Chernobyl's reactor No. 4 exploded on April 26, 1986, spewing radiation over a large swathe of the former Soviet Union and much of northern Europe. The new shelter - an arch-shaped steel structure 345 feet (105 metres) tall and 490 feet (150 metres) long - will enclose the concrete sarcophagus erected hastily after the 1986 accident. That structure has been crumbling and leaking radiation for more than a decade. The plan is to eventually dismantle the sarcophagus and the exploded reactor inside the new shelter.
"I am convinced that today, possibly for the first time, we can frankly tell the national and international community that the answer to the problem of sheltering the Chernobyl nuclear plant was found today," President Viktor Yushchenko said at the signing ceremony, according to the presidential Web site. Link