Microbial transformations of plutonium and implications for its mobility

Francis, A.J.

doi:10.1016/s1569-4860(01)80015-2

Cited by 13 publications

(12 citation statements)

References 32 publications

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“…5a) indicating mobilisation and migration of Pu towards the anode, consistent with the migration of Pu as a negatively charged (anionic) complex. While the difficulty in accurately modelling element speciation (in the case here, Pu, which can co-exist in four different oxidation states, III-VI, in the same solution) in such a complex system under extreme pH gradients has been noted above, Pu is present in the soil environment mostly as hydroxides and oxides of Pu(IV) which have low solubility [23]. Surface sorption is a dominant feature of plutonium behaviour in soil systems, with strong sorption of Pu to mineral (Fe and Mn oxides, clays) and organic surfaces [24,25].…”

Section: Effect Of Soil Porewater Ionic Strength/application Of Soil mentioning

confidence: 89%

Electrokinetic remediation of plutonium-contaminated nuclear site wastes: Results from a pilot-scale on-site trial

Agnew

Cundy

Hopkinson

et al. 2011

Journal of Hazardous Materials

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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.

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Section: Effect Of Soil Porewater Ionic Strength/application Of Soil mentioning

confidence: 89%

Electrokinetic remediation of plutonium-contaminated nuclear site wastes: Results from a pilot-scale on-site trial

Agnew

Cundy

Hopkinson

et al. 2011

Journal of Hazardous Materials

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“…Microbial processes may also have a significant effect on the long-term behaviour and mobility of Pu (Francis, 2001;Francis et al, 2008). The oxidation state of Pu significantly affects its geochemical behaviour.…”

Section: Behaviour Of Pu In the Marine Environmentmentioning

confidence: 99%

Plutonium isotopes as tracers for ocean processes: A review

Lindahl

Lee

Worsfold

et al. 2010

Marine Environmental Research

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Since the first nuclear weapons tests in the 1940s, pulsed inputs of plutonium isotopes have served as excellent tracers for understanding sources, pathways, dynamics and the fate of pollutants and particles in the marine environment. Due to the well-defined spatial and temporal inputs of Pu, the long half- Pu and its unique chemical properties, Pu is a potential tracer for various physical and biogeochemical ocean processes, including circulation, sedimentation and biological productivity, and hence a means of assessing the impacts of global climate change. Due to the source dependency of the Pu isotopic signature, plutonium isotopes are beginning to be exploited as tools for the evaluation and improvement of regional and global ocean models that will enhance understanding of past and future changes in the oceans. This paper addresses the major sources of Pu and the physical and biogeochemical behaviour in the marine environment. Finally, the use of Pu isotopes as tracers for various oceanic processes (e.g. water mass transport, particle export, and sedimentation) is considered.

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“…Many experimental sorption studies were carried out under specific physicochemical conditions (anoxic conditions, high alkalinity, low organic content) that are difficult to extrapolate to surface soils (Moulin and Moulin, 1995;Kim et al, 1997;Kersting et al, 1999;Francis, 2001;Grigoriev et al, 2001;Artinger et al, 2002;Fjeld et al, 2003). Although current research has demonstrated some of the mechanisms governing the mobility of transuranides in soils, operational models either implicitly or explicitly use the classic coefficient, K d .…”

Section: Introductionmentioning

confidence: 99%