Validation of a numerical release model (REPCOM) for the Finnish reactor waste disposal systems

The aim of the work is to model experimentally the inner structures and materials of the reactor waste repositories and to use the results for validation of numerical near field release model, REPCOM. The laboratory arrangements include the following test materials: bituminized resin and cemented ion-exchange resin, concrete, crushed rock, and water corresponding to the materials in the planned disposal systems. Cs-l37, Co-60, Sr-85, and Sr-90 are used as tracers, with which the ion-exchange resin, water or crushed rock is labelled depending on the specimen type. The basic specimen geometries are cylindrical and cubic. The gamma active nuclides in the cylindrical samples have been measured non-destructively with a scanner in order to determine the activity profiles in the samples. The gamma active nuclides in the cubic samples and the beta emitting Sr-90 in separate samples have been measured after splitting the samples