Description

The presence and effects of electrochemical gradients within the waste and/or the EBS. Galvanic coupling refers to the establishment of an electrical current through chemical processes. Electrophoresis is the motion of charged particles in a colloid under the influence of an applied electric field. Electrochemical gradients may be established in the supercontainer owing to the presence of different metals in the supercontainer envelope, overpack and waste. Electrochemical effects may also arise from different local micro-environments (e.g. Eh, pH) on the surface of these metals. Natural currents occurring in the ground, known as “telluric currents”, may also create electrochemical gradients.

Category

Category of FEP

Supercontainer EBS

Sub-category

Sub-category of FEP

Chemical processes

Ondraf Niras FEP Number

Ondraf Niras FEP Number

32

FEP Effects

Description of FEP Effects

Galvanic coupling and electrochemical gradients may influence corrosion of the supercontainer overpack and envelope and affect the mobility of charged radionuclide species (by electro-osmosis) and particulates (by electrophoresis) in the EBS.

NEA TN2 IFEP Reference(s)

Related IFEPs from the NEA TN2 List of Proposed IFEP Revisions [NEA/RWM/R(2013)8]

Not mentioned.