In　this　study,　based　on　the　code　Fuel　ROd　Behavior　Analysis　(FROBA),　a　thermal-mechanical　analysis　code　initially　developed　for　traditional　UO2-Zr　fuel　elements　by　our　research　group,　a　modified　version　was　developed　to　perform　the　fuel　performance　simulation　of　accident　tolerant　fuels　(ATFs),　named　FROBA-ATF.　Compared　with　initial　version,　the　cladding　could　be　divided　into　arbitrary　number　control　volumes　with　different　materials　in　the　new　code,　so　it　can　be　used　to　perform　the　calculation　for　multilayer　coatings.　In　addition,　a　new　nonrigid　pellet-cladding　mechanical　interaction　(PCMI)　calculation　model　was　established　in　the　new　code.　The　FROBA-ATF　code　was　used　to　predict　PCMI　performance　of　two　kind　fuels　with　coated　claddings,　including　the　internal　surface　coating　and　external　surface　coating.　The　calculation　result　indicates　that　because　the　coating　surface　was　close　to　the　inner　surface　of　the　cladding　where　also　was　the　PCMI　surface,　the　absolute　value　of　the　combine　pressure　of　internal　surface-coated　cladding　was　substantial　larger　than　that　of　the　external　surface-coated　cladding,　which　might　be　harmful　the　coating　behavior.　However,　the　internal　surface-coated　mode　can　provide　a　protection　for　alloy　due　to　the　isolation　from　direct　contact　with　fuel　pellets,　which　can　result　in　a　much　lower　equivalent　stress　of　zirconium　body　during　the　PCMI.　©　2019　by　ASME.