Alert

Due to a lapse in appropriations, the NRC has ceased normal operations. However, excepted and exempted activities necessary to maintain critical health and safety functions—as well as essential progress on designated critical activities, including those specified in Executive Order 14300—will continue, consistent with the OMB-Approved NRC Lapse Plan.

Coolant

A substance circulated through a nuclear reactor to remove or transfer heat. The most commonly used coolant in the United States is water. Other coolants include heavy water, air, carbon dioxide, helium, liquid sodium, and a sodium-potassium alloy.

Page Last Reviewed/Updated Tuesday, March 09, 2021