Ceramics for a New Generation of Nuclear Energy Systems and Applications: Nuclear Waste Management
Sponsored by: TMS Nuclear Materials Committee, ACerS Energy Materials and Systems (EMSD) Division
Program Organizers: Ming Tang, Clemson University; Enrique Martinez Saez, Clemson University; Yongfeng Zhang, University of Wisconsin; Krista Carlson, University of Nevada, Reno; Yutai Katoh, Oak Ridge National Laboratory; Jean Paul Crocombette, CEA Saclay; Erofili Kardoulaki, Los Alamos National Laboratory; Levi Gardner, Argonne National Laboratory; Jian Zhang, Xiamen University; Charmayne Lonergan, Missouri University of Science and Technology

Wednesday 2:00 PM
October 12, 2022
Room: 329
Location: David L. Lawrence Convention Center

Session Chair: Krista Carlson, University of Nevada, Reno; Jake Amoroso, Savannah River National Laboratory


2:00 PM  Invited
Development of Novel TRU-containing Ceramics for Nuclear Waste Immobilization: Jake Amoroso1; 1Savannah River National Laboratory
    Nuclear waste form development has evolved behind a regulatory history that has motivated different approaches to designing, testing, and evaluating waste form materials. Many of the challenges related to vitreous waste forms are well-known whereas, comparatively less fundamental understanding is available for ceramic and other non-vitreous waste forms. New approaches to material synthesis combined with recent advances in computational and experimental approaches, provide the foundation and pathway to address waste immobilization challenges. The Center for Hierarchal Waste Form Materials (CHWM) was created to conduct fundamental research to develop the chemistry and structure motifs needed to create materials that effectively immobilize nuclear waste in novel, persistent architectures. Recent progress and advancements made towards the development of transuranic containing structures will be presented. Experiment, characterization, and modeling of oxide and fluoride systems will be discussed.

2:30 PM  Invited
Environmental Degradation of Ceramic Materials in Nuclear Energy Systems: Hwasung Yeom1; Kumar Sridharan1; 1University of Wisconsin Madison
    Ceramics have been considered as fuel forms, structural and coating materials, and for waste storage in nuclear energy systems. For example, environmental degradation of ceramic materials such as SiC/SiCf composite, graphite, C/Cf composite, and borosilicate glass have been investigated for applications including accident tolerant fuel cladding, moderator material, control rod sheath, and waste immobilization. Ceramic coatings have been proposed for Zr-alloy cladding to improve the oxidation resistance in light water reactors (LWRs), and for minimizing corrosion and liquid metal embrittlement of steels in lead fast reactors (LFRs). The high temperature gas-cooled reactor (HTGR) also provides unique opportunities for use of ceramics. In molten salt reactors (MSRs), ceramic coatings may be beneficial for corrosion resistance and as diffusion barriers for tritium. Ceramic coatings have also been considered for neutron radiation shielding. With these applications as basis, the presentation will cover the scope and opportunities for ceramic materials in nuclear energy applications.

3:00 PM  
Single Component Variations in Glass Ceramic Waste Forms: Ryan Kissinger1; 1Lawrence Livermore National Laboratory
    A 51-sample composition variation study was performed on glass-ceramic waste forms for a raffinate waste stream from aqueous reprocessing of used nuclear fuel containing high fractions of Mo, alkalis, alkaline earths (AEs), and rare earths (REs). The study was designed with a single-component-at-a-time variation approach off a centroid composition. The components that were varied included Al, B, Ca, Li, Mo, Na, REs, Si, Zr, and Others (containing minor components). Data analysis included crystallization curves, microstructure, and phase compositions. A number of components (i.e., Li2O, B 2O3, REOx, MoO3, Na2O, and ZrO2) significantly impacted the concentration and chemistry of phases, especially the primary phases of oxyapatite [i.e., Ca2RE8(SiO4)6O2] and powellite (i.e., AEMoO4), precipitated in the slow cool heat-treated waste forms; minor phases included cerianite [i.e., CexZr(1- x)O2], Ba- molybdate [i.e., Ba(Gd0.67Mo0.33)O3], noble metals, pollucite (i.e., CsAlSiO4), and RE- borosilicate (i.e., RE3BSi2O10).

3:20 PM Break

3:40 PM  Invited
Sulfur Retention of Low Activity Waste Glasses : Austin Stanfield1; Jake Amoroso1; 1Savannah River National Laboratory
    As a consequence of the high corrosivity of sulfate salts, models have been developed to mitigate sulfate segregation in Hanford Tank Waste Treatment and Immobilization Plant (WTP) melters, which rely on experimental data inputs. However, a disparity exists between the thermodynamic solubility limit in crucible-scale testing and the measured retained sulfur content in large scale test melters, with larger retention values corresponding to larger scale testing. A laboratory scale melter system was created to measure sulfur retention in simulated Hanford low-activity waste glass. The melter system is designed to simulate processing conditions, and was operated with simulants with matched physicochemical properties to melter feed, as opposed to reagent chemicals. This was undertaken to determine sulfur retention and elucidate the nature of the differences between crucible and melter testing. The resulting outcome should facilitate more applicable comparisons to be made between crucible melts and pilot-scale melts with the varied feed stocks.

4:10 PM  
Bismuth Loaded Carbon Foam as an Effective Radio Iodine Sorbent: Karthikeyan Baskaran1; Casey Elliott1; Muhammad Ali1; Hammad Malik1; Brian Riley2; Krista Carlson1; 1University of Nevada, Reno; 2Pacific Northwest National Laboratory
    Radioiodine (I-129) is a common byproduct in nuclear waste processing facilities. Carbon-based materials loaded with bismuth metal have shown ability to capture iodine and possess advantage over other adsorbents, such as silica-based aerogels, in humid atmosphere. In this work, bismuth is loaded on carbon foam using three different approaches: electrodeposition, hydrothermal and in-situ reduction. Resulting carbon foam properties from these processes as well as the iodine capture capability are investigated. Understanding the effects of each process on carbon foam provides important information to develop tailored-materials for different applications.

4:30 PM  
Synthesis and Characterization of Super Occluded LiCl-KCl in Zeolite-4A as a Chloride Salt Waste Form Intermediate: Allison Harward1; Krista Carlson2; Tae-Sic Yoo3; Guy Frederickson3; Mike Patterson3; Michael Simpson1; 1University of Utah; 2University of Nevada-Reno; 3Idaho National Laboratories
    Electrorefiners are currently operating at Idaho National Laboratory, processing irradiated driver and blanket assemblies from Experimental Breeder Reactor-II in a molten salt consisting of eutectic LiCl-KCl with NaCl, UCl3, PuCl3, and numerous fission product chlorides. Methods are being investigated to condition this salt for interim storage. If untreated, the salt is deliquescent, so a means of mitigating moisture uptake and corrosion of metallic canisters may be needed. Results of experiments in which LiCl-KCl was occluded zeolite-4A up to 75 wt% will be presented. The zeolite is very effective at reducing uptake of water and minimizing potential corrosion of canisters in a controlled, humid environment because the free, unoccluded salt is primarily NaCl, which forms from the Na+ ions present in the zeolite framework ion exchanging with occluded LiCl-KCl.