The U.S. Nuclear Regulatory Commission (NRC) uses the computer code Fuel Analysis under
Steady-state and Transients (FAST) to model steady-state and transient fuel behavior to support
regulatory decisions. FAST relies on a material properties library (MatLib) that contains the thermal
and mechanical properties of the nuclear materials and coolants of interest to support the US
commercial nuclear industry. MatLib contains properties for a variety of nuclear fuels, cladding and
other structural materials, gases, and coolants.
In this document, material property correlations for the materials contained within MatLib are presented
and discussed. When available, comparisons are made between the material property correlations
and available data. Additionally, uncertainties are quantified on the material properties,
which is then used by the NRC to support uncertainty quantification for best-estimate plus uncertainty
safety evaluation reviews.
This document describes MatLib-1.0, which is the first official version of the MatLib library. This
document is one of a series of documents on FAST; the other documents detail the models used
by FAST as well as its integral assessment to experiments and commercial data.