Deep Dive: Energy & Security

What Is It Used For?

Uranium by enrichment level: From medicine to power to defense.

Scientific Briefing TPO Explains

The Enrichment Spectrum

0%
0.7%
3–5%
20%
90%+
landscape
0.7% U-235

Natural & Depleted

  • CANDU Reactors

    Heavy-water reactors run on unenriched uranium.

  • Radiation Shielding

    Dense depleted U for medical & industrial shielding.

  • Armor & Ballast

    Tank armor, aircraft counterweights.

As Mined
bolt
3–5% U-235

Power Grade

  • Power Plants

    440+ light water reactors — ~10% of global electricity.

  • Advanced Reactors

    SMRs & next-gen designs, some up to 19.75%.

  • Fuel Cycle

    Rods replaced every 3–5 years; spent fuel stored on-site.

Low Enriched
science
5–20% U-235

Research Grade

  • Research Reactors

    University & national lab neutron experiments.

  • Medical Isotopes

    Mo-99 → Tc-99m used in 40M+ scans/year.

  • Cancer Treatment

    Neutron activation produces therapeutic radioisotopes.

Low Enriched
anchor
20–90% U-235

Naval Grade

  • Nuclear Submarines

    US/UK subs refuel once in 25 years; unlimited range.

  • Aircraft Carriers

    Nimitz & Ford-class — 50-yr lifespan, dual reactors.

  • Space Reactors

    Compact HEU reactors for deep space power.

Highly Enriched
≥ 90% U-235 Highly Enriched

Weapons Grade

Nuclear Weapons

Gun-type & implosion designs; critical mass is approximately 52 kg.

Deterrence Stockpiles

~13,000 warheads held by 9 nations worldwide as of current records.

IAEA Monitored

NPT strictly restricts enrichment above 20% for non-weapons states.