Criticality of low-enriched-uranium (LEU) and mixed-oxide (MOX) assemblies at the VVER-1000-type Balakovo nuclear power plant is investigated. Effective multiplication factors for fresh fuel assemblies on the railroad platform, fresh fuel assemblies in the within-plant fuel transportation vehicle, and fresh fuel assemblies in the spent fuel storage pool are calculated. If there is no absorber between the units, the configurations with all MOX assemblies result in higher effective multiplication factors than the configurations with all LEU assemblies when the system is dry. When the systems are flooded, the configurations with all LEU assemblies result in higher effective multiplication factors. For normal operating conditions, effective multiplication factors for all configurations are below the presumed upper subcritical limit of 0.95. For an accident condition of a fully loaded within-plant fuel transportation vehicle that is "flooded" with low-density water (possibly from a fire suppression system), the presumed upper subcritical limit is exceeded by configurations containing either LEU or a combination of LEU and MOX assemblies.