Investigations into Potential Fuel Salts for Molten Salt Reactors: Synthesis, Characterization, and Property Determination

with Toni Karlsson, Research Scientist,
Idaho National Laboratory

April 26, 2024,  10:10 am, 6-051, VTRC, Arlington,
1000 Torgersen Hall, Blacksburg (In-Person)

For remote access, register here.

Interest in molten salts for use as a coolant and/or fuel for molten salt reactors (MSRs) or as an energy storage media is rapidly increasing. Today, there exists a growing number of MSR vendors and research institutions interested in fabricating novel fuel salt compositions and obtaining reproducible thermal property data with low uncertainty. However, many actinide salts are not readily available and must be synthesized and characterized before use. Additionally, due to its hygroscopic nature, corrosivity, and wettability, measuring the thermal properties of molten salts can be difficult. Researchers at the Idaho National Laboratory have been developing methods for measuring impurities, density (solid/liquid), viscosity, heat capacity, and phase behavior of chloride and fluoride molten salt systems. Through the journey of developing our synthesis, characterization, and thermal/chemical property capabilities, researchers have incorporated many lessons learned, to provide reliable data sets needed to design new MSRs. Therefore, this presentation will discuss our ongoing research and highlight potential opportunities for collaboration.

Toni Karlsson is a Research Scientist and is currently the lead scientist for the Molten Salt Thermophysical Examination Capability (MSTEC) a shielded hot cell containing advanced high temperature thermophysical and thermochemical characterization equipment. Her research targets thermal property measurements of actinide bearing salt such as uranium and plutonium chlorides and fluorides. Toni is also working on development of analytical techniques for analysis of salts as well as development of methods and procedures for reducing sampling error. Toni is actively engaged in the development of NQA-1 measurement procedures and adopting those to encompass thermophysical property measurements for research and molten salt reactor vendors.

At INL, Dr. Karlsson has investigated phase stability of molten salts in a uranium electrorefiner and how the build-up of fission products in the salt impacts the thermal properties. This work made it possible to predict a spent fuel treatment processing scenario under which electrorefining could no longer be performed as a result of increasing liquidus temperatures of the salt. Dr Karlsson has research experience in highly radioactive, remote, and high temperature environments.

One of Dr. Karlsson’s passions is the advancement of current and future researchers. She has a special interest and focus on workforce development through collaborations with other DOE laboratories, DOE campaigns, internships, educational outreach, and industry.