U.S. Conducts Year’s First A-Test : Kremlin Had Earlier Said Blast Will End Its Moratorium

The top Soviet arms negotiator repeated today that the Kremlin’s 18-month-old moratorium on nuclear weapons tests will end with the next U.S. test blast. Shortly afterward, the United States conducted its first nuclear test of 1987.

“The button that triggers our nuclear test ranges is on the desk in the White House,” Deputy Foreign Minister Yuli M. Vorontsov said at the opening session of the 40-nation 1987 Geneva Disarmament Conference.

U.S. Energy Department spokesman Jack Campbell announced today’s test, conducted 700 feet beneath the surface of Yucca Flat, 86 miles northwest of Las Vegas in the Nevada desert.

The test, code-named Hazebrook, had an explosive yield of less than 20 kilotons. All announced tests are listed as having an explosive yield of less than 20 kilotons or 20 to 150 kilotons.

Thought to Be Set for Thursday

Anti-nuclear activists and Washington sources had reported that Hazebrook was to be conducted Thursday.

In Moscow, Tass press agency took swift note of the Nevada test blast, calling it a challenge to world opinion.

“The Reagan Administration, clearly challenging world opinion, has again ignored the Soviet Union’s call to join its unilateral moratorium on nuclear tests and confirmed its intention to follow a dangerous course for the escalation of the nuclear arms race,” Tass said.

Tass did not indicate in a brief dispatch if the Soviet Union would take any immediate action in response to the blast.

Soviets to Press for Talks

Vorontsov said the Soviet Union would continue to press for “full-scale negotiations” whether or not the United States conducted a test.

Swedish Ambassador Maj Britt Theorin noted that a comprehensive test ban treaty has been the conference’s “professed goal for 25 years.”

“It would indeed be deplorable if such fireworks should mark the opening of this session,” she said, referring to the imminent U.S. test and Moscow’s response.

Vorontsov said the Soviet program for economic reforms and “serious and profound democratization” launched by Kremlin leader Mikhail S. Gorbachev requires peace and security.

‘Security Is Indivisible’

“Political realism in today’s interdependent world . . . makes it imperative to recognize that security is indivisible,” he said.

The Nevada test came at 7:20 a.m. as hundreds of anti-nuclear protesters geared up for a demonstration, scheduled for Thursday, at the Nevada Test Site.

The Soviet Union announced late last year that it would end a test moratorium that began in August of 1985 when the United States conducted its first test in 1987. The Kremlin called on Washington to join the moratorium, but the Reagan Administration refused, saying weapons tests were necessary and that a ban could not be adequately verified.

Campbell would not say whether the detonation was advanced in light of Thursday’s planned protest by anti-nuclear activists. He said many test schedules change for a number of reasons.