Today, millions of people live on contaminated land. A central core, is closed forever to human habitation. The governments of Belarus and Ukraine devote 5 percent of their national budgets to treating survivors and patrolling the no go zone.

Despite this legacy, there was little optimism back in February when the European Bank of Reconstruction and Development (EBRD) took reporters on a tour of Chernobyl, hoping to raise world interest in paying for the new containment shell.

Then on March 11, a wall of water crashed into the nuclear power plants in Fukushima, on the Pacific Coast of Japan. Balthasar Lindauer, deputy nuclear safety director at the European Bank, described the Fukushima factor.

"Today at the pledging conference, Fukushima was mentioned very frequently, and I think it certainly has drawn attention to Chernobyl," said Lindauer.

European Commission President Jose Manuel Barroso told the conference that Chernobyl and recent events in Fukushima, Japan, were a reminder that nuclear risks may not stop at a country's borders.

He pledged $156 million from the European Union to rebuild the Chernobyl containment shell. The United States delegation, led by former United States National Security Advisor Zbigniew Brzezinski made the largest single nation donation: $123 million.

By the end of the day, pledges had come in for three quarters of a final $1 billion needed to complete the project. All in all the new shell is to cost $2 billion and should be complete by the end of 2015.