Bismuth phosphate process

The bismuth-phosphate process was used to extract plutonium from irradiated uranium taken from nuclear reactors. It was developed during World War II by Stanley G. Thompson, a chemist working for the Manhattan Project at the University of California, Berkeley. This process was used to produce plutonium at the Hanford Site. Plutonium was used in the atomic bomb that was used in the atomic bombing of Nagasaki in August 1945. The process was superseded in the 1950s by the REDOX and PUREX processes. During World War II, the Allied Manhattan Project attempted to develop the first atomic bombs. One method was to make a bomb using plutonium, which was first produced by deuteron bombardment of uranium in the cyclotron at the Berkeley Radiation Laboratory at the University of California, Berkeley. It was isolated on 14 December 1940 and chemically identified on 23 February 1941, by Glenn T. Seaborg, Edwin McMillan, Joseph W. Kennedy and Arthur Wahl. It was thought that plutonium-239 would be fissile like uranium-235 and suitable for use in an atomic bomb. Plutonium could be produced through the irradiation of uranium-238 in a nuclear reactor, although no one had yet built one. This was not the Manhattan Project's chemists' problem; theirs was to develop a large-scale process for separating fission products, some of which were dangerously radioactive; uranium, the chemistry of which little was known; and plutonium, the chemistry of which almost nothing at all was known and which at first was only available in microscopic quantities. Four methods of separation were pursued. Seaborg performed the first successful separation of a weighable quantity of plutonium in August 1942, using a process involving lanthanum fluoride. Isadore Perlman and William J. Knox, Jr., looked into peroxide separation because most elements form soluble peroxides in neutral or acid solution. They soon discovered that plutonium was an exception. After a good deal of experimentation, they found that they could precipitate it by adding hydrogen peroxide to a dilute uranyl nitrate solution.