Soviet dissident Yuri Orlov, whose release from Siberian exile was part of the U.S.-Soviet deal to free journalist Nicholas Daniloff last week, arrived in America today amid wellwishers' cheers tempered by his own mixed emotions.

Stepping off an Aeroflot jetliner and into a room jammed with shouting reporters and photographers at John F. Kennedy International Airport, the diminutive Orlov said through an interpreter that he was grateful to "start a new life . . . where I can say whatever I want freely."

But he added, "I have very complicated feelings. I have left my homeland . . . my native language, my native culture."

This appeared to be a reference to what reporters have described as Orlov's long-held hope to be released from prison and exile but remain in the Soviet Union as a free citizen. Supporters say he had not sought to emigrate and viewed his part in the Daniloff release agreement as expulsion.

Accompanying Orlov on the plane today was Richard Combs, deputy chief of mission at the U.S. Embassy in Moscow. Orlov thanked Combs and other U.S. officials for gaining his release, a move that came after the Soviet Union released Daniloff, a U.S. News & World Report correspondent charged with espionage, and the United States released Soviet U.N. employe Gennadi Zakharov, also charged with espionage. The arrangement was made to help keep a scheduled U.S.-Soviet summit meeting on track.

Looking tired but alert, Orlov, 62, with his wife, Irina, 40, spoke briefly at a news conference and then was hustled away by State Department officials and New York Port Authority police.

He described his health as "not bad" and said his immediate plans in America are to continue studies as a physicist.

"I'm just happy that at last my husband is free," said Irina Orlov.

Reuter reported that as she left Moscow, Irina Orlov looked confused and dispirited. Asked how she felt to be leaving the Soviet Union, she replied: "It's hard."

While her husband was taken to the airplane separately by Soviet personnel, she checked in at the departure counter and went through passport control and customs like a normal passenger.

Irina Orlov took only two small bags with her out of the country. A friend of the family, Yevgeny Yakir, told reporters: "She has left everything behind except her husband." Like Orlov's sons Lev, Alexander and Dmitri, Irina Orlov's elderly mother and brother Vladimir are staying in the Soviet Union.

Yuri Orlov, wearing a gray jacket and open gray shirt, said he does not know where they will live in the United States.

He said he not only had mixed emotions about leaving his native country but experienced something akin to guilt "about leaving other [dissidents] still in prison."

Orlov had headed the Moscow branch of an unofficial committee established in 1976 to monitor Soviet compliance with the human rights provisions of the East-West Helsinki accords of 1975.

He made numerous reports to Western diplomats and reporters, alleging violations. He was arrested and convicted under laws prohibiting anti-Soviet propaganda and sentenced in 1978 to seven years in prison and five years in internal exile in Siberia.

During his imprisonment, Orlov suffered from kidney problems, bad teeth, low blood pressure, cystitis and other ailments, according to dissident movement leaders.

He said today that his health improved in more recent years when he lived in exile in the Siberian town of Kobyai. "I had a garden and raised potatoes," he said.

Orlov, who was greeted by several dozen friends and wellwishers with flowers, is one of the best known Soviet dissidents, along with fellow physicist Andrei Sakharov and Jewish activist Anatoly Shcharansky.

Members of several U.S.-based dissident support groups were also on hand to welcome Orlov today, providing an interpreter and helping arrange the news conference.