Combined License (COL)

The Combined License (COL) is the NRC's streamlined one-step licensing mechanism under 10 CFR Part 52, Subpart C, combining the construction authorization and operating license into a single regulatory proceeding. Once a COL is granted, the holder is authorized to construct the nuclear power plant and, upon successful completion and verification that the as-built facility conforms to the license, proceed directly to fuel loading and operation without a second licensing hearing. This approach was designed to eliminate the regulatory uncertainty that beset nuclear projects in the 1970s and 1980s, when plants built under Part 50 Construction Permits sometimes faced contentious operating license hearings that delayed or prevented commercial operation after billions in construction spending.

The COL process is most efficient when it references a previously certified reactor design (Design Certification under Part 52, Subpart B) and a pre-approved site (Early Site Permit under Part 52, Subpart A). In this scenario, the COL review focuses primarily on site-specific design features, operational programs, and the integration of the certified design with the specific site characteristics. The NRC has issued COLs for several AP1000 units, including the Vogtle 3 and 4 reactors in Georgia, which were the first new U.S. nuclear units to enter commercial operation in decades. Vogtle's experience, while ultimately successful in delivering operating reactors, also illustrated the COL process's limitations when applied to first-of-a-kind construction, with significant cost overruns and schedule delays.

For the current generation of SMR developers, the choice between pursuing a Part 50 Construction Permit and a Part 52 COL involves weighing schedule flexibility against regulatory finality. Kairos Power and TerraPower both chose the Part 50 CP route for their demonstration projects, allowing construction to begin while operating license reviews proceed in parallel. The COL pathway is generally considered more suitable for subsequent commercial deployments where the design is mature and construction risks are better understood. Oklo's Aurora, which is preparing its Combined License Application (COLA) Phase 1 submission in 2026, represents one of the most high-profile COL pursuits among advanced reactor developers, building on lessons learned from an earlier NRC application that was rejected and subsequently redesigned.