Technical Report NTB 81-03
On the Connection between lnjection Rate and Repository Boundary Concentration in Geospheric Transport Models
For geospheric radionuclide transport calculations the source at the repository can be described by either a concentration boundary or an injection rate given by the leaching model. In the present work the exact relation between the two descriptions is given for an arbitrary chain of decaying nuclides in a one-dimensional transport model with plane source. The result is compared to a simple approximation frequently in use. This gives strongly differing repository concentrations. To some extent these differences smooth out when considering the concentrations at the outlet of the geologic column. Nevertheless, a strict treatment of repository concentration calculations may become very important if chemical reactions such as precipitation play an important role.