Nuclear and Small Modular Reactors: Siting Considerations for Data Centers

Nuclear generation offers large amounts of firm, low-carbon power with very high availability. That profile matches a data center’s round-the-clock load well. Developers look at it in three ways: taking power from an existing nuclear plant, locating near an existing plant site that may add units, or planning a campus around one or more future small modular reactors (SMRs) or other advanced reactors.

Each path has very different timing. Power from an existing plant is a contract and grid question, closer to the co-location arrangements in our guide to co-locating data centers with power plants. New reactors are a licensing, construction and supply chain question measured in years, and for first-of-a-kind designs the schedule is hard to predict.

Commercial nuclear reactors in the U.S. are licensed by the Nuclear Regulatory Commission (NRC). No reactor can be built or operated without its approval, and that approval covers both the design and the specific site. The main regulatory paths are well established:

• A two-step process under 10 CFR Part 50: a construction permit, followed later by an operating license.
• A combined construction and operating license under 10 CFR Part 52, which can reference a standard design the NRC has already approved and an approved early site permit.
• An early site permit, also under Part 52, which resolves site suitability questions in advance, before a specific reactor is chosen.

A new license application also triggers environmental review under NEPA, with the NRC as the lead federal agency. The NRC’s licensing framework has been the subject of ongoing modernization for advanced and smaller reactors, and the details may change over a project’s life. What does not change is that licensing is a multi-year process with public participation, and that the site itself is reviewed in depth.

NRC reactor site criteria, found mainly in 10 CFR Part 100, look at the site’s physical characteristics and its surroundings. Those criteria rule out land that would be fine for a data center.

Our guide to slope, soils and geotechnical review covers the ordinary data center side. For a reactor, that work is a starting point at most.

Licensed reactors have emergency planning zones (EPZs) around them. For large light-water reactors, the plume exposure pathway EPZ has historically extended about 10 miles from the plant, with an ingestion pathway zone of about 50 miles. Within these zones, operators, states and local governments maintain emergency plans, warning systems and protective action procedures.

For smaller and advanced reactors, NRC rules allow the plume exposure EPZ to be sized based on the facility’s potential consequences, which in some cases could shrink it to the site boundary. Whether a particular design at a particular site qualifies is decided case by case through licensing. It should not be assumed at the site selection stage.

• A data center inside a reactor’s EPZ is generally possible, but it becomes part of the emergency plan, with implications for staffing, access and evacuation.
• A reactor on the data center campus brings security perimeters, controlled areas and an exclusion area that must be under the licensee’s control.
• Local land use planning around the reactor may restrict some future development nearby.

Most operating U.S. reactors are light-water designs that reject large amounts of heat, usually through cooling towers or once-through cooling from a river, lake or ocean. That is why many nuclear plants sit on major water bodies. Withdrawals and discharges need state water rights or permits and Clean Water Act authorizations, and thermal discharges face their own limits.

Some advanced and smaller designs use different coolants or air-cooled heat rejection and may need far less water. That depends entirely on the design and is still being demonstrated for many technologies. At the site stage, assume a reactor may need significant water unless the specific design says otherwise. Our guide to data center water requirements covers the data center’s own water needs, which come on top.

Land and transmission matter too. A reactor site needs room for the plant, its exclusion area, security, laydown during construction and switchyards. Even if the data center uses most of the output, a grid connection is normally needed for backup, for reactor startup and for periods when the reactor is offline for refueling or maintenance.

New nuclear has long lead times: site characterization, licensing, environmental review, supply chain, construction and startup all add up. For advanced designs that need specialized fuel, fuel supply is another dependency. First-of-a-kind projects carry more schedule uncertainty than designs with an operating track record. No one can give a reliable date for a reactor that has not yet been licensed.

For a data center developer, the practical approach is to treat nuclear as one option in a phased power strategy:

1. 01Secure a site with a credible near-term power path, from the grid, on-site generation or both.
2. 02Check the land against basic reactor siting factors: geology, population, flooding, nearby hazards and water.
3. 03Hold enough contiguous acreage, and enough distance to neighbors, to keep a future reactor possible.
4. 04Favor sites near existing nuclear plants or with prior site characterization where available.
5. 05Revisit the nuclear option as licensing progresses and specific designs mature.

When we screen land with nuclear in mind, we keep the two questions separate: can this site host a data center on a useful timeline, and does it keep a future reactor on the table? A site that only passes the second test is not yet a data center site.