Langzeit Auslaug- und Korrosionsexperimente an zementierten 1:1 Gebinden in der Schachtanlage Asse. Preobennahme und Auswertung 2003

The paper presents the follow-up of experimental findings from full-scale leach tests performed on simulated cemented waste forms for more than 20 years in salt brines and water. Measurements cover pH, density, and the composition of leachates as well as the release of radionuclides such as Cs, U and Np. Indicators for waste form corrosion and radionuclide release is Cs and NO 3 - . Corrosion of cemented waste forms depends on the pore volume of the hardened cement which is correlated to the water/cement ratio. The release of radionuclides is evaluated and compared to small-scale laboratory tests. Excellent interpretation of observed concentrations is obtained for uranium and neptunium by comparison with model calculations.