Fourth Collaborative Materials Exercise of the Nuclear Forensics International Technical Working Group

Schwantes, Jon M.; Marsden, Olivia J.; Reilly, Dallas D.

doi:10.1007/s10967-017-5663-6

Cited by 12 publications

(7 citation statements)

References 8 publications

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“…In this context, accurate and precise U isotopic data of a seized material, delivered in a timely manner, is a key parameter. To foster the capability of nuclear forensics laboratories to provide such high quality data, the Nuclear Forensics International Technical Working Group (ITWG) organises regularly Collaborative Materials Exercises (CMXs) to identify and share best analytical approaches in this scientific area among the participants [ 3 , 4 ].…”

Section: Introductionmentioning

confidence: 99%

Analytical considerations in the determination of uranium isotope ratios in solid uranium materials using laser ablation multi-collector ICP-MS

Krachler

Varga

Nicholl

et al. 2019

Analytica Chimica Acta: X

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Validated analytical measurement protocols for the fast and accurate determination of the uranium (U) isotopic composition ( 234 U, 235 U, 236 U, 238 U) of solid nuclear materials were developed employing ns-laser ablation (LA) coupled to multi-collector ICP-MS. The accuracy of the analytical procedure was assured by frequent ( n = 65) analysis of a pressed pellet of certified isotopic reference material CRM U-030 (∼3 wt% 235 U). The expanded uncertainty ( k = 2) for the n ( 235 U)/ n ( 238 U) ratio was as low as 0.05%, rising to 0.62% and 1.09% for n ( 234 U)/ n ( 238 U) and n ( 236 U)/ n ( 238 U) ratios, respectively. LA-MC-ICP-MS measurements of a pressed pellet of certified isotopic reference material CRM U-020 (∼2 wt% 235 U) before analysis of each sample allowed calculation of the ion counter gains and mass bias correction. Both individual spot analysis and line scan analysis were used to measure n ( 234 U)/ n ( 238 U), n ( 235 U)/ n ( 238 U), and n ( 236 U)/ n ( 238 U) ratios in two low-enriched UO 2 pellets from the fourth Collaborative Materials Exercise (CMX-4), four seized low-enriched UO 2 pellets intercepted from illicit trafficking and one metal sample consisting of depleted U. LA-MC-ICP-MS results of all investigated samples matched well with U isotope ratios obtained by thermal ionisation mass spectrometry (TIMS). This independent confirmation of the LA-MC-ICP-MS results by TIMS underpinned the high quality of generated analytical data. Acquisition of several thousand data points within a couple of minutes during line scan analysis yielded detailed information on the spatial distribution of the U isotopic composition of selected UO 2 pellets, revealing straightforwardly their (in˗)homogeneity on the μm-scale. Calculating skewness and half width of the frequency distributions of the n ( 235 U)/ n ( 238 U) amount ratio allowed the quantitative assessment of the (in-)homogeneity of the investigated samples. This information allows drawing conclusions on the starting materials used for the production of the pellets. From a nuclear forensics perspective, LA-MC-ICP-MS provides quick, accurate results on the spatial di...

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Section: Introductionmentioning

confidence: 99%

Analytical considerations in the determination of uranium isotope ratios in solid uranium materials using laser ablation multi-collector ICP-MS

Krachler

Varga

Nicholl

et al. 2019

Analytica Chimica Acta: X

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“…Pellets are made of UO 2 , whereas ES-1 was a mixture of UO 2 and higher U-oxides. Further details on the exercise samples are provided in the introductory article of this Special Section [ 1 ].…”

Section: Sample Descriptionmentioning

confidence: 99%

“…Results of uranium isotopic abundance measurements by gamma spectrometry and community average values by mass spectrometry for comparison are summarized in Table 3 . The mass spectrometry average is calculated from the data given in graphical form in the CMX-4 After-Action report [ 1 ]. For this calculation the outliers were removed.…”

Section: Determining Major U Isotopic ( 234 U mentioning

confidence: 99%

“…Presence of 232 U in ES-1 and ES-3 indicates that the samples were manufactured from material mixed or contaminated with reprocessed uranium. According to mass spectrometric results [ 1 ], the concentration of 236 U in both samples is about 0.0020 ± 0.0004% on average, but near the detection limit in ES-2 (≤ 10 −4 ). This confirms the conclusion from HRGS that ES-1 and ES-2 contained some reprocessed material, while ES-2 did not.…”

Section: U Age Datingmentioning

confidence: 99%

“…This paper presents the state of practice in gamma spectrometry for nuclear forensics exercises. The Nuclear Forensics International Technical Working Group (ITWG) organized its fourth interlaboratory exercise in 2014, called Collaborative Materials Exercise (CMX-4) [ 1 ]. This paper documents the collective experience with gamma spectrometry during the CMX-4 exercise and it gives a snapshot of the applied approaches.…”

Section: Introductionmentioning

confidence: 99%

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Gamma spectrometry in the ITWG CMX-4 exercise

Lakosi

Zsigrai

Kocsonya

et al. 2018

J Radioanal Nucl Chem

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Low enriched uranium samples of unknown origin were analyzed by 16 laboratories in the context of a Collaborative Materials Exercise (CMX), organized by the Nuclear Forensics International Technical Working Group (ITWG). The purpose was to compare and prioritize nuclear forensic methods and techniques, and to evaluate attribution capabilities among participants. This paper gives a snapshot of the gamma spectrometric capabilities of the participating laboratories and summarizes the results achieved by gamma spectrometry.

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