Operational and Safety Aspects of Vitrified Waste Casks

For the countries which have chosen reprocessing, closing the fuel cycle implies in particular to take back the resulting vitrified high active waste (HAW). The final solution envisaged worldwide for HAW is the burying into deep geological layers. But because of the high residual heat power, it is generally considered that this operation should not take place before a long cooling period. Therefore, an intermediate storage of long duration will be necessary. For the time being, two technical solutions have been developed for the interim storage: - one is based on forced structure, similar to storage adjacent to reprocessing sites; air cooled pits set out in a concrete that presently provided as buffer the Vitrification Facilities on - the other relies upon transportable storage casks standing vertically on a storage pad, following principles similar to those already implemented with spent fuel storage casks. Considering these two solutions for interim storage, TRANSNUCLEAIRE has developed two main types of transportable casks for vitrified HAW; one is a routine transport cask called hereafter \"transport cask\"; the other is a transportable storage cask called \"storage cask\". Both are covered by the generic name TN28V and have been already described in previous papers. This paper is devoted to the major aspects related to the safety and operation of the casks under both transport and storage conditions.