MOSCOW — The Soviet Union today conducted its second underground nuclear blast in the two weeks since the Kremlin abandoned its 19-month unilateral testing moratorium.
Moscow also denied U.S. claims that its first test violated treaties by releasing radioactive fallout.
Tass press agency said today's blast had a yield of 20 kilotons, or 20,000 tons of TNT, and was conducted "with a view to upgrading military technology."
It occurred at 5 a.m. Moscow time at the military testing site at Semipalatinsk, in the Central Asian republic of Kazakhstan, about 1,800 miles southeast of Moscow.
The announcement came a day after the State Department said the last Soviet underground test, conducted Feb. 26, released a small amount of radioactive debris into the atmosphere in violation of the 1963 Limited Test Ban Treaty. The State Department said there was no health danger.