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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
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
Desperate Measures To restart one or more reactors, Rosatom must lift the reactors’ control rods and dilute the boronic acid in the plant’s primary cooling water.
—IEEE Spectrum, 7 July 2023
Within seconds, control rods positioned above reactors at Ukraine’s three working plants dropped into cores to absorb neutrons and stop the chain reaction that could lead to a meltdown.
—Marc Santora, New York Times, 11 Apr. 2023
In the case of an accident in any reactor, control rods crafted from neutron-absorbing materials like cadmium plummet into the core and halt a runaway chain reaction that could otherwise lead to a core meltdown.
—Michael Koziol, IEEE Spectrum, 1 June 2018
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Word History
First Known Use
1906, in the meaning defined above
Dictionary Entries Near control rod
Cite this Entry
“Control rod.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/control%20rod. Accessed 23 Nov. 2024.
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