Welcome to the User Area for the GRS Software AC²!

The software package AC² consists of the GRS thermal-hydraulic system codes ATHLET, ATHLET-CD and COCOSYS, complemented by the simulator software ATLAS.

AC² is developed and distributed by GRS (Gesellschaft für Anlagen- und Reaktorsicherheit gGmbH). This User Area provides up-to-date information about ATHLET, ATHLET-CD, COCOSYS and ATLAS, such as program documentation, user experiences, patches or hints. Users with a valid software licence have the possibility to download the respective code version from the download page. Detailed information on the granting of a program license are provided by the description of the Code Transfer Process.

The GRS User Area is restricted to registered program users. Access requires a valid authorization. Usually, one user ID is provided for each organization, derived from their internet address (e.g. XXX.de-grscodes). In addition, one email address per company is required to which changes in the User Area will be automatically sent. This might be the email address of a member of staff (who should forward the emails to the colleagues) or a dedicated address from where incoming mail is automatically forwarded to the code users within the organization.

For questions and comments related to the codes please contact the respective program manager:

                    Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) gGmbH
                    Bereich Reaktorsicherheitsforschung/Division Reactor Safety Research
                    Forschungszentrum, Boltzmannstr. 14
                    85748 Garching n. München

                    Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) gGmbH
                    Schwertnergasse 1
                    50667 Köln