Abstract
An experimental validation of a nuclear forensics methodology for the source reactor-type discrimination of separated weapons-useable plutonium is presented. The methodology uses measured values of intra-element isotope ratios of plutonium and fission product contaminants. MCNP radiation transport codes were used for various reactor core modeling and fuel burnup simulations. A reactor-dependent library of intra-element isotope ratio values as a function of burnup and time since irradiation was created from the simulation results. The experimental validation of the methodology was achieved by performing two low-burnup experimental irradiations, resulting in distinct fuel samples containing sub-milligram quantities of weapons-useable plutonium. The irradiated samples were subjected to gamma and mass spectrometry to measure several intra-element isotope ratios. For each reactor in the library, a maximum likelihood calculation was utilized to compare the measured and simulated intra-element isotope ratio values, producing a likelihood value which is proportional to the probability of observing the measured ratio values, given a particular reactor in the library. The measured intra-element isotope ratio values of both irradiated samples and its comparison with the simulation predictions using maximum likelihood analyses are presented. The analyses validate the nuclear forensics methodology developed.
Original language | English |
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Pages (from-to) | 384-393 |
Number of pages | 10 |
Journal | Nuclear Engineering and Technology |
Volume | 51 |
Issue number | 2 |
DOIs | |
State | Published - Apr 2019 |
Externally published | Yes |
Funding
A small portion of the funding (<5%) for this work including mass spectrometry sample aliquot preparation and mass spectrometry analysis was supported by the U.S. Department of Energy National Nuclear Security Administration through the Nuclear Science and Security Consortium under Award Number(s) DE-NA0003180 and/or DE-NA0000979 . This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. The majority of the funding for this work (>95%) including the irradiation campaigns, computational efforts, and maximum likelihood analysis was supported by the U.S. Department of Homeland Security , Domestic Nuclear Detection Office under Grant Award Numbers: NSF Grant No. ECCS-1140018 , DHS-2012-DN-077-ARI1057-02&03 , and DHS-2015-DN-077-ARI1099 . The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Department of Homeland Security. The majority of the funding for this work (>95%) including the irradiation campaigns, computational efforts, and maximum likelihood analysis was supported by the U.S. Department of Homeland Security, Domestic Nuclear Detection Office under Grant Award Numbers: NSF Grant No. ECCS-1140018, DHS-2012-DN-077-ARI1057-02&03, and DHS-2015-DN-077-ARI1099. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Department of Homeland Security.A small portion of the funding (<5%) for this work including mass spectrometry sample aliquot preparation and mass spectrometry analysis was supported by the U.S. Department of Energy National Nuclear Security Administration through the Nuclear Science and Security Consortium under Award Number(s) DE-NA0003180 and/or DE-NA0000979. This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
Keywords
- Intra-element isotope ratios
- Maximum likelihood
- Nuclear forensics
- Reactor-type discrimination
- Weapons-useable plutonium