control rod
noun
plural control rods
: a rod of a neutron-absorbing material (such as boron carbide) used to regulate the rate of nuclear fission in a reactor
Examples of control rod in a Sentence
Recent Examples on the Web
The quake tripped the plant’s emergency-response system, and control rods were automatically inserted into the fuel assemblies in the units numbered one, two, and three.
—
Elizabeth Kolbert, New Yorker, 7 Apr. 2025
For example, the United States is largely dependent on China for rare earths used in fiber optics, lasers, batteries, nuclear control rods, medical imaging, metallurgy, permanent magnets, catalysts, electronics, aerospace alloys, solid state devices, and data storage devices.
—Deborah Wince-Smith, Forbes, 21 Feb. 2025
In the basement, a worker mistakenly raised a few of the control rods that can reduce and, if necessary, completely shut down the chain reaction in the reactor.
—Ian Austen, New York Times, 4 Jan. 2025
While other reactors rely on control rods which can lead to overheating if removed, the AHR is self-regulating.
—David Hambling, Forbes, 5 Dec. 2024
This reaction is kept at moderate levels using control rods made of neutron-absorbing materials, usually boron or cadmium, that limit the number of neutrons that can trigger fission.
—Jacek Krywko, Ars Technica, 22 July 2024
Reactors are dialed up or down by moving the control rods in and out of the core.
—Jacek Krywko, Ars Technica, 22 July 2024
In the reactors used at Fukushima, the control rods thrust up into the pressure vessel from below, and the housings around each control rod’s entry point were essentially weak spots.
—IEEE Spectrum, 31 Oct. 2011
Within 5 seconds, control rods thrust upward into the three operational reactors and stopped the fission reactions.
—IEEE Spectrum, 31 Oct. 2011
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Elizabeth Kolbert, New Yorker, 7 Apr. 2025
For example, the United States is largely dependent on China for rare earths used in fiber optics, lasers, batteries, nuclear control rods, medical imaging, metallurgy, permanent magnets, catalysts, electronics, aerospace alloys, solid state devices, and data storage devices.
—Deborah Wince-Smith, Forbes, 21 Feb. 2025
In the basement, a worker mistakenly raised a few of the control rods that can reduce and, if necessary, completely shut down the chain reaction in the reactor.
—Ian Austen, New York Times, 4 Jan. 2025
While other reactors rely on control rods which can lead to overheating if removed, the AHR is self-regulating.
—David Hambling, Forbes, 5 Dec. 2024
This reaction is kept at moderate levels using control rods made of neutron-absorbing materials, usually boron or cadmium, that limit the number of neutrons that can trigger fission.
—Jacek Krywko, Ars Technica, 22 July 2024
Reactors are dialed up or down by moving the control rods in and out of the core.
—Jacek Krywko, Ars Technica, 22 July 2024
In the reactors used at Fukushima, the control rods thrust up into the pressure vessel from below, and the housings around each control rod’s entry point were essentially weak spots.
—IEEE Spectrum, 31 Oct. 2011
Within 5 seconds, control rods thrust upward into the three operational reactors and stopped the fission reactions.
—IEEE Spectrum, 31 Oct. 2011
Cite this Entry
“Control rod.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/control%20rod. Accessed 21 Jul. 2025.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
Share