide Recycle Fast Breeder Reactor (named ARFBR in this paper), which contribute to the reduction of burdens to environments and to enhance the capability to prevent the nuclear proliferation as the entire nuclear recycle system (named Advanced Fuel Recycling FBR system (AFRFS) in this paper), and also investigating the ARTR for developing the ARFBR. The investigation of the ARTR consists of the design study of the ARTR and R&Ds of key technology existing in ARTR concept. The conceptual design study of the ARTR is planed to be conducted for 2 years from 1995 to 1996 as first stage. 1995's design study have been performed with drawing over all plant concept with supposing various tests in reactor and usage of reactor. Followings are distinctive feature of 1995's design study. (1)Maximum reactor power is 400MWt with about 1.6m diameter irradiation (burning) cores, which are designed to be operated up to 150GWd/t as average burn up. Maximum core diameter is about 2.5m for low power nuclear physics tests which are designed to be able to estimate characteristics of large scale core by using the test results. (2)Mixed oxide (MOX) and Mixed nitride (MN) core is designed respectively to be able to be used for static nuclear physics test, for nuclear and thermal transient test, and for full power irradiation or burning test. Each core is designed to terminate ATWS events passively, with using GEM for MOX core and with using spectral adjustment for MN core. (3)Fuel assembly is employed ductless type which is a promising candidate for the ARFBR. Sizing of a fuel assembly is determined in basis on MOX fuel design because MOX fuel pin length covers MN fuel pin which accommodates lesser FP gases because of its lower temperature. Fuel assembly is managed to be held by hydraulic force in case of freeing mechanical stopper by requirement of testability. (4)Reactor assembly is designed based on so called Head Access Loop Type Reactor. Main changes ...

Journal Articles

None

Shono, Akira; ; ; Tozawa, Katsuhiro; ;

Nichiro Kosokuro Semmon Kaigi, , 

None

Journal Articles

None

; ; Tozawa, Katsuhiro; ; ;

Proceedings of International Conference on Future Nuclear Systems (Global'97), Vol.2, , 

None

Oral presentation

Development of an fuel handling system for commercialized fast breeder reactor, 1; Conceptual design of fuel handling system

Usui, Shinichi; Chikazawa, Yoshitaka; Konomura, Mamoru; Tozawa, Katsuhiro*; Hori, Toru*; Toda, Mikio*; Ikeda, Hirotsugu

no journal, , 

no abstracts in English

30 (Records 1-20 displayed on this page)