The World : U.S. Monitors Soviet A-Test

The Soviet Union conducted its first nuclear test explosion to be directly monitored by U.S. scientists on Soviet territory. A group of 45 U.S scientists, diplomats and nuclear experts were on hand at Semipalatinsk as part of a U.S.-Soviet agreement signed at the Moscow summit meeting in June to exchange monitoring teams. Last month, a group of Soviet scientists for the first time witnessed a U.S. nuclear test in Nevada as part of the exchange program. The short-range purpose of the program is to prove that the size of nuclear tests can be accurately measured on-site without jeopardizing the military secrets of either nation. The official Soviet news agency Tass said the Semipalatinsk blast carried a yield of between 100 and 150 kilotons, the equivalent of 100,000 to 150,000 tons of TNT.