Electrokinetic In situ Decontamination of Entrained Radioactivity (EIDER)

Concrete is ubiquitous on nuclear sites as construction, shielding & plant/pond materials and may be readily contaminated by exposure to emitter bearing fluids. Such contamination may be “fixed” and difficult to remove e.g. held within oxide layers, surface cracks/pores etc. Decontamination is then usually destructive, removing the top few mm of contaminant containing concrete.
There are four common decontamination techniques for concrete, all with limitations: scarifying (produces airborne particulates); abrasive blasting (significant secondary wastes); high pressure liquid jetting (significant contaminated waste water arisings); and laser ablation (may also give rise to airborne particulates). There is then a need for novel, non-destructive contamination removal techniques for concrete that ideally generate neither airborne particulates or significant liquid wastes.
One potential method that is widely employed in the environmental remediation of metal ion contaminated soils is electrokinetic decontamination. Electrokinetic effects are a general class of phenomena that involve the movement of charged ions or particles through a liquid medium under the influence of an applied electric field. Of relevance to this project is that that liquid may permeate through a porous solid material such as concrete.
The use of electrokinetics to decontaminate concrete is new. In the few studies that exist, this involves placing electrodes close to concrete sample surfaces to drive electrokinetic ion transport through those samples. It has the advantages of treating contaminants in low permeability zones, with subsurface clean up to near 90% of the target radionuclide.
Building on a highly successful previous work at Lancaster, we seek in this project to use electrokinetic techniques for the in situ decontamination of and control of leaks through, building structures such as spent fuel storage pond walls. This will involve the large scale demonstration of the electrokinetic displacement of radionuclides from both the surface and bulk interior of concrete and other mineral based building materials such as brick, stonework etc.
Novel aspects include: in situ deployment on bulk / intact structures rather than crushed / demolished materials; the use of the structure’s rebar as one of the system’s driving electrodes; and the use of simple, inexpensive salt-based washes to assist contaminant desorption.

Applicants should have a First or Upper Second Class UK honours degree, or equivalent, in a relevant subject such as chemical engineering, nuclear engineering, materials science, chemistry, radiochemistry or related disciplines.