Description
The movement of molecules or particles (containing radionuclides) both parallel and transverse to the direction of advection in response to Brownian forces. Also transverse movement of radionuclides that are advected along fractures or connected void spaces into stagnant porewater in the adjacent matrix - termed matrix diffusion.
Category
Category of FEP
Supercontainer EBS
Sub-category
Sub-category of FEP
Hydraulic processes
Ondraf Niras FEP Number
Ondraf Niras FEP Number
38
FEP Effects
Description of FEP Effects
Diffusion occurs in the presence of chemical and thermal gradients, and may affect the transport and spread of dissolved radionuclides.
NEA TN2 IFEP Reference(s)
Related IFEPs from the NEA TN2 List of Proposed IFEP Revisions [NEA/RWM/R(2013)8]
2.4.1.3 Diffusion (waste form). 2.5.2.3 Molecular diffusion (waste package). 3.3.2.3 Molecular diffusion (GDF).