4.6 Article

An Alternative Conceptual Model for the Spent Nuclear Fuel-Water Interaction in Deep Geologic Disposal Conditions

Journal

APPLIED SCIENCES-BASEL
Volume 11, Issue 18, Pages -

Publisher

MDPI
DOI: 10.3390/app11188566

Keywords

spent nuclear fuel; long-term safety assessment; radioactive waste disposal; radiolysis; interfacial processes

Funding

  1. DOE BES Grant [DE-FC02-04ER15533]
  2. U.S. Department of Energy (DOE) [DE-FC02-04ER15533] Funding Source: U.S. Department of Energy (DOE)

Ask authors/readers for more resources

This passage discusses the importance of long-term safety assessment of spent nuclear fuel disposal in deep geologic repositories, and presents a conceptual model to explain radionuclide release rates. It suggests that current estimations of radionuclide release rates may be overestimated, and provides suggestions for future research directions.
Featured Application Long-term safety assessment of spent nuclear fuel deep geologic repositories. For the long-term safety assessment of direct disposal of spent nuclear fuel in deep geologic repositories, knowledge on the radionuclide release rate from the UO2 matrix is essential. This work provides a conceptual model to explain the results of leaching experiments involving used nuclear fuel or simulant materials in confirmed reducing conditions. Key elements of this model are: direct effect of radiation from radiolytic species (including defects and excited states) in the solid and in the first water layers in contact with its surface; and excess H-2 may be produced due to processes occurring at the surface of the spent fuel and in confined water volumes, which may also play a role in keeping the spent fuel surface in a reduced state. The implication is that the fractional radionuclide release rate used in most long-term safety assessments (10(-7) year(-1)) is over estimated because it assumes that there is net UO2 oxidation caused by radiolysis, in contrast with the alternative conceptual model presented here. Furthermore, conventional water radiolysis models and radiation chemical yields published in the literature are not directly applicable to a heterogeneous system such as the spent fuel-water interface. Suggestions are provided for future work to develop more reliable models for the long-term safety assessment of spent nuclear fuel disposal.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.6
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available