Special Seminar: Fluoride-Salt-Cooled High-Temperature Test Reactor Thermal Hydraulic Licensing and Uncertainty Propagation Analysis

Rebecca Romatoski, Massachusetts Institute of Technology

All dates for this event occur in the past.

E525 Scott Lab
E525 Scott Lab
201 W. 19th Ave.
Columbus, OH 43210
United States

The Fluoride-salt-cooled High-temperature Reactor (FHR) concept employs liquid-salt coolant and coated TRISO particle fuel for operation at high temperature and low pressure. A test reactor is a key step in the development and commercialization of FHR technology. Given the limited data and high uncertainty (up to 20%) of coolant thermophysical properties, a method to perform a thermal hydraulic safety analysis for test reactor licensing that incorporates uncertainty quantification is developed. The analysis combines Monte Carlo uncertainty propagation for salt coolant properties with a thermal hydraulic hot channel model to perform a limiting system safety settings (LSSS) licensing analysis. The LSSS operational power region is calculated based on ensuring sufficient margin to fuel and material limits during steady-state operation. Uncertainty propagation will provide a first look at the statistical effects of coolant property uncertainties on LSSS power. A pebble bed design, the solid fueled test reactor of the thorium molten salt reactor project (TMSR-SF1) being developed in China, and the prismatic core design, the Transportable FHR (TFHR) being developed in the United States, are analyzed using the methodology. The reactor designs are analyzed for two flow regimes—forced flow and natural circulation flow—and two candidate primary salt coolants—LiF-BeF2 (flibe) and NaF-ZrF4 (nafzirf). Considering thermal hydraulic temperature limits, overall, the pebble bed core is more resilient to coolant selection and has a larger LSSS operating region than the prismatic core. The statistical effects of thermophysical property uncertainty combining all property uncertainties has a 95% confidence interval on LSSS power ranging from 0.04-1.45 MW or 2.76-11.66%.

About the Speaker

Rebecca Romatoski is a doctoral candidate in the Department of Nuclear Science and Engineering with a specialization in the Fluoride-salt-cooled High-temperature Reactor (FHR) design at Massachusetts Institute of Technology. She is interested in advanced reactor design, thermal fluids and using nuclear power to mitigate carbon emissions. More specifically, her work examines effects of thermophysical property uncertainties on heat transfer in FHRs and compares the pebble bed and prismatic test reactor core designs.

Hosted by Professor Carol Smidts