Plutonium in groundwater at the 100K-Area of the U.S. DOE Hanford Site

Dai, Minhan; Buesseler, Ken O.; Pike, Steven

doi:10.1016/j.jconhyd.2004.08.004

Cited by 67 publications

(55 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…strain EPS-1W, a common environmental bacterium previously isolated from the Pu-contaminated groundwater at the NNSS. Groundwater conditions at the NNSS are oxic, ϳpH 8, and of low ionic strength (45), similar to other contaminated sites, such as the Hanford Site in Washington and the Rocky Flats Environmental Technology Site in Colorado (46,47). While our results are not directly linked to the Pu transport detected at the NNSS, our observations of Pu interaction with a common soil bacterium, Pseudomonas sp., suggest the potential importance of microbes and the specific role of EPS in facilitating redox transformation and sorption of Pu.…”

Section: Discussionsupporting

confidence: 66%

Interactions of Plutonium with Pseudomonas sp. Strain EPS-1W and Its Extracellular Polymeric Substances

Boggs

Jiao

Dai

et al. 2016

Appl Environ Microbiol

View full text Add to dashboard Cite

Safe and effective nuclear waste disposal, as well as accidental radionuclide releases, necessitates our understanding of the fate of radionuclides in the environment, including their interaction with microorganisms. We examined the sorption of Pu(IV) and Pu(V) to Pseudomonas sp. strain EPS-1W, an aerobic bacterium isolated from plutonium (Pu)-contaminated groundwater collected in the United States at the Nevada National Security Site (NNSS) in Nevada. We compared Pu sorption to cells with and without bound extracellular polymeric substances (EPS). Wild-type cells with intact EPS sorbed Pu(V) more effectively than cells with EPS removed. In contrast, cells with and without EPS showed the same sorption affinity for Pu(IV). In vitro experiments with extracted EPS revealed rapid reduction of Pu(V) to Pu(IV). Transmission electron microscopy indicated that 2-to 3-nm nanocrystalline Pu(IV)O 2 formed on cells equilibrated with high concentrations of Pu(IV) but not Pu(V). Thus, EPS, while facilitating Pu(V) reduction, inhibit the formation of nanocrystalline Pu(IV) precipitates. IMPORTANCEOur results indicate that EPS are an effective reductant for Pu(V) and sorbent for Pu(IV) and may impact Pu redox cycling and mobility in the environment. Additionally, the resulting Pu morphology associated with EPS will depend on the concentration and initial Pu oxidation state. While our results are not directly applicable to the Pu transport situation at the NNSS, the results suggest that, in general, stationary microorganisms and biofilms will tend to limit the migration of Pu and provide an important Pu retardation mechanism in the environment. In a broader sense, our results, along with a growing body of literature, highlight the important role of microorganisms as producers of redox-active organic ligands and therefore as modulators of radionuclide redox transformations and complexation in the subsurface.T he civil production of nuclear energy and military production of nuclear materials have resulted in an estimated worldwide inventory of over 2,000 metric tons of plutonium (Pu) (1). This inventory continues to increase at a rate of approximately 70 metric tons per year as a result of global nuclear energy production (2). Due to its long half-life (24,100 years for 239 Pu) and high radiotoxicity (3), Pu is an important driver in public health risk assessments for nuclear waste repositories and radiologically contaminated sites. However, predicting how Pu behaves in the environment and ultimately calculating its human health risk are limited by our understanding of the dominant biogeochemical processes controlling its behavior.The behavior of Pu in the environment is strongly dependent on its oxidation state and concentration. Among all the actinides, Pu has one of the most complex chemical, redox, and surface sorption behaviors. At low concentrations, Pu can exist as aqueous species in the III, IV, V, and/or VI oxidation states, all of which have different solubilities (4), mineral sorption affinities (5-7), and hence...

show abstract

Section: Discussionsupporting

confidence: 66%

Interactions of Plutonium with Pseudomonas sp. Strain EPS-1W and Its Extracellular Polymeric Substances

Boggs

Jiao

Dai

et al. 2016

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…Also a greater number of field studies did not detect any significant colloid-facilitated transport [3,192,201].…”

Section: Field Studies On Colloid-associated Contaminant Transportmentioning

confidence: 99%

Review on subsurface colloids and colloid-associated contaminant transport in saturated porous media

Sen

Khilar

2006

Advances in Colloid and Interface Science

379

View full text Add to dashboard Cite

“…A study of the chemistry of plutonium in groundwater has been conducted at the 100-K Area (Buesseler et al 2003;Dai et al 2005). The concentration, size distribution, reduction-oxidation (redox) state, and isotopic composition of plutonium in groundwater from the 100-K Area were examined.…”

Section: Chemistry Of Plutonium In Groundwater At the 100-k Areamentioning

confidence: 99%

Transuranic Contamination in Sediment and Groundwater at the U.S. DOE Hanford Site

Cantrell¹

2009

View full text Add to dashboard Cite

SummaryThis document presents a review of transuranic radionuclide contamination in sediments and groundwater at the U.S. Department of Energy (DOE) Hanford Site. The review focuses primarily on plutonium-239/240 and americium-241; however, other transuranic nuclides are discussed as well, including neptunium-237, plutonium-238, and plutonium-241. The scope of the review includes liquid process wastes intentionally disposed to constructed waste disposal facilities such as trenches, cribs, and burial grounds, as well as unplanned releases to the ground surface. The review does not include liquid wastes disposed to tanks or solid wastes disposed to burial grounds.It is estimated that more than 11,800 Ci of plutonium-239; 28,700 Ci of americium-241; and 55 Ci of neptunium-237 have been disposed as liquid waste to the near surface environment at the Hanford Site. Despite the very large quantities of transuranic contaminants disposed to the vadose zone at the site, only minuscule amounts have entered the groundwater. Currently, no wells onsite exceed the DOE-derived concentration guide for plutonium-239/240 (30 pCi/L) or any other transuranic contaminant in filtered samples. The DOE-derived concentration guide was exceeded by a small fraction in unfiltered samples from one well ( The primary reason that disposal of these large quantities of transuranic radionuclides directly to the vadose zone at the Hanford Site has not resulted in widespread groundwater contamination is that under the typical oxidizing and neutral to slightly alkaline pH conditions of the Hanford vadose zone, transuranic radionuclides (plutonium and americium in particular) have a very low solubility and high affinity for surface adsorption to mineral surfaces common within the Hanford vadose zone. In addition, the vadose zone is typically very thick (hundreds of feet), and the net infiltration rate is very low due to the desert climate.In some cases in which transuranic radionuclides have been co-disposed with acidic liquid waste, transport through the vadose zone for considerable distances has occurred. For example, at the 216-Z-9 Trench, plutonium-239 and americium-241 have moved to depths in excess of 36 m (118 ft) below ground surface. Acidic conditions and the presence of possible complexants could increase the solubility of these contaminants and reduce adsorption to mineral surfaces. Subsequent neutralization of the acidity by naturally occurring calcite in the vadose zone (particularly in the Cold Creek unit) appears to have effectively stopped further migration. iv Characterization studies for most of the sites reviewed in the document are generally limited. The most prevalent characterization methods used centered around geophysical logging. Characterization of a number of sites included laboratory analysis of borehole sediment samples specifically for radionuclides and other contaminants, as well as for geologic and hydrologic properties. In some instances, more detailed research-level studies were conducted.The 216-Z-9 Trench is a case...

show abstract

Plutonium in groundwater at the 100K-Area of the U.S. DOE Hanford Site

Cited by 67 publications

References 49 publications

Interactions of Plutonium with Pseudomonas sp. Strain EPS-1W and Its Extracellular Polymeric Substances

Interactions of Plutonium with Pseudomonas sp. Strain EPS-1W and Its Extracellular Polymeric Substances

Review on subsurface colloids and colloid-associated contaminant transport in saturated porous media

Transuranic Contamination in Sediment and Groundwater at the U.S. DOE Hanford Site

Contact Info

Product

Resources

About