There was no red button, no switches, just an electronic timer that ticked the minutes away until a 100 kiloton to 150 kiloton nuclear explosive was detonated beneath the Nevada desert at 10 a.m. (11 a.m. MDT) Wednesday while U.S. and Soviet officials looked on.

The ground moved slightly about three seconds after the bomb was detonated at the Control Point 30 miles from the bomb. Dust could be seen jumping from the ground above the 2,050-foot-deep test hole on video monitors viewing the site from a helicopter circling above the test.Weather and other conditions were described as being near perfect for a test by Department of Energy spokesman Chris West.

Having Soviet officials at the test site during a nuclear shot is something that would have been hard to believe one year ago, said Igor M. Palenykh, head of the Soviet delegation to the Nuclear Testing Talks in Geneva, which are ongoing. Palenykh is one of 43 Soviets at or near the Control Point when the test was fired.

It would have been just as difficult for Soviets to believe Americans would be on their turf, at the Semipalatinsk Test Site for the second half of the test scheduled Sept. 14, Palenykh said. Joseph F. Salgado, acting Department of Energy deputy secretary and under secretary, said the test Wednesday sets a new precedent for test verification and is the result of four years of diplomatic exchanges between the United States and the Soviet Union.

After the Soviet test next month, "We have every hope that the ultimate conclusion of this process will be an agreement on effective verification measures which will permit ratification of (both) the Threshold Test Ban and the Peaceful Nuclear Explosions Treaty," he said.

The Threshold Test Ban was signed by diplomats from both countries in 1974, but was never ratified by the U.S. Senate. It sets a test limit of 150 kilotons.

Palenykh lauded the progress also, but accused the United States of dragging its feet. If it were up to the Soviet Union only, he said through a State Department interpreter, a treaty banning all nuclear tests could be signed tomorrow.

Ambassador C. Paul Robinson, chief U.S. negotiator at the Geneva talks, focused his comments not on a unilateral test ban, but on the U.S. position that nuclear testing would be important to this country as long as nuclear weapons are in the nation's military stockpile.

Palenykh also accused the U.S. of violating provisions of the agreement when several members of the U.S. delegation last week removed some unauthorized items from the Russian test site. Those items included rocks, a piece of barbed wire and a hammer. It was the United States' provision that visiting delegation workers not remove earth, rock or metal objects from the host country's test site.

Robinson said the United States did not send a James Bond figure to the Soviet Union to pilfer objects from their test site. Rather the individuals who removed the items were more akin to a Don Knotts type character.

About 20 protesters outside the test site tried to block the road when buses carrying reporters entered earlier in the morning. Three people who tried to physically block the buses were detained, West said.

Another test-day obstacle was removed, literally, on Monday when a Nevada man and a Utah woman were spotted by security while hiking onto the test site in an unsuccessful attempt to stop the Wednesday blast. (See separate story)

The yield verification procedures are being tested because of the possibility that Soviet presence at United States tests, and vice versa, could become protocol for future high-yield tests if the 1974 Threshhold Test Ban Treaty is ratified. Robinson said the issue of whose verification techniques are the best is not as important as creating a menu of approved methods for verifying the yield of tests in each other's countries.

Another unusual addition to Wednesday's test was the presence of dozens of American and European journalists in the Control Point complex. More than 60 reporters and photographers registered with DOE to attend. A pool of 20 reporters and photographers, including the Deseret News, was allowed to cover the events from inside the Control Point during the test.

A team of Soviet reporters was also expected to participate but never showed up, DOE spokesman Chris West said Tuesday. Palenykh called their absence disappointing.

West said DOE would not say whether the nuclear device, code named Kearsarge, was manufactured specifically for the test or whether it was taken from somewhere in the nation's weapons stockpile. He did say the yield of the weapon would approach the 150 kiloton limit set by the threshold treaty.

Bombs this big frequently cause ground movement in Las Vegas, and movement can sometimes be felt on the top floors of tall buildings there, West said.

The exact design yield of the bomb would be made known to the Soviets, but not until after all of the test data has been exchanged and evaluated, said Nick C. Aqualina, manager of the Department of Energy's Nevada Operations Office.