Uranium Enrichment

Alleged Israeli Attacks on Iranian Nuclear Facilities

• Allegation: Israel has reportedly carried out attacks on Iran’s nuclear facilities.
• Justification (Israeli Allegation): Israel alleges that Tehran was getting close to obtaining a nuclear weapon.
• Targets: Three of Iran’s key nuclear facilities were reportedly targeted:
  • Natanz: Uranium enrichment site.
  • Isfahan: Provides raw materials for enrichment.
  • Fordow: Uranium enrichment site.
• Casualties: Several Iranian nuclear scientists were reportedly killed.
• Facility Characteristics: The facilities are described as heavily fortified and largely underground.
• Damage Assessment: There are conflicting reports regarding the extent of the damage.
• Impact if Damaged: Any significant damage to these sites would limit Iran’s ability to produce nuclear weapons, as Natanz and Fordow are key enrichment sites and Isfahan supplies raw materials.

Understanding Uranium and Nuclear Enrichment

• Natural Uranium Composition:
  • Uranium-238 (U-238): Makes up approximately 99.27% of natural uranium. It has 92 protons and 146 neutrons.
  • Uranium-235 (U-235): Accounts for only about 0.72% of natural uranium. It has 92 protons and 143 neutrons.
  • Other Isotopes: The remaining 0.01% consists of other isotopes.
• Why Enrichment is Needed: For nuclear power reactors or weapons, the proportions of these isotopes need to be changed.
  • Fission Chain Reaction: Only Uranium-235 can sustain a nuclear fission chain reaction. In this process, one neutron causes an atom to fission, releasing energy and more neutrons, which in turn cause further fission, and so on.
• What is Enrichment?
  • Enrichment is the process of increasing the concentration of Uranium-235 while simultaneously removing Uranium-238 from naturally occurring uranium.
• How Enrichment is Achieved (Centrifuges):
  • Since U-235 is naturally present in very small quantities, scientists use ultra-advanced centrifuges to separate it from U-238.
  • Principle: Centrifuges exploit the fact that U-238 is approximately 1% heavier than U-235.
  • Process: Uranium hexafluoride gas is spun at incredibly high speeds within these machines. Similar to how a washing machine pushes heavier clothes to the outer drum, the heavier U-238 moves outward, while the lighter U-235 collects closer to the center.
• Levels of Enrichment:
  • Low-Enriched Uranium (LEU): Contains 3-5% U-235. This is typically used in most civilian nuclear reactors and is considered safe under international norms.
  • Weapons-Grade Uranium: Requires enrichment to around 90% U-235. This is the material needed for nuclear weapons.
  • Risky Territory: Even enrichment to 20% U-235 is considered risky, as it significantly reduces the technical hurdles required to reach bomb-grade material.