To be approved, a package dedicated to the transport of radioactive material must withstand several tests required by the IAEA SSR-6 regulations, one of which is a 30-minute 800 °C fire test. To demonstrate the safety of the package, such a test may be performed on a package mock-up or numerically with boundary conditions representative of the fire. IAEA regulations specify values for flame emissivity and package surface absorptivity. However convection is addressed in the IAEA SSG-26 guidelines with a suggested coefficient of 10 W.m-2K"1 correlated with a range of flame velocity between 5 and 10 m.s-1. Recent research [REF 2] suggests that this value may not always be representative of such a fire and could be scaled up. What could be the influence of higher convection coefficients on the temperature of the package? In order to answer that question, IRSN performed sensitivity calculations on transport packages models and studied the influence of the convection coefficient over a range from 0 (no convection) to 100 W.m"2.K-1 (very high convection, not necessarily representative of real fires). The temperatures in the package models during the fire and cooling phases were analyzed and put in perspective with safety issues