Geometry input specification, especially for non-latice, heterogenous systems (as the radial reflector, for example), is a very laborous and demanding task. Definition of more complicated structures and their break-down to a sufficiently fine computing mesh is a long and error-prone process, which moreover, has to be repeated after any geometry change.

KIRKÉ uses vector drawing (produced by an appropriate CAD tool) to define geometry and automatically converts it to HELIOS input format, automatically subdividing the regions with a regular, user-specified mesh (either square or triangular).