THE TN 24 GET DUAL PURPOSE CASK FOR THE TRANSPORT AND STORAGE OF SPENT FUELS FROM TRINO, GARIGLIANO AND ELK RIVER REACTORS

ENEA (Italian National Agency for New Technology, Energy and the Environment) operates the Italian nuclear research centers at the sites of Saluggia and Trisaïa. Both these sites currently store spent fuel pools. In 1999, Transnucléaire was contracted by ENEA to design and license a dual purpose cask for the safe interim storage of the Elk River fuel at the Trisaïa site. The cask had to be designed so that it could be readily adapted for containing the Garigliano and Trino type fuels presently stored at the Saluggia site. Although the total quantities of fuel is quite modest (1,74 t of heavy metal) their form differs widely: square section assemblies, cruciform section assemblies and some dismantled fuel pins held in special bottles. The Elk River fuel is Thorium based and has a different isotope range from the uranium dioxide based fuels of Trino and Garigliano. Thus the radiation shielding design requirements are not uniform. Both sites have specific weight and geometrical handling limits. The whole project is a real challenge. With the close collaboration of ENEA engineers, Transnucléaire was able to propose effective solutions based on the TN 24 dual purpose cask. The TN 24 GET cask weighs 52 t (with fuel assemblies and shock absorbing covers) and can safely handle all the specified fuel types in both transport and storage configurations. This paper recalls the technical parameters of the fuel and shows how the cask design was developed to suit such diversity. Scale model drop testing was undertaken to demonstrate compliance with IAEA transport regulations and test results are presented together with the programme for in-site interim storage licensing.