Strength test of C/C composite high performance control rod for HTGRs

High performance control rods are required to improve the high temperature gas cooled reactor (HTGR) performance. In present study. a dummy control ro d, with the same design parameter of HTTR (High Temperature enginnering Tes t Reactor), was fabricated with two dimensional reinforced C/C composites t o testify productivity of the high performance control rod for HTGR with th ese composite materials and clarify its mechanical properties. Dummy contro l rod elements, that are, sheath elements consisted of outer tube (outer di ameter x length x thickness=113 x 300 x 4 mm) and inner tube (75 x 300 x 7. 5 mm), and joint elements of the screws (M16 and M8), were fabricated and t ested on its mechanical properties. From these results, the following conclusions were derived; (1) High performance control rods for HTGR can be fabricated by the convent ional manufacturing process of C/C composite materials. (2) Mechanical strength of sheath elements reached to the design strength l evel of the materials, however, fiber enforcement to the radial direction o f the sheath is to be required to improve tensile and buckling strength of the tubes, and high strength of the screw elements was obtained.