Idaho National Laboratory (INL) researchers have performed a nuclear safety test for a loss of coolant accident, the first test of its kind in the United States for over 35 years.
All commercial nuclear reactors in the U.S. use water to cool their cores, and a loss of coolant accident (LOCA) occurs if water rushes out of a reactor faster than it may be replaced, resulting in damage to the system.
The INL’s experiment holder, the “TWIST” capsule, may be loaded into its Transient Reactor Test Facility (TREAT), which is currently used for nuclear research and controlled nuclear safety testing. The test includes a capsule with a sample of nuclear fuel that is surrounded by water that may be drained in testing. To simulate a loss of coolant accident conditions, TREAT creates short, sudden bursts of energy that are five times more powerful than a commercial reactor.
“Loss of coolant accident testing is essential to developing new fuels that will boost the performance of our nuclear power plants and help them run more efficiently,” said Bill McCaughey, director of advanced fuel technologies for DOE’s Office of Nuclear Energy. “Bringing this testing capability back to the U.S. ensures the timely deployment of accident-tolerant fuels that our industry has worked so hard to develop.”
With LOCA testing now available in the U.S., researchers will be able to conduct experiments that are otherwise only available in Russia.
Nuclear energy is currently the largest source of carbon-free power in the U.S., producing about half of the country’s clean energy. As the country works to further scale up the use of nuclear energy, LOCA testing and other safety measures support the development of accident-tolerant fuels, overall leading to less waste and lower fuel costs over the lifetime of a nuclear plant.
The new LOCA testing capabilities will help in testing the DOE's MARVEL microreactor at the TREAT facility, as well as testing during the development of TerraPower’s Natrium small modular reactor. The MARVEL microreactor has a smaller, more compact design than large-scale nuclear plants, and it allows for experimental capabilities to explore the features and behaviors of microreactors that may be used for clean energy generation in the near future.
TREAT will also be used for sodium loop testing and LOCA testing for Terrapower’s Natrium reactor, a project supported by the DOE’s Advanced Reactor Demonstration Project Program.
According to the International Energy Agency, nuclear power may continue to play a key role in providing clean energy worldwide, but the share of its supply has been declining in recent years. New nuclear technologies and projects such as MARVEL and Natrium are encouraged by the IEA in order to change this trend.
