Hello, I am graduate student in NE within the US. I am working on a grant that examines a small (10-100 microns) ceramic film region on the outside of the cladding region. I have assessed the neutronic impact, as well as a thermal impact (heat transfer coefficients, etc.) of the additional region will have, but now I am too evaluate the impact during transient conditions (will the region yield more time before fuel melts, etc.). I am completely lost where to begin this evaluation. I have heard of a licensing code RELAP that could be used for this analysis, but I am unfamiliar with this code. Any assistance would be much appreciated. Thanks in advance.