Retired Army Lt. Gen. William C. Gribble Jr., 62, a former Chief of Army Engineers, died of cancer Saturday at DeWitt Army Hospital at Fort Belvoir.

While serving as director of reactor development with the old Atomic Energy Commission in the mid 1950s, he developed the technical specifications for the Army's first nuclear power plant, which is located at Fort Belvoir.

Gen. Gribble was director of the Army Nuclear Power Program in the early 1960s. He later was the Army's deputy chief of research and develppment and then deputy chief of staff for force development.

He commanded Fort Belvoir and the Army Engineer Center and school there for two years before becoming chief of Army research and development in 1971. In 1973, he became Chief of Army Engineers, a post he held until retiring in 1976.

Gen. Gribble was born in Ironwood, Mich. He was commissioned in the Corps of Engineers following his 1941 graduation from the U.S. Military Academy at West Point.

His World War II duty included the command of an engineer combat battalion of the 43rd Division in the Pacific.

Following the war, he earned a master's degree at the University of Chicago, attended the National Reactor School at Oak Ridge, Tenn., and served in the Los Alamos Scientific Laboratory. He also was a graduate of the Command and General Staff College and the National War College.

His decorations include the Bronze Star Medal, the Distinguished Service Medal with oak leaf cluster and the Legion of Merit.

Gen. Gribble was a member of the Society of American Military Engineers and the American Defense Preparedness Association.

He is survived by his wife, Jane W., of the home in Alexandria; two sons, William C. III, of Great Falls, Va., and Donald J., of Gainesville, Ga.; two daughters, Nancy Heflin, of Salisbury, Md., and Judith Babuschak, of Stafford, Va.; his mother, Grace Gribble, and a sister, Grace Wylie, both of Wausau, Wis., and seven grandchildren.

The family suggests that expressions of sympathy be in the form of contributions ot the American Cancer Society, or to the Army Engineer's Memorial Fund, c/o the Office of Chief of Engineers, Washington. CAPTION: Picture, LT. GEN. WILLIAM C. GRIBBLE JR.