Types of Uranium enrichment techniques. 1.Diffusion techniques 2.Centrifuge techniques 3.Laser technique 4.Some Other techniques Uranium enrichment techniques used in Pakistan.

1. SABIR RASHEED
URANIUM ENRICHMENT TECHNIQUES

2. Statement
Enriched uranium is a type of uranium in which the percent composition of uranium-
235 (written 235U) has been increased through the process of isotope separation .
Three major isotopes:
1.uranium-238(238U with 99.2739–99.2752% natural abundance),
2.Uranium-234 (234U, 0.0050–0.0059%).
3.uranium-235 (235U, 0.7198–0.7202%)
235U is the only nuclide existing in nature (in any appreciable amount) that is fissile with thermal
neutrons

3. Enrichment Techniques
1. Diffusion techniques
2. Centrifuge techniques
3. Laser technique
4. Some Other techniques

4. Diffusion Techniques
Gaseous diffusion uses semi-permeable
membranes to separate enriched uranium
1. Gaseous Diffusion Technique:
Used to produce enriched uranium by forcing
gaseous uranium hexafluoride (hex) through semi-
permeable membranes.
In 2008 accounted for about 33% of enriched uranium
production
but in 2011 was deemed an obsolete technology that is
steadily being replaced by the later generations of
technology as the diffusion plants reach their ends-of-life.

5. Diffusion Techniques
2. Thermal Diffusion Technique:
Thermal diffusion utilizes the transfer of heat across a
thin liquid or gas to accomplish isotope separation.
The lighter 235U gas molecules will diffuse toward a hot
surface,
And the heavier 238U gas molecules will diffuse toward a
cold surface.

6. Centrifuge Techniques
1. Gas Centrifuge Technique:
Uses many rotating cylinders in series and parallel formations.
Each cylinder's rotation creates a strong centripetal force.
The heavier gas molecules containing 238U move tangentially toward the outside of the
cylinder and the lighter gas molecules rich in 235U collect closer to the center.
Gas centrifuge techniques produce close to 100% of the world's enriched uranium.

8. Centrifuge Techniques
2. Zippe Centrifuge Technique:
Improved version of the gas centrifuge.
The primary difference being the use of heat.
This improved centrifuge design is used commercially
by Urenco to produce nuclear fuel and was used
by Pakistan in their nuclear weapons program.
.
Diagram of the principles of a Zippe-type gas
centrifuge with U-238 represented in dark blue and
U-235 represented in light blue

9. Laser Techniques
1. Atomic vapor laser isotope separation (AVLIS)
2. Molecular laser isotope separation (MLIS)
3. Separation of isotopes by laser excitation (SILEX)

10. Other Techniques
1. Aerodynamic processes
2. Electromagnetic isotope separation
3. Chemical methods
4. Plasma separation

11. Other Techniques
1. Aerodynamic processes
Aerodynamic enrichment processes
include the Becker jet nozzle
techniques developed by E. W. Becker
and associates using the LIGA process
and the vortex tube separation process.
Schematic diagram of an aerodynamic
nozzle. Many thousands of these small foils
would be combined in an enrichment unit.

12. The X-ray based LIGA manufacturing process was originally developed at the
Forschungszentrum Karlsruhe, Germany, to produce nozzles for isotope enrichment.

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Other Techniques
2. Electromagnetic isotope separation
In the electromagnetic isotope
separation process (EMIS), metallic
uranium is first vaporized, and then
ionized to positively charged ions.
Schematic diagram of uranium isotope separation in
a calutron shows how a strong magnetic field is used to
redirect a stream of uranium ions to a target, resulting in a
higher concentration of uranium-235 (represented here in dark
blue) in the inner fringes of the stream.

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Other Techniques
3. Chemical Method
One chemical process has been demonstrated to pilot plant stage but not used for production.
The French CHEMEX process exploited a very slight difference in the two isotopes' tendency to
change valency in oxidation/reduction.
4. Plasma Separation
In this process, the principle of ion cyclotron resonance is used to selectively energize the 235U
isotope in a plasma containing a mix of ions.

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Global Enrichment Facilities
The following countries are known to operate enrichment facilities:
Argentina, Brazil, China, France, Germany, India, Iran, Japan, the Netherlands, North Korea, Pakistan,
Russia, the United Kingdom, and the United States.
Belgium, Iran, Italy, and Spain hold an investment interest in the French Eurodif enrichment plant,
with Iran's holding entitling it to 10% of the enriched uranium output.
Countries that had enrichment programs in the past include Libya and South Africa, although Libya's
facility was never operational.
Australia has developed a laser enrichment process known as SILEX, which it intends to pursue
through financial investment in a U.S. commercial venture by General Electric.
It has also been claimed that Israel has a uranium enrichment program housed at the Negev Nuclear
Research Center site near Dimona.

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Enrichment Techniques Used in Pakistan
Since Pakistan does not publish uranium production data.
Estimates of Pakistan’s domestic uranium production reported in the “ Red Book”
Pakistan initially explored a number of techniques for uranium enrichment, including
1.Laser,
2.Centrifuge and
3.Diffusion
Pakistan’s weapon-grade uranium is produced at two main sites.
1.Kahuta site, named Khan Research Laboratories (KRL), near Rawalpindi.
2.At Gadwal near Wah.

17. Northern (original) production area of the Kahuta enrichment plant (IKONOS satellite imagery
courtesy of GeoEye).

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Enrichment Techniques Used in Pakistan
A 1986 report claims that at Kahuta the two types of centrifuges were housed in “two big halls set
slightly at an angle to each other containing about 7000 centrifuges.
An internal U.S. memo to Henry Kissinger in 1986 claimed that Kahuta had a “enough weapons
grade material to build several nuclear devices per year.
A U.S. official claimed in late 1991 that Pakistan had sufficient HEU for as many as six weapons.
South African court concerning a project located there to manufacture an enrichment plant for export
to Libya using a Pakistani design provided by the A.Q. Khan network

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Enrichment Techniques Used in Pakistan
A possible scenario for the first phase of Pakistan’s enrichment program (until about 1990) may be
as follows:
1. Pakistan had no substantial enrichment capacity until approximately 1982;
2. It achieved sufficient capacity to make 20 kg/yr of HEU during 1983–1985. (This calls for a
separative power of approximately 3000 SWU, produced by approximately 1000 centrifuges of 3
SWU each),
3. It increased the capacity linearly to 9000–15,000 SWU by 1990, through a mix of P-1 and the
more powerful and less problematic P-2 machines.

20. Southern production area of the Kahuta enrichment plant (IKONOS satellite imagery courtesy of GeoEye).

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Enrichment Techniques Used in Pakistan
An increase in enrichment capacity from 15,000 to 30,000 SWU starting from 1999, possibly from
6000 P-2 machines.
An increase in enrichment capacity from 15,000 to 75,000 SWU starting from 1999, coming
possibly from cascades of 3000 P-2 machines and 3000 P-4 machines.
Characteristics of Pakistani centrifuges.

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Enrichment Techniques Used in Pakistan
Pakistan is estimated to have produced the following quantities of plutonium and weapon-grade
uranium for nuclear weapons through 2014.

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Enrichment Techniques Used in Pakistan
The total enrichment capacity need not be at Kahuta alone. It could be distributed across additional
sites. There have been claims that Pakistan may have enrichment facilities at Sihala, Golra and
Gadwal.
Gadwal was described recently as a facility where enriched uranium is enriched
further to weapons grade.
The maximum capacity considered here is 75,000 SWU.
Since it will be safeguarded, the proposed 600,000 SWU enrichment plant at Chak Jhumra,
near Faisalabad, in Punjab province.