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Your search keyword '"Kayzar-Boggs, Theresa M."' showing total 18 results
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18 results on '"Kayzar-Boggs, Theresa M."'

8. Updated uranium reference material 231Pa/235U consensus model ages for nuclear forensics.

Author

Edwards, Mark A., Varga, Zsolt, Gaffney, Amy M., Denton, Joanna S., Engel, John R., Gonzales, Matthew S., Kayzar-Boggs, Theresa M., Mayer, Klaus, Nicholl, Adrian, Sanborn, Matthew E., Steiner, Robert E., Tarng, Cheng, Treinen, Kerri C., Wallenius, Maria, and Wende, Allison M.

Subjects
NUCLEAR chemistry, FORENSIC chemistry, RADIOACTIVE substances, CRIME laboratories, REFERENCE sources
Abstract

Radiochronometry provides the model age of nuclear materials, which is useful for understanding the production history of materials found outside of regulatory control. Certified reference materials (CRMs) are important for radiochronometry to increase confidence in measurement quality; however, the absence of 231Pa/235U CRMs necessitates that nuclear forensic laboratories measure the 231Pa/235U model ages of preexisting uranium reference materials. Here, new consensus 231Pa/235U model ages are reported from three nuclear forensic laboratories for three reference materials using current analytical methods. These updated consensus values can be used for quality control of 231Pa/235U model age measurements. [ABSTRACT FROM AUTHOR]

Published
2024
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14. The application of radiochronometry during the 4th collaborative materials exercise of the nuclear forensics international technical working group (ITWG)

Author

Kristo, Michael J., Williams, Ross, Gaffney, Amy M., Kayzar-Boggs, Theresa M., Schorzman, Kerri C., Lagerkvist, Petra, Vesterlund, Anna, Ramebäck, Henrik, Nelwamondo, Aubrey N., Kotze, Deon, Song, Kyuseok, Lim, Sang Ho, Han, Sun-Ho, Lee, Chi-Gyu, Okubo, Ayako, Maloubier, Didier, Cardona, Danièle, Samuleev, Pavel, Dimayuga, Ike, Varga, Zsolt, Wallenius, Maria, Mayer, Klaus, Loi, Elaine, Keegan, Elizabeth, Harrison, Jennifer, Thiruvoth, Sangeeth, Stanley, Floyd E., Spencer, Khal J., and Tandon, Lav

Published
2018
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16. Separation of protactinium from uranium-niobium alloys for 231Pa–235U radiochronometry in nuclear forensic investigations.

Author

Chen, Christine Yifeng, Higginson, Matthew A., Kayzar-Boggs, Theresa M., Denton, Joanna S., Dunne, James, Edwards, Mark A., Eng, Charlotte, Engel, John R., Gaffney, Amy M., Gilligan, Chris, Morris, Maya N., Rolison, John M., Sanborn, Matthew E., and Wende, Allison M.

Subjects
FUEL cycle, FORENSIC sciences, URANIUM, ALLOYS, CRIME laboratories, STANDARD operating procedure, URANIUM ores
Abstract

The isolation and purification of protactinium from uranium materials is essential for 231Pa–235U radiochronometry, but separating Pa from uranium-niobium alloys, a common material in the nuclear fuel cycle, is challenging due to the chemical similarity of Pa and Nb. Here we present three resin chromatography separation techniques for isolating Pa from U and Nb which were independently developed by three different laboratories through ad hoc adaptations of standard operating procedures. Our results underscore the need for and value of purification methods suitable for a diversity of uranium-based materials to ensure the operational readiness of nuclear forensics laboratories. [ABSTRACT FROM AUTHOR]

Published
2023
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17. Improved methods to age-date uranium certified reference materials for nuclear forensics using the 231Pa/235U radiochronometer.

Author

Denton, Joanna S., Wende, Allison M., Kayzar-Boggs, Theresa M., Cardon, April R., Edwards, Mark A., Sanborn, Matthew E., and Steiner, Robert E.

Subjects
RADIOACTIVE substances, REFERENCE sources, URANIUM, FORENSIC sciences, QUALITY control, GOVERNMENT laboratories
Abstract

Improved methods employed at Los Alamos National Laboratory for 231Pa/235U radiochronometry are outlined. We present elution curves obtained during 233Pa tracer preparation from 237Np. Additionally, we report model ages for uranium certified reference materials (CRMs) exhibiting a range of 235U enrichments including the first 231Pa/235U model ages for CRMs U200 and U900. Our results enable these CRMs to be used, with increased confidence, as quality control materials during nuclear forensics investigations. [ABSTRACT FROM AUTHOR]

Published
2022
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18. Analysis of sub-picogram quantities of 238Pu by thermal ionization mass spectrometry.

Author

Maassen, Joel, Inglis, Jeremy D., Wende, Allison, Kayzar-Boggs, Theresa M., Steiner, Robert E., and Kara, Azim

Subjects
MASS spectrometry, ION exchange chromatography, ELECTROSPRAY ionization mass spectrometry, PLUTONIUM
Abstract

A multiple ion-counting total evaporation technique has been developed for precise analysis of sub-picogram (pg) quantities of 238Pu by thermal ionization mass spectrometry (TIMS). A resin bead loading procedure was tailored to minimize uranium (U) contamination during loading. This loading technique, coupled with a mass spectrometry protocol that minimizes U ionization and removal of bulk U with ion exchange chromatography, allows for single pg-sized aliquots of plutonium (Pu) to be measured without interference from 238U. This technique has the potential to provide complete isotopic characterization of trace amounts of Pu by TIMS, without the need for alpha spectrometry. [ABSTRACT FROM AUTHOR]

Published
2019
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