Presently, the vast majority of electricity from nuclear power is produced by nuclear fission of uranium and plutonium.
Nuclear decay processes are used in niche applications such as radioisotope thermoelectric generators.
Generating electricity from fusion power remains at the focus of international research.
This article mostly deals with nuclear fission power for electricity generation.
In June 1942, Marshall was placed in charge of the Manhattan Project, then known as the Laboratory Development of Substitute Materials. Although superseded as head of the project by Brigadier General Leslie R. Groves Jr., in September, he was Manhattan District engineer from 13 August 1942 to 13 August 1943. In November 1943 he became Assistant Chief of Staff (G-4) of the United States Army Services of Supply (USASOS) in the Southwest Pacific Area, serving in Australia, New Guinea and the Philippines.
Marshall left the Army in 1947, and moved to Riverside, Connecticut, where he worked for M. W. Kellogg. He later joined Koppers, building a coal loading facility in Turkey, and worked on mining projects in Africa. He was Commissioner of Highways in Minnesota from 1961 to 1965.