This report fulfills the milestone (M4SF-17PN010501041 Report on Radiolysis Modeling for the Defense Repository) to discuss continued integration of the PNNL Radiolysis Model and the ANL Mixed Potential Model. This work concerns the development of an integrated Radiolysis Model (RM) for evaluating defense waste materials (oxide and metal) degradation and radionuclide mobilization. Within an anoxic repository environment, primary oxidizing species (e.g., hydrogen peroxide (H2O2), OH• radicals, as well as chlorate and other oxidizing species depending on the disposal environment) will be generated at the surface of the nuclear waste forms as a function of their specific activity.
RM development has included expansion of chemical environments considered to encompass species for various disposal environments. PNNL has been coordinating this effort with ANL on the integration of the radiolysis work with the fuel degradation model.
In this study, we demonstrate and approximate possible effects of iodide on H2O2 generation. As has been shown these are conditions for which H2O2 generation is reduced. We find that the presence of the iodide ion reduces the steady-state H2O2 concentration, but not to the same degree as bromide at micro-molar concentrations.
Revised: February 11, 2020 |
Published: July 28, 2017