Nuclear weapons testing

NEWS ANALYSIS Michael Heylin , C&EN Washington Ever since the first nuclear test explosion 43 years ago, there have been efforts to ban, or at least constrain, such tests. Such efforts have been spotty and have met with only modest success. For 25 years there have been treaty limits on where tests can be conducted: They must be underground. For 12 years there have been limits on their size: not larger than the equivalent of 150 kilotons of TNT. But these constraints have done nothing to hamper development and deployment of new nuclear weapons systems. There are no treaty limits on the number of tests and they go on unabated. Last year there were 47 worldwide. The long-term average is 42 per year. That first nuclear blast, which brightened the early morning sky near Alamogordo, N.M., on July 16, 1945, has been followed by more than 1750 nuclear explosions conducted by at least six nations. Nuclear ...