scholarly journals Separation of Lanthanide Isotopes from Mixed Fission Product Samples

Separations ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 104
Author(s):  
Leah M. Arrigo ◽  
Jun Jiang ◽  
Zachary S. Finch ◽  
James M. Bowen ◽  
Staci M. Herman ◽  
...  
Keyword(s):  
Fission Product ◽  
Fission Products ◽  
Nuclear Data ◽  
Product Analysis ◽  
Data Production ◽  
Thermal Irradiation ◽  
Nuclear Events ◽  
Lanthanide Separation ◽  
Enriched Uranium ◽  
Fission Yields

The measurement of radioactive fission products from nuclear events has important implications for nuclear data production, environmental monitoring, and nuclear forensics. In a previous paper, the authors reported the optimization of an intra-group lanthanide separation using LN extraction resin from Eichrom Technologies®, Inc. and a nitric acid gradient. In this work, the method was demonstrated for the separation and quantification of multiple short-lived fission product lanthanide isotopes from a fission product sample produced from the thermal irradiation of highly enriched uranium. The separations were performed in parallel in quadruplicate with reproducible results and high decontamination factors for 153Sm, 156Eu, and 161Tb. Based on the results obtained here, the fission yields for 144Ce, 153Sm, 156Eu, and 161Tb are consistent with published fission yields. This work demonstrates the effectiveness of the separations for the intended application of short-lived lanthanide fission product analysis requiring high decontamination factors.

scholarly journals Data assimilation of post irradiation examination experiments to adjust fission yields

2020 ◽  
Vol 239 ◽  
pp. 13004
Author(s):  
Daniel Siefman ◽  
Mathieu Hursin ◽  
Andreas Pautz
Keyword(s):  
Data Assimilation ◽  
Fission Product ◽  
Fission Products ◽  
Nuclear Data ◽  
Relative Difference ◽  
Model Parameters ◽  
Spent Fuel ◽  
Post Irradiation ◽  
Relative Standard ◽  
Fission Yields

Nuclear data, especially fission yields, create uncertainties in the predicted concentrations of fission products in spent fuel. Herein, we present a new framework that extends data assimilation methods to burnup simulations by using data from post-irradiation examination experiments. The adjusted fission yields improve the bias and reduce the uncertainty of predicted fission product concentrations in spent fuel. Our approach modifies fission yields by adjusting the model parameters of the code GEF with post-irradiation examination experiments. We used the BFMC data assimilation method to account for the non-normality of GEF's fission yields. In the application that we present, the assimilation decreased the average bias of the predicted fission product concentrations from 26% to 15%. The average relative standard deviation decreased from 21% to 14%. The GEF fission yields after data assimilation agreed better with those in ENDF/B-VIII.O. For Pu-239 thermal fission, the average relative difference from ENDF/B-VIII.O was 16% before data assimilation and 11% after. For the standard deviations of the fission yields, GEF's were, on average, 16% larger than those from ENDF/B-VIII.O before data assimilation and 15% smaller after.

scholarly journals Fission Product Yield Measurements from Neutron-Induced Fission of 235,238 U and 239Pu

2020 ◽  
Vol 232 ◽  
pp. 03006
Author(s):  
M. A. Stoyer ◽  
A. P. Tonchev ◽  
J. A. Silano ◽  
M. E. Gooden ◽  
J. B. Wilhelmy ◽  
...  
Keyword(s):  
Fission Product ◽  
Nuclear Physics ◽  
Fission Products ◽  
Product Yield ◽  
Tandem Accelerator ◽  
Precision Data ◽  
High Precision Data ◽  
Induced Fission ◽  
The Impact ◽  
Fission Yields

Fission product yields (FPY) are one of the most fundamental quantities that can be measured for a fissioning nucleus and are important for basic and applied nuclear physics. Recent measurements using mono-energetic and pulsed neutron beams generated using Triangle Universities Nuclear Laboratory’s tandem accelerator and employing a dual fission chamber setup have produced self-consistent, high-precision data critical for testing fission models for the neutron-induced fission of 235,238U and 239Pu between neutron energies of 0.5 to 15.0 MeV. These data have elucidated a low-energy dependence of FPY for several fission products using irradiations of varying lengths and neutron energies. This paper will discuss new measurements just beginning utilizing a RApid Belt-driven Irradiated Target Transfer System (RABITTS) to measure shorterlived fission products and the time dependence of fission yields, expanding the measurements from cumulative towards independent fission yields. The uniqueness of these FPY data and the impact on the development of fission theory will be discussed.

scholarly journals Interaction of Noble Metal Fission Products with Pyrolytic Silicon Carbide

1982 ◽  
Vol 40 ◽  
pp. 566-567
Author(s):  
R. J. Lauf ◽  
D. N. Braski
Keyword(s):  
Silicon Carbide ◽  
Fission Product ◽  
Noble Metals ◽  
Fission Products ◽  
Pyrolytic Carbon ◽  
Enriched Uranium ◽  
Fuel Particles ◽  
The Many ◽  
Sic Coatings ◽  
Palladium Group

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain layers of pyrolytic carbon and silicon carbide, which act as a miniature pressure vessel and form the primary fission product barrier. Of the many fission products formed during irradiation, the noble metals are of particular interest because they interact significantly with the SiC layer and their concentrations are somewhat higher in the low-enriched uranium fuels currently under consideration. To study fission product-SiC interactions, particles of UO2 or UC2 are doped with fission product elements before coating and are then held in a thermal gradient up to several thousand hours. Examination of the SiC coatings by TEM-AEM after annealing shows that silver behaves differently from the palladium group.

scholarly journals Data assimilation of post-irradiation examination data for fission yields from GEF

2020 ◽  
Vol 6 ◽  
pp. 52
Author(s):  
Daniel Siefman ◽  
Mathieu Hursin ◽  
Henrik Sjostrand ◽  
Georg Schnabel ◽  
Dimitri Rochman ◽  
...  
Keyword(s):  
Data Assimilation ◽  
Marginal Likelihood ◽  
Fission Products ◽  
Nuclear Data ◽  
Optimization Method ◽  
Model Parameters ◽  
Spent Fuel ◽  
Post Irradiation ◽  
Relative Standard ◽  
Fission Yields

Nuclear data, especially fission yields, create uncertainties in the predicted concentrations of fission products in spent fuel which can exceed engineering target accuracies. Herein, we present a new framework that extends data assimilation methods to burnup simulations by using post-irradiation examination experiments. The adjusted fission yields lowered the bias and reduced the uncertainty of the simulations. Our approach adjusts the model parameters of the code GEF. We compare the BFMC and MOCABA approaches to data assimilation, focusing especially on the effects of the non-normality of GEF’s fission yields. In the application that we present, the best data assimilation framework decreased the average bias of the simulations from 26% to 14%. The average relative standard deviation decreased from 21% to 14%. The GEF fission yields after data assimilation agreed better with those in JEFF3.3. For Pu-239 thermal fission, the average relative difference from JEFF3.3 was 16% before data assimilation and after it was 12%. For the standard deviations of the fission yields, GEF’s were 100% larger than JEFF3.3’s before data assimilation and after were only 4% larger. The inconsistency of the integral data had an important effect on MOCABA, as shown with the Marginal Likelihood Optimization method. When the method was not applied, MOCABA’s adjusted fission yields worsened the bias of the simulations by 30%. BFMC showed that it inherently accounted for this inconsistency. Applying Marginal Likelihood Optimization with BFMC gave a 2% lower bias compared to not applying it, but the results were more poorly converged.

scholarly journals Using CGMF to estimate corrections for fission yields measured via γ-ray spectroscopy

2020 ◽  
Vol 242 ◽  
pp. 03003
Author(s):  
P. Jaffke ◽  
P. Talou ◽  
M. Devlin ◽  
N. Fotiades
Keyword(s):  
Fission Product ◽  
Nuclear Structure ◽  
Fission Products ◽  
Spin Distribution ◽  
Product Yields ◽  
Fission Fragments ◽  
Fission Product Yields ◽  
Γ Ray ◽  
The Impact ◽  
Fission Yields

Fission product yields have been inferred using γ-ray spectroscopy for several decades. Typically, these efforts have focused on even-Z even-A fission products as their nuclear structure are less complicated. To further simplify the situation, it is often assumed that no side-feeding to the ground-state occurs and multiplicity cuts have a negligible effect on the inferred yields. Using CGMF, a Hauser-Feshbach statistical decay model for the primary fission fragments, we estimate the impact of these assumptions and determine corrections for specific fission product yields. We report on these corrections and investigate their sensitivity to various nuclear parameters, specifically the spin distribution of the fission fragments and the assumed nuclear structure. Our results indicate that even in the simplest of cases, say the 2+ → 0+ transitions in even-Z even-A fragments, average level corrections are on the order of 75%.

scholarly journals Toward short-lived and energy-dependent fission product yields from neutron-induced fission

2020 ◽  
Vol 239 ◽  
pp. 03001
Author(s):  
Anton P Tonchev ◽  
Jack A Silano ◽  
Chris Hagmann ◽  
Roger Henderson ◽  
Mark A Stoyer ◽  
...  
Keyword(s):  
Fission Product ◽  
Fission Products ◽  
Incident Neutron ◽  
Tandem Accelerator ◽  
Precision Data ◽  
Product Yields ◽  
Fission Product Yields ◽  
Induced Fission ◽  
Energy Dependent ◽  
Fission Yields

Fission product yields (FPYs) are an important source of information that are used for basic and applied physics. They are essential observables to address questions relevant to nucleosynthesis in the cosmos that created the elements from iron to uranium, for example, in energy generating processes from fission recycling in binary neutron star mergers; resolving the reactor neutrino anomaly; decay heat release in nuclear reactors; and many national security applications. While new applications will require accurate energy-dependent FPY data over a broad set of incident neutron energies, the current evaluated FPY data files contain only three energy points: thermal, fast, and 14-MeV incident energies. Recent measurements using mono-energetic and pulsed neutron beams at the Triangle Universities Nuclear Laboratory (TUNL) tandem accelerator and employing a dual fission ionization chambers setup have produced self-consistent, high-precision data critical for testing fission models for the neutron-induced fission of the major actinide nuclei. This paper will present new campaign just beginning utilizing a RApid Belt-driven Irradiated Target Transfer System (RABITTS) to measure shorter-lived fission products and the time dependence of fission yields, expanding the measurements from cumulative towards independent fission yields.

Fission Products Particular Peak Measurement for UO2-Gd2O3-MOX γ-Scanning Renormalization in 100% MOX ABWR Mock-Up Cores

2004 ◽  
Author(s):  
P. Blaise ◽  
S. Cathalau ◽  
N. Thiollay ◽  
P. Fougeras ◽  
V. Laval ◽  
...  
Keyword(s):  
Radioactive Decay ◽  
Fission Products ◽  
Nuclear Data ◽  
Scaling Factor ◽  
Experimental Program ◽  
Fission Rate ◽  
Good Consistency ◽  
Different Sources ◽  
Fission Yields ◽  
Systematical Uncertainty

This paper presents the principles of the peak check measurements by gamma spectrometry. One details the main equations used for the analysis of the raw data as the calculation of the different sources of uncertainties and their propagation on the result. The method is illustrated with actual examples from the French-Japanese BASALA ABWR 100% MOX experimental program. • For each individual fission rate, the systematical uncertainty due to the radioactive decay data is smaller than the statistical uncertainty due to the counting process. • The main part of the final uncertainty on the scaling factor is brought by the systematical uncertainty on the average fission yields. This study enables to propose some recommendations for fission products and nuclear data evaluation used. • Only the analysis of the 140La peak at 1596 keV leads to acceptable uncertainties on the fission rate maps renormalization, with a good consistency with the integral γ-scanning results. • The JEF-2.2 evaluation on the fission yields and their associated uncertainties seems more realistic than the ENDF/B-6 and is recommended for the scaling factor analysis.

scholarly journals Summation Calculations for Reactor Antineutrino Spectra, Decay Heat and Delayed Neutron Fractions Involving New TAGS Data and Evaluated Databases

2019 ◽  
Vol 211 ◽  
pp. 01001
Author(s):  
M. Estienne ◽  
M. Fallot ◽  
L. Giot ◽  
V. Guadilla-Gomez ◽  
L. Le Meur ◽  
...  
Keyword(s):  
Fission Product ◽  
Neutron Emission ◽  
Fission Products ◽  
Nuclear Data ◽  
Delayed Neutron ◽  
Data Bases ◽  
Decay Data ◽  
Decay Heat ◽  
Reactor Antineutrino ◽  
Decay Properties

Three observables of interest for present and future reactors depend on the β decay properties of the fission products: antineutrinos from reactors, the reactor decay heat and delayed neutron emission. In these proceedings, we present new results from summation calculations of the first two quantities quoted above, performed with evolved independent yields coupled with fission product decay data, from various nuclear data bases or models. New TAGS results from the latest experiment of the TAGS collaboration at the JYFL facility of Jyväskylä will be displayed as well as their impact on the antineutrino spectra and the decay heat associated to fission pulses of the main actinides.

scholarly journals Fission yields and cross sections: correlated or not?

2021 ◽  
Vol 7 ◽  
pp. 5
Author(s):  
Dimitri Alexandre Rochman ◽  
Eric Bauge
Keyword(s):  
Experimental Data ◽  
Cross Sections ◽  
Previous Analysis ◽  
Fission Products ◽  
Nuclear Data ◽  
Isotopic Compositions ◽  
Different Types ◽  
Fission Yields ◽  
Integral Data ◽  
Selection Of

Cross sections and fission yields can be correlated, depending on the selection of integral experimental data. To support this statement, this work presents the use of experimental isotopic compositions (both for actinides and fission products) from a sample irradiated in a reactor, to construct correlations between various cross sections and fission yields. This study is therefore complementing previous analysis demonstrating that different types of nuclear data can be correlated, based on experimental integral data.

A MASS SPECTROMETER INVESTIGATION OF THE ISOTOPES OF XENON AND KRYPTON RESULTING FROM THE FISSION OF U235 BY THERMAL NEUTRONS

1947 ◽  
Vol 25a (1) ◽  
pp. 1-14 ◽  
Author(s):  
H. G. Thode ◽  
R. L. Graham
Keyword(s):  
Stable Isotopes ◽  
Stable Isotope ◽  
Fission Product ◽  
Mass Spectrometer ◽  
Half Life ◽  
Fission Products ◽  
Rare Gas ◽  
Thermal Neutrons ◽  
Yield Values ◽  
Fission Yields

Mass spectrometer investigations have been made of rare gas fission products extracted from uranium irradiated with thermal neutrons. The irradiated uranium rods were allowed to stand for various periods of time after irradiation to permit the decay of most fission product chains to stable isotopes. Four stable isotopes of xenon were found having mass numbers 131, 132, 134, and 136, and three stable isotopes of krypton with mass numbers 83, 84, and 86. Kr86, the most abundant of the latter group, is probably formed directly in fission. In addition a long lived krypton with mass 85 was discovered which is isomeric with a 4.0 hr. Kr85 reported previously.The relative abundances of these isotopes which are related directly to fission yields of the corresponding mass chains have been determined with an accuracy of 1% or better. The mass numbers of these fission chains can now be identified with certainty by comparing mass spectrometer abundance data with known yield values of the active chain members. Finally, the half-life of krypton 85 was determined by comparing its concentration to that of a stable isotope over a period of time.

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