Plutonium

Weigel, F.; Katz, Joseph; Seaborg, Glenn T.

doi:10.1007/978-94-009-4077-2_7

Cited by 33 publications

(43 citation statements)

References 527 publications

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“…Under less competitive conditions (i.e., with lower or negligible concentrations of other metals, such as iron and aluminum, to compete with the uranium for ion exchange sites), the K d s for the undifferentiated (mixed) inorganic and organic IXM did not change appreciably with difference in acid composition and were about 4 mL/g in 6 M HNO 3 /0.4 M Ce(NO 3 ) 4 , 5 to 6 mL/g in 4 M HNO 3 , and 3 to 6 mL/g in 0.1 M HNO 3 /0.2 M H 2 C 2 O 4 . In comparison, the K d of U(VI) onto strong-base anion exchange resin is 3.9 mL/g at 7 M HNO 3 (Weigel et al 1986). …”

Section: 2mentioning

confidence: 98%

Uranium Metal Analysis via Selective Dissolution

Delegard¹,

Sinkov²,

Schmidt³

et al. 2008

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SummaryUranium metal, which is present in sludge held in the Hanford Site K West Basin, can create hazardous hydrogen atmospheres during sludge handling, immobilization, or subsequent transport and storage operations by its oxidation/corrosion in water. A thorough knowledge of the uranium metal concentration in sludge therefore is essential to successful sludge management and waste process design.The goal of this work was to establish a rapid routine analytical method to determine uranium metal concentrations as low as 0.03 wt% in sludge even in the presence of up to 1000-fold higher total uranium concentrations (i.e., up to 30 wt% and more uranium) for samples to be taken during the upcoming sludge characterization campaign and in future analyses for sludge handling and processing. This report describes the experiments and results obtained in developing the selective dissolution technique to determine uranium metal concentration in K Basin sludge. The work described in this report:• provides a technical underpinning of the validity of the selective dissolution method, including the influence of various sludge components, in five test series using simulated and genuine sludges of widely varying composition• establishes analytical parameters (concentrations, quantities, temperatures, and times) necessary to develop the selective dissolution sludge-digestion analytical procedure.The uranium metal detection limit is estimated to be about 0.004 wt% based on the testing performed with actual sludge, thus meeting the goal detection limit of 0.03 wt%. The detection limit largely is established by the trace residual uranium carryover that exists in the leached and rinsed sludge. In the final series of method validation tests using actual K Basin sludge, spiked with uranium metal at concentrations ranging from 0.025 to 1.29 wt%, uranium metal recoveries averaged 99.4% with a standard deviation of 3.3%.

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Section: 2mentioning

confidence: 98%

Uranium Metal Analysis via Selective Dissolution

Delegard¹,

Sinkov²,

Schmidt³

et al. 2008

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“…Coprecipitation of plutonium is well known and was the basis for the separation and purification of plutonium by a number of precipitating agents, 7 including iron 8 . Hobbs investigated the coprecipitation of uranium and plutonium from solutions featuring iron, aluminum, manganese, and nickel ion concentrations expected for residues from SRS fuel reprocessing operations.…”

Section: Forms Of Plutonium In Tank 18 Residuesmentioning

confidence: 99%

Form and Aging of Plutonium in Savannah River Site Waste Tank 18

Hobbs¹

2012

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SUMMARYThis report provides a summary of the effects of aging on and the expected forms of plutonium in Tank 18 waste residues. The findings are based on available information on the operational history of Tank 18, reported analytical results for samples taken from Tank 18, and the available scientific literature for plutonium under alkaline conditions. These findings should apply in general to residues in other waste tanks. However, the operational history of other waste tanks should be evaluated for specific conditions and unique operations (e.g., acid cleaning with oxalic acid) that could alter the form of plutonium in heel residues. Based on the operational history of other tanks, characterization of samples from the heel residues in those tanks would be appropriate to confirm the form of plutonium.During the operational period and continuing with the residual heel removal periods, Pu(IV) is the dominant oxidation state of the plutonium. Small fractions of Pu(V) and Pu(VI) could be present as the result of the presence of water and the result of reactions with oxygen in air and products from the radiolysis of water. However, the presence of Pu(V) would be transitory as it is not stable at the dilute alkaline conditions that currently exists in Tank 18.

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“…The time required to achieve disproportionation equilibrium in <1 M HN03 is about 15-20 hours. The plutonium valence distribution as a fiction of HN03 concenb-ation is shown in Figure 1 (Artyukhin et al 1959;Connick 1954;Weigel et al 1986;Toth et al 1990). Disproportionation is an equilibrium process.…”

Section: Plutonium Precipitation By Reaction With Magnesium Hydroxidementioning

confidence: 99%

“…,Therefore, solid Mg(OH)z reacts with dissolved Pu(NO~)ato produce solid hydrated plutonium oxide (PUOZ"XHZO), dissolved Mg(N03)2, and some water. There is no indication in the technical literature of formation of ternary oxides or hydroxides of Pu(IV) and magnesium [e.g., MgPu03] by precipitation (Weigel et al 1986;Cunningham 1954). Rather, the-discrete oxides PuO, and MgO are found when acidic plutoniundmagnesium nitrate solutions are precipitated by ammonium hydroxide and the washed precipitates calcined (Kurina and Moseev 1997).…”

Section: Plutonium Precipitation By Reaction With Magnesium Hydroxidementioning

confidence: 99%