Plutonium oxide polishing for MOX fuel fabrication

Alwin, Jennifer Louise; Coriz, Fawn; Danis, Jan A.; Bluhm, Brian K.; Wayne, David M.; Gray, Devin W; Ramsey, K.B.; Costa, David Antônio da; Bluhm, Elizabeth A.; Nixon, Archie E.; Garcia, Daniel J.; Roybal, Judy D.; Saba, M.T.; Valdez, Jose A.; Martinez, D.; Martinez, Joe Ray; Martinez, Cathy M.; Martinez, Yvonne A.; Martinez, Carl M.

doi:10.1016/j.jallcom.2007.04.271

Cited by 9 publications

(4 citation statements)

References 3 publications

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“…The column-loaded Pu will then be eluted with low concentration (e.g., 0.35 M) HNO 3 solution. [9,17] The elution will be conducted in a downflow configuration. This Pu-containing eluate will be captured in a receiving tank for storage and delivery to the precipitation area of the glovebox.…”

Section: Purification By Ion Exchangementioning

confidence: 99%

Design of the Laboratory-Scale Plutonium Oxide Processing Unit in the Radiochemical Processing Laboratory

Lumetta

Meier

Tingey

et al. 2015

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This report describes a design for a laboratory-scale capability to produce plutonium oxide (PuO 2) for use in identifying and validating nuclear forensics signatures associated with plutonium production, as well as for use as exercise and reference materials. This capability will be located in the Radiochemical Processing Laboratory at the Pacific Northwest National Laboratory. The key unit operations are described, including PuO 2 dissolution, purification of the Pu by ion exchange, precipitation, and reconversion to PuO 2 by calcination. v Summary The National Technical Nuclear Forensics Center (NTNFC) within the Domestic Nuclear Detection Office (DNDO) of the Department of Homeland Security (DHS) has funded Pacific Northwest National Laboratory (PNNL) to establish a laboratory-scale (up to 200 g Pu per batch) capability to produce plutonium oxide (PuO 2) for use in identifying and validating nuclear forensics signatures associated with plutonium production, as well as for use as exercise and reference materials. This capability is being installed in Room 604 in the Radiochemical Processing Laboratory (RPL). The key unit operations for producing PuO 2 are as follows. The feed plutonium material is received in the RPL in oxide form. The as-received oxide is dissolved in nitric acid media (with fluoride added as needed). The resulting solution is subjected to ion exchange to remove impurities from the plutonium stream, and then the plutonium is precipitated in the form of a salt (e.g., oxalate, peroxide, or hydroxide). Finally, this Pu salt is converted back to PuO 2 by heating (calcining). In order to make this capability a useful tool for identifying and validating nuclear forensics signatures, the system is designed to be flexible, allowing variations in the different process parameters (e.g., temperature, manner of reagent addition, or type of precipitating agent). This report describes the laboratory-scale PuO 2 production capability being established at PNNL. The key features include:  Plutonium oxide is received at the RPL and 200 g aliquots are transferred to a glovebox in RPL Room 604 for processing.  The PuO 2 is dissolved in nitric acid media. If necessary, fluoride (in the form of calcium fluoride or hydrofluoric acid) is added to aid in dissolving the PuO 2.  The plutonium solution is clarified by filtration and then purified by anion exchange using Reillex HPQ ® anion-exchange resin, or another suitable anion-exchange resin.  Although the design allows for a variety of plutonium precipitation steps, the design is based primarily on Pu(III) oxalate [Pu 2 (C 2 O 4) 3 •10H 2 O] precipitation. The purified Pu solution is adjusted to the +3 oxidation state with ascorbic acid, then is treated with oxalic acid to precipitate Pu 2 (C 2 O 4) 3 •10H 2 O.  The Pu 2 (C 2 O 4) 3 •10H 2 O is calcined in a muffle furnace to convert it to PuO 2.  The PuO 2 product is packaged and distributed as directed by the NTNFC. Functional descriptions are provided for each unit operation, and the various requirements f...

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Section: Purification By Ion Exchangementioning

confidence: 99%

Design of the Laboratory-Scale Plutonium Oxide Processing Unit in the Radiochemical Processing Laboratory

Lumetta

Meier

Tingey

et al. 2015

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“…0.35 M) HNO 3 solution. [12,18] This Pu-containing eluate will be captured in a receiving tank for storage and delivery to the precipitation area of the glovebox.…”

Section: Purificationmentioning

confidence: 99%

Conceptual Design for the Pilot-Scale Plutonium Oxide Processing Unit in the Radiochemical Processing Laboratory

Lumetta¹,

Meier²,

Tingey³

et al. 2014

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This report describes a conceptual design for a pilot-scale capability to produce plutonium oxide for use as exercise and reference materials, and for use in identifying and validating nuclear forensics signatures associated with plutonium production. This capability is referred to as the Pilot-scale Plutonium oxide Processing Unit (P3U), and it will be located in the Radiochemical Processing Laboratory at the Pacific Northwest National Laboratory. The key unit operations are described, including plutonium dioxide (PuO 2 ) dissolution, purification of the Pu by ion exchange, precipitation, and conversion to oxide by calcination. v SummaryThe National Technical Nuclear Forensics Center (NTNFC) has funded Pacific Northwest National Laboratory (PNNL) to establish a pilot-scale (up to 200 g Pu per batch) capability to produce plutonium oxide for use as exercise and reference materials, and for use in identifying and validating nuclear forensics signatures associated with plutonium production. This capability is referred to as the Pilot-scale Plutonium oxide Processing Unit, abbreviated as "P3U." The P3U will be established in Room 604 in the Radiochemical Processing Laboratory (RPL).The key unit operations for producing plutonium dioxide (PuO 2 ) are as follows. Plutonium will be received in the RPL in oxide form. The as-received oxide will be dissolved in nitric acid media. The resulting solution will be subjected to ion exchange to remove impurities from the Pu stream, and then the Pu will be precipitated in the form of a salt (e.g., oxalate, peroxide, hydroxide, or fluoride). This Pu salt will be converted back to PuO 2 by heating (calcining). In order to make this capability a useful tool for identifying and validating nuclear forensics signatures, the system will be designed to be flexible, allowing variations in the different process parameters (e.g., temperature, manner of reagent addition, type of precipitating agent, etc.). This report conceptually describes the P3U to be established at PNNL. The key features include  Plutonium oxide will be received and placed in a glovebox in RPL/Room 604. The PuO 2 will be dissolved in nitric acid media. Hydrofluoric acid will be added to aid in dissolution of the oxide. The dissolved Pu solution will be clarified by filtration and will then be purified by anion exchange using Reillex HPQ ® anion exchange resin. Although the design allows for a variety of Pu precipitation steps, the conceptual design is based on Pu(III) oxalate precipitation. The purified Pu solution is adjusted to the +3 oxidation state with ascorbic acid, then is treated with oxalic acid to precipitate Pu 2 (C 2 O 4 ) 3 •10H 2 O. The Pu(III) oxalate will be calcined in a muffle furnace to convert it to PuO 2 . The PuO 2 product will be packaged and distributed as directed by the NTNFC.Functional descriptions are provided for each unit operation, and the various requirements for these operations are identified in this report.vii

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“…For decades, plutonium(IV) oxide has been studied in both laboratory and industrial scale settings to understand how the physical characteristics and chemical stability are controlled by changes in process parameters of the production process. − Several dependencies have been linked to the different chemical preparation routes, for example, peroxide, oxalate, hydroxide precipitation, or metal oxidation. However, the most commonly studied synthetic route via Pu(III/IV) oxalate intermediate precipitation produces diverse final oxide characteristics depending on the processing conditions .…”

Section: Introductionmentioning

confidence: 99%

Impact of Precipitation Parameters on the Specific Surface Area of PuO₂

2021

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Controlling the properties of PuO 2 through processing is of vital importance to environmental transport and fate, production of nuclear fuels, nuclear forensic analyses, stockpile stewardship, and storage of nuclear wastes applications. A number of processing conditions have been identified to control final product properties, including specific surface area (SSA), residual carbon content, adsorption of volatile species, morphology, and particle size. In this paper, a novel approach is developed for the prediction of PuO 2 SSA via the synthetic route of Pu(IV) oxalate precipitation followed by calcination. The proposed model utilizes multivariate regression methodology and leave one out formalism to link Savannah River Site (SRS) precipitation and calcination production data to the SSA of the final product. A comparison among the models provides insight into the accuracy and ability to identify variations amongst the processing data. Additionally, the models may also be used to fit new data outside of the parameters explored in a production facility. Finally, the trained model was compared to a similarly trained conventional model form to illustrate the influence of precipitation parameters on the prediction of the final SSA. The models presented here attempt to provide new methods for more accurate prediction of the PuO 2 product properties in a production scale environment for key environmental and nuclear applications.

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Plutonium oxide polishing for MOX fuel fabrication

Cited by 9 publications

References 3 publications

Design of the Laboratory-Scale Plutonium Oxide Processing Unit in the Radiochemical Processing Laboratory

Design of the Laboratory-Scale Plutonium Oxide Processing Unit in the Radiochemical Processing Laboratory

Conceptual Design for the Pilot-Scale Plutonium Oxide Processing Unit in the Radiochemical Processing Laboratory

Impact of Precipitation Parameters on the Specific Surface Area of PuO₂

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Plutonium oxide polishing for MOX fuel fabrication

Cited by 9 publications

References 3 publications

Design of the Laboratory-Scale Plutonium Oxide Processing Unit in the Radiochemical Processing Laboratory

Design of the Laboratory-Scale Plutonium Oxide Processing Unit in the Radiochemical Processing Laboratory

Conceptual Design for the Pilot-Scale Plutonium Oxide Processing Unit in the Radiochemical Processing Laboratory

Impact of Precipitation Parameters on the Specific Surface Area of PuO2

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Impact of Precipitation Parameters on the Specific Surface Area of PuO₂