Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

To help with the decommissioning of the unit 2 of the Greifswald NPP, this study aims at determining the activities of 3H, 14C, 60Co, 152Eu and 154Eu in the concrete to estimate the maximal activity in the entire bioshield.
The study will focus on the activity as a function of depth in the concrete layer, as well as composition of the mineral phases. As the flux of neutrons generated during fission reaction encounters the mineral phases of concrete, the natural elements present in these phases absorb neutrons, which leads to the formation of their radioactive isotopes. Therefore, the elemental composition of each mineral phase in the concrete is important in the activation process, and the concrete being a heterogeneous material, different phases will present different activities.
A precise knowledge of the activities and of the elemental composition of the concrete and its mineral phases helps refining the models to calculate and predict the activities in a long-term scale. The calculations and the experimental results support the sorting of the materials for disposal.
This study will analyze the concrete with three main objectives:

• Activation;
• Chemical composition;
• Structure of the concrete and mineral phases.