(GRS 196) Comparison of long-term safety of repositories for spent CANDU or LWR fuels in hard rock

D. Buhmann (GRS), M. Pavelescu (SCN), A. Ionescu (SCN), A. Rizoiu (SCN), R. Storck (GRS)

A long-term safety analysis for direct disposal of spent nuclear fuel from power plants of CANDU type has been performed. The results are compared with previous results for disposal of spent LWR fuel. Additional parameter variations have been performed for both fuel types. CANDU reactors use natural uranium as nuclear fuel, while LWR fuel elements are made of enriched Uranium. The study was jointly performed by a Romanian institute and a German company. Thus, the input data for the calculations are taken from the corresponding national data bases.
In the present study, disposal is assumed to take place in a granite formation. The longterm safety of repositories in such formations has been investigated in detail in a recent project of the European Commission, called Spent fuel disposal Performance Assessment (SPA project). Results of the German participant of that project regarding spent LWR fuel have been published in detail separately. The latter report is the basis for the actual investigations.