[1][2] He was president and manager of the first privately owned uranium-enrichment facility in the United States, Louisiana Energy Services.
[1] He was general manager of the Advanced Energy Systems Division of Westinghouse Electric Company.
[1] In 1974, he was elected to the National Academy of Engineering for his contributions to the systems engineering of light-water nuclear power plants and to the design of commercial pressurized water reactors for nuclear systems.
[2] In 2004, United States President George W. Bush appointed Dr. Arnold to the U.S. Nuclear Waste Technical Review Board.
With his wife, Josephine (Routheau), his daughter is Chemical Engineering Professor and 2018 Nobel Prize winner Frances Arnold.