Ceramics in the Nuclear Fuel Cycle: Waste Form Development
Sponsored by: ACerS Energy Materials and Systems
Program Organizers: Cory Trivelpiece, Savannah River National Laboratory; Kyle Brinkman, Clemson University; Philip Edmondson, The University Of Manchester; Djamel Kaoumi, North Carolina State University

Wednesday 8:00 AM
November 4, 2020
Room: Virtual Meeting Room 11
Location: MS&T Virtual


8:00 AM  
A First-principles Database Approach to Predicting Trans-Uranic Waste Forms: Matthew Christian1; Vladislav Klepov1; Kristen Pace1; Gregory Morrison1; Theodore Besmann1; Hans-Conrad zur Loye1; 1University of South Carolina
    The search for stable nuclear waste forms is vital in order to increase viability of nuclear power expansion to reduce carbon emissions as well as to safely store legacy waste. First-principles density-functional theory (DFT) provides an efficient way to screen waste form candidates. This study uses known parent structures as the basis to generate over five-hundred trans-uranic arsenate, molybdenite, phosphate and vanadium oxide crystals. The calculated formation enthalpies for the candidate structures are then compared to formation enthalpies of competing reaction products as reported in the Open Quantum Materials Database (OQMD) to speculate formation probability. Results are compared to experiment where applicable.

8:20 AM  
Multi-scale Cs Sorbents Easily Transformable into Waste Confinement Matrices: Agnes Grandjean1; Micheal Maloney1; Clément Cabaud1; N. Massoni1; Scott Misture2; 1CEA, DEN, Univ. Montpellier; 2Alfred University
    We demonstrate multimodal materials with the ability to selectively entrap Cs+ from a radioactive multi-ion liquid phase, after which they are easily transformable into the final waste form using a simple thermal treatment. we focus on K-containing copper (II) hexacyanoferrate (II) nanoparticles. Selectivity to Cs ions was studied, and we show that insertion of Cs+ into the structure leads to a weakening of the local bonds and a decrease in Jahn-Teller distortions around the metal centers. By anchoring the HCF sorption centers into porous silica, it become feasible to directly calcine (no additives) Cu-HCF functionalized silica after Cs-exchange at 1000°C without Cs loss. We attribute this desirable performance to in-situ formation of an alkali silicate glass zone that that immobilize by-products of decomposed HCF (Cs, K, Cu, Fe ) and Si coming from the siliceous matrix.