Nevada DOE’s Nevada Operations Office, when discussing off-site detection of radiation from tests, sometimes has used the term stmospheric to describe any test where the release of radioactivity to the atmosphere was anticipated and wasa factor in test planning. Nineteen were not designed to be contained. See Categorization of NTS Nuclear Tests (page v) for a comparison oftest totals listed by the placementcriterion used in this document with those listed by the designed to be contained criterion. i iv vada Test Site Even Unless otherwise noted, all nuclear tests at the NTS or the Bombing Range prior to September 15, 1961, produced radioactivity detected off site.* Unless otherwise noted, no test at the NTS or the Bombing Rangeon or after September 15, 1961, had a release of radioactivity that was detected off site. The release of radioactivity from a test can occur: e e e Accidentally as a result of a containmentfailure. Accidentally or deliberately as a result of post-event operations. Deliberately as a result of post-event controlled purging of gases from a tunnel. All releases resulting from a containmentfailure, even if not detected off site, are reported. Radiation releases resulting from tunnel purging or normal operations are not reported in this document untess detectedoff site, since they are carefully monitored and do not have an impact on the public. *See Glossary for definition of "off site.” U.S. In July 1992 the White House announced that future U.S. nuclear tests would be conducted only to ensure the reliability and safety of U.S. deterrent forces. Past tests have been described as being for one of seven purposes (see pageviii). Weaponsrelated tests are conducted to gather data on nuclear devices; weaponseffects tests are conducted, usually by the DoD, to determine the effects of nuclear detonations on military offensive and defensive systems. As now mandatedby law,the only purpose for a weaponsrelated test is to ensure either the safety or the reliability of U.S. nuclear weapons, and the only purpose for weapons effects tests is to ensure the reliability of U.S. deterrent forces. The law further stipulates that plans to test for reliability of a specific nuclear deterrent receive Congressional approval prior to test execution. The purpose of tests conducted for the United Kingdom (UK) will continue to be shown as “Joint US-UK.” As for U.S. tests, the only purpose is to ensure the safety or the reliability of the UK deterrent. A note following each test entry indicates whether the test was for safety or reliability.