THE APPLICATION OF THE CASTOR HAW 20/28 CG AND CASTOR V/19 FOR TRANSPORT AND STORAGE IN GERMANY

Since 1993 the interim storage of spent fuel and high-level vitrified residues in transport and storage casks has taken an important part in the fuel cycle in Germany. Up to now, about 400 casks have been stored at the German storage facilities at Ahaus, Gorleben, Greifswald and at the research center in JUiich. Under the current reprocessing contracts concluded between the German base-load customers and COGEMA the vitrified residues have to be returned to Germany by 2003, i. e. about 2800 high-level waste canisters corresponding to I 00 casks. Additional 700 high-level waste canisters will be returned by 2005 under the current reprocessing contracts concluded with BNFL. At present, these residues are transported from COGEMA with the CASTOR HAW 20/28 CG transport and storage cask and stored at Gorleben for at least 40 years. The Gorleben storage facility started its operation in 1995 and a total of eight large transport and storage casks had been placed into storage by October 1997. In March 1997, the first three transport and storage casks of the advanced design CASTOR V/ 19, containing 19 large PWR fuel assemblies each (1300 MW reactors), were also stored at Gorleben. This cask has been designed for higher bumups up to 60 GWd/t, as requested by the German utilities. Practical experience has been gained during the licensing procedures and in the course of manufacture, handling and loading, transport and storage of the casks. This experience forms the basis for verification of the design calculations with the experimental data as well as for the optimization of future cask designs. Up to now, comparisons show that measured and calculated values are in close agreement. Based on the CASTOR V/ 19 design, new cask types have been developed and licensed in Germany, such as the CASTOR V/52 accommodating 52 BWR fuel assemblies including shrouds (1300 MW reactors), the CASTOR V/21 accommodating 2 1 short PWR fuel assemblies (1300/900 MW reactors), and the CASTOR 440/84 accommodating 84 fuel assemblies (VVER440 MW reactors). The use of these casks is expected in the near future.