Expanded method for the determination of burnup in nuclear fuels using multiple neodymium isotopes

Grant W. Helmreich; John D. Hunn; Fred C. Montgomery; Darren J. Skitt; Tamara J. Keever; Benjamin D. Roach; Kayron T. Rogers; James W. Sterbenz

doi:10.1016/j.jnucmat.2025.156411

Expanded method for the determination of burnup in nuclear fuels using multiple neodymium isotopes

Grant W. Helmreich
, John D. Hunn
, Fred C. Montgomery
, Darren J. Skitt
, Tamara J. Keever
, Benjamin D. Roach
, Kayron T. Rogers
, James W. Sterbenz

Research output: Contribution to journal › Article › peer-review

1 Scopus citations

Abstract

Established methods for the determination of burnup in nuclear fuels commonly rely on the measurement of ¹⁴⁸Nd in the spent fuel in concert with known fission product yields to determine the atom percent of fissions in the fuel. This isotope of neodymium is used for various reasons, including chemical and radioactive stability, ease of measurement, and low rates of formation and destruction due to neutron flux apart from fission. However, careful calculation of effective cumulative fission yields and correction factors for (n,γ) capture reactions allows for additional stable and long-lived isotopes of neodymium to be used to provide additional independent measurements of burnup, reducing statistical uncertainty. This method was developed and successfully applied to measure the burnup of compacts from the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. The mean burnup measured using ¹⁴³Nd, ¹⁴⁵Nd, ¹⁴⁶Nd, ¹⁴⁸Nd, and ¹⁵⁰Nd was statistically observed to be the same as that measured using ¹⁴⁸Nd alone, but the statistical uncertainty in the measurement was reduced by a factor of 2, providing a tighter confidence interval in the final results.

Original language	English
Article number	156411
Journal	Journal of Nuclear Materials
Volume	622
DOIs	https://doi.org/10.1016/j.jnucmat.2025.156411
State	Published - Mar 2026

Funding

This work was sponsored by the US Department of Energy, Office of Nuclear Energy, Advanced Reactor Technologies as part of the Advanced Gas Reactor Fuel Development and Qualification Program . Handling of irradiated samples was completed by staff at the ORNL Irradiated Fuels Examination Laboratory and chemical analyses were performed by staff at the ORNL Radioactive Materials Analytical Laboratory. This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ).

Keywords

Analytical chemistry
Burnup determination
TRISO

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10.1016/j.jnucmat.2025.156411

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@article{e684898926f9456ab5b57fc201bedec0,

title = "Expanded method for the determination of burnup in nuclear fuels using multiple neodymium isotopes",

abstract = "Established methods for the determination of burnup in nuclear fuels commonly rely on the measurement of 148Nd in the spent fuel in concert with known fission product yields to determine the atom percent of fissions in the fuel. This isotope of neodymium is used for various reasons, including chemical and radioactive stability, ease of measurement, and low rates of formation and destruction due to neutron flux apart from fission. However, careful calculation of effective cumulative fission yields and correction factors for (n,γ) capture reactions allows for additional stable and long-lived isotopes of neodymium to be used to provide additional independent measurements of burnup, reducing statistical uncertainty. This method was developed and successfully applied to measure the burnup of compacts from the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. The mean burnup measured using 143Nd, 145Nd, 146Nd, 148Nd, and 150Nd was statistically observed to be the same as that measured using 148Nd alone, but the statistical uncertainty in the measurement was reduced by a factor of 2, providing a tighter confidence interval in the final results.",

keywords = "Analytical chemistry, Burnup determination, TRISO",

author = "Helmreich, \{Grant W.\} and Hunn, \{John D.\} and Montgomery, \{Fred C.\} and Skitt, \{Darren J.\} and Keever, \{Tamara J.\} and Roach, \{Benjamin D.\} and Rogers, \{Kayron T.\} and Sterbenz, \{James W.\}",

note = "Publisher Copyright: Copyright {\textcopyright} 2025. Published by Elsevier B.V.",

year = "2026",

month = mar,

doi = "10.1016/j.jnucmat.2025.156411",

language = "English",

volume = "622",

journal = "Journal of Nuclear Materials",

issn = "0022-3115",

publisher = "Elsevier",

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T1 - Expanded method for the determination of burnup in nuclear fuels using multiple neodymium isotopes

AU - Helmreich, Grant W.

AU - Hunn, John D.

AU - Montgomery, Fred C.

AU - Skitt, Darren J.

AU - Keever, Tamara J.

AU - Roach, Benjamin D.

AU - Rogers, Kayron T.

AU - Sterbenz, James W.

PY - 2026/3

Y1 - 2026/3

N2 - Established methods for the determination of burnup in nuclear fuels commonly rely on the measurement of 148Nd in the spent fuel in concert with known fission product yields to determine the atom percent of fissions in the fuel. This isotope of neodymium is used for various reasons, including chemical and radioactive stability, ease of measurement, and low rates of formation and destruction due to neutron flux apart from fission. However, careful calculation of effective cumulative fission yields and correction factors for (n,γ) capture reactions allows for additional stable and long-lived isotopes of neodymium to be used to provide additional independent measurements of burnup, reducing statistical uncertainty. This method was developed and successfully applied to measure the burnup of compacts from the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. The mean burnup measured using 143Nd, 145Nd, 146Nd, 148Nd, and 150Nd was statistically observed to be the same as that measured using 148Nd alone, but the statistical uncertainty in the measurement was reduced by a factor of 2, providing a tighter confidence interval in the final results.

AB - Established methods for the determination of burnup in nuclear fuels commonly rely on the measurement of 148Nd in the spent fuel in concert with known fission product yields to determine the atom percent of fissions in the fuel. This isotope of neodymium is used for various reasons, including chemical and radioactive stability, ease of measurement, and low rates of formation and destruction due to neutron flux apart from fission. However, careful calculation of effective cumulative fission yields and correction factors for (n,γ) capture reactions allows for additional stable and long-lived isotopes of neodymium to be used to provide additional independent measurements of burnup, reducing statistical uncertainty. This method was developed and successfully applied to measure the burnup of compacts from the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. The mean burnup measured using 143Nd, 145Nd, 146Nd, 148Nd, and 150Nd was statistically observed to be the same as that measured using 148Nd alone, but the statistical uncertainty in the measurement was reduced by a factor of 2, providing a tighter confidence interval in the final results.

KW - Analytical chemistry

KW - Burnup determination

KW - TRISO

UR - https://www.scopus.com/pages/publications/105026752050

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DO - 10.1016/j.jnucmat.2025.156411

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SN - 0022-3115

VL - 622

JO - Journal of Nuclear Materials

JF - Journal of Nuclear Materials

M1 - 156411

ER -

Expanded method for the determination of burnup in nuclear fuels using multiple neodymium isotopes

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Keywords

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