Program on Technology Innovation: Technology Assessment of a Molten Salt Reactor Design -- The Liquid Fluoride Thorium Reactor (LFTR)
EPRI collaborated with Southern Company on an independent technology assessment of an innovative molten salt reactor (MSR) design—the liquid-fluoride thorium reactor (LFTR)—as a potentially transformational technology for meeting future energy needs in the face of uncertain market, policy, and regulatory constraints. The LFTR is a liquid-fueled, graphite-moderated thermal spectrum breeder reactor optimized for operation on a Th-233U fuel cycle. The LFTR design considered in this work draws heavily from the 1960s-era Molten Salt Reactor Experiment and subsequent design work on a similar two-fluid molten salt breeder reactor design. Enhanced safety characteristics, increased natural resource utilization, and high operating temperatures, among other features, offer utilities and other potential owners/operators access to new products, markets, applications, and modes of operation. The LFTR represents a dramatic departure from today’s dominant and proven commercial light water reactor technology. Accordingly, the innovative and commercially unproven nature of MSRs, as with many other advanced reactor concepts, presents significant challenges and risks in terms of financing, licensing, construction, operation, and maintenance.
This technology assessment comprises three principal activities based on adaptation of standardized methods and guidelines: 1) rendering of preliminary LFTR design information into a standardized system design description format; 2) performance of a preliminary process hazards analysis; and 3) determination of technology readiness levels for key systems and components. The results of the assessment provide value for a number of stakeholders. For utility or other technology customers, the study presents structured information on the LFTR design status that can directly inform a broader technology feasibility assessment in terms of safety and technology maturity. For the developer, the assessment can focus and drive further design development and documentation and establish a baseline for the technological maturity of key MSR systems and components. For EPRI, the study offers an opportunity to exercise and further develop advanced nuclear technology assessment tools and expertise through application to a specific reactor design.
The early design stage of the LFTR concept indicates the need for significant investment in further development and demonstration of novel systems and components. The application of technology assessment tools early in reactor system design can provide real value and facilitate advancement by identifying important knowledge and design performance gaps at a stage when changes can be incorporated with the least impact to cost, schedule, and licensing.