Nuclear fuel cycle facilities, especially uranium enrichment plants, are highly electricity-intensive and rely on an uninterrupted power supply, making them vulnerable to electricity cost fluctuations and grid stability. Micromodular reactors, with electrical outputs of 5–25 MWe, offer an option for dedicated on-site power generation within existing nuclear security perimeters, yet no systematic cross-vendor comparison of first-of-a-kind and Nth-of-a-kind cost trajectories exists, nor has financial viability been assessed at a specific U.S. enrichment facility. This study develops first- and Nth-of-a-kind cost trajectories for seven U.S.-relevant micromodular reactor vendors across four technology families, i.e., liquid-metal fast reactors, heat-pipe microreactors, gas-cooled reactors, and light-water reactors, and evaluates the 50-year economic viability of co-siting at Centrus Energy Corp.’s American Centrifuge Plant under two demand scenarios. Capital costs were estimated using a standardized account-level methodology; Nth-of-a-kind trajectories follow learning curve modeling with category-specific learning rates. A 50-year levelized cost of electricity and net present value analysis was conducted under three investment tax credit levels (0%, 30%, and 50%), incorporating escalating operations and maintenance costs (3%/year), nuclear fuel cost escalation (2.5%/year), and an increasing grid outage exposure (2%/year). Non-light-water designs average 57% lower first-of-a-kind capital costs than light-water alternatives, and Nth-of-a-kind costs decline by 44–64% by the 100th unit. Without tax incentives, micromodular reactor electricity costs exceed the grid baseline; a 30% investment tax credit achieves grid parity, and a 50% credit yields costs roughly 32% belowgrid. Under a 30% investment tax credit, the net present value turns positive at the 10th unit, marking the transition from government-supported to commercially self-sustaining deployment, with a 50-year net present value advantage of $1.75B–$2.65B over grid-only supply. These results support micromodular reactor co-siting as commercially viable within a decade, with investment tax credit support primarily needed at first-of-a-kind deployment.