Safeguards Nuclear Data Needs and Motivations

WANDA 2021 Safeguards Nuclear Data Needs N A T I O N A L N U C L E A R S E C U R I T Y A D M I N I S T R A T I O N N A T I O N A L N U C L E A R S E C U R I T Y A D M I N I S T R A T I O N Christopher Ramos, Ph.D. Senior Program Manager Defense Nuclear Nonproliferation R&D

Safeguards Nuclear Motivations Why is the field of Safeguards interested in nuclear data? A transition to physics-based NDA for SNM Improvements in analysis techniques and a trend toward predictive methods These physics-based methods rely on high quality atomic and nuclear data 2 Defense Nuclear Nonproliferation R&D

Safeguards Nuclear Roadmap Passive Counting -Ray Neutron Coincidence Multiplicity Counting Quantitative gamma-ray analysis systems Hybrid K-Edge X-Ray Mass Attenuation Coefficients Atomic Cross Sections Spontaneous fission yields (fis/sec/g) in, Pi( ) sn , Ps( ) (E) Photoelectric cross sections Shape & absolute magnitude of K-edge cross section of the actinides Atomic s of U and Pu from 60 to 300 KeV Gamma-ray yields Gamma-ray energies Half-life MGA FRAM Isotopic analysis codes Self attenuation corrections MACs for U, Pu, Am and Th to 0.1% 1 3 4 2 3 Defense Nuclear Nonproliferation R&D

NA-221 Funded Project 4 Defense Nuclear Nonproliferation R&D

Examples of Data Needs Spontaneous Fission Yields (fis/sec/gram) Spontaneous Neutron Multiplicity Factorial Moments and Distributions, sn, Ps( ) (Fission Neutron) Induced Neutron Multiplicity Moments and Distributions, in, Pi( ) Neutron Energy Distributions, (E), to first order characterized by the mean energies Comment Isotope Parameter Uncertainty Goal SF half-life 240Pu g, fis/s/g 0.82% <0.25% Nu-bar 240Pu s1, n/fis s2, n2/fis s3, n3/fis i1 i2 i3 <EPu>/<ECf> 0.20% <0.25% 2nd factorial moment 3rd factorial moment 240Pu 0.30% <0.25% 240Pu 1.30% <0.25% Averaged over a PFNS 239Pu 0.20% <0.20% 239Pu 0.50% 0.80% <0.20% <0.20% 239Pu Mean emission energy 240Pu : 252C ~2% <0.1% 5 Defense Nuclear Nonproliferation R&D