Subcritical reactors have been proposed both as a means of generating electric power and as a means of transmutation of nuclear waste, so the gain is twofold. However, the costs for construction, safety and maintenance of such complex installations are expected to be very high, not to mention the amount of research needed to develop a practical design (see above). There exist cheaper and reasonably safe waste management concepts, such as the transmutation in fast-neutron reactors. However, the solution of a subcritical reactor might be favoured for a better public acceptance – it is considered more acceptable to burn the waste than to bury it for hundreds of thousands of years. For future waste management, a few transmutation devices could be integrated into a large-scale nuclear program, hopefully increasing only slightly the overall costs.