Charles S. Williamson, security manager Exelon Generation Company, right, talks to a worker next to rows of 55,000-pound concrete blocks, that act as barriers to vehicular attack, Monday, Oct. 25, 2004, at the Clinton Power Station in Clinton, Ill. New post-9/11 federal rules designed to protect nuclear reactors from terrorist assaults have lead to the sprouting of seven 20-foot-high tan-colored guard towers which now ring the station.
