Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Sumita, Junya; Fujita, Ichiro; Shibata, Taiju; Makita, Taiyo*; Takagi, Takashi*; Kunimoto, Eiji*; Sawa, Kazuhiro; Kim, W. J.*; Park, J. Y.*
IOP Conference Series; Materials Science and Engineering, 18(16), p.162010_1 - 162010_4, 2011/09
Times Cited Count：1 Percentile：52.59(Materials Science, Ceramics)For control rod element of Very High Temperature Reactor, carbon fiber reinforced carbon matrix composite (C/C composite) is one of the major candidate materials for its high strength and thermal stability. Since the crack propagation of the C/C composite is complicated, the fracture behavior is one of the most important subjects of the design methodology for the control rod with the C/C composite. In this study, in order to assess the Mode-II fracture behavior of the two-dimensional (2D-) C/C composite which has the layer structure of laminas composed of fibers and matrix, bending test with oxidized end notched flexure specimen was carried out. The interlaminar fracture toughness decreased with increasing the oxidation for the 2D-C/C composite. The oxidized matrix causes reduction of fracture toughness and the reduction ratio is dependent on the matrix type. The crack initiates at the boundary between fiber bundles and grows along them without breaking the fiber. It is thought that the cracks which were initiated at the interface between matrix and fiber were gathered into the voids in the boundary between fiber bundles, and then the crack grows up in the matrix.
Shibata, Taiju; Sumita, Junya; Makita, Taiyo*; Takagi, Takashi*; Kunimoto, Eiji*; Sawa, Kazuhiro; Kim, W. J.*; Jung, C. H.*; Park, J. Y.*
Nihon Kikai Gakkai Rombunshu, A, 76(764), p.383 - 385, 2010/04
no abstracts in English
Shibata, Taiju; Sumita, Junya; Makita, Taiyo*; Takagi, Takashi*; Kunimoto, Eiji; Sawa, Kazuhiro
Ceramics in Nuclear Applications, Vol.30, Issue 10, p.19 - 32, 2009/11
Japan Atomic Energy Agency (JAEA) carries out R&Ds for Very High Temperature Reactor (VHTR). Since the core components in VHTR will be used at severer condition than in the High Temperature Engineering Test Reactor (HTTR), it is important to develop heat-resistant ceramic composite. C/C and SiC/SiC composites are major candidates substitute for metallic control rod. JAEA studies on the application of the composite materials for the VHTR control rod following the scheme; (1) Database establishment, (2) Design and (3) Demonstration test by HTTR. In this paper, the development plan was explained. It was expressed that the irradiation effects on graphitized C/C composite showed similar trend with that of graphite. It is possible to evaluate the irradiation effects based on the existing graphite irradiation database. The HTTR can irradiate large component. It is possible to demonstrate the structural integrity of the mock-up of the composite control rod being necessary for the final phase.
Takagi, Takashi*; Makita, Taiyo*; Kunimoto, Eiji; Shibata, Taiju; Sawa, Kazuhiro
JAEA-Technology 2008-094, 22 Pages, 2009/03
JAEA-Technology-2008-094.pdf:5.49MB
To advance the performance and safety of High Temperature Gas-cooled Reactors (HTGRs), it is expected to use heat-resistant materials substitute for metallic materials in the core internal structural components of HTGRs at higher temperature. Carbon fiber reinforced carbon-carbon composite (C/C composite) is one of candidates as heat-resistant materials, and investigations are under going to apply the core internal structural components such as the control rod for the Very High Temperature Reactor (VHTR). This report describes the experimental results of irradiation effects on dimensional change, coefficient of thermal expansion and elastic modulus obtained by PIE (Post-Irradiation Examinations) for C/C composite irradiated in 03M-47AS capsule at the Japan Materials Testing Reactor (JMTR).
Shibata, Taiju; Makita, Taiyo*; Takagi, Takashi*; Kunimoto, Eiji; Sawa, Kazuhiro
no journal, ,
no abstracts in English
Shibata, Taiju; Sumita, Junya; Makita, Taiyo*; Takagi, Takashi*; Kunimoto, Eiji; Sawa, Kazuhiro; Park, Y.*; Kim, W. J.*; Jung, C. H.*
no journal, ,
no abstracts in English
Shibata, Taiju; Makita, Taiyo*; Sumita, Junya; Takagi, Takashi*; Fujita, Ichiro; Kunimoto, Eiji*; Sawa, Kazuhiro
no journal, ,
no abstracts in English
Shibata, Taiju; Sumita, Junya; Takagi, Takashi*; Makita, Taiyo*; Fujita, Ichiro; Sawa, Kazuhiro
no journal, ,
VHTR is one of the Generation-IV reactor systems and being developed internationally. Since the core components in the VHTR will be used at severe temperature condition, it is important to develop heat-resistant ceramic composite material. JAEA is carrying out the application study on two-dimensional (2D-) C/C composite to the control rod of VHTR. 2D-C/C composite of CX-270G grade, graphitized at 2800 
C, was used to evaluate the change of material properties by neutron irradiation. The samples were irradiated by JMTR at 600 C up to the neutron fluence of 8.2
10
n/m
(E
1.0MeV) corresponding to 1.2 dpa. The irradiation-induced dimensional change, thermal conductivity, coefficient of thermal expansion and Young's modulus were evaluated. The test results were evaluated in comparison with the irradiation database of graphite of JAEA. It was shown that the graphite database is effective to support the evaluation of the irradiation test results of the graphitized C/C composite.
