REA analysis of the Iranian VVER-1000 core by modification of PRORIA code for annular pellets

► Rod ejection accident in VVER-1000 reactor core is investigated using PRORIA-IR code (modified version of PRORIA code). ► The maximum values of fuel temperature and radial-enthalpy do not reach the threshold values. ► The hole in the center of fuel pellet improves the safety of fuel rod. ► Doppler reactivity effect of annular pellet is higher than the solid pellet.