Seaborg Institutes: Emerging Topics in Actinide Materials and Science: Radiochemistry/Thermophysical Properties
Sponsored by: TMS Structural Materials Division, TMS: Nuclear Materials Committee
Program Organizers: J. Rory Kennedy, Idaho National Laboratory; Taylor Jacobs, Helion Energy; Krzysztof Gofryk, Idaho National Laboratory; Assel Aitkaliyeva, University of Florida; Don Wood, Idaho National Laboratory
Wednesday 2:00 PM
March 22, 2023
Room: 28A
Location: SDCC
Session Chair: Don Wood, INL; Rory Kennedy, INL
2:00 PM Invited
The Heavy Side of Radiochemistry: Revisiting Actinide Chemistry with Tailored Macromolecules: Gauthier Deblonde1; Christopher Colla1; Ian Colliard2; Joseph Cotruvo3; Annie Kersting1; Jon Lee1; Harris Mason1; Joseph Mattocks3; Keith Morrison1; May Nyman2; April Sawvel1; Paul Wooddy1; MAvrik Zavarin1; 1Lawrence Livermore National Laboratory; 2Oregon State University; 3Penn State University
The vast majority of the literature on actinide chemistry is focused on small compounds (e.g. metals, oxides, small inorganic or organometallic complexes). The emergence of new f-element radioisotopes for use in medicine, combined with a continued push to understand the behavior of nuclear waste in the environment, call for the expansion of f-element chemistry to novel chelators, beyond the classic small molecules. Our team uses macromolecules, whether natural or synthetic, for targeting f-elements, including the most elusive ones. Our multi-pronged strategy led us to investigate actinium and transuranic element chemistries in the presence of the recently discovered lanmodulin protein. Our comprehensive thermodynamic and spectroscopic studies revealed potential new mechanisms for actinide migration in the environment and innovative separation pathways for radioisotopes. Our approach also leverages polyoxometalate macroligands to isolate and characterize f-elements, and revealed otherwise unnoticeable differences between solution-state versus solid-state actinide chemistry, as well as actinide versus lanthanide chemistry.
2:30 PM Invited
Actinide Radiation Chemistry and Used Nuclear Fuel Reprocessing: Gregory Horne1; 1Center for Radiation Chemistry Research, Idaho National Laboratory
Although the actinides boast many unique physical and chemical properties, their inherent susceptibility to radioactive decay—and subsequent consequences of radiation-induced chemistry—are what make them truly interesting and challenging elements to understand. From a closed nuclear fuel cycle perspective, the ability to predict and control the effects of actinide-driven radiolysis is critical for the design, development, and deployment of advanced used nuclear fuel reprocessing strategies and technologies. The absorption of ionizing radiation from actinide decay leads to the formation of a variety of transient and steady-state radicals, ions, and molecular radiolysis products that can lead to significant changes in a reprocessing solvent system’s physical and chemical properties, which ultimately limits that process’ efficiency and longevity. Presented here is an overview of recent advances in actinide radiation chemistry as it applies to used nuclear fuel reprocessing.
3:00 PM
Genetic Algorithm Approach to Interpreting Pu Radiation Damage in EXAFS Data: Daniel Olive1; Corwin Booth2; Ari Foley1; Meghan Gibbs1; Kasey Hanson1; Sarah Hickam1; Taylor Jacobs1; Jeremy Mitchell1; Alison Pugmire1; 1Los Alamos National Laboratory; 2Lawrence Berkeley National Laboratory
Plutonium and its compounds, with their complex phase diagrams and ever present self-irradiation damage, have always posed a challenge in terms of understanding radiation damage in these materials from a fundamental standpoint. While many complementary techniques can be brought to bear on this problem, Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy offers a unique, short-range and element specific view of local structure. Interpreting the data requires selecting physically meaningful and statistically relevant set of paths. However, in contrast to pristine samples, those suffering from radiation damage present a challenge to traditional fitting. Here, we present recent efforts using a genetic algorithm (GA) approach to EXAFS fitting. The GA approach can explore the complicated parameter space, and potentially remove operator bias, giving insight on radiation damage at small length scales useful for informing Pu aging and metallurgy, as well as for comparison with first principals calculations.
3:20 PM Break
3:40 PM Invited
Superconductivity and Magnetism in Complex Actinide-based Materials: Eteri Svanidze1; 1MPI CPfS
Scientific breakthroughs are often driven by experimental discoveries of new materials. Unfortunately, the majority of these discoveries are "accidental". To address this issue, I share several systematic ways in which new materials can be designed [1-3]. Given complexity of compounds containing actinides, I will show examples of our empirical search methods. I will highlight several solid-state compounds that were found as a result and discuss their chemical and physical properties, focusing on magnetic and superconducting systems. Additionally, I will present several materials which pose multiple experimental challenges – from extreme air-sensitivity to atomic imperfections.[4-7] [1] E. Svanidze et al., PRB 99, 220403 (2019) [3] E. Svanidze et al., PRM 5, 074801 (2021) [4] P. Kozelj et al., Sci. Rep. 11, 22352 (2021) [5] A. Amon et al., Angew. Chemie 58, 2 (2019) [6] A. Amon et al., Sci. Rep. 8, 10654 (2018)[7] Yu. Prots et al., submitted (2022)
4:10 PM Invited
Design and Implementation of the Experimental Setup of The Three-Omega Method for Thermal Conductivity Measurements of Molten Actinide Salts: Maria Del Rocio Rodriguez Laguna1; 1Idaho National Laboratory
Molten salt reactors (MSRs) are one of the most promising next-generation nuclear reactor designs which use molten salts as the fuel and coolant. To design, model, predict, and operate MSRs, the behavior of the fuel and coolant must be understood as a function of temperature and irradiation. Of particular importance is the reliable and reproducible measurement of thermal conductivity of molten salts at high temperatures (> 500 °C). Thermal conductivity provides information on the rate at which heat passes through a specific material. To produce high fidelity thermal conductivity data, a measurement technique needs to be developed that will reduce the effect of convection in the liquid at high temperatures. At Idaho National Laboratory (INL) we are developing a frequency-domain technique based on the three-omega method. This method requires a small volume of sample and works in a very fast time window, which will help suppress interference due to convection.
4:40 PM
Dynamical System Scaling for Thermomechanical Properties of Uranium and Plutonium in Pulsed Reactor Experiments: Ari Foley1; Edward Lum1; Daniel Olive1; 1Los Alamos National Laboratory
Experiments on actinide samples in high dose neutron environments has re-emerged as an area of interest for assessing the behavior after rapid heating. Pulsed reactor testing of materials exposes targets to environments that simulate atypical conditions, such as short pulses of high power, providing valuable information on the thermophysical material properties and phase change. These experiments not only provide information on the effects of rapid heating, but the radiation damage, gas release characteristics, and annealing in that material. The Dynamical System Scaling (DSS) Methodology has been demonstrated to use non-dimensionalization of system parameters to quantify distortions in transient systems with respect to neutron pulse parameters. DSS is assessed as a design tool to produce experimental measurements analogous to desired conditions by minimizing distortions in the thermomechanical responses for varying pulse conditions. This research investigates pulsed reactor experiments of actinides and application of DSS to experiment design.
5:00 PM
A Young's Modulus Comparison Study in Alpha and Delta Plutonium: Clarissa Yablinsky1; Taylor Jacobs1; Meghan Gibbs1; Carlos Archuleta1; Christopher Cordova1; Tomas Martinez1; Todd Martinez1; Tarik Saleh1; 1Los Alamos National Laboratory
Addressing the need for modulus data in plutonium can be done with both mechanical testing and resonant ultrasound spectroscopy (RUS). While RUS is a powerful tool to accurately measure bulk and shear moduli, allowing us to calculate Young’s modulus, acquiring RUS data when investigating materials with texture or voids is not as accurate when compared to more isotropic microstructures. Furthermore, limited work has been done to measure Young’s Modulus using traditional mechanical testing. The density of each sample was measured before measuring C11 and C44 using RUS, and then subsequent mechanical testing at a strain rate of 1x10-3/s was performed on each sample. Comparisons of both measured and calculated Young’s modulus will be reported. A strong collection of Young’s modulus data from both mechanical testing and RUS calculations is necessary to understand the relationship between the two techniques.