NRC's Computer Codes for Fuel Performance, Reactor Physics, and Severe Accidents

Office of Nuclear Regulatory Research

NRC uses a suite of computer codes to support licensing activities and perform confirmatory analysis in the areas of fuel performance (FAST), reactor physics (SCALE), and severe accidents (MELCOR). FAST (Fuel Analysis under Steady-state and Transients) is a modern thermal-mechanical nuclear fuel performance code that is replacing FRAPCON/FRAPTRAN, and allows more flexibility for treating complex geometries and new materials. SCALE (Standardized Computer Analysis for Licensing Evaluations) is used to perform reactor physics, criticality safety, and radiation shielding, and spent fuel characterization for nuclear facilities. MELCOR is a fully integrated, engineering-level computer code designed to model the progression of postulated severe accidents and evaluate the source term. The various regulatory source terms establish and confirm the design basis of the nuclear facility by ensuring that the plant design meets the safety and numerical radiological criteria set forth in the Code of Federal Regulations. For all these codes, current activities include development and implementation of new and improved models to predict the behavior of various reactor (both light water and non-light water), spent fuel pool, and accident-tolerant fuel designs. This presentation will highlight the functionality of these codes as well as their relationships and integration in various analyses.

Page Last Reviewed/Updated Monday, August 26, 2019