FROM NOTHING TO MEGATONS

FROM EXTRACTION OF URANIUM TO ITS USE IN BOMB

URANIUM Uranium is a silvery-gray

metallic, radioactive chemical element.

The most common isotopes in natural uranium are U238 (99.27%) and U235 (0.72%)

All uranium isotopes present in natural uranium are radioactive and U235 is fissile

ORIGIN OF URANIUM According to the theories developed, the Earth's

uranium was produced in one or more supernovae.

Multiple supernovae from over 6 billion to about 200 million years ago were involved.

The present-day abundance of uranium in the 'depleted' mantle exposed on the ocean floor is about 0.004 ppm. The continental crust, on the other hand, is relatively enriched in uranium at some 1.4 ppm.

History of Uranium Uranium was found in 1789 by the German chemist

Martin Heinrich Klaproth in his laboratory in Berlin.

It was named after the planet Uranus which was discovered eight years earlier

The French professor Eugène in Paris in 1841 was the first who isolated a sample of Uranium.

1896 Antoine Becquerel discovered the concept of radioactivity

Enrico Fermi in 1934 discovered that bombarding uranium produced emission of beta rays.

December 2, 1942, team led by Enrico Fermi was able to produce the first artificial nuclear chain reaction.

URANIUM DEPOSITS

It can be found almost everywhere in rock, soil, rivers, and oceans.

largest deposits found in Australia, Kazakhstan and Canada.

High-grade deposits are only found in the Athabasca Basin region of Canada.

Uranium deposits are generally classified based on host rocks, structural setting and mineralogy of the deposit.

URANIUM DEPOSITS AND THEIR TYPES

Unconformity-related deposits Sandstone deposits Quartz-pebble conglomerate deposits Vein deposits Breccia complex deposits Intrusive deposits Phosphorite deposits Collapse breccia pipe deposits Volcanic deposits Surficial deposits Metasomatite deposits Metamorphic deposits Lignite Black shale deposits Other types of deposits

URANIUM DEPOSITS CLASSIFICATION

Mary Kathleen uranium mine Mt. Painter Inlier, South Australia (enriched in U, Cu, Th ) (Uranium-rich breccia )

(Vein type deposits) (Sandstone and mudstone)

Uranium ore (pitchblende in dolomite) A uranium mine, near Moab, Utah

Chalcopyrite-rich ore specimen Ranger 3 open pit,Australia (Olympic dam) (Unconformity-related deposits)

TOP 10 MINES

URANIUM RESERVES OF PAKSITAN

Uranium deposits occurrences are reported from the Dera Ghazi Khan District, Sulaiman Range, Bannu Basin, and Issa Khel, Mianwali District, in central Pakistan, and from the Kirthar Range in south Pakistan.

Number of radioactive localities associated with alkaline igneous rocks, pegmatites, and schists have been discovered in the mountainous northern part of Pakistan.

D.G KHAN RESERVES

The Dera Ghazi Khan District lies in the Sulaiman Range.

Sandstone-type U deposits confined to a single horizon near the base of the Middle Siwalik Member in a N-S strip.

Reported deposits include Baghal Chur , Rakuchur, Rakhi Munh, Nangar Nai, Kaha Nalo and Rajanpur.

Regional Geological Setting of Mineralization

Rocks from Jurassic to Pleistocene age occur in the Sulaiman physiographic province, the central core of which is marked by mafic and ultramafic intrusions.

The Middle Miocene to Lower Pleistocene Siwalik group is exposed in the Sulaiman range as a narrow north-south trending belt.

Upper Siwalik Division, 1800–2400 m thick.

Middle Siwalik Division, 1800–2400 m thick

Lower Siwalik Division, 1500 m thick

At a cutoff grade of 0.03% U, the ore had grades of 0.1% U as maximum.

By 1976 uranium resources of Pakistan were calculated at 150000t of ore at a grade of 0.12% U, containing 181t U based on a cutoff grade of 0.09% U.

Baghal Chur

The blanket sandstone-type Baghal Chur deposit lies about 40 km NNW of Dera Ghazi Khan.

The deposit was mined from 1971 to 1999 by conventional methods and is depleted.

Strata dip with 5–10° at Baghal Chur at other U deposits in the district dips approach 50–60°

Qabul Khel, Surghar Range

Qabul Khel, named after a small nearby village, is located in the southern Surghar Range.

A number of small ore bodies were explored in the early 1980s.

At the deposit, the sandstone beds are 40–60 m and the intercalated shales 10–15 m thick

Coffinite and pitchblende are the principal U minerals.

The Nuclear Fuel Cycle

Uranium Mining and Milling

EXTRACTION METHODS

Open pit

Underground uranium mining

Heap leaching

In-situ leaching

WORLD URANIUM PRODUCTION BY MINING METHODS USED

Yellow Cake

Final Product of Milling Step – 70 to 80 % uranium

NUCLEAR REACTORS

Nuclear reactor is a device to initiate, control and sustain a nuclear chain reaction.

Classified on number of factors.

REACTORS TYPES Boiling Water Reactors

(BWR).

Pressurized Water Reactor (PWR)

Candu reactor

Fast Breeder Reactor (FBR)

Conversion, Enrichment and Fuel Fabrication

Natural Uranium

235U only fissile nuclide – only 1 atom of 235U in 140 atoms of 238U

Enrichment A number of enrichment processes have been demonstrated

in the laboratory Only two, the gaseous diffusion process and the centrifuge

process, are operating on a commercial scale In both of these, UF6 gas is used as the feed material Molecules of UF6 with U-235 atoms are about one percent

lighter than the rest, and this difference in mass is the basis of both processes

Large commercial enrichment plants are in operation in France, Germany, Netherlands, UK, USA, and Russia, with smaller plants elsewhere

Enrichment: UF6 Feed Container

Enrichment: Centrifuge Process Vacuum tubes, each containing

a rotor one to two metres long and 15-20 cm diameter.

Heavier molecules with U-238 increase in concentration towards the cylinder's outer wall

There is a corresponding increase in concentration of U-235 molecules near the centre.

Enriched gas forms part of the feed for the next stages, depleted UF6 gas goes back to the previous stage (cascade)

Enrichment: Centrifuge Process

CENTRIFUGE DESIGN

Enrichment: Gaseous Diffusion Process Involves forcing UF6 under pressure through a porous

membranes

As U235 molecules are lighter than the U238 molecules they move faster and have a slightly better chance of passing through the pores in the membrane

The UF6 which diffuses through the membrane is thus slightly enriched, while the gas which did not pass through is depleted in U235

Enriched UF6 is withdrawn from one end of the cascade and depleted UF6 is removed at the other end

The gas must be processed through some 1400 stages to obtain a product with a concentration of 3% to 4% U235

Electromagnetic Isotope Separation (EMIS)

Ions of U238 and U235 are separated because they describe arcs of different radii when they move through a magnetic field.

A production-scale mass spectrometer named the Calutron was developed during World War II that provided some of the U235 used for the Little Boy

Aerodynamic enrichment processes

Aerodynamic enrichment processes include the Becker jet nozzle techniques.

High proportion of carrier gas required in relation to UF6.

Conversion and Nuclear Fuel Fabrication

UF6, in solid form in containers, is heated to gaseous form, and the UF6 gas is chemically processed to form LEU uranium dioxide (UO2) powder

this powder is then pressed into pellets, sintered into ceramic form (fuel pellets)

pellets are then loaded into Zircaloy tubes that are afterwards hermetically closed (fuel rods)

rods are constructed into fuel assemblies fuel assemblies are made with different dimensions

and number of fuel rods, depending on the type reactor

UO2, Pellets and Fuel Assembly

Fuel Rods

FISSION AND FUSION In nuclear physics

and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts.

NUCLEAR FUSION

nuclear fusion is the process by which multiple atomic nuclei join together to form a single heavier nucleus.

HYBIRD FUSION

Hybrid nuclear fusion is the use of a combination of nuclear fusion and fission processes to generate power.

The goal is to use fuel pellets of deuterium and tritium

NUCLEAR SITES OF PAKISTAN

USES OF URANIUM IN MILITARY

WEAPON GRADE URANIUM

Highly enriched uranium more than 84%

Special centrifuge technique is used to get such a uranium

ATOMIC BOMB STRUCTURE

KHAN’s Network and Threat To OUR NUCLEAR ARSENAL

YOUR QUESTIONS