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 to registered program users 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 under the link: https://user-codes.grs.de/code-transfer

For questions and comments related to the AC² code please contact AC2@grs.de

Regarding any concerns for the single system code please contact the 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

GRS codes make use of different third-party software products. The downloads requested by the related license conditions you can find under https://user-codes.grs.de/code-transfer/third-party-software/third-party-software-used-by-grs-codes.