U.S. Weapon-Grade Uranium Production Tops Estimates

The U.S. government produced far greater quantities of highly enriched, weapon-grade uranium from 1945 to 1992 than previously known, Energy Secretary Hazel O’Leary disclosed Monday.

Government factories in Ohio and Tennessee produced 994 metric tons of weapon-grade uranium, well above the usual estimate of about 700. Almost 259 metric tons of the material, which is highly radioactive and relatively easy to convert into bombs, remains in the U.S. stockpile, according to Energy Department figures declassified Monday.

Weapon-grade uranium may be converted to civilian use, but the Energy Department has not made a long-term decision about what to do with the surplus material. Some of it is to be retained as fuel for Navy reactors, officials said.

But the Energy Department wants to reduce the stockpile, and the Russian stockpile of about 500 metric tons, to limit the threat that the material could fall into the wrong hands. A bomb could be fashioned from 25 kilograms, according to the International Atomic Energy Agency, so each metric ton could make 40 devices.

The uranium figures were contained in hundreds of pages of material about the U.S. nuclear weapon program made public by O’Leary in the second phase of her “openness initiative,” an ambitious attempt to dismantle the department’s history of classification and secrecy.

O’Leary also made public 48 radiation experiments conducted by the government on humans since the 1920s, including several cases in which radioactive isotopes were given to pregnant women, mental patients, or terminally ill persons.

But the Defense Department blocked disclosure of two other secrets long sought by independent researchers and anti-nuclear activists: the total number of warheads produced by the United States each year and the number now in the U.S. nuclear arsenal.