Idaho National Laboratory Unveils First-of-a-Kind Molten Salt Test Loop

Idaho National Laboratory recently debuted a new molten salt test loop that will support the development of advanced reactors using molten salts. 

It will also be used to help support the world’s first fast-spectrum, salt-fueled reactor experiment at the lab scheduled to begin in the 2030s.   

Molten Salt Reactors Bring the Heat 

Molten salt reactors use molten salt as a coolant, and in some instances as a liquid fuel too. They offer enhanced safety features and operate at high temperatures to generate reliable and secure electricity, as well as process heat which can be used by industry. 

A key challenge in molten salt reactor research is finding materials, sensors and instrumentation that can withstand the hot and corrosive environment within the reactor created by molten salt. 

To better understand how sensors and instrumentation might perform in this type of reactor, researchers at Idaho National Laboratory (INL) developed a new way to test materials by creating a molten salt test loop that more closely mimics a molten salt reactor. 

In addition to creating a flowing environment, where salt moves through heating and cooling conditions, the test loop can also drain and store salt in a tank when inactive, increasing the test bed’s usage and longevity. 

“The instrumentation and sensor testing in flow loop environment is one-of-a-kind,” said Ruchi Gakhar, a lead scientist for INL’s Advanced Technology of Molten Salts program. “By understanding how sensors react to high temperature flowing molten salt, we hope to advance the readiness of future molten salt reactors.”  

What’s Next? 

The new molten salt flow loop will inform the development of molten salt reactors, such as the Molten Chloride Reactor Experiment (MCRE), by helping to identify corrosion-resistant materials, sensors, and instrumentation capable of persisting in high-temperature environments.   

MCRE is one of several advanced reactor designs being supported by the Department of Energy’s Advanced Reactor Demonstration Program to help unleash more reliable, affordable, and secure energy in the United States. 

Research for the molten salt test loop was supported by INL’s Laboratory Directed Research and Development program.