Curtis Andrew Nelson Sr., 98, who retired in 1969 as director of inspections at the Atomic Energy Commission, died of congestive heart failure April 3 at Sibley Memorial Hospital. He lived in Chevy Chase.

Mr. Nelson was born near Bristow, Neb., and graduated from the University of Nebraska.

He was an engineer with the Federal Works Commission in Nebraska and Minnesota in the 1930s and served in the Army Reserve.

He was assigned by the Army Corps of Engineers to work in Oak Ridge, Tenn., during World War II. There he recruited scientists to work on the atomic bomb project. He was awarded a Legion of Merit.

Mr. Nelson joined the AEC in 1947, working initially as assigned as liaison officer at Chalk River in Ontario.

He was appointed manager in 1950 of the AEC's Savannah River operations in South Carolina and was named director of inspections at AEC headquarters in 1955.

Mr. Nelson volunteered as a Job Corps mentor and with the Boy Scouts, which honored him with a Silver Beaver award. He was a member of the Cosmos Club, Chevy Chase United Methodist Church and Catholic Shrine of the Most Blessed Sacrament in Washington.

Survivors include his wife of 67 years, Eileen Antony Nelson of Chevy Chase; four children, Patricia Nelson Muscari of Denver, Robert Antony Nelson of Washington, Curtis Andrew Nelson Jr. of Silver Spring and Mary Eileen Nelson of Denton, Md.; a brother; seven grandchildren; and seven great-grandchildren.