More than 20 years after the disastrous meltdown, formal plans to encase and dismantle Chernobyl's nuclear reactor have begun. Announced yesterday by Ukrainian President Viktor Yushchenko, the project calls for a $1.4 billion steel covering to be constructed over the next five years. Currently, the reactor is surrounded by the dilapidated and ineffective concrete encasement erected shortly after the accident—the replacement will be built just a short distance away and then slid over the entire structure. Some 95 percent of the reactor's original nuclear material remains.—Abby Seiff
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.