Improved Silicon Carbide Components for Nuclear Applications

Silicon carbide based ceramic matrix composites may become the predominant material system from which reactor core components are manufactured. Manufacturing large, high aspect ratio, components using silicon carbide composite materials presents unique manufacturing challenges to maintain dimensional tolerance and meet the performance needs for in core reactor components. Physical Sciences Inc. will utilize our pre-ceramic polymer and laser machining expertise to develop the manufacturing process necessary for cost effective production of nuclear grade silicon carbide composite components for use in the core of nuclear systems. In Phase I, PSI demonstrated the ability to produce high aspect ratio, thin walled tubular components greater than 2 meters in length with diameters of 1.1 cm to 10 cm that maintained tolerances of +/- 0.005cm. The components met strength and dimensional requirements. In addition, we demonstrated the ability to laser machine the components to surface smoothness of 20 microns or less. In Phase II, PSI will develop and produce full size prototype components conforming to the dimensions of NGNP and LWRS designs. We will iteratively combine CMC process improvements and materials analysis, including transmission electron microscopy and mass spectrometry, to optimize the polymer precursor and resulting matrix for in-core nuclear reactor environments. These will be validated by radiation testing. Commercial Applications and Other Benefits: 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.