A high-ranking Soviet official told Sen. Paul Simon (D-Ill.) on July 9 that dissident physicist Andrei Sakharov would never be permitted to leave the Soviet Union because his emigration would violate the 1969 nuclear nonproliferation treaty, according to documents provided by Simon's office.

The State Department, in internal documents, characterized the Soviet arguments as "ludicrous" and "bizarre."

Simon, whose congressional career has focused heavily on educational matters, was in Moscow to discuss the possibility of expanding educational, cultural and scientific exchanges.

During the discussions with Soviet officials, he raised the issue of Sakharov, a world-famous physicist known as "the father of the Soviet H-bomb." In recent years, Sakharov has been a critic of the Soviet regime and for the past several years has been confined to the city of Gorki, which is off-limits to foreigners.

Simon reportedly was told by Anatoly Petrovich Alexandrov, president of the Soviet Academy of Sciences, that allowing Sakharov to emigrate would be a violation of the nonproliferation treaty, which was signed by the United States and the Soviet Union, among other nations.

Alexandrov said that since Sakharov had been privy to nuclear secrets and knowledge of how to construct nuclear weapons, he could transmit this knowledge to other countries or groups if allowed to emigrate. Another Soviet official present reportedly interrupted to suggest that the knowledge could even land in the hands of terrorists.

Alexandrov reportedly also complained that when Sakharov's wife, Yelena Bonner, was allowed to go to Italy for medical treatment, she had also visited the United States without permission and without announcing her plans.

In a telephone interview yesterday, Tanya Yankelevich, daughter of Bonner and stepdaughter of Sakharov, confirmed that Bonner had visted her and other relatives in the United States for about a month in February 1979. Yankelevich said Bonner had not publicly announced the visit because she wanted it to be a family matter and "she never tried to use her visits abroad to slander any person or any country. The fact that this was not known to you proves her good intentions."

Yankelevich also said the idea that Sakharov is confined to prevent him giving away nuclear secrets is "a silly excuse," because he had had many opportunities to do so when foreign scientists had visited him, but had not done so. "Not once did Dr. Sakharov offer these secrets to anyone," she said.