Novel Phosphate Waste Forms to Enable Efficient Dehalogenation and Immobilization of Salt Waste

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Redwood City, California
Project Term:
05/02/2022 - 05/01/2025

Technology Description:

Citrine Informatics will use a combination of state-of-the-art artificial intelligence, physics-based simulations, and experimental results to design novel phosphate waste forms (including glasses, ceramics, and their composites) to enable dehalogenation (removal of halides) and more secure immobilization of salt waste from molten salt reactors (MSRs). Current disposition pathways for salt wastes from MSRs, or used nuclear fuel reprocessing, produce waste forms with relatively low halide loading potential, large volumes, poor thermal stability, and poor mechanical durability. Citrine’s project would culminate in a kilogram-scale proof-of-concept of the designed waste form, demonstrating a >6x increase in waste mass loading and 80% decrease in waste form volume over existing technologies. The proposed technology could result in 60% decreases in the capital and operating expenditures of waste form processing.

Potential Impact:

By identifying and addressing challenges at the back end of the fuel cycle before the deployment of future AR technologies, ONWARDS will:


Support the growth of advanced nuclear energy with safe and sustainable domestic fuel stocks.


Play a vital role in significantly reducing GHG emissions, proactively mitigate the disposal impact of AR UNF with integrated non-proliferation safeguards, and provide transformative solutions to improve the management and disposal of radioactive waste and UNF.


Complement ARPA-E’s existing nuclear energy research portfolio, such as the MEITNER and GEMINA programs in AR R&D, further ensuring the commercial viability of innovative new ARs.


ARPA-E Program Director:
Dr. Robert Ledoux
Project Contact:
James Saal
Press and General Inquiries Email:
Project Contact Email:


University of North Texas
Pacific Northwest National Laboratory

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