An International Atomic Energy Agency team is in Moscow negotiating an agreement for on-site inspection of civilian nuclear facilities that Director-General Hans Blix said could set a precedent for verifying a U.S.-Soviet arms control pact in the future.

"I think a new perspective has been opened with the Soviet Union's voluntary offer to us to come and safeguard some of their peaceful nuclear installations," Blix said in an interview. "This clearly raises the question to what extent the safeguards technique could be employed in a nuclear disarmament context."

A team of four atomic energy agency officials flew to Moscow on Monday to discuss which Soviet facilities will be opened to international inspection, sources said. The Soviets so far have agreed only to permit inspectors to visit atomic power plants and research reactors, the sources said.

Blix conceded that Soviet willingness to permit inspection of "peaceful, identified installations" was not the same as agreeing to let monitors of a disarmament agreement "roam the territory."

Nevertheless, State Department officials said they believe that Moscow's reversal of its longstanding refusal to open any of its atomic program to international inspection--and its acceptance of the principle of institutionalized on-site inspection and related verification measures--represent at least a modest step forward.

Blix, who has been attending an IAEA conference on radioactive waste management here, said he found it "very interesting that in a number of recent Soviet statements they have placed a great emphasis on safeguards as a model for verification methods in the field of disarmament."

Though he conceded that the current arms control climate does not appear to be "a very hopeful one," he suggested that a future approach might be for the United States and the Soviet Union to agree to cease further production of the plutonium and highly enriched uranium needed for nuclear weapons.

"We now have the experience, and are increasing our experience, in safeguarding reprocessing plants and enrichment plants, which are the installations that produce weapons-grade material," Blix said. "So if one day the great powers wish to ask themselves, could we have a cutoff of fissionable material for weapons purposes, the techniques are there to monitor it," he said.

This approach to arms control is similar to the "plutonium freeze" proposal currently being circulated in Congress by Sen. Gary Hart (D-Colo.) and Rep. Richard L. Ottinger (D-N.Y.).

Verification of U.S.-Soviet arms agreements never has included on-site inspection, but always has relied on monitoring from outside the country and satellite reconnaissance.

Nevertheless, Blix said he felt that "the more recent Soviet statements on verification and control" suggest that Moscow is open to this approach.

The United States, Britain and France for some time have permitted the IAEA to inspect some of their civilian nuclear facilities. China, the fifth nuclear weapons state, does not have a civilian atomic program and is not open to IAEA inspectors.