Richard B. Smith, 69, an employe of the old Atomic Energy Commission for 28 years before retiring as a senior process safety engineer in 1974, died of cancer last Tuesday at his home in Kensington.

Mr. Smith moved to Washington in 1947 as chief of the AEC's Fire Protection Program. Upon retiring in 1974, he was given an award by the commission for his work in the "technology of pyrophoric metals" and his leadership in fire prevention work.

He was a past chairman of the National Fire Protection Association's Committee on Combustible Metals and a member of the American Society of Safety Engineers and the American Institute of Chemical Engineers.

He had been a member of the Byeforde Civic Association, the Masons, the Elks and the Kiwanis. He also had been a Cub Scout leader.

Mr. Smith was a native of Chicago Heights, Ill., and earned a bachelor's degree in chemical engineering at Purdue University in 1935. He joined the E.I. du Pont de Nemours chemical company later that year. During World War II, he was a safety and fire protection engineer with the Manhattan District.

Survivors include his wife of 41 years, Sarah Saulsbury, of Kensington; two sons, R. Bruce Jr., of Ashton, Md., and Air Force Lt. Stephen M. Smith, of Homestead Air Force Base, Fla.; a brother, Warren W. Jr., of Lawton, Calif., and three sisters, Josephine Fortmiller, of Alhambra, Calif., Ella Mae Richey, of Minneapolis, and Mary Phelan, of Northwood, Ill.

The family suggests that expressions of sympathy be in the form of contributions to Make Today Count, c/o the American Cancer Society in Silver Spring, to the American Lung Association in Rockville, or to the Rev. William Wendt, c/o the St. Francis Counseling Society, Washington, D.C.