MOSCOW, JAN. 31 -- Part of the area around the Chernobyl nuclear power plant has been decontaminated sufficiently to allow people to return to live there, a leading Soviet medical specialist said in an interview released here today.

Medical specialist Leonid Ilyin said the southeast portion of an 18-mile zone evacuated after the April 1986 explosion and fire at the plant is now fit for habitation.

About 115,000 people were evacuated from the farming towns around Chernobyl following what was the world's worst nuclear accident.

But Ilyin, who is vice president of the Soviet Academy of Medical Sciences, stopped short of recommending that the area be resettled, saying that farming remains dangerous because of pockets of high radiation in the countryside.

"The radiation situation . . . allows the population to come back," Ilyin said. But, he added, "for people to return, they need to be provided with their habitual work."

In an interview with the official newspaper Sovietskaya Rossiya, Ilyin said his position on resettlement would be "restrained."

The area around the Chernobyl plant in the northern Ukraine contains the most extensive damage of any nuclear reactor accident and the approach to decontamination and resettlement taken by Soviet authorities there could set an important precedent.

Ilyin said that "production grown by {returned residents} would need to be permanently controlled, and other problems would arise." Ilyin noted that decontamination efforts included the burial of about 650,000 cubic yards of irradiated topsoil and the encasement in concrete of Chernobyl's damaged Number 4 reactor.

The area's water supply is now safe, he said.

The Chernobyl accident resulted in 31 known deaths. In today's interview, Ilyin said that 24 of the 237 people who suffered radiation sickness from the accident remain invalids.