What is the risk of nuclear materials falling into the wrong hands?
At the international level, a considerable amount of work is being done to prevent the proliferation of nuclear materials. In the post cold war era, for example, Russia has dismantled a large number of the earlier design highly enriched uranium bombs and diluted the U235 isotope for use in civil reactors. By the end of 2003, more than 200 metric tons of Russian weapons-grade uranium (enough for 8000 nuclear weapons) had been diluted and made into nuclear power plant fuel. Roughly one half of the uranium being used in US power plants today comes from this source.
