This work concerns the development of a semi-technical scale test installation for separation of concrete constituents. As only a relatively thin layer of concrete structures will be contaminated or activated, the proposed process consists in a further volume reduction of the material to dispose off by separation of the radioactive constituents (cementstone) from the supposed non-radioactive part (aggregates) of this removed concrete cover.

The material that will be conditioned originates from decommissioning activities at the Kahl nuclear power plant.

The research programme could be useful for developing an industrial-scale manufacturing process. Furthermore, the experience gained in this field by Taywood (CEC contract FI1D0042) will be applied to solidification.
This work concerns the development of a semitechnical scale test installation for separation of concrete constituents. As only a relatively thin layer of concrete structures will be contaminated or activated, the proposed process consists in a further volume reduction of the material by separation of the radioactive constituents (cementstone) from the supposed nonradioactive part (aggregates) of this removed concrete cover.

By separation of dense aggregate particles and porous cementstone a substantial volume reduction of contaminated concrete is achieved. This method can be applied to contaminated concrete where the contamination is concentrated in the cementstone and the aggregates are clean. It could be proved before that quartz aggregates are not contaminated and that their activation is of minor importance. This is also true for limestone concrete but not for baryte concretes. It was also found that separation of barytes is less effective because they are crushed during milling. For separation of mainly quartz and limestone concretes the separation pilot plant was engineered.
WORK PROGRAMME

1.Selection of a separation technique: determined by the importance of the activation/ contamination of the concrete constituents. (KEMA)

2. Determination of process variables for the conceptual design of the test installation. (KEMA)

3. Design of a small-scale transportable test installation. (KEMA)

4. Construction of the test installation. (KEMA)

5. Testing and optimization of the installation with non-radioactive concrete. (KEMA)

6. Verification with radioactive concrete. (KEMA)

7. Immobilization and solidification of concrete debris. (Taywood)

8. Evaluation of the results with respect to equipment, costs, released activity etc. (KEMA)