Use of CASTOR® and CONSTOR® casks for RBMK and VVER fuel assemblies

The dry storage of spent nuclear fuel from Russian type reactors was successfully realised the first time worldwide in CASTOR® casks developed by the GNS/GNB company in the nineteen eighties and nineties. These casks made of Ductile Cast Iron are licensed for both transport and storage. They are in operation since 1983. Advanced CASTOR® cask design adaptations are able to accommodate VVER 440 fuel with higher enrichment and higher burn up. The CONSTOR® design was developed as an alternative multipurpose cask concept for transport and dry storage, and in principle for final disposal of Russian spent nuclear fuel. This steel cask sandwich concept with heavy concrete as an additional shielding material fulfills the same safety criteria as the CASTOR® cask design. The maximum removable heat load is approx. 30 kW per cask. The main advantage of the CONSTOR® design is its cost-effective manufacturing by conventional engineering technologies and materials. In the following, the different design versions of CASTOR® and CONSTOR® casks for Russian nuclear fuel will be presented. The status of its safety assessment and licensing is described and the operational experiences with CASTOR® and CONSTOR® casks are evaluated.