9 nuclear accident zones still closed to the public

Some of the most radioactive ground on Earth has never been reopened to ordinary use, decades after the accidents and weapons tests that created it. Fences, checkpoints and abandoned buildings still mark the edges of these sites, from a Ukrainian city frozen in 1986 to a Pacific atoll evacuated twice. Here are nine nuclear accident zones that remain closed to the public today.

1. Chernobyl Exclusion Zone: Reactor 4’s Permanent No-Go Zone

Reactor 4 at the Chernobyl plant exploded on April 26, 1986, and the firefighters who reached the roof within minutes absorbed lethal doses before anyone understood what had happened. The United Nations recovery programs that followed have run continuously for four decades, and the roughly 1,000-square-mile exclusion zone around the plant is still closed to permanent residents.

Soil, groundwater and the abandoned city of Pripyat carry radioactive isotopes with half-lives measured in decades, so resettlement was never on the table even as tourism crept in around the edges. Engineers, scientists and a shrinking population of self-returned residents are the only people who spend real time inside the fence.

2. Fukushima difficult-to-return zone: Where The Evacuation Order Never Lifted

Fukushima Prefecture still labels a ring of towns around the wrecked Daiichi plant as areas where the 2011 evacuation order was expected to last for “an extended period,” and its own tracking portal shows that access has reopened only inside small, individually designated reconstruction-base pockets.

Streets in towns like Futaba still carry barricades and idle traffic signals more than a decade after the meltdown, even as decontamination crews work outward from the reopened patches. Full return for most residents depends on radiation readings falling further, not on a calendar date.

3. East Urals Radioactive Trace: The Explosion Moscow Tried To Bury

A cooling failure inside a waste storage tank at the Mayak plutonium plant triggered a chemical explosion in September 1957, throwing a plume of fission products across the southern Urals in what became known as the Kyshtym disaster.

Soviet authorities evacuated thousands of people from the worst-contaminated villages and folded that land into the East Ural State Reserve, a fenced-off buffer that still bars public entry. The accident stayed secret for two decades, disclosed to the West only after a defector described it in 1976.

4. Windscale Pile 1: Britain’s Sealed-Up Reactor Fire

A routine heat treatment on Pile 1 at the Windscale site went wrong in October 1957, setting the graphite core alight and sending radioactive iodine drifting over the Cumbrian countryside in what remains Britain’s worst nuclear accident.

Workers extinguished the blaze with water rather than risk a hydrogen explosion, then sealed the damaged pile with roughly 15 tons of uranium fuel still inside. Decommissioning crews only began removing that fuel decades later, and the chimney’s filter gallery and the pile itself are still being dismantled piece by piece today.

5. Palomares: The Village That Caught Two H-Bombs

A U.S. Air Force B-52 collided with its refueling tanker over this Spanish farming village in January 1966, and the conventional explosives packed around two hydrogen bombs detonated on impact, scattering plutonium across the fields below in what is known as the 1966 Palomares incident.

Cleanup crews shipped tons of contaminated soil to a U.S. storage site, but Spain and the United States only finished negotiating a deal to remove the last of the buried plutonium decades later. Fenced-off farmland still sits behind warning signs on the edge of town.

6. Rocky Flats Plant: A Sealed Core Inside A Wildlife Refuge

Northwest of Denver, the former Rocky Flats Plant manufactured plutonium pits for the nation’s nuclear arsenal for four decades and suffered major fires before its 1989 raid and eventual shutdown, according to the Department of Energy’s Office of Legacy Management.

Cleanup turned most of the surrounding buffer land into a wildlife refuge open to hikers and cyclists, but the central operable unit where the plutonium work actually happened stays fenced off and under permanent federal control, closed to the public indefinitely. DOE continues monitoring groundwater and soil there under a long-term stewardship plan.

7. Runit Dome: A Concrete Cap Over A Crater

On Runit Island in the Marshall Islands’ Enewetak Atoll, a concrete dome caps more than 100,000 cubic yards of radioactive soil and debris sealed into the unlined Cactus Crater in the late 1970s, according to the U.S. Department of Energy.

The Department of Energy reported to Congress on the dome’s condition in June 2020, and the crater beneath it was never lined, so groundwater and any future storm surge remain open questions for the atoll. Runit Island itself stays off limits, one more Pacific test site where cleanup meant containment rather than removal.

8. Semipalatinsk Test Site: Four Decades Of Soviet Detonations

The Soviet Union fired several hundred nuclear tests over the Kazakh steppe at this site between 1949 and 1989, and the United Nations now marks its 1991 closure every August 29 on the International Day against Nuclear Tests.

One underground blast in 1965 gouged out a crater that filled with groundwater and is now known locally as Atomic Lake, still measurably radioactive along parts of its shoreline. Kazakhstan keeps large sections of the roughly 7,000-square-mile former range under government control rather than open the land to settlement or farming.

9. Bikini Atoll: The Lagoon Still Too Hot To Farm

The United States detonated twenty-three nuclear devices over this Marshall Islands atoll between 1946 and 1958, including the 15-megaton Castle Bravo shot that remains the largest bomb the U.S. ever tested, according to Bikini Atoll’s historical record.

Residents removed before the tests began were told decades later that radiation levels made resettlement safe, moved back, then were evacuated a second time when cesium-137 turned up in their crops. No permanent population has lived there since, and visitors still need special government authorization just to set foot on the atoll’s beaches.