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Table A-2. Other Isotope Separation Technologies
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A. Discarded Technologies
Thermal Diffusion
Electromagnetic (the Calutron Process)
B. Developing Technologies
Photo-Exci tation Methods (Laser)
Chemical Exchange Methods
Aerodynamic Methods (Other Than the Becker Nozzle
and the Fixed Wall Centrifuge)
P1 asma Based Processes
The discarded technologies listed in Table A-2 have been used to produce
enriched uranium.
A large-scale, liquid-phase, thermal-diffusion plant was constructed in 1945
by the Manhattan Project.14 This plant produced very slightly enriched uranium
(0.86%). Thermal diffusion is impractical for commercial enrichment of uranium
isotopes because of its very high energy requirements. Compared to gaseous diffusion,
the energy requirement is over 200 times greater.
The electromagnetic or Calutron methods were used during the Manhattan Project
to produce highly enriched uranium. 14 The process was discarded shortly after the
more economical gaseous diffusion plant began ,operation. A brief description of the
process follows.
The Calutron Process involved the vaporization of a salt feed material,
typically UC14, from an electrically heated charge bottle through slots into an arc
chamber where the salt was ionized by an electron beam which travels along the lines
of flux of the magnet. The ionized uranium, as the U+ ion for the most part, passed
through another slot where it was accelerated by other slotted electrodes into the
vacuum tank which filled the pole area of a large electromagnet. The ions from the
accelerating electrodes diverged several degrees from the slots and at the 90" point
passed by some baffles as a rather thick beam. This beam was brought to a focus at the
slots of a receiver system as curved lines by the shimmed magnetic field. In the
large units, 96-in. beam diameter, there were up to four of these beams in a given
tank. The divergent trajectories of the ions from the four sources intersected some
few degrees from the accelerating electrodes and separated as distinct beams, again a
similar distance from the receivers. There were various side beams of UCl', U++, and
other ions which hit the baffles and the walls of the tank at a series of locations.
The uranium content of these beams condensed as various compounds of uranium. The
product was, for the most part, converted to UC by interaction of the very high
voltage uranium ions with the graphite of the receivers. Since, in even the most
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