[en] In this report the safety problems are described which are related to the installation of a nuclear boiling generator in KNK II. Key problems are the stress of the cladding and the safety instrumentation. Stress analysis and out-of-pile experiments so far indicate that the cladding material to be used should withstand the stresses during local boiling. The stress and strain as well as the creep and fatigue behavior due to temperature oscillations should however still be analyzed more accurately on the basis of improved material coefficients. This might not be necessary, if it can be proved, that the out-of-pile experiments give complete information about the behavior of the cladding in the nuclear generator. The instrumentation being proposed is suitable for controlling the boiling process, under the condition that the results from out-of-pile experiments can reliably be used for temperature calculations in the nuclear boiling generator. This has still to be checked. The influences of the boiling generator on possible reactor malfunctions, to be kept under control by the automatic reactor shutdown system, and on reactivity coefficients are compatible with the requirements of the reactor safety. The same holds for the special design of the boiling generator in order to limit the damage in the very unlikely event of a failure