NRC does not indicate whether or not the flowers in its file photo of Limerick are spiderwort mutated by radioactivityNatural Resources Defense Council (NRDC) has filed a petition, backed up by technical declarations, to intervene with the U.S. Nuclear Regulatory Commission (NRC), challenging the 20 year license extension sought by Exelon, the largest U.S. nuclear utility, for its twin-reactor Limerick Nuclear Power Plant near Pottstown, PA. Limerick is just 21 miles northwest of Philadelphia, with 8 million people living within 50 miles. NRDC argues that after the Fukushima nuclear catastrophe, Limerick's two decade old severe accident mitigation alternatives analysis is obsolete and far from sufficient. The Philadelphia Enquirer, Associated Press, WHYY (Philly NPR), and Pennsylvania NPR, among others, covered the story.  States News Service carried NRDC's media statement. NRC has rubberstamped 71 license extensions in the past dozen years. In 1982, an NRC sponsored study (which the agency unsuccessfully tried to cover up) reported that a major accident at Limerick could cause 74,000 "peak early fatalities" (second worst in the U.S. after Salem in New Jersey), 610,000 "peak early injuries" (by far the worst in the country), 34,000 "peak cancer deaths," and around $200 billion in property damage ($450 billion when adjusted for inflation). The population downwind of Limerick has grown by over a million since that study was produced. Both Limerick units are General Electric boiling water reactors with Mark 2 containment designs, similar in many ways to the catastrophically failed Fukushima Daiichi GE Mark 1s. Given the large population surrounding Limerick, and the old age of Exelon's emergency plans, NRDC questions the adequacy of preparedness for a serious accident at the twin-reactor complex.