Molten Salt Nuclear Reactors Reach U.S. Milestone, Continue Global Progress

Written by Paul Wiseman for IIR News Intelligence (Sugar Land, Texas)

Summary

Molten salt reactor projects are progressing across the globe.

Molten Salt Moves Ahead

The future of molten salt reactors took a huge step forward this month as the U.S. Department of Energy (DOE) officially approved the Nuclear Safety Design Agreement (NSDA) for Natura Resources' 1-megawatt (MW) reactor at Abilene Christian University (ACU) in Texas (Industrial Info Resources Project ID 301057778). This is the first-ever such approval from the DOE for molten salt reactors (MSRs). The Industrial Info Resources Global Market Intelligence (GMI) Power Project Database offers a detailed report of the Texas MSR project.

According to the International Atomic Energy Association (IAEA), MSRs are nuclear fission reactors in which either the fuel and/or the coolant is a molten salt. Molten salt liquifies at elevated temperatures and can store massive amounts of thermal energy.

Natura said in a press release that the agreement "will enable alignment of design requirements, safety analysis methodology, regulatory engagement, and key safety decisions that support DOE authorization to construct and operate a nuclear facility."

According to Industrial Info Resources data, there are at least eight molten salt projects across the globe, with a total investment value of nearly $680 million. These include four reactors and four others that vary in function from heat storage to processing of the salt. Of the four reactors, their total power capacity upon completion would be 42 MW. Two are in France, one is in the Czech Republic and the remaining one is the ACU plant.

Safety Features of Molten Salt Cooling and Reactors

Molten salt is not actually new, having been researched in the early days of nuclear power in the 1950s. And from 1965 to 1969 the Oak Ridge National Laboratory operated the Molten Salt Reactor Experiment (MSRE) which, according to the Natura press release, "demonstrated the viability of liquid-fueled reactor technology." Natura said the DOE awarded them and nine others some of the fuel developed by that experiment.

The phrase "molten salt" can actually mean either of two things. Molten salt can be used instead of water to cool a traditional type reactor. Or it can be used as a carrier for the fuel.

In either case there are safety features that make incidents such as at Three Mile Island (1979) or Chernobyl (1986) or even Fukushima (2011) very unlikely, according to proponents.

Here's how the IAEA explains molten salt as a coolant vs traditional cooling: "The majority of nuclear power plants around the world currently use pressurized water reactors (PWRs). In these, water is used as a coolant and is pumped under high pressure to the reactor core. There, the water is heated by the energy released by the fission of nuclei and released as steam, which drives turbines to produce electricity.

However, if salt is used as a primary coolant rather than water, it can absorb huge amounts of heat at atmospheric pressure, enabling reactors using this technology to operate at very high temperatures."

In a reactor, the molten salt carries the fissile material itself. In either case, says the IAEA, it is less likely to melt down.

"...if a reactor in an MSR overheats, the liquid salt expands and naturally increases the leakage of neutrons from the reactor core, meaning they are no longer available to cause fission. This reduces the nuclear fission rate and the temperature" before it reaches a dangerous level.

There is also less spent fuel, and it can use more-abundant thorium instead of uranium, reducing mining costs.

By the Numbers

• One: The number of times the DOE has approved an MSR's NDSA
• Eight: Number of molten salt projects Industrial Info Resources is tracking worldwide

Key Takeaways

• MSRs operate at lower pressures and offer other safety features.
• The DOE's NDSA approval for the ACU project gives it a significant head start over other U.S. MSR projects.

Industrial Info Resources (IIR) is the leading provider of industrial market intelligence. Since 1983, IIR has provided comprehensive research, news and analysis on the industrial process, manufacturing and energy related industries. IIR's Global Market Intelligence (GMI) helps companies identify and pursue trends across multiple markets with access to real, qualified and validated plant and project opportunities. Across the world, Industrial Info Resources is tracking over 250,000 current and future projects worth $30.2 Trillion (USD).