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Title: Peak fitting applied to low-resolution enrichment measurements

Abstract

Materials accounting at bulk processing facilities that handle low enriched uranium consists primarily of weight and uranium enrichment measurements. Most low enriched uranium processing facilities draw separate materials balances for each enrichment handled at the facility. The enrichment measurement determines the isotopic abundance of the {sup 235}U, thereby determining the proper strata for the item, while the weight measurement generates the primary accounting value for the item. Enrichment measurements using the passive gamma radiation from uranium were developed for use in US facilities a few decades ago. In the US, the use of low-resolution detectors was favored because they cost less, are lighter and more robust, and don`t require the use of liquid nitrogen. When these techniques were exported to Europe, however, difficulties were encountered. Two of the possible root causes were discovered to be inaccurate knowledge of the container wall thickness and higher levels of minor isotopes of uranium introduced by the use of reactor returns in the enrichment plants. the minor isotopes cause an increase in the Compton continuum under the 185.7 keV assay peak and the observance of interfering 238.6 keV gamma rays. The solution selected to address these problems was to rely on the slower, moremore » costly, high-resolution gamma ray detectors when the low-resolution method failed. Recently, these gamma ray based enrichment measurement techniques have been applied to Russian origin material. The presence of interfering gamma radiation from minor isotopes was confirmed. However, with the advent of fast portable computers, it is now possible to apply more sophisticated analysis techniques to the low-resolution data in the field. Explicit corrections for Compton background, gamma rays from {sup 236}U daughters, and the attenuation caused by thick containers can be part of the least squares fitting routine. Preliminary results from field measurements in Kazakhstan will be discussed.« less

Authors:
; ;  [1];  [2]; ; ; ;  [3]
  1. Los Alamos National Lab., NM (United States)
  2. Lawrence Livermore National Lab., CA (United States)
  3. Ulba Metallurgical Facility, Ust-Kamenogorsk (Kazakhstan)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
296666
Report Number(s):
LA-UR-98-2436; CONF-980733-
ON: DE99001211; TRN: 99:002450
DOE Contract Number:  
W-7405-ENG-36
Resource Type:
Technical Report
Resource Relation:
Conference: 39. Institute of Nuclear Materials Management (INMM) annual meeting, Naples, FL (United States), 26-30 Jul 1998; Other Information: PBD: [1998]
Country of Publication:
United States
Language:
English
Subject:
05 NUCLEAR FUELS; 44 INSTRUMENTATION, INCLUDING NUCLEAR AND PARTICLE DETECTORS; SLIGHTLY ENRICHED URANIUM; MATERIAL BALANCE; NUCLEAR MATERIALS MANAGEMENT; GAMMA DETECTION; NAI DETECTORS; DATA ANALYSIS; EXPERIMENTAL DATA

Citation Formats

Bracken, D, McKown, T, Sprinkle, Jr, J K, Gunnink, R, Kartoshov, M, Kuropatwinski, J, Raphina, G, and Sokolov, G. Peak fitting applied to low-resolution enrichment measurements. United States: N. p., 1998. Web. doi:10.2172/296666.
Bracken, D, McKown, T, Sprinkle, Jr, J K, Gunnink, R, Kartoshov, M, Kuropatwinski, J, Raphina, G, & Sokolov, G. Peak fitting applied to low-resolution enrichment measurements. United States. https://doi.org/10.2172/296666
Bracken, D, McKown, T, Sprinkle, Jr, J K, Gunnink, R, Kartoshov, M, Kuropatwinski, J, Raphina, G, and Sokolov, G. 1998. "Peak fitting applied to low-resolution enrichment measurements". United States. https://doi.org/10.2172/296666. https://www.osti.gov/servlets/purl/296666.
@article{osti_296666,
title = {Peak fitting applied to low-resolution enrichment measurements},
author = {Bracken, D and McKown, T and Sprinkle, Jr, J K and Gunnink, R and Kartoshov, M and Kuropatwinski, J and Raphina, G and Sokolov, G},
abstractNote = {Materials accounting at bulk processing facilities that handle low enriched uranium consists primarily of weight and uranium enrichment measurements. Most low enriched uranium processing facilities draw separate materials balances for each enrichment handled at the facility. The enrichment measurement determines the isotopic abundance of the {sup 235}U, thereby determining the proper strata for the item, while the weight measurement generates the primary accounting value for the item. Enrichment measurements using the passive gamma radiation from uranium were developed for use in US facilities a few decades ago. In the US, the use of low-resolution detectors was favored because they cost less, are lighter and more robust, and don`t require the use of liquid nitrogen. When these techniques were exported to Europe, however, difficulties were encountered. Two of the possible root causes were discovered to be inaccurate knowledge of the container wall thickness and higher levels of minor isotopes of uranium introduced by the use of reactor returns in the enrichment plants. the minor isotopes cause an increase in the Compton continuum under the 185.7 keV assay peak and the observance of interfering 238.6 keV gamma rays. The solution selected to address these problems was to rely on the slower, more costly, high-resolution gamma ray detectors when the low-resolution method failed. Recently, these gamma ray based enrichment measurement techniques have been applied to Russian origin material. The presence of interfering gamma radiation from minor isotopes was confirmed. However, with the advent of fast portable computers, it is now possible to apply more sophisticated analysis techniques to the low-resolution data in the field. Explicit corrections for Compton background, gamma rays from {sup 236}U daughters, and the attenuation caused by thick containers can be part of the least squares fitting routine. Preliminary results from field measurements in Kazakhstan will be discussed.},
doi = {10.2172/296666},
url = {https://www.osti.gov/biblio/296666}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Dec 01 00:00:00 EST 1998},
month = {Tue Dec 01 00:00:00 EST 1998}
}