Architecture and management of a geological repository - Andra

11 – Operational SafetyA special case is that in which a fire develops during work in a dead-end drift. Personnel may findthemselves between the fire and the end of the drift, unable to reach an interconnecting drift in order toescape. In this situation, they would have to take shelter in a mobile refuge (equipped with compressedair and water) which would be designed to be fire-resistant and smoke-proof. Once there, personnelwould wait to be rescued by a rescue team which should arrive at the scene of the fire in order to act asquickly as possible.Feedback from underground work sites indicates that particular effort must go into preventivemeasures and personnel training, with regular exercises in order to learn essential emergency reflexactions. If personnel are well trained and have adequate resources in order to intervene effectively inthe event of a fire, they generally manage to extinguish the fire before it has time to develop. The useof specialised personnel, equipped with full fire fighting gear, would only be required in about 10 % offires [115].11.5 Study of the consequences of a fire in a vehicle transporting thetransfer transfer casks (B, C and CU)The transfer transfer casks for waste disposal packages are loaded in the nuclear surface installationson a transport vehicle. This vehicle brings the transfer casks to the package transfer shaft and placesthem on a metallic support in the cage, which lowers them to the underground installations. Thetransfer casks are then recovered by a vehicle similar to the one used on the surface and transported bythis vehicle to the disposal cells.In addition to the usual consequences resulting from a fire (temperature increase, smoke, …) treated inthe previous section, if this vehicle is on fire, it could have radiological consequences if the fireimpacts on the protection ensured by the transfer cask (protection against external exposure) and theprimary package (maintaining the containment).The purpose of this section is to estimate by means of simulation studies [107] whether radiologicalconsequences may result and propose, if necessary, additional measures to prevent this risk or protectagainst it.11.5.1 Assessment of the consequences of a fire in the transport vehicle on the transfer transfercask and its contentsThis assessment is based on the assumption of a fire breaking out in a transfer cask transfer vehicle (B,C or spent fuel) despite recommended preventive measures (cf. section 11.4). The nature of transferedpackages, the evolution of their characteristics versus the temperature to which they are raised and themain characteristics of the transfer transfer casks are referred to in Table 11.5.1.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM464/495