Applications of HPGe-detected high energy gamma rays toward quantifying neutron emission rates and 234U enrichment in UF6 cylinders

Allison T. Greaney; Susan K. Smith; Ramkumar Venkataraman; Jason M. Richards; Glenn A. Fugate

doi:10.1016/j.nima.2020.163912

Applications of HPGe-detected high energy gamma rays toward quantifying neutron emission rates and ²³⁴U enrichment in UF₆ cylinders

Allison T. Greaney, Susan K. Smith, Ramkumar Venkataraman, Jason M. Richards, Glenn A. Fugate

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

2 Scopus citations

Abstract

This study presents a ²³⁴U enrichment meter that uses high energy gamma and neutron count rate as measured by a portable, high-purity germanium gamma ray detector. Twenty-one 30B cylinders containing UF₆ of varying origin were analyzed with an HPGe detector for high-energy gamma ray and neutron counts. Excellent correlations (R² ≥ 0.95) between various regions of ≥3.0 MeV gamma rays, neutron count rate, and uranium enrichment were found. These neutron and high-energy gamma data are used to create calibration-dependent enrichment meters for ²³⁴U. The ²³⁴U enrichment calculated from the neutron count rate and 4 – 6 MeV gamma count rate is more accurate than methods that rely on the 120.9 keV peak which is strongly attenuated inside commercial sized UF₆ cylinders. These neutron and high-energy gamma enrichment calculators can also be used to determine a ²³⁵U enrichment, assuming mass-based enrichment from natural uranium, but the results are not as accurate as the traditional 185.7 keV peak enrichment meter.

Original language	English
Article number	163912
Journal	Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Volume	972
DOIs	https://doi.org/10.1016/j.nima.2020.163912
State	Published - Aug 21 2020

Funding

This work was supported by the U.S. National Nuclear Security Administration's (NNSA) Human Capital Development Program and National Nuclear Security Administration's (NNSA) Defense Nuclear Nonproliferation R&D (NA-22). This work was supported by the U.S. National Nuclear Security Administration’s (NNSA) Human Capital Development Program and National Nuclear Security Administration’s (NNSA) Defense Nuclear Nonproliferation R&D (NA-22).

Funders	Funder number
Defense Nuclear Nonproliferation R&D
National Nuclear Security Administration's
U.S. National Nuclear Security Administration's
National Nuclear Security Administration
Office of Defense Nuclear Nonproliferation	NA-22

Keywords

Enrichment
High energy gamma rays
NDA
Neutrons
Uranium

Access to Document

10.1016/j.nima.2020.163912

Cite this

Greaney, A. T., Smith, S. K., Venkataraman, R., Richards, J. M., & Fugate, G. A. (2020). Applications of HPGe-detected high energy gamma rays toward quantifying neutron emission rates and ²³⁴U enrichment in UF₆ cylinders. Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 972, Article 163912. https://doi.org/10.1016/j.nima.2020.163912

@article{4855c62eee544972be7e86f8b41534be,

title = "Applications of HPGe-detected high energy gamma rays toward quantifying neutron emission rates and 234U enrichment in UF6 cylinders",

abstract = "This study presents a 234U enrichment meter that uses high energy gamma and neutron count rate as measured by a portable, high-purity germanium gamma ray detector. Twenty-one 30B cylinders containing UF6 of varying origin were analyzed with an HPGe detector for high-energy gamma ray and neutron counts. Excellent correlations (R2 ≥ 0.95) between various regions of ≥3.0 MeV gamma rays, neutron count rate, and uranium enrichment were found. These neutron and high-energy gamma data are used to create calibration-dependent enrichment meters for 234U. The 234U enrichment calculated from the neutron count rate and 4 – 6 MeV gamma count rate is more accurate than methods that rely on the 120.9 keV peak which is strongly attenuated inside commercial sized UF6 cylinders. These neutron and high-energy gamma enrichment calculators can also be used to determine a 235U enrichment, assuming mass-based enrichment from natural uranium, but the results are not as accurate as the traditional 185.7 keV peak enrichment meter.",

keywords = "Enrichment, High energy gamma rays, NDA, Neutrons, Uranium",

author = "Greaney, {Allison T.} and Smith, {Susan K.} and Ramkumar Venkataraman and Richards, {Jason M.} and Fugate, {Glenn A.}",

note = "Publisher Copyright: {\textcopyright} 2020 Elsevier B.V.",

year = "2020",

month = aug,

day = "21",

doi = "10.1016/j.nima.2020.163912",

language = "English",

volume = "972",

journal = "Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment",

issn = "0168-9002",

publisher = "Elsevier",

}

Greaney, AT , Smith, SK , Venkataraman, R, Richards, JM & Fugate, GA 2020, 'Applications of HPGe-detected high energy gamma rays toward quantifying neutron emission rates and ²³⁴U enrichment in UF₆ cylinders', Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 972, 163912. https://doi.org/10.1016/j.nima.2020.163912

Applications of HPGe-detected high energy gamma rays toward quantifying neutron emission rates and ²³⁴U enrichment in UF₆ cylinders. / Greaney, Allison T.; Smith, Susan K.; Venkataraman, Ramkumar et al.
In: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 972, 163912, 21.08.2020.

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

TY - JOUR

T1 - Applications of HPGe-detected high energy gamma rays toward quantifying neutron emission rates and 234U enrichment in UF6 cylinders

AU - Greaney, Allison T.

AU - Smith, Susan K.

AU - Venkataraman, Ramkumar

AU - Richards, Jason M.

AU - Fugate, Glenn A.

PY - 2020/8/21

Y1 - 2020/8/21

N2 - This study presents a 234U enrichment meter that uses high energy gamma and neutron count rate as measured by a portable, high-purity germanium gamma ray detector. Twenty-one 30B cylinders containing UF6 of varying origin were analyzed with an HPGe detector for high-energy gamma ray and neutron counts. Excellent correlations (R2 ≥ 0.95) between various regions of ≥3.0 MeV gamma rays, neutron count rate, and uranium enrichment were found. These neutron and high-energy gamma data are used to create calibration-dependent enrichment meters for 234U. The 234U enrichment calculated from the neutron count rate and 4 – 6 MeV gamma count rate is more accurate than methods that rely on the 120.9 keV peak which is strongly attenuated inside commercial sized UF6 cylinders. These neutron and high-energy gamma enrichment calculators can also be used to determine a 235U enrichment, assuming mass-based enrichment from natural uranium, but the results are not as accurate as the traditional 185.7 keV peak enrichment meter.

AB - This study presents a 234U enrichment meter that uses high energy gamma and neutron count rate as measured by a portable, high-purity germanium gamma ray detector. Twenty-one 30B cylinders containing UF6 of varying origin were analyzed with an HPGe detector for high-energy gamma ray and neutron counts. Excellent correlations (R2 ≥ 0.95) between various regions of ≥3.0 MeV gamma rays, neutron count rate, and uranium enrichment were found. These neutron and high-energy gamma data are used to create calibration-dependent enrichment meters for 234U. The 234U enrichment calculated from the neutron count rate and 4 – 6 MeV gamma count rate is more accurate than methods that rely on the 120.9 keV peak which is strongly attenuated inside commercial sized UF6 cylinders. These neutron and high-energy gamma enrichment calculators can also be used to determine a 235U enrichment, assuming mass-based enrichment from natural uranium, but the results are not as accurate as the traditional 185.7 keV peak enrichment meter.

KW - Enrichment

KW - High energy gamma rays

KW - NDA

KW - Neutrons

KW - Uranium

UR - http://www.scopus.com/inward/record.url?scp=85085274271&partnerID=8YFLogxK

U2 - 10.1016/j.nima.2020.163912

DO - 10.1016/j.nima.2020.163912

M3 - Article

AN - SCOPUS:85085274271

SN - 0168-9002

VL - 972

JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

M1 - 163912

ER -

Greaney AT , Smith SK , Venkataraman R, Richards JM, Fugate GA. Applications of HPGe-detected high energy gamma rays toward quantifying neutron emission rates and ²³⁴U enrichment in UF₆ cylinders. Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 2020 Aug 21;972:163912. doi: 10.1016/j.nima.2020.163912