Reclaiming Nuclear Innovation: The Molten Salt Reactor’s Strategic Edge

👥 Authors

The paper was authored by the following experts:

• Claude Renault – Commissariat à l'énergie atomique (CEA), France

• Miloslav Hron – Nuclear Research Institute, Czech Republic

• Rudy Konings – Joint Research Centre, Institute for Transuranium Elements, EU

• David-Eugene Holcomb – Oak Ridge National Laboratory, USA

Major contributions were also noted from:

• E. Merle-Lucotte and S. Delpech (CNRS, France)

• V. Ignatiev (RRC-KI, Russia), for input on ISTC MSR projects

🧪 Summary

Presented at: GIF Symposium – Paris, France, 9–10 September 2009

This paper delivers a high-level international overview of the Molten Salt Reactor (MSR) as one of the promising Generation IV nuclear reactor concepts. It focuses on the MSFR (Molten Salt Fast Reactor) and AHTR (Advanced High Temperature Reactor) pathways, highlighting their design features, R&D status, and projected benefits for next-generation nuclear energy.

Key Highlights:

🔥 MSR and MSFR Technology

• MSRs use molten fluoride salts as both fuel and coolant, enabling unique advantages over solid-fuel reactors:

  • Continuous fission product removal

  • High-temperature operation

  • Negative temperature and void reactivity coefficients (a major safety improvement)

  • Easier refueling and material utilization

• MSFR: A fast-spectrum reactor, with a graphite-free core and a eutectic salt mixture of LiF and actinide fluorides. Offers excellent safety due to strong negative feedback coefficients and has potential for actinide burning and breeding.

♻️ Fuel Cycle Innovation

• Two startup options:

  • 233U-started MSFR with a 50-year doubling time

  • TRU-started MSFR with 35 years

• Advanced fuel salt clean-up schemes involve both on-line gaseous extraction (e.g., for Xe, Kr) and batch chemical/electrochemical separation for lanthanides and actinides.

🧱 Materials and Salt Chemistry

• Extensive work on identifying optimal carrier salt compositions (e.g., ⁷LiF-BeF₂, ⁷LiF-ThF₄) for both fuel and coolant roles.

• Corrosion resistance, solubility, thermal properties, and fission product behavior remain key R&D focus areas.

🔬 Experimental Validation

• The SPHINX Project at the LR-0 reactor (Czech Republic) supports MSR and AHTR neutronics validation.

• AHTR studies focus on pebble bed reactors with graphitic matrix fuel and salt coolants, demonstrating promising thermal efficiency and power density improvements.

🌐 International Collaboration

• Coordinated through Generation IV International Forum (GIF), involving Europe (EURATOM), France, USA, and support from Russian institutes and ISTC.

• Collaboration emphasizes cross-cutting needs in salt chemistry, structural materials, reactor physics, and safety.

Click on the document image to view or download the document!