Architecture and management of a geological repository - Andra

11 – Operational SafetyFigure 11.5.1Temperature distribution in the primary packages of bituminised sludge(B2.1) 17611.5.1.4 Results related to a fire on the transfer transfer cask, the disposal package and thevitrified waste (C) packageIn the case of C waste packages (cf. Table 11.5.3), the simulations show that the transfer cask’sthickness and the presence of the PPB neutrophage material (Plaster Polyethylene Boron), which actsas a thermal shield, would allow limiting the temperature at the wastes to approximately 90°C.This result appears to be a maximum value, given that the temperature on the external surface of thetransfer cask is estimated at approximately 1 400°C, while experience shows that fires in anunderground environment normally reach temperatures between 800 and 1200 °C [116], [117].The integrity of the disposal package (over pack / container) therefore appears to be guaranteed andthe temperature reached in the primary package would not be liable to change the characteristics of thevitreous matrix of the C wastes.176 In this figure, the fire source is located under the packages, and the concrete envelope of the disposal package is not represented.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM467/495