Citation:
S.P. Martinson, “Destructive and Nondestructive Analyses of Plutonium Separated from a Low-Burnup Now-Enriched Uranium for Nuclear Forensics”, Ph.D. Dissertation, Nuclear Engineering, Texas A&M University, College Station, TX (2022).
Abstract:
The ever-changing global geopolitical landscape greatly influences how nuclear threats grow and evolve. To counteract these threats, equal growth must be present in the research and development (R&D) sector to counter the use of nuclear weapons or nuclear explosive devices. The work presented here examines tools and techniques which have been used for nuclear forensics (NF), international nuclear safeguards, and nuclear nonproliferation. These tools include neutronics codes, radiochemistry, mass spectrometry, radiation spectroscopy, machine learning, etc.rnThe objective of the dissertation research was to validate NF techniques developed at Texas A&M University that can attribute “interdicted” Pu by determining the reactor-type that produced it, fuel burnup (a measure of irradiation time in a reactor), and time since irradiation completed (TSI). The research conducted here aimed to add an additional experimental point (coordinates: reactor-type, fuel burnup, and TSI) in the database of isotopic signature ratios estimated as a function of reactor-types, fuel burnup, and TSI by performing Monte Carlo radiation transport code (MCNP) simulations. Specifically, this research investigated the capability of MCNP to accurately predict technical forensic signatures of Low-Burned Low-Enriched Uranium (LEU) fuel material irradiated in a thermal neutron spectrum. Forensic signatures, which included intra-elemental ratios of Pu and fission products, were to be fed to statistical based technical NF methods. Furthermore, MCNP calculations were to be validated with the experimental data obtained from irradiated LEUO2, chemically separated Pu, and by characterizing the LEUO2 material used for neutron irradiation.