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RELAP5-3D is the latest in the RELAP5 code series developed at Idaho National Laboratory (INL) for the analysis of transients and accidents in water–cooled nuclear power plants and related systems as well as the analysis of advanced reactor designs.

The RELAP5–3D code is an outgrowth of the one-dimensional RELAP5/MOD3 code developed at INL.  The most prominent attribute that distinguishes RELAP5–3D from its predecessors is the fully integrated, multi-dimensional thermal-hydraulic and kinetic modeling capability.

RELAP5–3D is available from INL through membership in the International RELAP5 Users Group (IRUG).

The code is currently configured to run on both Linux and Windows. Operating systems and compilers supported are:

  • O/S

    • Linux: OpenSUSE: 42.2 (x86_64)

    • Windows: Windows 7, SP1

  • Intel compiler designation

    • On Linux: Version 16.0.4

    • On Windows: Composer XE 2013, SP1, Update 2

RELAP5–3D News

Training and IRUG Seminar

The next Training and International RELAP5 Users Group seminar will be April  30 - May 4, 2018. 

Go to the IRUG Seminar for more information and to register for the seminar and training.

Code Version 
The most recent RELAP5–3D release is Version 4.3.4.

For information on how to obtain the code, please contact Mr. Gary Smith at:

Mr. Gary Smith
Sr. Commercialization Manager
Idaho National Laboratory
PO Box 1625
Idaho Falls, ID 83415
Phone: (208) 526-3780