WASHINGTON -- U.S. Energy Secretary Hazel O'Leary Tuesday revealed the full extent of U.S. nuclear weapons testing during the Cold War, saying the number of tests was more extensive than previously revealed or believed.
In an effort to 'come clean' about the extent of testing, O'Leary said during a news conference that of the 925 total nuclear tests performed since 1945, 204 -- 20 percent -- were kept secret. The United States conducted its first secret nuclear test in 1963 and the last in May 1990.
'The reason only 80 percent has been released is that 20 percent of that information is considered to be a national security risk, such as, if someone who were interested in proliferating might get that information and now be able to get into some mischief,' she said.
After the Cold War ended and the Soviet Union collapsed, O'Leary said the United States decided it was safe to declassify some information previously kept secret for national security reasons.
She also said the department wanted to responed to requests from scientists, environmentalists, health and safety officials, nonproliferation activists and others who have been asking for the information for years.
O'Leary revealed for the first time that the United States is storing 33.5 metric tons of plutonium in warehouses in six states.
In addition, 55.5 tons of government-manufactured plutonium is contained in nuclear weapons, which are being stored at an assembly plant in Texas, or hasbeen dispersed in small quantities at buildings where nuclear weapons are assembled.
She said she was 'most appalled' about the condition of facilities and 'the waste material left nearby.'
'We've got to clean up house in respect to our ethic and our responsibility,' she said.
The disclosures are part of the department's effort to be more open and responsive to the public, as well as to reveal the environmental and health effects involved in conducting such tests, she said.
'The fact that this is now known again lets the public assess clearly the impact both to health and safety and, again, puts us honestly out front as a nation willing to share and hoping that the other nuclear nations will do the same,' she said.
As part of this effort, she said the department will release more information about experiments conducted by the Atomic Energy Commission in the late 1940s and early 1950s that involved 18 people who were given small amounts of plutonium to test the effects of exposure.
Some of those involved with the experiments may not have given their consent, she added.
'What I think I know and have processed with respect to the 18 citizens of our country leave me both appalled, shocked and deeply saddened,' she said.
She also said that the number of people involved may have actually been much higher, perhaps as many as 800. She said the department is trying to gather more details on these people and promised to share additional infomation.
O'Leary also disclosed for the first time that 24 million pounds of mercury was used at the Oak Ridge nuclear plant in Tennessee to enrich lithium, a key ingredient used in nuclear arms.
She said the department is reviewing some 32 million pages of information stored at the Energy Department or the National Archives for declassification.