Aug. 5, 1962 - The Soviet Union resumed its nuclear tests in the atmosphere early today with a powerful high-altitude blast believed to have been in the 40-megaton range. The blast, over Novaya Zemlya, in the Arctic, appeared to have been the second most potent nuclear explosion ever achieved. The record is held by the Soviet Union, which detonated last Oct. 30 a nuclear device with an explosive force estimated at the equivalent of 58 megatons of TNT. A megaton is 1 million tons. The U.S. Government called today’s resumption a “somber episode” but expressed the hope that Moscow would nonetheless cooperate in working for an effective treaty prohibiting all tests of nuclear weapons.