[en] In Finland the operating waste from four nuclear power plant units will be disposed of in two repositories to be built in the granitic bedrock at the two power plant sites. The aim of this work is to model experimentally the inner structures and materials of the reactor waste repositories and to use the results for the validation of a numerical near field release model, REPCOM. The laboratory arrangements included the following test materials: bitumenized and cemented ion-exchange resin, concrete, crushed rock, and water corresponding to materials in the existing and planned disposal systems. ¹³⁷Cs, ⁶⁰Co, ⁸⁵Sr, and ⁹⁰Sr were used as tracers, with which the ion-exchange resin, water or crushed rock was labelled depending on the specimen type. ( 7 refs., 43 figs.)