Dr. Robert P. Gale, head of a team of western doctors helping victims of the Chernobyl nuclear disaster, said today that as many as 100,000 Soviets may have suffered radiation doses with long-term health effects.

Gale, a UCLA specialist in using bone-marrow transplants to treat radiation and leukemia victims, said Soviet and foreign doctors expect to monitor residents of the Chernobyl area for several years to see whether cancers or other diseases associated with radiation appear in unusual numbers.

"I expect we will be returning there at 3- to 6-month intervals for the next several years," Gale told reporters at UCLA Medical Center.

Gale returned here Friday night after two weeks in Moscow and said he plans to return to Moscow next Friday.

"There are about 50,000 to 100,000 individuals who have received at least some dose of radiation that may be of long-term concern," he said, adding that he has volunteered to visit the Chernobyl area.

Of about 300 radiation victims brought to Moscow Hospital No. 6, Gale said, he and his team helped treat 35 with the most severe radiation exposure.

Nineteen of the 35 have been given marrow or other transplants, and 11 of the 35 have died, although doctors have not said whether any of the dead underwent transplants. The overall death toll is 13, including two persons killed in the initial explosion.

Gale, who said more will die, added that the greatest difficulty facing doctors now is trying to keep the victims from succumbing to infection and bleeding problems.

As is his custom, Gale spoke today strictly about medical details of his mission. He is a thin, intense and serious physician who does not talk readily about personal experiences in the Soviet Union.

However, reached by telephone late Saturday afternoon as he relaxed with his wife and children beside their pool in suburban Bel Air, Gale discussed a few vivid moments of his fortnight in Moscow.

He revealed a collage of skirmishes with formal procedure, breakfasts eaten on the run, growing admiration for Soviet medical ingenuity, and 3 a.m. telephone calls from Los Angeles.

Gale has been involved in notable clashes with standard operating procedure in this country. For example, he and other UCLA doctors were officially reprimanded in 1980 for trying new techniques on dying leukemia patients without proper approval.

But he has remained an international expert in his field as chairman of the advisory committee of the International Bone Marrow Transplant Registry. In his cancer work, he came to know Dr. Armand Hammer, chairman of Occidental Petroleum Corp. and of the President's Advisory Committee on Cancer.

When word of the Chernobyl accident reached Gale, he contacted Hammer with an offer of help. Hammer, who has a long history of close ties to the Soviets, arranged an invitation to Moscow for Gale and his team.

During the six hours between the time he was called by the Soviet Embassy May 1 and his flight to Moscow, Gale said, he alerted colleagues in Seattle, New York and Europe of the need to ready donor and equipment lists.

By the next evening, he was in Moscow, holding a quick organizational meeting and making the first of hundreds of telephone calls to gather equipment and personnel.

Dr. Paul I. Terasaki, 56, a tissue-typing expert at UCLA, set up a new laboratory in Moscow with some of the $500,000 worth of equipment brought to accelerate procedures such as matching tissue donor and patient. Dr. Richard Champlin, 37, another UCLA colleague, arrived to help Gale with primary patient care.

Gale said he and Hammer discovered how willing the Soviets were to suspend normal procedure when Yair Reisner, an Israeli biophysicist sought by Gale to help with tissue-rejection problems, was given a visa at the Moscow airport although the Soviets have no diplomatic relations with Israel.

Gale said he worked closely at Hospital No. 6 with Drs. Aleksandr Baranov, hematology chief, and Angelina K. Guskova, hospital director, both of whom speak English. Most of the Soviet doctors there were women, he said, but four male physicians acted as interpreters.

Gale said his personal interpreter, Victor Voskresenskiy, "was with me up to 20 hours a day."

Gale said his team made a daily routine of taking breakfast items to nibble for lunch. Long days at the nine-story, brown-brick hospital were followed by a hotel dinner at 9 p.m. and planning sessions that often lasted until 1 a.m.

"Sleep was somewhat erratic," he recalled, because of the need for telephone conversations with Los Angeles that often could not be arranged until 3 a.m.

Gale shared a hotel suite with his wife, Tamar, who went to help with complicated logistics. He said he often spoke by telephone to Hammer or to Rick Jacobs, Hammer's assistant at Occidental's Los Angeles office who helped to find equipment worldwide.

When Gale's team sought a break from Soviet cuisine, he said, Jacobs sent bagels from Los Angeles and ale from London.

Gale, who had attended a conference in Moscow in 1978, said he knew none of the doctors treating the 300 radiation victims there. The Soviet Union had not been part of the international bone marrow transplant registry -- "They are now," he noted -- and had published little in English on radiation research.

He said he discovered quickly, however, that the Soviets had developed a sophisticated analysis of foreign and Soviet radiation-related accidents and a proven technique for estimating amounts of exposure after reviewing each patient's symptoms.

Gale and his fellow foreigners, conscious that speed is crucial in treating radiation victims, had their own approach to red tape, he recalled.

If movers were late in relocating a heavy piece of laboratory gear, team members pushed it along the floor themselves. If customs personnel could not process the large amount of equipment arriving at the airport, team members drove miles to help them open crates.

To his surprise, Gale said, he found that many Soviets were infused with the same spirit. "One doctor almost got arrested for trying to take a microscope from another institution," he said.

Addicted to a daily jog, Gale said he welcomed the chance to let off steam in the early morning sunlight of the long Russian day.

He and Champlin ran 10 kilometers before breakfast each day, despite the stares, he said. "I guess at 6 o'clock in the morning a guy running in Red Square with a USA singlet does seem unusual," he added.

Gale and his wife, an Israeli whom he met in Jerusalem, have three children, daughters Tal, 9, and Shir, 7, and a son Elan, 2. All speak Hebrew at home.

Gale said he remembers the tears in the eyes of the Soviets who saw him off at the Moscow airport. He mentioned repeatedly that people in 15 countries contributed to a rescue effort that would not have gone nearly as well if local regulations or political differences had intruded.

"This is not a national, but an international, effort," he said.

"We have been thinking and planning and doing transplants for the equivalent of these types of patients for a number of years," he said. "All of us working in this field have been aware of the possibility."