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PNNL -14480
3.2.5.2 Electric power control
Centrifuges rotate at a very high, precise speed; therefore, control of the frequency of
rotation is very important. Important elements include:
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• Frequency converters
• SCADA systems
• Stable off-site power supplies
• Very stable electric power grid
3.2.5.1 Fluorine related equipment
As with gaseous diffusion facilities, fluorine related equipment is necessary. These
include:
• Feed autoclaves used for passing UF 6 to the centrifuge cascades
• Desublimers (or cold traps) used to remove UF 6 from the cascades
• Product and tails stations used for passing UF 6 into containers
3.3 ELECTROMAGENTIC ISOTOPE SEPARTION TECHNOLOGY HISTORY
3.3.1 Technology Description
3.3.1.1 Origin
The process of electromagnetic isotope separation (EMIS) was developed in the United
States as a part of the Manhattan project. Starting in 1941 and using already existing
cyclotrons to demonstrate the technology, the U.S. decided to build bigger machines
called “calutrons” to produce enriched uranium. Calutrons produced the first HEU, using
slightly enriched uranium from other processes as feed. When the first gaseous diffusion
plant began operating effectively, the use of calutrons for enriching uranium ceased.
They are, however, still being used for other isotopic separation tasks.
3.3.1.2 Basic theory
The EMIS approach is based on the physical principal that ions of the same energy but of
different masses describe different trajectories in a magnetic field. In particular, the
trajectory of 238 U will have a larger diameter than that of 235 U. The different diameters
allow for separation and collection of the material in receivers or “collection pockets”.
EMIS is a batch process that produces weapons grade HEU from natural uranium in only
two steps. However, hundreds to thousands of units would be required to produce large
quantities of HEU due to the process’s relatively low product collection rate and the long
cycle time required to recover material between runs.
In the uranium EMIS process, uranium ions are generated within an evacuated enclosure
(called a “tank”) located in a strong magnetic field. For the EMIS ion source, solid
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