This study focuses on planning and evaluating alternative concepts for dealing with the back-end of the nuclear fuel cycle. Emphasis is laid on the underground part of this system consisting in the disposal of radioactive waste/spent fuel that generates considerable heat. A given amount of spent fuel discharged from LWRs is subject to disposal and reprocessing, respectively. For the emerging mix of waste and spent fuel packages a sizeable variety of disposal variants is designed conceptually, thereby providing the database for further near- and far-field analyses as well as dose and cost calculations. The technical alternatives were compared with one another by a panel of experts relying on a set of objectives (criteria) which belong to seven criteria fields. Concept BD1 (borehole and drift emplacement) and concept D3* (three-level drift emplacement) best meet the requirements as stated by the criteria. The comparative analysis also helped detect areas of insufficient knowledge which introduced a degree of uncertainty into the systems evaluation and gave rise to a continuation of the research programme.