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If every U.S. reactor melted down at once.

A worst-case map of the potential fallout plumes from all 56 operating U.S. nuclear power plants, assuming they all suffer a core meltdown at the same time. Each plume drifts downwind on the real 500 mb winds; the population living under each contamination tier is estimated from census-tract data. Click anywhere to check the fallout at your own location. Educational — a simplified dispersion model, not an NRC/RASCAL calculation.

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Prevailing winds shift through the year — winter is strong & westerly, summer is lighter & more southerly.
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Assume each plant's spent-fuel pool also loses coolant and burns — releasing decades of accumulated caesium-137 that mainly enlarges the long-term relocation & screening zones.
All 56 operating U.S. commercial plants — every one assumed to melt down simultaneously. Larger plants release more, so their plumes reach farther.
Click anywhere to check the fallout there
Fallout zones — tap to toggle
Estimates for education & preparedness planning. Each plume is a simplified Gaussian-style downwind footprint scaled by reactor size, release severity and the local mid-level wind — not an NRC RASCAL or HYSPLIT dispersion run. Contamination tiers are illustrative of evacuation / relocation / screening distances seen at Chernobyl and Fukushima, not dose calculations. Population assigns census-tract counts to the worst tier reached and ignores sheltering, evacuation and terrain. A simultaneous meltdown of every plant is a deliberately extreme thought experiment, not a forecast.

You can't stop the release. You can plan for the plume.

Knowing whether you live downwind of a reactor, where the shelter window lies, and when to leave is the first step to a fallout plan.

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