China’s First-ever Thorium Fuel Conversion Paves Way for 100MW Molten-salt Reactor

Syllabus: GS3/Science and Technology

Context

• China has successfully achieved the first-ever conversion of thorium into uranium fuel within a Thorium Molten Salt Reactor (TMSR).

About

• It is the first time in the world that scientists have been able to acquire experimental data on thorium operations from inside a molten salt reactor.
• The achievement makes the 2 megawatt liquid-fuelled thorium-based molten salt reactor (TMSR) the only operating example of the technology in the world to have successfully loaded and used thorium fuel.

What is a Molten Salt Reactor (MSR)?

• It is a fourth-generation nuclear reactor that uses molten salt as both fuel carrier and coolant, instead of solid fuel rods and water.
• The reactor operates at atmospheric pressure and high temperatures (≈700°C).
• It allows continuous circulation of liquid fuel, enabling on-the-fly refuelling.
• Thorium-to-Uranium Conversion Process: Thorium-232 absorbs a neutron → becomes Thorium-233 → decays to Protactinium-233 → decays to Uranium-233 (fissile).
  • This creates a “burn while breeding” cycle – self-sustaining and highly fuel-efficient.
  • The conversion occurs inside the reactor core, eliminating the need for external fuel fabrication.

Key Advantages of TMSR

• Safety: Operates at atmospheric pressure; molten salts trap radioactive materials; automatic drain system for leak containment.
• Efficiency: Continuous fuel circulation allows full fuel utilisation and minimal waste.
• Low Water Requirement: No need for cooling water; suitable for inland or arid areas.
• Reduced Radioactive Waste: Produces less long-lived nuclear waste than uranium reactors.
• Fuel Abundance: Thorium is 3–4 times more abundant than uranium.

Strategic Significance for China

• Energy Security: Thorium reserves could potentially supply energy for tens of thousands of years.
  • Enables energy independence from imported uranium.
• Resource Utilisation: One mine tailings site in Inner Mongolia is estimated to hold enough of the element to power China entirely for more than 1,000 years.
• Climate and Carbon Goals: TMSR supports low-carbon energy systems, complementing solar and wind.
  • High-temperature heat can aid green hydrogen production.
• Technological Leadership: China now leads the world in operational thorium MSR technology, positioning itself at the forefront of fourth-generation nuclear innovation.
• Strategic Sectors: The country is exploring thorium-powered ships and lunar reactors for future moon bases.

Challenges and Limitations

• Material Durability: Molten salts are corrosive; reactor materials need to withstand extreme conditions.
• Radioactive Handling: Managing protactinium and uranium isotopes safely is complex.
• Economic Viability: High initial R&D and infrastructure costs.
• Regulatory Framework: Global safety and licensing standards for MSRs are still evolving.

Way Forward

• China aims for commercial-scale TMSR deployment by 2035.
• The success could reshape global nuclear energy by providing a sustainable, low-carbon alternative to fossil fuels and conventional uranium reactors.
• If scalable, thorium MSRs could be pivotal in achieving net-zero targets and ensuring long-term energy security.

Source: BS