Bonding of Impermeable SiC Ceramic Nuclear Reactor Components

The high temperature operation of Generation IV nuclear systems will require silicon carbide ceramic composites in the reactor core to minimize operational costs and enhance safety. Currently, no ceramic composite fabrication method has been successfully demonstrated that enables rapid, affordable bonding of impermeable SiC subcomponents to each other. The bonding technology will be a critical component in the manufacture of SiC reactor components. Physical Sciences Inc. will developmethods of forming robust joints between both silicon carbide (SiC) ceramic matrix composite (CMC) nuclear components and monolithic SiC components. The laser based production methods will be suitable for not only advanced reactor technologies but also cladding and other component manufacture for current generation plants. The bonded joints must survive the nuc lear environment over the predicted lifetime. The work in the Phase I program included iterative development and test of joints and joint designs in configurations and environments relevant to both VHTR and current LWR reactor designs. These included thermo-mechanical testing, permeability testing, and preliminary high pressure hot water/steam exposure. What is planned for the Phase II project? PSI will develop and produce bonded joints on prototype components conforming to the dimensions of NGNP and LWRS designs. We will iteratively combine joining improvements and materials analysis, including transmission electron microscopy and mass spectrometry, to optimize the joint properties for in-core nuclear reactor environments. These will be validated by radiation testing. Commercial Applications and Other Benefits (limited to the space provided). Silicon carbide composite reactor components will enable safer, more efficient operation of present and future nuclear systems. The radiation tolerant nature of silicon carbide composites will reduce the likelihood of component failures due to embrittlement from radiation exposure. The materials will enable maintenance cycles of next generation nuclear plants to be determined by fueled components and will reduce the waste produced by nuclear systems.