Many technical problems must be solved in order to adopt advanced fuel cycles at nuclear power plants with VVER-1000 reactors. The TVS-2 structure was initially developed in the process of solving these problems; it gave high technical performance and cost-effectiveness and provided a base for subsequent upgrading. The TVS-2M structure with a larger fuel load was developed on the basis of tested and new technological solutions to maximize fuel utilization in VVER-1000 reactors.