didn't that only apply to open circuit cooling, rather than the closed circuit cooling that you would expect in most reactors ? > The precise situation depends

didn't that only apply to open circuit cooling, rather than the closed circuit cooling that you would expect in most reactors ? > The precise situation depends on the reactor. But in general terms, water is either returned directly, which is known as an open circuit, which can lead to general downstream river temperatures increasing several degrees, or the water is returned after cooling in air-cooling towers, known as a closed circuit, which typically leads to lower rises of downstream river temperatures, of a few tenths of a degree.