three widows, their children and the parents of a 14-year-old boy, claiming millions of dollars in damages, yesterday charged that radioactive fallout from atomic tests in Nevada killed their husbands, fathers and son.

The action is the first time that death claims have been filed against the government on behalf of civilians whose only connection with the bomb testing program was to have lived in the path of its radioactive clouds.

The relatives alleged, in damage claims filed with the U.S. government here, that negligence or carelessness in the aboveground testing of scores of A-bombs in the 1950s resulted in three fatal cases of leukemia and one lumphoma.

The claims are apparently only the first in an expected series of attempts to officially pin responsibility on the nuclear testing program for the loss of loved ones.

Relatives of four other southwest Utah and northwest Arizona residents are expected to file similar claims soon. These will link three more leukemia deaths and one of multiple myeloma to the A-bomb fallout that time and again wafted over the area's residents despite repeated assurances of safety from federal officials.

For years, many people living downind of the testing site had believed that radioactive fallout was responsible for a seemingly high incidence of leukemia and other cancers in their midst.

They have now been moved to act, apparently because of disclosures of leukemia cases among soldiers at a 1947 test blast dubbed Smoky, and the awarding of veterans benefits to one serviceman who blamed his leukemia on Smoky.

The leukemia and other cancer deaths among civilians have left sorrow and bitterness among friends and relatives on the ranches and in the tiny towns that dot the mountains and valleys of southwest Utah and northwest Arizona.

They caustically recall that bombs were set off only when the wind would set off only when the wind would blow fallout toward them, and not when the fallont would be carried to Las Vegas.

"We were just guinea pigs, and then we became statistics," said Irma Thomas, a St. George, Utah, resident who has waged a long, fruitless effort for federal recognition of the issue. "We were expendable."

The death claims were filed with the Department of Energy's Nevada operations center. Officials here cited privacy regulations and refused to disclose details of the claims.

Dale Haralson, a Tucson lawyer, said that claims related to eight deaths had been filed or were imminent. He said his clients alone represent six leukemias among 2,000 people in the Kanab, Utah, and Fredonia, Ariz., area. A normal rate, he said, is six cases in a population of 100,000.

Haralson declined to reveal the amount of damages being sought to offset the lost income, the medical bills and the emotional suffering. One official here put the amount at "$1 million or more" for each claim by the 18 relatives of the four victims.

He said the Department of Energy has sex months to grant or deny the claims, an administrative process that must be followed before any court action. "I would hope that the federal government would respond," he said, "and if they don't, we will file suit."

Such a suit could lead to enormous legal complications as relatives seek to pry from the government information that officlas may want to cloak in the secrecy oftne associated with weapons programs.

The claims filed so far are on behalf of the survivors of : Gayneld Mackeprang, who died of lekemia in August 1974. A school superintendent who hunted rocks around Fredonia, in the ranges and mountains where others contracted leukemia, he left a wife and seven children.

LaVier Tait, a friend of Mackelprang who loaded logs into trucks in the same area where Mackelprang hunted rocks, and who died of leukemia 13 months after Mackelprang. Tait left a wife and five children.

Vaynard D. Mackelprang, 14 a son of Bessie and Arthur Mackelprang, who died of leukemia in August 1956 in neighboring Kanab.

Joseph G. Chatterly, also of Kanab, who died in 1971 of lymphoma and who left a wife and four children.