Nth of a Kind (NOAK) refers to reactor units built after the initial first-of-a-kind (FOAK) deployments have established manufacturing processes, construction techniques, supply chains, and regulatory frameworks. NOAK economics incorporate learning curve benefits, where each successive unit is cheaper and faster to build than its predecessor due to workforce experience, tooling optimization, design standardization, supplier maturation, and factory production efficiencies. The nuclear industry's standard learning rate assumption is that costs decline by 10-20% for each doubling of cumulative production, consistent with manufacturing experience across other complex industrial products such as aircraft, gas turbines, and shipbuilding.
The entire economic thesis of small modular reactors rests on achieving NOAK cost reductions that make nuclear competitive with alternative generation technologies. SMR designs are specifically engineered for factory fabrication and modular assembly, maximizing the potential for manufacturing learning. NuScale's VOYGR architecture envisions producing 77 MWe modules on assembly lines and shipping them to sites for installation, with each 12-module plant representing an order of magnitude more unit production than conventional one-of-a-kind nuclear construction. Rolls-Royce SMR's UK program, selected as the UK's technology of choice in June 2025, explicitly targets fleet deployment of multiple identical 470 MWe units, starting at Wylfa, Anglesey, with up to 8 units planned to amortize FOAK costs across the fleet. Radiant Industries plans production of 50 Kaleidos microreactors per year at its R-50 facility in Oak Ridge, Tennessee, a manufacturing scale that would rapidly drive NOAK learning.
Industry projections for NOAK LCOE vary by design but generally target the $50-70/MWh range, which would be competitive with new-build natural gas combined cycle plants and substantially below the system cost of wind and solar when integration costs (storage, transmission, curtailment) are included. TerraPower's Natrium aims for significant cost reductions through its integrated energy storage system and partnership with Hyundai and KHNP for fleet manufacturing. The BWRX-300's use of standard LEU fuel and simplified BWR design is intended to leverage the existing light-water reactor supply chain for faster NOAK cost convergence. Achieving credible NOAK economics is the central challenge for the industry, as current FOAK project costs remain elevated and the learning curve assumptions have not yet been validated at commercial scale for any advanced reactor design.