8 U.S. nuclear reactors had "near misses" of an accident on the scale of Chernobyl since 1986.

Greenpeace Report: AN AMERICAN CHERNOBYL: Nuclear “Near Misses” at U.S. Reactors Since 1986

See above to download and read a 2006 study by Greenpeace using U.S. Nuclear Regulatory documents that looks at accidents that happened at U.S. nuclear reactors since 1986. They found among other things that in 8 cases accidents at U.S. nuclear power plants led to conditions that had a 1-in-1,000 chance of causing a total meltdown of the reactor core, meaning an accident on the scale of Chernobyl or worse.

On page 5 of the report it is revealed that nuclear reactors in Illinois not far from Chicago were responsible for 15 of 46 'frequent' near miss incidents that could have led to a reactor core meltdown and the explosion and release of radioactive clouds accross the region just like the Chernobyl disaster or worse. That means that since 1986, Illinois reactors have had 1/3 of the frequent near misses in the United States.

The report continues:

The reactors that experienced the most “near misses” since Chernobyl, DC Cook 1 and Dresden 3 [located 20 miles south west of Joliet], both have containments that offer the public little or no defense in the event of a meltdown.

Later, the report explains that in 1986 right after the Chernobyl disaster the Nuclear Regulatory Commission testified to Congress about how dangerous U.S. nuclear power was:

Less than a month after the disaster, NRC Commissioner James K. Asselstine testified that, "given the present level of safety being achieved by the operating nuclear power plants in this country we can expect to see a core meltdown accident within the next 20 years and it is possible that such an accident could result in off site releases of radiation which are as large as or larger than the releases estimated to have occurred at Chernobyl."

"While we hope that their occurrence is unlikely, there are accident sequences for U.S. plants that can lead to rupture or bypassing of containment in U.S. reactors which would result in the off-site release of fission products comparable or worse than the releases estimated by the NRC staff to have taken place during the Chernobyl accident."

"That is why the Commission told Congress recently that it could not rule out a commercial nuclear power plant accident in the United States resulting in tens of billions of dollars of property losses and injuries to the public."