8 research outputs found
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SNM measurement uncertainties: Potential impacts for materials disposition
A brief discussion of various issues relative to nuclear measurement uncertainties and impacts to the Materials Disposition (MD) program is presented. Today`s nuclear measurement technology is well situated to handle most of materials analysis concerns while controlling uncertainties to a high degree of confidence. However many of the options under consideration by the disposition program will present new challenges. Some of these challenges include significant material processing throughputs, a variety of material forms, unique waste streams, and difficult to measure matrices. There are also some questions as to a facility`s ability to achieve IAEA verification requirements and to maintain measurement uncertainties within the significant quantity level
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Verification of classified fissile material using unclassified attributes
This paper reports on the most recent efforts of US technical experts to explore verification by IAEA of unclassified attributes of classified excess fissile material. Two propositions are discussed: (1) that multiple unclassified attributes could be declared by the host nation and then verified (and reverified) by the IAEA in order to provide confidence in that declaration of a classified (or unclassified) inventory while protecting classified or sensitive information; and (2) that attributes could be measured, remeasured, or monitored to provide continuity of knowledge in a nonintrusive and unclassified manner. They believe attributes should relate to characteristics of excess weapons materials and should be verifiable and authenticatable with methods usable by IAEA inspectors. Further, attributes (along with the methods to measure them) must not reveal any classified information. The approach that the authors have taken is as follows: (1) assume certain attributes of classified excess material, (2) identify passive signatures, (3) determine range of applicable measurement physics, (4) develop a set of criteria to assess and select measurement technologies, (5) select existing instrumentation for proof-of-principle measurements and demonstration, and (6) develop and design information barriers to protect classified information. While the attribute verification concepts and measurements discussed in this paper appear promising, neither the attribute verification approach nor the measurement technologies have been fully developed, tested, and evaluated
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Secondary, non-resonant cw laser ionization efficiency enhancement for resonance ionization mass spectrometry
Secondary, non-resonant laser ionization is used to significantly enhance the ionization efficiency of lutetium in CW Resonance Ionization Mass Spectrometry (RIMS). Spectral line-narrowing of hyperfine components is observed and understood in terms of a Raman mechanism. 7 refs., 3 figs
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Isotopically selective, Doppler-free, saturation spectroscopy of lutetium isotopes via resonance ionization mass spectrometry
A new technique utilizing RIMS to obtain very high resolution atomic spectra with isotopic selectivity has been demonstrated. This technique allows the precise determination of HF splitting constants, limited only by the transition's natural linewidth. In addition, it is also feasible with this technique to accurately determine atomic isotope shifts. The exact determination of HF component line positions provides data for isotopically selective ionization which, in turn, will increase RIMS' dynamic range. Future work includes the incorporation of a /open quotes/vibrating/close quotes/ mirror and the study of rarer isotopes, i.e., /sup 174/Lu, /sup 173/Lu, /sup 172/Lu, /sup 171/Lu, and possibly, /sup 170/Lu. 13 refs., 3 figs
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High-fidelity in isotope ratio measurements for resonance ionization mass spectrometry
Calculations are performed to gauge the effect of the convolution of atomic spectral characteristics with laser sources upon isotope ratio measurements by Resonance Ionization Mass Spectrometry (RIMS). Comparison with experimental data is included. 7 refs., 3 figs
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Resonance ionization mass spectrometry of lead and bismuth mixtures
Resonance ionization of lead and bismuth has been demonstrated using an excimer laser pumped dye laser in three-photon, one-color ionization schemes, using a quadrupole mass spectrometer for detection
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Use of Stable Noble Gases as a Predictor of Reactor Fuel Type and Exposure
Ensuring spent reactor fuel is not produced to provide weapons-grade plutonium is becoming a major concern as many countries resort to nuclear power as a solution to their energy problems. Proposed solutions range from the development of proliferation resistant fuel to continuous monitoring of the fuel. This paper discusses the use of the stable isotopes of the fissiogenic noble gases, xenon and krypton, for determining the burnup characteristics, fuel type, and the reactor type of the fuel from which the sample was obtained. The gases would be collected on-stack as the fuel is reprocessed, and thus confirm that the fuel is as declared