On October 31, 1958, the United States entered into a unilateral testing moratorium announced by President Eisenhower with the understanding that the Soviet Union would also refrain from conducting tests. The Soviet Union resumedtesting in September 1961 with a series of the largest tests ever conducted. On September 15, 1961, tha United States resumed testing at the NTS on a year-round basis with Operation Nougat. From that time to the present, tests have been groupedfor fiscal and reporting purposes according to the fiscal year in which they took place. For example, fiscal year 1963 tests -- which began July 1, 1962, and extended through June 30, 1963 -- were in the Operation Storax series. Between April and November of 1962, the United States conducted Operation Dominic, which included the Department of Defense (DoD} Operation Fishbowl high-altitude tests, in the Pacific. The DoD also conducted four weapons effects tests at the NTS in July 1962 as Operation Sunbeam. In 1976, the federal government changed the fiscal year to begin on October 1 and end on September 30. Accordingly, the fiscal year 1976 series, Operation Anvil, did not end on June 30, but was extended through September 30, 1976, a period of 15 months. Yields The nomenciaturefor test yields varied according to information policy governing specific years. In some cases, no yield information has been released; in a few cases, the terms “very slight” and “slight” were used without amplification. Except for tests where specific yields or relative specific yields such as “about 2 kt,” “several MT,” "less than 0.1 kt,” etc., were announced, test yields are given in these terms: 1945 through 1963 Low (less than 20 kt} Intermediate (20 to 200 kt) -- all tests except Operation Dominic Intermediate (20 to 1,000 kt) -- Operation Dominic Submegaton (less than 1 MT, but more than 200 kt) Low Megaton (from 1 to several MT) Megaton Range 1964 through February 1976 Less than 20 kt 20 to 200 kt 200 to 1,000 kt