This week’s 2.2-magnitude earthquake that shook parts of northern Westchester and Putnam County is another reminder that the Indian Point nuclear plant remains a danger to the region.

Indian Point sits just one mile south of the Stamford-Peekskill line, part of the Ramapo Fault Zone. Researchers at Columbia University’s Lamont-Doherty Earth Observatory say that this fault zone can produce at least a magnitude 6, and perhaps a magnitude 7 earthquake. The earthquake’s epicenter, in Yorktown, is near the Stamford-Peekskill line and about 8 miles east of Indian Point.

While the recent earthquake was not enough to disrupt operations at the plant, it reminds us that the plant’s proximity to known faults puts the plant at a greater risk. In fact, in 2011 the Nuclear Regulatory Commision has ranked Indian Point’s Unit 3 reactor the highest in risk of failure from earthquakes among all U.S. nuclear power plants.

At the typical U.S. nuclear reactor, there’s a 1-in-74,176 chance each year that the core could be damaged from the effects of an earthquake (the effects of a secondary event, such as a tsunami are not calculated). Designed to withstand a magnitude 6.1 earthquake, the chance of core damage from a quake at Indian Point 3 is calculated to be 1-in-10,000 each year. And according to NRC specifications, that’s dangling on the edge of what it deems “immediate concern regarding adequate protection” of the public. (The Indian Point Unit 2 reactor is rated the 25th most susceptible to the effects of a significant earthquake with a 1-in-30,303 chance each year.)

Columbia University has identified the risk of a 7 magnitude earthquake in the region. Even the NRC believes core damage is seven times more likely than at most reactors, but held off requiring higher post-Fukushima standards to be met at Indian Point. So far we got lucky that no big earthquakes have hit. We can’t get lucky forever, so it's lucky we got smart and decided to close Indian Point.