Abstract
Japan Atomic Energy Agency (JAEA) carries out R&D on Very High Temperature Reactor (VHTR). It can provide high temperature helium gas about 1000℃ to the reactor outlet. It is possible to utilize this high temperature helium gas not only for power generation but also for process heat source of hydrogen production system. For in-core components of VHTR, it is important to develop heat-resistant ceramics composite materials substitute for metallic materials, and carbon fiber reinforced carbon matrix composite (C/C composite) is a major candidate for control rod materials. It is important to investigate the fracture mechanism of the C/C composite for component design. Fracture behaviors of two dimensional (2D-) C/C composites were examined by SENB specimens with four-point bending test. The following results were obtained through mode-I fracture tests. (1) Three types of the composites were evaluated by tentatively using the stress intensity factor equation for metallic materials. It was expected that the fracture mechanism for the composite materials could be assessed by this test method. (2) Delaminating in the specimens during fracture tests was observed. Fracture mechanism for the 2D- C/C composites including the delaminating will be evaluated in the next step.
