title: Electrokinetic remediation of plutonium-contaminated nuclear site wastes: results from a pilot-scale on-site trial.
abstract: This paper examines the field-scale application of a novel low-energy electrokinetic technique for the remediation of plutonium-contaminated nuclear site soils, using soil wastes from the Atomic Weapons Establishment (AWE) Aldermaston site, Berkshire, UK as a test medium. Soils and sediments with varying composition, contaminated with Pu through historical site operations, were electrokinetically treated at laboratory-scale with and without various soil pre-conditioning agents. Results from these bench-scale trials were used to inform a larger on-site remediation trial, using an adapted containment pack with battery power supply. 2.4 m(3) (ca. 4t onnes) of Pu-contaminated soil was treated for 60 days at a power consumption of 33 kWh/m(3), and then destructively sampled. Radiochemical data indicate mobilisation of Pu in the treated soil, and migration (probably as a negatively charged Pu-citrate complex) towards the anodic compartment of the treatment cell. Soil in the cathodic zone of the treatment unit was remediated to a level below free-release disposal thresholds (1.7 Bq/g, or <0.4 Bq/g above background activities). The data show the potential of this method as a low-cost, on-site tool for remediation of radioactively contaminated soils and wastes which can be operated remotely on working sites, with minimal disruption to site infrastructure or operations.
authors.affiliation: AWE PLC, Aldermaston, Berks RG7 4PR, UK.
authors.forename: Kieran
authors.initials: K
authors.lastname: Agnew
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Cundy
authors.forename: Laurence
authors.initials: L
authors.lastname: Hopkinson
authors.forename: Ian W
authors.initials: IW
authors.lastname: Croudace
authors.forename: Phillip E
authors.initials: PE
authors.lastname: Warwick
authors.forename: Philip
authors.initials: P
authors.lastname: Purdie
mesh_terms: D004563:Electrochemistry; D004566:Electrodes; D052918:Environmental Restoration and Remediation; D006256:Hazardous Waste; D006863:Hydrogen-Ion Concentration; D054043:Nuclear Weapons; D010865:Pilot Projects; D011005:Plutonium / Q000302:isolation & purification*; D011850:Radioactive Waste / Q000032:analysis*; D012990:Soil Pollutants, Radioactive / Q000032:analysis
chemical_list: D006256:Hazardous Waste; D011850:Radioactive Waste; D012990:Soil Pollutants, Radioactive; D011005:Plutonium