Hudson Heights is 28 miles from Indian Point Nuclear Energy Facility, operated by Entergy Inc. in northern Westchester County. According to the company's website, the "emergency planning zone" extends in a radius just 10 miles from the plant, well north of New York City. But as the recent tragedy in Japan has shown, elevated radiation levels may extend beyond 10 miles in a worst-case scenario. For example, on March 20, the Japanese government warned villagers 19 miles from the Fukushima Plant not to drink their groundwater due to radiation concerns.
There are major differences between Indian Point and Fukushima. The Japanese plant has more reactors (6 to Indian Point's 2), sits a known active faultline and is located directly on the ocean. On the other hand, like Fukushima, Indian Point stores its "spent" nuclear fuel onsite because of the lack of other disposal space in the United States.
New York State has generally opposed the re-licensing of Indian Point, a process that is in its final stages before the U.S. Nuclear Regulatory Commission. Mayor Mike Bloomberg, on the other hand, supports the re-licensing because Indian Point supplies a whopping 25% of the City's electricity.
For more information about Indian Point, I like the Hudson Riverkeeper website. This organization is the unofficial steward of the river and has been working for years to close Indian Point. For a different perspective, Entergy's own website, www.safesecurevital.com, provides useful information about the plant.