b'Project Description:Several accident tolerant fuel (ATF) concepts have been proposed to improve fission product retention in the event of a beyond design basis accident.One concept uses a ceramic as fuel cladding and requires the ability to fabricate toughened ceramic materials.CVD and CVI are versatile and scalable technologies that enable advanced ATF cladding and core structure concepts through manufacturing of ceramic matrix composite and/or depositing overcoatings. Development of coating technologies are imminent needs for SiC composite-based claddings and core structures to ensure environmental protection in oxidizing water chemistry. Ensuring hermeticity against gaseous fission products release is an additional essential need for SiC composite-based claddings. Moreover, seal-coating technologydevelopment of high dose radiationFigure 2.25mm diameter SiC/SiC for end-plugging is another pressingresistant composite for advancedcomposite fabricated with new lab need for the ceramic claddings. In areactor applications. With these futurescale CVI system.longer term, development of improvedobjectives, the current effort focuses fiber-matrix interfaces that are moreon establishing a CVD/CVI capability oxidation-resistant in both waterthat offers adequate configurational and steam environments than theversatility and flexibility for precursor current pyrolytic carbon technologyspecies and deposition conditions.is desired for future SiC composite- Accomplishments:based light water reactor (LWR)An experimental CVD/CVI system claddings and core components. In(Figure 1) has been designed, installed addition, modification of the fiber- and demonstrated at Oak Ridge matrix interfaces is essential for theNational Laboratory (ORNL) allowing 2019|AFC ACCOMPLISHMENTS 19'