Influence of Winding Patterns and Infiltration Parameters on Chemical Vapor Infiltration Behaviors of SiC_f/SiC Composites

Abstract

SiC and its composites have been considered for use as nuclear fuel cladding materials of pressurized light water reactors. In this study, a SiC f /SiC composite as a constituent layer of SiC triplex fuel cladding was fabricated using a chemical vapor infiltration (CVI) process in which tubular SiC fiber preforms were prepared using a filament winding method. To enhance the matrix density of the composite layer, winding patterns, deposition temperature, and gas input ratio were controlled. Fiber arrangement and porosity were the main parameters influencing densification behaviors. Final density of the composites decreased as the SiC fiber volume fraction increased. The CVI process was optimized to densify the tubular preforms with high fiber volume fraction at a high H 2 /MTS ratio of 20 at 1000 o C; in this process, surface canning of the composites was effectively retarded.

Applicability of Swaging as an Alternative for the Fabrication of Accident-Tolerant Fuel Cladding

“…Several alternative ATF claddings have been developed in and outside of Korea, including the M5 physical vapor deposition (PVD)-coated cladding by AREVA [5], the Fe-Cr-Al alloy by ORNL [6], the SiC/SiCf composite by MIT [7], and the Cr laser coating by KAERI [8,9]. However, the ATF cladding fabrication techniques described above have the following disadvantages: it is difficult to achieve uniform surface modifications, such as coatings, on long fuel rods, and issues such as peeling can occur due to thermal shock [10]; FeCrAl alloys experience neutron absorption and tritium emission problems [11]; SiC/SiC f composite claddings consist of ceramics and are therefore exceedingly unstable in terms of fatigue behavior; and, finally, the abovementioned claddings are difficult to mass-produce, and also incur high production costs [12,13]. To overcome these shortcomings, we propose swaging as an alternative method for the production of ATF claddings.…”