Ivan C. Atkinson, 94, a retired colonel who served in the Air Force for three decades, died Aug. 4 at the Fairfax nursing home at Fort Belvoir.

The former North Arlington resident had a blood disease, his daughter Ruth E. Soulier said.

Col. Atkinson retired in 1971 as a lead researcher on nuclear weapons technology at the Air Force Systems Command at Andrews Air Force Base. He had worked previously at Wright-Patterson Air Force Base in Ohio, where he studied thermal radiation and directed research on propulsion systems for nuclear missiles.

His other assignments included Air Force investigations of UFO sightings.

Ivan Charles Atkinson was born in Youngstown, Ohio. He worked at steel and chemical plants there and in Pittsburgh before joining the Army Air Forces in 1942. During World War II, he was a fighter pilot headquartered in the Panama Canal Zone.

Col. Atkinson was a 1938 graduate of Case Western Reserve University in Cleveland, where he studied chemical engineering. He received a master’s degree in nuclear engineering from North Carolina State University in 1953.

His decorations included two awards of the Legion of Merit, the Air Force Commendation Medal and the Air Force Outstanding Unit Award.

He was a member of numerous professional organizations, including North Carolina State University’s chapter of the Phi Kappa Phi honor society.

Col. Atkinson married the former Ruth V. Henry in 1939. They divorced four years later and were remarried in 1945. She died in 1973.

Survivors include his wife of 37 years, the former Phyllis Mason of Fort Belvoir; a daughter with his first wife, Ruth E. Soulier of Arlington County; three stepsons, Gary R. Mason of Newburg, David V. Mason of Alexandria and Robert K. Mason of Harrisburg, Pa.; eight grandchildren; eight great-grandchildren; and four great-great grandchildren.

— Emily Langer