A NEW APPROACH FOR THE ANALYSIS OF A GAS EXPLOSION IN A TYPE B PACKAGE

DGDM is originally a type B package designed by the CEA to transport technological solid waste. This waste contains organic elements which are subject to flammable gas production by radiolysis and thermolysis.This paper will present a new approach which is conducted in the safety analysis report of how the containment system (especially the bolted lid) withstand explosion. It has recently obtained a special arrangement for 18 months.Different steps have been followed:• Analytical calculation of conservative values of gas reached within the packaging during normal or accident conditions of transport (within limited time of transportation);• Finite Element (FE) calculation in 3D model of the chemical reaction of detonation of the gas mixture;• FE mechanical calculation of the structural response, with focus on the stresses on the lid and bolts and deformations (containment O-ring compression set; mechanical interferences with other components);• Justification of the safety. The modelling of the pressure vs time profiles in the cylindrical internal cavity of the package is innovative, taking into account the pressure wave progression, the multiple reflections with associated amplification factors. Different axial and radial locations for the ignition point are studied, focusing on their effect on the lid response. The potential reflection effect of the presence of a drum (containing the waste) in the cavity during the explosion is also analysed.