15th International Conference on Nuclear Data for Science and Technology (ND2022)

Session

Covariances

27 Jul 2022, 06:00

Delta King

Conveners

Covariances: I

• Oscar Cabellos

Covariances: II

• Kent Parsons (LANL)

134. (WITHDRAWN) Reactor Antineutrino Energy Spectra and Associated Uncertainties Using the GEF Model

Magali Estienne (Subatech)

27/07/2022, 06:00

Reactor antineutrino energy spectra are the subject of active experimental researches nowadays, either through large reactor neutrino experiments, short baseline neutrino experiments at research reactors or through dedicated nuclear physics measurements of the properties of the fission products. The summation method relies on the use of nuclear data to build the reactor antineutrino energy...

135. Toward an exact Bayesian inference of fission nuclear data

David Regnier

27/07/2022, 06:24

Evaluating nuclear data reduces the information of a set of experimental data and theoretical models to provide the best estimate of a physical quantity. In the last decade safety applications pushed the evaluation community toward better quantification of the uncertainties associated to evaluated nuclear data. The Bayesian inference appears as a standard and versatile mathematical framework...

136. Surrogate Modeling for Fission Cross Sections, Criticality Studies, and Uncertainty Quantification

Christian Brazell (Texas A&M University)

27/07/2022, 06:36

Christian Brazell
10/15/21
TAMU-LLNL
LLNL-ABS-827556
ND2022

Surrogate Modeling for Fission Cross Sections, Criticality Studies, and Uncertainty Quantification
ABSTRACT

Computational methods have advanced to the point where, in many cases, the main source of uncertainty in neutronics calculations comes from the underlying Nuclear Data (ND). Assessing the impact of the underlying uncertainties...

137. Stochastically Estimated Fission Yield Covariance Matrices

Eric Matthews

27/07/2022, 06:48

A Monte-Carlo method for the generation of correlation and covariance matrices for independent and cumulative fission yields has been developed. The method uses a constrained Monte-Carlo resampling structure in order to vary evaluated fission yield libraries in a way that meets basic conservation principles. This results in the generation of correlation/covariance matrices with limited model...

138. Uncertainty Quantification for Phenomenological Optical Potentials

Cole Pruitt (Lawrence Livermore National Laboratory)

27/07/2022, 07:00

Phenomenological optical model potentials (OMPs) have played an essential role in scattering calculations for several decades. Despite their successes, none have had their parametric uncertainty fully quantified, making reliable extrapolation difficult. To address this gap, we have developed a generic OMP uncertainty quantification framework that leverages Markov-Chain Monte Carlo for OMP...

140. Impact of uncertainties on non-LWR reactivity analysis with ENDF/B-VII.0, ENDF/B-VII.1 and ENDF/B-VIII.0

Friederike Bostelmann (Oak Ridge National Laboratory)

27/07/2022, 07:45

Non-light water reactor (non-LWR) concepts under development throughout the industry are significantly different from traditional LWR designs with respect to geometry, materials, and operating conditions. These differences result in significant differences with respect to the reactor physics behavior of non-LWRs as compared to LWRs. Given the limited operating experience with non-LWRs, the...

141. Towards an ENDF/B-VIII.0-Based Processed Covariance Library at LANL

Nathan Gibson

27/07/2022, 08:09

In the last few decades, the field of nuclear data has been increasingly more diligent in the generation and use of uncertainty information related to nuclear data. This increased interest is fueled by the more wide-spread request for characterization of uncertainties, perhaps for quantifying performance margins or for identifying the best use of experimental resources. Use cases range, for...

142. EMU: Evaluated Means and Uncertainties

Kyle Wendt (Lawrence Livermore National Laboratory)

27/07/2022, 08:21

Evaluated Means and Uncertainties, or EMU, is a new suite of tools for generating statistical realizations of nuclear data libraries encoded in the Generalized Nuclear Database Structure (GNDS). Built upon the For Updating Data and Generating Evaluations (FUDGE) package from LLNL, EMU is capable of reading and generating realizations of nearly any accessible nuclear data library, whether they...

163. Uncertainty Considerations that Impact the Use of Dosimetry Metrics in Modern Semiconductors

Patrick Griffin

27/07/2022, 08:33

Silicon provides a good exemplar for a consideration of the critical parameters that affect the uncertainty for neutron dosimetry metrics, e.g., total kerma, ionizing kerma, displacement damage energy. In addition to the energy-dependent cross section uncertainty found in the ENDF-6 formatted nuclear data files, one must also address uncertainty due to: a) models used, e.g., modeling of the...

165. Study of nuclear data measurement with covariances and uncertainty quantification

Mr Aman Gandhi (Department of Physics, Banaras Hindu University, Varanasi-221005, India)

27/07/2022, 08:45

144. (WITHDRAWN) CEFR criticality uncertainty analysis based on different nuclear data covariance libraries

Augusto Hernandez Solis (SCK-CEN)

The China Experimental Fast Reactor (CEFR) is a 65 MWth pool-type sodium cooled fast reactor. The International Atomic Energy Agency (IAEA) launched a Coordinated Research Project (CRP) based on different released and available start-up tests of CEFR when it first reached criticality in 2010. Therefore, the main objectives of this CRP aim at improving fast reactor simulation analytical...

139. Multivariate statistical reduction of cross-section uncertainties in neutron reactions

Prof. Cristiana Oprea (JINR)

Nuclear reactions induced by fast neutrons starting from 0.5 MeV up to 25 MeV with emission of alpha particles were investigated. Cross-sections and their uncertainties, angular correlations, and forward-backward asymmetry effects were evaluated with Talys, SPSS, and the author’s own computer codes. Contribution to the cross-section of nuclear reaction mechanisms like direct, compound, and...