Process Monitoring and Measurement Considerations for MSR Safeguards

The International Atomic Energy Agency (IAEA) has not yet developed a safeguards approach for liquid-fueled molten salt reactors (MSRs), and future safeguards will require new methods to verify dynamic, bulk inventories of nuclear material in the challenging MSR operations environment. Process monitoring and measurement (PM&M) tools may be well suited for MSR safeguards because they can provide the IAEA with diverse, real-time information on in-process materials, typically without an inspector present. However, using PM&M for safeguards at an MSR could require significant preparation integrating PM&M instruments into operator systems and making sure they reflect the requirements of the IAEA and other stakeholders. As a result, outlining PM&M options and needs may represent a long-lead item in MSR safeguards planning and an important focus for safeguards by design (SBD). The paper reviews potential safeguards applications for PM&M for liquid-fueled MSRs and outlines associated R&D and implementation needs. The types of process monitoring tools reviewed include optical methods, gamma and neutron-based methods, electrochemical methods, and various tools for characterizing salt quantities and flows. Significant work will be needed to deploy mature PM&M systems within an effective and efficient IAEA safeguards approach. Reactor development, measurement technology development, and domestic/international safeguards planning are mutually dependent and need to evolve in coordination with one another. This paper outlines potential next steps in a variety of areas, including sensor technology development, collection of information to support safeguards approach planning, simulation and safeguards analysis, and SBD.