Could it happen here? That's the question on everyone's mind as we watch the nuclear emergency unfold at Japan's Fukushima Dai-ichi nuclear plant. As it turns out, the U.S. government has long been asking the same question. The Nuclear Regulatory Commission recently provided MSNBC with an updated list of the American plants most at risk of core damage (which can lead to meltdowns and radiation release) in the event of an earthquake. What parts of the country are most at risk? You may be surprised. Most people would assume California plants, built around the turbulent San Andreas fault line, might...