93 Nuclear Reactors and Their Danger Zones

Data source: ZipCheckup analysis of NRC reactor data, EPA SDWIS, FEMA flood zones

The Nuclear Regulatory Commission licenses 93 commercial nuclear reactors across 28 states. Around each one, federal law requires a 10-mile Emergency Planning Zone — a radius within which state and local governments must maintain evacuation plans in case of a radiological emergency.

The NRC publishes reactor locations. FEMA maintains the emergency plans. But few people connect these zones to the broader environmental and water safety picture for their ZIP code.

The Geography of Nuclear Power

America's 93 operating reactors cluster in specific regions. The highest concentrations:

• Illinois — 11 reactors across 6 sites, the most of any state
• Pennsylvania — 9 reactors at 5 sites
• South Carolina — 7 reactors at 4 sites
• New York — 6 reactors at 4 sites (including Indian Point, now decommissioning)
• Alabama — 5 reactors at 3 sites
• North Carolina — 5 reactors at 3 sites

These plants serve about 100 million Americans within the broader 50-mile ingestion pathway zones. Within the critical 10-mile plume exposure zones, millions more live, work, and drink local water.

What the 10-Mile Zone Actually Means

The 10-mile EPZ isn't a danger zone in the colloquial sense. It's an emergency preparedness boundary. Within it:

• Evacuation routes must be mapped and maintained
• Potassium iodide (KI) distribution plans must exist to protect against thyroid radiation uptake
• Sirens must be tested regularly — the NRC requires alert systems capable of notifying the population within 15 minutes
• Annual emergency drills are conducted with state, local, and federal agencies

The 50-mile ingestion pathway zone extends the planning further. Within this radius, authorities must have plans to monitor and control the food and water supply in case of a radioactive release.

The Compound Risk Factor

What makes nuclear-adjacent ZIP codes interesting from a water safety perspective isn't radiation risk — nuclear power plants operate under the strictest safety regime in the energy sector. It's the compound environmental burden these areas often carry.

Many nuclear plants were sited near:

• Military installations — our data shows significant overlap between nuclear facilities and military bases. The Department of Defense has identified PFAS contamination at hundreds of bases, and several sit within or adjacent to nuclear EPZs.
• Industrial corridors — nuclear plants require transmission infrastructure, cooling water, and transportation access. These same features attract industrial development. ZIP codes near nuclear sites frequently show elevated TRI (Toxic Release Inventory) activity.
• Aging infrastructure — many plants began operating in the 1970s and 1980s. The surrounding communities often have water infrastructure from the same era, meaning pipes and treatment systems are now 40-50 years old.

The Top 10 Most-Populated Nuclear Zones

These are the most heavily populated areas within nuclear EPZs, based on our ZIP-level population data:

Turkey Point in South Florida stands out: it sits in a zone projected to see 14 inches of sea level rise, with $19.2 billion in historical FEMA flood payouts statewide. The compound risk of nuclear proximity plus climate exposure makes this area uniquely worth monitoring.

What Decommissioning Means for Your Water

When a reactor shuts down — as Indian Point did in 2021 — the radioactive risk diminishes, but water quality concerns can persist or even increase:

• Spent fuel storage continues on-site for decades in dry cask storage
• Decommissioning activities disturb soil and groundwater that may contain tritium or other isotopes
• Economic shifts as the plant closes can reduce local tax revenue, leading to deferred infrastructure maintenance
• Contaminated groundwater from decades of operations may require long-term monitoring

The NRC requires decommissioning funds and environmental monitoring, but the process takes 20+ years. During that time, surrounding ZIP codes may see their water infrastructure age without the tax base that once maintained it.

How to Check Your Proximity

Your ZipCheckup safety report includes data on nearby environmental risk factors, including:

• Superfund sites within 5, 10, and 25 km of your ZIP
• Military base proximity and associated PFAS risk
• TRI facility density and chemical release data
• Infrastructure age — median housing year as a proxy for pipe age
• Flood risk from FEMA claims data

While we don't yet map EPZ boundaries directly to ZIP codes, the overlapping environmental data paints a clear picture of compound risks in nuclear-adjacent areas.

Check your ZIP code now →

Methodology: Reactor data from the U.S. Nuclear Regulatory Commission. Population estimates from Census ACS 2023. Environmental overlay data from EPA TRI, FEMA NFIP, military base locations, and ZipCheckup's composite safety scoring. Plant ages refer to the year of first commercial operation. Population figures for EPZ areas are approximations based on ZIP-level census data within estimated 10-mile radii.