2018 | AFC ACCOMPLISHMENTS 72 Analysis of SiC BWR Channel Box Performance under Normal Operating Conditions Principal Investigator: Gyan Singh, Oak Ridge National Lab; University of Tennessee, Knoxville Collaborators: J. Gorton3 , Danny Schappel2 , Nick Brown3, Yutai Katoh1, Brian Wirth1,2 , and Kurt Terrani1 ; 1 Oak Ridge National Lab, 2 University of Tennessee, Knoxville, 3 Pennsylvania State University Figure 1. a) Spatial temperature distribution of the channel box in the simulation. Walls 2 and 3, and 1 and 4 share borders. b) Spatial distribution of fast flux in the channel box for the simulation. Replacement of the reference zirconium channel box with a silicon carbide composite (SiC-SiC composite) provides the potential to significantly reduce hydrogen generation in a boiling water reactor (BWR). Qualification of new channel box materials encounters many challenges similar to those of a new cladding material. Dimensional stability is a paramount requirement of channel box materials given the impact to thermohydraulic performance and core cooling. The swelling behavior of SiC-SiC composites is therefore a critical