Archaeology with Reactors


Image of a smiling man with glasses © Copyright: Foto Braitsch


Lukas Rademacher

Doctoral Student


  Nuclear Reactor Cell with Logos of Programs Copyright: © Lukas Rademacher

Information about the past operation of reactors can be obtained by examining changes in their reactor structural elements. Components such as fuel tubes are subjected to irradiation with neutrons, leading to activation of their materials. Measuring their isotopic composition enables drawing conclusions about the received neutron flux, and in turn about the reactor operation producing this flux.

By analyzing multiple isotopes in parallel we want to obtain a detailed picture of the reactor operation. A special focus lies on unstable isotopes, which carry information about e.g. reactor power or shutdown periods.

Along with the possibility for more detailed information comes an increased difficulty of the analysis process. Since a direct inversion of the processes in the reactor is impossible, we instead must rely on repeated forward simulations. We can then apply numerical methods to develop an optimization algorithm, matching the input parameters to the measured ratios.

  Diagram showing the reconstruction of reactor parameters Copyright: © Lukas Rademacher