Material Insights · Understanding the Material World

Nuclear fission reactors and Uranium

Uranium is the fuel of almost all fission reactors, but it is a small part of the cost of nuclear power, so reactors keep running through uranium price swings. The risk lies in concentrated supply: Kazakhstan for mining, and Russia for conversion and enrichment.

Nuclear fission reactors (energy) and Uranium (energy): 5 relationships.

How they are linked

1. Reactor fuel

Physical flow · Strong · Uranium to reactors

Reactors make heat by splitting uranium-235 atoms, so every reactor needs a steady supply of fresh uranium fuel.

  • 60,213 tU world mine production, 2024
  • 90% of world reactor demand met by mines, 2024

The remaining tenth of reactor needs came from sources other than new mining. Mine disruptions therefore show up first in prices rather than in reactor output.

Sources: World Nuclear Association

2. Conversion and enrichment

Physical flow · Strong · Uranium through fuel cycle to reactors

Most reactors need uranium enriched from 0.7% to about 3 to 5% U-235, so mined uranium must be converted and enriched before it becomes fuel.

  • 100,000 to 120,000 SWU enrichment for a year's fuel for a 1,000 MWe light water reactor
  • almost half enrichment share of nuclear fuel cost (2006 estimate)

These middle steps are few and specialised, so they can be tighter bottlenecks than mining. Pressurised heavy water reactors, as used in India, can burn natural uranium and skip enrichment.

Sources: World Nuclear Association; World Nuclear Association

3. Small cost share

Cost and price · Asymmetric · Uranium price to power cost

Fuel is a small part of nuclear generating cost, and uranium is only part of fuel cost, so even large uranium price moves change power costs little.

  • 26% rise in fuel cost from a doubling of the uranium price, 2008 estimate
  • about 7% rise in electricity cost from the same doubling, 2008 estimate

This is why reactors run as baseload regardless of uranium prices, and why utilities care more about security of supply than price. For miners the link is the reverse: reactor demand is steady, so prices swing on supply news and contracting cycles.

Sources: World Nuclear Association

4. Concentrated supply

Shared risk · Strong · Few suppliers to all reactors

Uranium mining, conversion and enrichment are each dominated by a handful of countries, so sanctions or outages in one can hit fuel supply for reactors everywhere.

  • about 39% Kazakhstan's share of world uranium output, 2024 (23,270 of 60,213 tU)
  • about 46% Russia's share of world enrichment capacity, 2018
  • nearly 40% Russia's share of world conversion services, 2020

Kazakhstan, Canada and Namibia together produced about three quarters of 2024 output. A US law has banned imports of Russian low-enriched uranium since August 2024, with any waivers ending no later than 1 January 2028, so Western utilities must replace Russian enrichment within a few years.

Sources: World Nuclear Association; Columbia University Center on Global Energy Policy; US Nuclear Regulatory Commission

5. Reactor build-out

Transition · Rising · New reactors to uranium demand

Each new or life-extended reactor adds decades of fuel demand, so national nuclear targets translate directly into uranium needs.

  • 86,000 t possible reactor uranium needs by 2030, up a third
  • 150,000 t possible needs by 2040

The World Nuclear Association expects output from current mines to halve between 2030 and 2040, leaving a large gap to be filled by new mines. Mines take many years to develop, so contracting by utilities now shapes supply later.

Sources: NucNet

For investors

Key learnings

  1. Reactor demand for uranium is steady and price-insensitive, since a doubling of uranium prices raised power costs by only about 7% in a 2008 estimate.
  2. Supply is concentrated: Kazakhstan alone mined about 39% of 2024 output, and Russia held about 46% of enrichment capacity in 2018.
  3. World Nuclear Association scenarios see uranium needs rising to 86,000 t by 2030 while current mines decline later, which supports new mine and enrichment investment.

What to track

  • Uranium spot and term prices: Rising term prices signal utilities securing future supply (Weekly · UxC; TradeTech; Cameco)
  • Kazakhstan production guidance: Cuts tighten the market quickly (Quarterly · Kazatomprom)
  • Enrichment capacity additions outside Russia: New capacity eases the main fuel-cycle bottleneck (As announced · Urenco, Orano, Centrus)

For policymakers

Key learnings

  1. Because uranium is a small share of power cost, holding larger fuel stocks is a cheap way for reactor operators to buy security of supply.
  2. India's PHWRs use natural uranium and need no enrichment, which avoids the Russian enrichment bottleneck, but its safeguarded reactors still rely on imported uranium.
  3. India's goal of at least 100 GW of nuclear by 2047 would multiply its uranium needs, so long-term supply contracts matter now.

What to track

  • India uranium import contracts: New long-term deals secure fuel for planned reactors (As announced · Department of Atomic Energy; NPCIL)
  • Reactor capacity factors in India: Low factors can signal fuel shortages, as in 2008 (Yearly · NPCIL; CEA)

India

India's PHWRs burn natural uranium, and reactors under IAEA safeguards run on imported uranium from suppliers such as Kazakhstan and Canada; fuel shortages pushed load factors down to 40% in 2008, and the government targets at least 100 GW of nuclear by 2047.

Sources

  1. Uranium production by country, World Nuclear Association (2025)
  2. Uranium Enrichment (World Nuclear Association information paper, November 2006, archived copy), World Nuclear Association (2006)
  3. The Economics of Nuclear Power, World Nuclear Association (2008)
  4. Russia's role in global nuclear markets, Columbia University Center on Global Energy Policy (2022)
  5. Nuclear renaissance could create shortage of uranium supply, says WNA, NucNet (2025)
  6. Nuclear Power in India, World Nuclear Association (2026)
  7. Uranium import ban, US Nuclear Regulatory Commission (2024)