have FNU values very close to unity under the respective relative errors. These nuclides generally form stable oxides in solid solutions with the UO2 matrix and are released when the uranium dissolves [21].Radionuclides 101 Ru, 103 Rh, and 140 Ce show lower than matrix dissolution, as seen from the ≤ 1 FNU values. The trends observed for Ru and Rh release were consistent with other leaching studies since they had lower mobilities within the ɛ phases and were dependent on the dissolution of the surface uranium atoms to be leached out [22]. Table J-6. FNU values for sample FHT-C as a function of time.

This report summarizes the progress in the development of a phenomenological model of aerosol transport, deposition, and plugging through microchannels. The purpose of this effort is to introduce to a user community-involving researchers, regulators, and industry-a generic, reliable numerical model for the prediction of aerosol transport while accounting for potential deposition and plugging of the leak paths. In that regard, a graphical user interface (GUI) was generated by integrating the individual MATLAB scripts that make up the model and adding additional features to aid the user's general understanding of the problem. This report focuses on the model development and features included. Furthermore, predictions from the GUI are compared with experimental data (Sandia, 2018) for validation. The strength of the GUI is the ability of a user to plug in basic parameters, such as the initial pressure conditions and canister model specifications, to obtain a first-principles approximation of vital information such as the blowdown pressure differential, aerosol penetration, and deposition as a function of time. The user can obtain this without the know-how of the underlying MATLAB scripts, enabling the model to be readily applied by regulators, industry, and shareholders to reduce the uncertainty in off-site radiological consequence evaluations.

This report documents work performed under the Spent Fuel and Waste Disposition's Spent Fuel and Waste Science and Technology program for the US Department of Energy (DOE) Office of Nuclear Energy (NE). This work was performed to fulfill Level 2 Milestone M2SF-21OR010201032, "ORNL High Burnup Confirmatory Demo Sibling Rod Testing Results," within work package SF-21OR01020103 and is an update to the work reported in M2SF-19ORO010201026 and M2SF-19OR010201028.

This report documents work performed under the Spent Fuel and Waste Disposition's Spent Fuel and Waste Science and Technology program for the US Department of Energy (DOE) Office of Nuclear Energy (NE). This work was performed to fulfill Level 2 Milestone M2SF-22OR010201042, "FY2021 ORNL Report on High Burnup Sibling Pin Testing Results," within work package SF-22OR01020104 and is an update to the work reported in M2SF-21OR010201032, M2SF-19ORO010201026 and M2SF-Sister Rod Destructive Examinations

This report reflects technical work which could support future decision making by DOE. No inferences should be drawn from this presentation regarding future actions by DOE, which are limited both by the terms of the Standard Contract and Congressional appropriations for the Department to fulfill its obligations under the Nuclear Waste Policy Act including licensing and construction of a spent nuclear fuel repository.