Criticality studies for transportation of non-irradiated uranium by air in a new type B package

In application of art.683 of IAEA SSR-6 2012 edition, for packages to be transported by air, the package shall be subcritical under conditions consistent with the Type C package tests assuming reflection by at least 20 cm of water but no water in-leakage. Where the condition of the package following the tests cannot be demonstrated, worst case assumptions regarding the geometric arrangement of the package and the contents should be made, taking into account all moderating and structural components of the packaging and the package.As part of a new type B package design, the CEA is conducting criticality studies about air transportation of non-irradiated uranium taking into account a totally ruined package.These criticality safety analyses are performed to determine the reactivity effect of different modelling assumptions.This paper will provide an overview of these criticality studies and the most relevant results will be discussed.