About RELAP5-3D

The RELAP5 series of codes has been developed at Idaho National Laboratory; RELAP5-3D is the latest code version in the series. While RELAP5 was originally developed to model accidents and operational transients in light water reactor systems, the general nature of the code allows it to be used to simulate a wide variety of hydraulic and thermal transients in both nuclear and non-nuclear systems that can be stationary or moving. More than 25 working fluids are available in the code, including water, gases, liquid metals, refrigerants, and molten salts; 11 noncondensable gases are also available.

This brief paper describes and illustrates the performance of three key features in the RELAP5-3D computer code: the multidimensional hydrodynamic model, the multi-dimensional reactor kinetics model, and the BPLU matrix solver.

A more detailed RELAP5–3D paper is available.